Which Diets Are Best In 2021?

Which Diet Should You Choose?

Emoticon-BadMany of you started 2021 with goals of losing weight and/or improving your health. In many cases, that involved choosing a new diet. That was only 2 months ago, but it probably feels like an eternity.

For many of you the “bloom” has gone off the new diet you started so enthusiastically in January.

  • Perhaps the diet isn’t working as well as advertised…
  • Perhaps the diet is too restrictive. You are finding it hard to stick with…
  • Perhaps you are always hungry or constantly fighting food cravings…
  • Perhaps you are starting to wonder whether there is a better diet than the one you chose in January…
  • Perhaps you are wondering whether the diet you chose is the wrong one for you…

If you are rethinking your diet, you might want to know which diets the experts recommend. Unfortunately, that’s not as easy as it sounds. The diet world has become just as divided as the political world.

Fortunately, you have an impartial resource. Each year US News & World Report invites a panel of experts with different points of view to evaluate popular diets. They then combine the input from all the experts into rankings of the diets in various categories.

If you are still searching for your ideal diet, I will summarize the US News & World Report’s “Best Diets In 2021”. For the full report, click on this link.

How Was This Report Created?

Expert PanelUS News & World Report recruited panel of 25 nationally recognized experts in diet, nutrition, obesity, food psychology, diabetes, and heart disease to review the 39 most popular diets.  They rated each diet in seven categories:

  • How easy it is to follow.
  • Its ability to produce short-term weight loss.
  • Its ability to produce long-term weight loss.
  • its nutritional completeness.
  • Its safety.
  • Its potential for preventing and managing diabetes.
  • Its potential for preventing and managing heart disease.

They converted the experts’ ratings to scores 5 (highest) to 1 (lowest). They then used these scores to construct nine sets of Best Diets rankings:

  • Best Diets Overall combines panelists’ ratings in all seven categories. However, all categories were not equally weighted. Short-term and long-term weight loss were combined, with long-term ratings getting twice the weight. Why? A diet’s true test is whether it can be sustained for years. And safety was double counted because no diet should be dangerous.
  • Best Commercial Diets uses the same approach to rank 15 structured diet programs that require a participation fee or promote the use of branded food or nutritional products.
  • Best Weight-Loss Diets was generated by combining short-term and long-term weight-loss ratings, weighting both equally. Some dieters want to drop pounds fast, while others, looking years ahead, are aiming for slow and steady. Equal weighting accepts both goals as worthy.
  • Best Diabetes Diets is based on averaged diabetes ratings.
  • Best Heart-Healthy Diets uses averaged heart-health ratings.
  • Best Diets for Healthy Eating combines nutritional completeness and safety ratings, giving twice the weight to safety. A healthy diet should provide sufficient calories and not fall seriously short on important nutrients or entire food groups.
  • Easiest Diets to Follow represents panelists’ averaged judgments about each diet’s taste appeal, ease of initial adjustment, ability to keep dieters from feeling hungry and imposition of special requirements.
  • Best Plant-Based Diets uses the same approach as Best Diets Overall to rank 12 plans that emphasize minimally processed foods from plants.
  • Best Fast Weight-Loss Diets is based on short-term weight-loss ratings.

Which Diets Are Best In 2021?

The word WInner in white letters surrounded by a burst of colorful stars in 3d

Are you ready? If this were an awards program I would be saying “Envelop please” and would open the envelop slowly to build suspense.

However, I am not going to do that. Here are the top 5 and bottom 5 diets in each category (If you would like to see where your favorite diet ranked, click on this link). [Note: I excluded commercial diets from this review.]

Best Diets Overall 

The Top 5: 

#1: Mediterranean Diet

#2: DASH Diet (This diet was designed to keep blood pressure under control, but you can also think of it as an Americanized version of the Mediterranean diet.)

#3: Flexitarian Diet (A flexible semi-vegetarian diet).

#4: Mayo Clinic Diet

#5: MIND Diet (This diet is a combination of Mediterranean and DASH but is specifically designed to reduce cognitive decline as we age.)

The Bottom 5: 

#35: Modified Keto Diet

#36: Whole 30 Diet

#37: GAPS Diet (A diet designed to improve gut health).

#38: Keto Diet

#39: Dukan Diet

Best Weight-Loss DietsWeight Loss

The Top 5: 

#1: Flexitarian Diet

#2: Vegan Diet

#3: Volumetrics Diet (A diet based on the caloric density of foods).

#4: Mayo Clinic Diet

#5: Ornish Diet

The Bottom 5: 

#35: Fertility Diet

#36: Whole 30 Diet

#37: Alkaline Diet

#38: AIP Diet (A diet designed for people with autoimmune diseases)

#39: GAPS Diet

Best Diabetes Diets

The Top 5: 

#1: Flexitarian Diet

#2: Mediterranean Diet

#3: DASH Diet

#4: Mayo Clinic Diet

#5: Vegan Diet

The Bottom 5: 

#35: The Fast Diet

#36: AIP Diet

#37: GAPS Diet

#38: Whole 30 Diet (A diet designed for people with autoimmune diseases)

#39: Dukan Diet

strong heartBest Heart-Healthy Diets 

The Top 5: 

#1: DASH Diet

#2: Mediterranean Diet

#3: Ornish Diet (A diet based on the caloric density of foods).

#4: Flexitarian Diet

#5: Vegan Diet

The Bottom 5: 

#35: Keto Diet

#36: AIP Diet

#37: Whole 30 Diet

#38: Modified Keto Diet

#39: GAPS Diet

Best Diets for Healthy Eating

The Top 5: 

#1: DASH Diet

#2: Mediterranean Diet

#3: Flexitarian Diet

#4: TLC Diet (A diet designed to promote heart health)

#5: MIND Diet

The Bottom 5: 

#35: Atkins Diet

#36: Raw Food Diet

#37: Modified Keto Diet

#38: Dukan Diet

#39: Keto Diet 

Easiest Diets to FollowEasy

The Top 5: 

#1: Mediterranean Diet

#2: Flexitarian Diet

#3: MIND Diet

#4: DASH Diet

#5: Fertility Diet

The Bottom 5: 

#35: Keto Diet and Modified Keto Diet (tie)

#36: Whole 30 Diet

#37: Dukan Diet

#38: GAPS Diet

#39: Raw Foods Diet 

Best Fast Weight-Loss Diets

The Top 5 (Excluding Commercial Diets): 

#1: Atkins Diet

#2: Biggest Loser Diet

#3: Keto Diet

#4: Raw Food Diet

#5: Volumetrics Diet

Which Diets Are Best For Rapid Weight Loss?

Happy woman on scaleLet me start with some general principles:

#1: If you are looking for rapid weight loss, any whole food restrictive diet will do.

  • The Atkins and keto diets are meat heavy, low carb diets. They restrict fruits, some vegetables, grains, and most legumes.
  • The Biggest Loser diet relies on restrictive meal plan and exercise programs.
  • The restrictions of the raw food diet are obvious.
  • The volumetrics diet restricts foods with high caloric density.
  • The vegan diet, which ranks #7 on this list, is a very low fat diet that eliminates meat, dairy, eggs, and animal fats.
  • I did not include commercial diets that rated high on this list, but they are all restrictive in one way or another.

#2: Restrictive diets ultimately fail.

  • The truth is 90-95% of people who lose weight quickly on a restrictive diet regain most of that weight in the next two years. The pounds come back and often bring their friends along as well. Many people regain more weight than they lost. This is the famous “Yo-Yo Effect”.
  • If dieters paid for one of the commercial diets, they may as well have burned their money.
  • When I talk with people about weight loss, many of them tell me the Atkins diet is the only one they can lose weight on. That would be impressive if they were at a healthy weight, but most are not. They are overweight. I am starting to see the same thing from overweight people who have used the keto diet to lose weight and have regained their weight.

#3: We should ask what happens when we get tired of restrictive diets and add back some of your favorite foods.

  • If you lose weight on a vegan diet and add back some of your favorite foods, you might end up with a semi-vegetarian diet. This is a healthy diet that can help you maintain your weight loss.
  • If you lose weight on the Atkins or keto diets and add back some of your favorite foods, you end up with the typical American diet – one that is high in both fat and carbs. This is not a recipe for long-term success.
  • Long term weight loss is possible if you transition to a healthy diet after you have lost the weight. In a recent article in “Health Tips From The Professor” I wrote about an organization called the National Weight Control Registry. These are people who have been successful at keeping the weight off. For purposes of this discussion, two points are important.
  • They lost weight on every possible diet.
  • They kept the weight off by following a healthy reduced calorie, low fat diet. (For what else they did, click here).

Which Diet Should You Choose?

Which Diet Is BestWith rapid weight loss out of the way, let’s get back to the question, “Which Diet Should You Choose?” My recommendations are:

  • Choose a diet that fits your needs. That is one of the things I like best about the US News & World Report ratings. The diets are categorized. If your main concern is diabetes, choose one of the top diets in that category. If your main concern is heart health… You get the point.
  • Choose diets that are healthy and associated with long term weight loss. If that is your goal, you will notice that primarily plant-based diets top these lists. Meat-based, low carb diets like Atkins and keto are near the bottom of the lists.
  • Choose diets that are easy to follow. The less-restrictive primarily plant-based diets top this list – diets like Mediterranean, DASH, MIND, and flexitarian.
  • Choose diets that fit your lifestyle and dietary preferences. For example, if you don’t like fish and olive oil, you will probably do much better with the DASH or flexitarian diet than with the Mediterranean diet.
  • Finally, focus on what you have to gain, rather than on foods you have to give up.
    • On the minus side, none of the diets include sodas, junk foods, and highly processed foods. Teose foods should go on your “No-No” list. Sweets should be occasional treats and only as part of a healthy meal. Meat, especially red meat, should become a garnish rather than a main course.
    • On the plus side, primarily plant-based diets offer a cornucopia of delicious plant foods you probably didn’t even know existed. Plus, for any of the top-rated plant-based diets, there are websites and books full of mouth-watering recipes. Be adventurous.

The Bottom Line 

For many of you the “bloom” has gone off the new diet you started so enthusiastically in January. If you are rethinking your diet, you might want to know which diets the experts recommend. Unfortunately, that’s not as easy as it sounds. The diet world has become just as divided as the political world.

Fortunately, you have an impartial resource. Each year US News & World Report invites a panel of experts with different points of view to evaluate popular diets. They then combine the input from all the experts into rankings of the diets in various categories. In the article above I summarize the US News & World Report’s “Best Diets In 2021”.

There are probably two questions at the top of your list.

#1: Which diets are best for rapid weight loss? Here are some general principles:

  • If you are looking for rapid weight loss, any whole food restrictive diet will do.
  • Restrictive diets ultimately fail.
  • We should ask what happens when we get tired of restrictive diets and add back some of our favorite foods.
  • Long term weight loss is possible if you transition to a healthy diet after you have lost the weight.

#2: Which diet should you choose? Here the principles are:

  • Choose a diet that fits your needs.
  • Choose diets that are healthy and associated with long term weight loss.
  • Choose diets that are easy to follow.
  • Choose diets that fit your lifestyle and dietary preferences.
  • Finally, focus on what you have to gain, rather than on foods you have to give up.

For more details on the diet that is best for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Update On The “Truth About Vaccines”

The Four Biggest Unanswered Questions

Author: Dr. Stephen Chaney

newspaper heallinesAs someone who is not normally a proponent of vaccinations, I have done my best to provide a scientifically accurate evaluation of the vaccines for COVID-19. My purpose has not been to change people’s minds.

  • If you have already decided to get vaccinated, I applaud you.
  • If you have decided not to get vaccinated, I respect your opinion.

I have written my articles for those of you who recognize the dangers of COVID-19, want to get vaccinated, but are hesitant because of all the negative chatter about the vaccines you have seen on the internet.

I believe every vaccine should be evaluated on the basis of its risks and benefits.

The benefits are clear. COVID-19 is a deadly disease. It is hard to believe that anyone could look at what has happened in the United States and around the world and not realize COVID-19 is not the common flu. It is the most infectious and deadly disease we have seen in our lifetime. Anything that can help us conquer this deadly disease is tremendously beneficial.

However, every vaccine has risks. The risks are extremely low, but they are not zero. And some past vaccines have had unexpected risks. For that reason, I have evaluated potential risks, including those “risks” you have heard about on the internet, against actual data. I have asked, “Are the risks real?”, “Are they serious?”, and “Do they occur often enough to be of concern?”

The yardstick I use for “Do they occur often enough…?” is the 1 in a million to 1 in 10 million range. The chance of dying in a plane crash is 1 in 10 million. Yet that doesn’t stop us from getting on planes to fly where we want to go.

I think that is an apt analogy. Serious risks from the COVID-19 vaccines are in the 1 in 10 million range. I am willing to take that risk because it will take us to where we want to go – the other side of this pandemic.

I summarized the risks and benefits of the COVID-19 vaccines in a recent “Health Tips From The Professor” article (https://chaneyhealth.com/healthtips/the-truth-about-vaccination/). However, science marches on. That article was written just one month ago, but it is time to update the data and also acknowledge what we still don’t know.

Update On The “Truth About Vaccines”

 

Last week I recorded a talk on the “The Truth About Vaccines”. Part of my motivation was to provide people with audio and video files that would be easier to share. However, I also used that opportunity to update the information on vaccines. Here are the files. Consider them a gift you can use to spread the word about the vaccines. 

 

Video Link: 

https://zoom.us/rec/share/WkDiDdygAnsY4-8YO9HvT55jPOOH73xZ2cTy-cIMDBWSEhOOxgrxliUoH7iAtD5l.hVMILee_-bJg0Xvd

Passcode: FUfZ$3F$ 

Audio Link:

https://zoom.us/rec/play/vIXHPtXHzg-WV8KQb7JjZws49J0z_LY2yOKA5fWIN93GKvLUw08ViOpOa9QcLlvzEphIKibSvcwhgmoV.07AjXCj2j8Ac1cQy

Passcode: FUfZ$3F$

Note: If you want to share these audio and video files or the “Health Tips From The Professor” article I wrote a month ago, share the link rather than forwarding this email to them.

Similarly, if you would like to share this article with someone, share the link given at the beginning and end of this article rather than forwarding this email to them.

This is because if you forward this email to someone who unsubscribes because they aren’t in favor of vaccinations, it will unsubscribe you from receiving future issues of “Health Tips From the Professor”.

The Four Biggest Unanswered Questions

questionsIf you feel like the experts have been “flying by the seat of their pants”, that is because we are. When COVID-19 burst on the scene and spread like wildfire, it was a completely unknown entity. We had no idea what to expect or how effective measures to control it would be.

In fact, much of what we thought we knew was plain wrong. That is why:

  • We went from “masks are only important for health care workers” to “masks only protect others” to “masks protect us” to “maybe we need double masks”.
  • That is why a state like California, which has remained mostly locked-down and a state like Florida, which has remained mostly open, have ended up with about the same per capita cases and deaths from COVID-19.

Clearly some mitigation efforts are needed to “flatten the curve” and prevent our hospitals from being overwhelmed. We cannot just let the virus run rampant. But there is no clear agreement among experts as to which mitigation efforts are essential.

So, with perhaps a little humility, let me address the four greatest unanswered questions about COVID-19 and the vaccines. In each case, I will:

  • Give you the facts as we know them.
  • Give you my opinion.
  • Tell you what to watch for and what to do about it.

Here are the questions:

#1: How Long Will Immunity Last? Most headlines you have seen recently are asking this question with strong immune systemregards to the vaccines. But this question is equally important for those of you who have recovered from COVID-19. You also want to know if and how long you are protected from getting infected again.

Studies on this important question have mostly relied on measuring antibodies to COVID-19 in the bloodstream. And the answer appears to be similar for people who have been infected with COVID-19 and people who have been vaccinated, namely:

  • There are significant individual differences.
    • In some people, antibody levels decrease after a few months.
    • In other people, antibody levels appear to remain high for at least 6-8 months.

This is why the CDC is considering recommending a booster shot of the vaccine 6-12 months after you have completed your first round of vaccinations. It is also why some are recommending you get vaccinated even if you have recovered from COVID-19. The theory is that you will need to boost your antibody levels again to maintain full immunity from COVID-19.

But is a booster shot really necessary? As I have written previously:

  • Both the Pfizer and Moderna vaccines create memory cells as well as circulating antibodies.
    • Memory cells reside in the bone marrow and retain the blueprint for making more antibody-producing cells if the virus ever reappears. They are responsible for long-term immunity.
    • For example, many of you may remember a few years ago, a new variant of the flu virus appeared that hit young people much harder than people over 50. The explanation we were given at the time was that the new variant of the virus was similar to a flu virus that had widely circulated 30 years earlier. We had retained significant immunity to the previous virus, and it protected us from the new virus as well.
  • Because of memory cells, I am optimistic that we will retain significant immunity to COVID-19 even after circulating antibody levels have disappeared. But we won’t know for sure until we have accumulated enough data to know how well the vaccines protect us from COVID-19 a year or two down the road.
  • However, the data on patients who have recovered from COVID-19 is encouraging. So far, the reinfection rate seems to be around 1-2% and most of the recurring cases are mild.

So, should you get a booster shot? The risk of the vaccines will not change, so we need to look at the benefit side of the ledger.

  • If I am right and COVID cases are low 6-12 months from now, the benefit of getting a booster shot would be small. I’d give it a pass.
  • If I am wrong and COVID comes back with a vengeance, getting a booster shot might be prudent.

#2: Do We Need To Fear The Variants? You have seen the hype, “The new variants are highly contagious, Fearand vaccines may not work against them.” The first claim is correct, but existing evidence suggests that the second claim is overblown.

  • Tests with antibodies from patients who have recovered from COVID-19 and from patients who have been vaccinated find that these antibodies are 70-90% effective at neutralizing the new variants. To put that into context, 70-90% effectiveness is significantly higher than the average flu vaccine.
  • New data coming out of England, where one of the variants originated, reports that the reinfection rate for people who have recovered from COVID-19 is around 0.7%, and this has not changed since the British variant strain appeared. [If the antibodies produced from the original COVID infection were not effective against the new variant, we would have expected reinfection rates to increase as the new variant became the predominant version of COVID circulating in the country.]

Of course, these data have not deterred the fearmongers. They are telling you that it is only a matter of time until a variant comes along that is unaffected by vaccines. I consider this unlikely, and here is why.

  • Vaccines are directed against the spike protein of the virus. That is the same protein the virus uses to bind to our cells. Any mutations severe enough to eliminate antibody binding to the spike protein are also likely to prevent the spike protein from binding to our cells. If the spike protein can’t bind to our cells, the virus can’t enter our cells. Such mutant viruses would be non-infectious. They would die out spontaneously.
  • Because of that, I am optimistic that the current vaccines will retain significant effectiveness against new variants as they arise.

Once again, the CDC may recommend a booster shot to help protect against the variants. The pharmaceutical companies are also working on vaccines that are specific to the new variants.

Should you get one of these shots? Once again, we won’t know for sure until we see how well the vaccines protect us from the new variants.

  • If I am right and COVID cases are low 6-12 months from now, the benefit of getting a shot would be small. I’d give it a pass.
  • If I am wrong and a new variant causes a massive surge in COVID cases and deaths in people who have been vaccinated, getting another shot might be prudent.

#3: Can I Get My Life Back After Vaccination? You have probably heard the CDC recommendations that we can still get COVID-19 and pass it on to others after we have been vaccinated. We should, therefore, continue to wear masks and socially distance ourselves.

I have had many people say to me, “If that’s true, why should I even bother to get vaccinated?” Let me start by covering what we know and don’t know about this question. Then I will put it into perspective for you.

  • The immune cells in the upper respiratory tract are not in perfect sync with the rest of the immune system. That means that after vaccination we may not get quite the level of protection in our upper respiratory track that we do in the rest of our body.
  • In the initial studies with rhesus monkeys, the animals were vaccinated and subsequently a high titer of live virus was sprayed directly into their noses. Virus was detected in their nasal passages for about 3 days before it disappeared.
    • The animals did not have detectable levels of virus in their bloodstreams. Nor did they develop any disease symptoms.
    • However, the brief presence of live virus in their nasal passages led to the suggestion that one might still be able to pass the virus on to others after vaccination.
  • Small, preliminary studies with a subset of patients enrolled in the vaccine clinical trials suggested that the vaccines might only be around 60% effective at preventing upper respiratory tract infections.
    • That means if you are exposed to COVID-19, you might have a 40% chance of developing an upper respiratory tract infection. In most cases you will be asymptomatic, but you could pass the virus on to others.
    • The good news is that you are still 95% protected against severe disease, hospitalization, chronic long-term symptoms, and death. This is the answer to the “Why bother?” question.
  • However, new data out of Israel gives a more optimistic assessment. The latest study reported that the Pfizer vaccine is 89% effective at preventing even asymptomatic disease.

The bottom line is that the data are still coming in. It may be another 6-12 months before we have an accurate estimate of your risk of developing asymptomatic disease and passing the virus on to someone else if you are exposed to COVID-19 after being vaccinated.

So, what do I recommend? I can’t tell you what you should do, but I will tell you what I plan to do.

  • I still plan to wear a mask and social distance when I am out and about.
  • I am comfortable meeting with small groups of close friends and family without a mask, especially if they have also been vaccinated.
  • I am comfortable going back to church because our church follows an excellent social distancing protocol.
  • I am comfortable traveling to visit our family in California.
  • Once the number of COVID-19 cases has reached a low level, I will be comfortable resuming all my previous activities, subject, of course, to any state mandates.

News Flash: Yesterday the CDC updated their guidelines for people who are fully vaccinated. They now say that fully vaccinated people can:

  • Visit with other fully vaccinated people indoors without wearing masks or physically distancing.
  • Visit with unvaccinated people from a single household who are at low risk for severe COVID-19 disease indoors without wearing masks or physically distancing.
  • Refrain from quarantining and testing following a known exposure to someone with COVID-19 unless you develop symptoms.

The other CDC guidelines remain in place for now but are likely to change once a larger percentage of the population has been vaccinated.

#4: Why Not Rely On Diet And Supplementation? I have friends who tell me they are not going to get Vaccination Perspectivevaccinated. They will rely on diet and supplementation to keep their immune systems strong and protect them from COVID. I respect their choice.

In fact, I have a great deal of sympathy for that choice. When I think of protecting myself from colds and flu, my preference has always been to keep my immune system strong with diet, supplementation, and exercise rather than relying on vaccinations.

However, COVID is different story. It is a far deadlier disease. And even if it doesn’t kill you, it may impact your life for years to come. The long-term health consequences of COVID are perhaps even scarier than the 1% death rate.

Let’s take a realistic look at each of our options to defeat COVID:

  • In a previous issue of “Health Tips From the Professor” I shared some preliminary clinical studies showing that people with adequate vitamin D status were 60-70% less likely to be infected with COVID, hospitalized with COVID, in the ICU from COVID, and dying from COVID. That is impressive, but it is not 100% protection. And if your vitamin D levels are already adequate, you get no additional benefit from adding extra vitamin D to your diet.
  • In another issue of “Health Tips From the Professor” I shared a review written by a group of experts on respiratory diseases. They concluded that, in addition to a good diet, supplementation with a multivitamin and extra vitamin C, vitamin D, and omega-3s reduced the risk of dying from respiratory diseases. But they didn’t say it eliminated the risk. It did not guarantee 100% protection.
  • As for CDC guidelines, wearing a mask gives you somewhere between 30 and 70% protection. Social distancing and handwashing also help, but they don’t offer 100% protection.
  • Vaccination with the Pfizer and Moderna vaccines gives you at least 60% protection against upper respiratory infections from COVID-19 and 95% protection against severe disease, hospitalization, long term health consequences, and death. It is the single most effective tool we have at our disposal, but it does not give 100% protection. As one of my pessimist friends put it, “95% protection means I have a 1 in 20 chance of getting it.”

COVID-19 is throwing everything it has at us. When faced with a deadly disease and several things I can do that offer partial protection, I choose a holistic approach. I choose to use every tool at my disposal. I choose diet, supplementation, CDC guidelines, and vaccination. Everyone should make their own decision about how best to protect themselves from COVID-19, but my choice is clear. I want to do everything in my power to avoid this disease.

The Bottom Line 

In the article above, I have updated my information on vaccines with data from the latest studies, provided you with resources about the vaccines you can share, and have given you updates and perspective on the four biggest unanswered questions about COVID-19 and the vaccines, namely:

  • How long does immunity last?
  • Do we need to fear the new variants?
  • Can I get my life back after vaccination?
  • Why not rely on diet and supplementation?

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

What Do The US Dietary Guidelines Say About Supplementation?

What Do The US Dietary Guidelines Say About Your Diet?

Author: Dr. Stephen Chaney

US Dietary Guidelines 2020-2025Science is always changing, and nutritional science is no different. As we learn more, our concept of the “ideal diet” is constantly evolving. Because of that, the USDA and the US Department of Health & Human Services produce a new set of Dietary Guidelines for Americans every 5 years.

The 2020-2025 Dietary Guidelines for Americans have just been released. As usual, the process started with a panel of 20 internationally recognized scientists who produced a comprehensive report on the current state of nutritional science and made recommendations for updated dietary guidelines. After a period of public comment, the dietary guidelines were published.

There were two new features of the 2020-2025 Guidelines:

  • They provided dietary guidelines for every life stage from 6 months of life to adults over 60.
  • The guidelines also addressed personal preferences, cultural traditions, and budgetary concerns in so that each of us can develop a healthy diet that fits our lifestyle.

What Do The US Dietary Guidelines Say About Your Diet?

Here are the 2020-2025 Guidelines in a nutshell:healthy foods

  • Follow a healthy dietary pattern at every life stage.
  • Customize and enjoy nutrient-dense food and beverage choices to reflect personal preferences, cultural traditions, and budgetary considerations.
  • Focus on meeting food group needs with nutrient-dense foods and beverages and stay within calorie limits. They went on to say, “A healthy dietary pattern consists of nutrient-dense forms of foods and beverages across all food groups [emphasis mine], in recommended amounts, and within calorie limits.”

They said, “the core elements that make up a healthy dietary pattern include:”

    • Vegetables of all types – dark green, red, and orange vegetables; beans, peas, and lentils; starchy vegetables; and other vegetables.
    • Fruits – especially whole fruits.
    • Grains – at least half of which are whole.
    • Dairy – including fat-free or low-fat milk, yogurt, and cheese; lactose-free versions; and fortified soy beverages and soy yogurt as alternatives. [Other plant-based milk and yogurt foods were not recommended because they do not provide as much protein as dairy. So, they were not considered equivalent foods.]
    • Protein foods – including lean meats, poultry, and eggs; seafood; beans, peas, and lentils; and nuts, seeds, and soy products.
    • Oils – including vegetable oils and oils in food, such as seafood and nuts.
  • Limit foods and beverages higher in added sugars, saturated fat, and sodium; and limit No Fast Foodalcoholic beverages. Their specific recommendations are:
    • Added sugars – less than 10% of calories/day starting at age 2. Avoid foods and beverages with added sugars for those younger than 2.
    • Saturated fat – Less than 10% of calories starting at age 2.
    • Sodium – Less than 2,300 mg per day – even less for children younger than 14.
    • Alcoholic beverages – Adults of legal drinking age can choose not to drink, or to drink in moderation by limiting intake to 2 drinks or less in a day for men and 1 drink or less in a day for women, when alcohol is consumed. Drinking less is better for health than drinking more. There are some adults who should not drink alcohol, such as women who are pregnant.

For more details, read the 2020-2025 Dietary Guidelines for Americans.

The Dark Side Of The US Dietary Guidelines

Darth VaderThe US Dietary Guidelines point Americans in the right direction, but they are never as strong as most nutrition experts would like. The 2025 Dietary Guidelines are no exception. They have two major limitations:

#1: The food industry has watered down the guidelines. This happens every time a new set of guidelines are released. The food and beverage lobbies provide their input during the public comment period. And because they fund a significant portion of USDA research, their input carries a lot of weight. Here are the 3 places where they altered the recommendations of the scientific panel:

  • The scientific panel recommended that Americans decrease the intake of added sugar from 13% of daily calories to 6%. The final dietary guidelines recommended reducing sugar to 10% of daily calories.
  • The scientific panel recommended that both men and women limit alcoholic drinks to one a day. The final dietary guidelines recommended men limit alcoholic drinks to two a day.
  • The scientific panel included these statements in their report:
    • “Dietary patterns characterized by higher intake of red and processed meats, sugar-sweetened foods and beverages, and refined grains are…associated with detrimental health outcomes.”
    • “Replacing processed or high fat-meats…with seafood could help lower intake of saturated fat and sodium, nutrients that are often consumed in excess of recommended limits.”
    • “Replacing processed or high-fat meats with beans, peas, and lentils would have similar benefits.”

These statements are included in the final report, but they are buried in portions of the report that most people are unlikely to read. The summary that most people will read recommends shifts in protein consumption to “add variety” to the diet.

#2: The guidelines do not address sustainability and do not explicitly promote a shift to more Planetary Dietplant-based diets. Again, this was based on input from food lobby groups who argued that sustainability has nothing to do with nutrition.

If you are concerned about climate change and the degradation of our environment caused by our current farming practices, this is a significant omission.

I have covered this topic in a recent issue of “Health Tips From the Professor”. Here is a brief summary:

  • In 2019 a panel of international scientists was asked to conduct a comprehensive study on our diet and its effect on both our health and our environment.
  • The scientific panel carefully evaluated diet and food production methods and asked three questions:
    • Are they good for us?
    • Are they good for the planet?
    • Are they sustainable? Will they be able to meet the needs of the projected population of 10 billion people in 2050 without degrading our environment.
  • They developed dietary recommendations popularly known as the “Planetary Diet”. Here are the characteristics of the planetary diet.
    • It starts with a vegetarian diet. Vegetables, fruits, beans, nuts, soy foods, and whole grains are the foundation of the diet.
    • It allows the option of adding one serving of dairy a day.
    • It allows the option of adding one 3 oz serving of fish or poultry or one egg per day.
    • It allows the option of swapping seafood, poultry, or egg for a 3 oz serving of red meat no more than once a week. If you want a 12 oz steak, that would be no more than once a month.

Unless you are a vegan, this diet is much more restrictive than you are used to. However, if you, like so many Americans believe that climate change is an existential threat, I would draw your attention to one of the concluding statements from the panel’s report.

  • “Reaching the Paris Agreement of limiting global warming…is not possible by only decarbonizing the global energy systems. Transformation to healthy diets from sustainable food systems is essential to achieving the Paris Agreement.”

In other words, we can do everything else right, but if we fail to change our diet, we cannot avoid catastrophic global warming.

What Do The US Dietary Guidelines Say About Supplementation?

MultivitaminsThe authors of the 2020-2025 US Dietary Guidelines have relatively little to say about supplementation. However:

  • They list nutrients that are of “public health concern” for each age group. Nutrients of public health concern are nutrients that:
    • Are underconsumed in the American diet.
    • Are associated with health concerns when their intake is low.
  • They state that “dietary supplements may be useful in providing one or more nutrients that otherwise might be consumed in less than recommended amounts.”
  • They recommend specific supplements for several age groups.

Here are their nutrients of public health concern and recommended supplements for each age group:

#1: General population.

  • Nutrients of public health concern are calcium, dietary fiber, and vitamin D. They state that supplementation may be useful for meeting these needs.

#2: Breast Fed Infants.

  • Supplementation with 400 IU/day of vitamin D is recommended shortly after birth.

#3: Vegetarian Toddlers.

  • Iron and vitamin B12 are nutrients of concern.

#4: Children & Adolescents.

  • Calcium and vitamin D are nutrients of concern. Dairy and/or fortified soy alternatives are recommended to help meet these needs.
  • Iron, folate, vitamin B6, vitamin B12, and magnesium are also nutrients of concern for adolescent females.

#5: Adults (Ages 19-59).

  • 30% of men and 60% of women do not consume enough calcium and 90% of both men and women do not get enough vitamin D.

#6: Pregnant & Lactating Women:

  • Calcium, vitamin D, and fiber are nutrients of concern for all women in this age group.
  • In addition, women who are pregnant have special needs for folate/folic acid, iron, iodine, and vitamin D.
  • Women who are pregnant or thinking of becoming pregnant should take a daily prenatal vitamin and mineral supplement to meet folate/folic acid, iron, iodine, and vitamin D needs during pregnancy. They go on to say that many prenatal supplements do not contain iodine, so it is important to read the label.
  • All women who are planning or capable of pregnancy should take a daily supplement containing 400 to 800 mcg of folic acid.

#7: Older Adults (≥ 60).

  • Nutrients of concern for this age group include calcium, vitamin D, fiber, protein, and vitamin B12.
  • About 50% of women and 30% of men in this age group do not get enough protein in their diet.

My Perspective:

The US Dietary Guidelines use foods of public health concern as the only basis for recommending Supplementation Perspectivesupplementation. I prefer a more holistic approach that includes increased needs, genetic predisposition, and preexisting diseases as part of the equation (see the diagram on the right). I have discussed this concept in depth in a previous issue of “Health Tips From The Professor”.

I have also taken this concept and made supplement recommendations for various health goals in a free eBook called “Your Design For Healthy Living”.

Some people may feel I should have included more supplements in my recommendations. Others may feel I should have included fewer supplements in my recommendations. No list pf recommend supplements is perfect, but I have tried to include those supplements supported by good scientific evidence in my recommendations.

The Bottom Line 

The USDA and Department of Health & Human Services have just released the 2020-2025 US Dietary Guideline. In the article above I have summarized:

  • Their recommendations for a healthy diet.
  • Their recommendations for supplementation.
  • The dark side of the US Dietary Guidelines.

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Do Supplements Interfere With Chemotherapy?

Should You Avoid Supplement Use During Chemotherapy?

cancerSince much of my research career was devoted to cancer research, specifically developing new chemotherapeutic drugs for treating cancer, many of you have asked me the question: “Do food supplements interfere with chemotherapy?”

My answer has always been that it is theoretically possible, but that we don’t really know the answer because the necessary studies have not been done.

However, I do know that most cancer drugs are retained in the body for a short period of time. So, my pragmatic advice has always been to avoid supplementation for a day or two before to a day or two after each round of chemotherapy. That is a strategy designed to minimize the possibility that supplementation would interfere with chemotherapy and maximize the possibility that supplementation might aid in recovery between rounds of chemotherapy.

That is why I was interested when I saw the recent headlines claiming certain supplements may interfere with chemotherapy for breast cancer. I wanted to find out if someone had finally done a definitive study on the effect of supplementation on chemotherapy.

So, I have reviewed the study (CB Ambrosone et al, Journal of Clinical Oncology, 38, 804-815, 2020) behind the headlines and will share what I discovered.

How Was The Study Done?

Clinical StudyThis study was an offshoot of a much larger Phase III clinical trial designed to determine the best schedule for administering three drugs (doxorubicin, cyclophosphamide, and paclitaxel) to patients with high-risk early-stage breast cancer.

The 1,134 patients enrolled in this study were given questionnaires on their use of supplements when they registered for the study to determine supplement use prior to the study. They were also given questionnaires when they completed chemotherapy to determine supplement use during chemotherapy.

The questionnaires documented use of:

  • Multivitamins
  • The antioxidants vitamin C, vitamin A, vitamin E, carotenoids, and coenzyme Q10.
  • Vitamin D.
  • The B vitamins vitamin B6, vitamin B12, and folic acid.
  • The minerals iron and calcium.
  • Omega-3 fatty acids.
  • Glucosamine, melatonin, and acidophilus.

Recurrence of the breast cancer and death from breast cancer were measured 6 months after chemotherapy ended.

Do Supplements Interfere With Chemotherapy?

Questioning WomanThe study reported:

  • The number of patients using individual antioxidant supplements was too low to determine whether individual antioxidants had any effect on treatment outcomes.
  • When the patients using any antioxidant supplement were pooled into a single group, there was a nonsignificant association between antioxidant supplement use during chemotherapy and an increased risk of breast cancer recurrence and death from breast cancer.
  • Iron use during chemotherapy was significant associated with an increased risk of breast cancer recurrence.
  • Vitamin B12 use during chemotherapy was significantly associated with increased risk of breast cancer recurrence and death from breast cancer.
  • Multivitamin use was not associated with either recurrence or death from breast cancer.
  • The number of patients using the other supplements was too low to determine whether those supplements had any effect on treatment outcomes.

The authors concluded: “Associations between survival outcomes and use of antioxidant and other dietary supplements are consistent with recommendations for caution among patients when considering the use of supplements, other than a multivitamin, during chemotherapy.”

This is the conclusion that generated the headlines you may have seen.

However, in their discussion the authors conceded that a previous review concluded that, “…insufficient evidence existed with regard to the safety of dietary supplements [during chemotherapy] to make recommendations, and that still may be the case.”

I will discuss the reasons for their disclaimer below. However, I will point out that disclaimers like this never seem to make it into the headlines you read.

What Are The Strengths And Weaknesses Of This Study?

strengths and weaknessesThe only strength of this study is that it was performed in the context of an ongoing clinical trial, with surveys conducted before chemotherapy and during chemotherapy to assess supplement use.

However, the study had multiple weaknesses that limit the ability to draw any firm conclusions from the study.

#1: The number of people using supplements in this study was very small. For example:

  • Only 200 people took any antioxidants during chemotherapy.
  • Only 137 people took a vitamin B12 supplement during chemotherapy.
  • Only 109 people took an iron supplement during chemotherapy.

To put this into perspective, if a drug company were submitting a new drug for approval to the FDA, they would be required to submit data from ~50-100-fold more cancer patients to prove that the drug was effective.

With this small number of supplement users, even “statistically significant” observations are questionable.

In contrast, the number of people taking a multivitamin during chemotherapy was 497. Thus, those data were a little stronger than the data for individual supplements.

#2: They did not ask why people were taking supplements. It turns out that the patients who used supplements were older and sicker. They were more likely to be overweight and to have type 2 diabetes.

These are patients who are also more likely to have poor outcomes from chemotherapy. The authors tried to correct for that, but it is virtually impossible to make these corrections when the number of patients taking supplements is so low.

#3: They did not ask about the dose of supplements people were taking.

  • Multivitamins typically contain RDA levels of antioxidants and vitamin B12, so it would be safe to assume that RDA levels of antioxidants and vitamin B12 are safe during chemotherapy.
  • Approximately 50% of the women in the study were premenopausal, so it is likely that they were taking a multivitamin with iron. That suggests that RDA levels of iron are safe during chemotherapy for premenopausal women.

In short, the association between supplement use and poorer outcomes from chemotherapy is tenuous. If there is any association, it is likely with high dose individual supplements rather the lower levels of the same nutrients found in a multivitamin.

Is An Effect Of Supplement Use On Chemotherapy Plausible?

As a biochemist, the next question I ask is whether there is a plausible mechanism for an effect of any of these Look forsupplements on chemotherapy outcomes.

  • For two of the drugs in the regimen (paclitaxel and cyclophosphamide), free radical formation may contribute to their effectiveness, but it is not their main mechanism of action. Thus, it is plausible that high dose antioxidant supplements could make these drugs less effective, but the effect should be relatively small.
  • Tumors require high amounts of iron for proliferation, so it is plausible that excess iron could make tumors more resistant to chemotherapy. However, for premenopausal women, multivitamins with iron did not interfere with the drugs used in this study. Thus, it appears likely that RDA levels of iron, where appropriate, do not interfere with chemotherapy.
  • The authors said that the reason for the observed effects of vitamin B12 on chemotherapy in their study “remains to be understood”. However, the answer might be found in the dosage of vitamin B12. A previous study reported that doses of vitamin B12 that were greater than 20 times the RDA increased the risk of lung cancer.

If people in this study were taking doses of vitamin B12 in excess of 20 times the RDA, it would provide a plausible explanation for B12 interfering with chemotherapy. If not, there is no known explanation. In any case, I do not recommend taking such high doses of any supplement.

Should You Avoid Supplement Use During Chemotherapy?

AvoidNow, let’s get back to the original question: “Should you avoid supplement use during chemotherapy?” If you read the headlines saying, “Supplement Use During Chemotherapy May Be Risky”, you might think that the answer is an unqualified yes. That is also what your doctor is likely to think.

However, when you analyze the study behind the headlines you realize that the evidence supporting the headlines is very weak.

So, that puts us back to where we were before the study was published. Simply put:

  • It is theoretically possible that supplements interfere with chemotherapy, but we don’t know for sure.
  • A pragmatic approach is to avoid supplementation for a day or two before to a day or two after each round of chemotherapy. This is a strategy designed to minimize the possibility that supplementation would interfere with chemotherapy and maximize the possibility that supplementation might aid in recovery between rounds of chemotherapy.

Note: This is generic advice. I am not a medical doctor, so it would be unethical for me to provide individualized advice on how to minimize interactions between supplements and chemotherapy. What I recommend is that you ask your doctor whether my generic recommendations make sense for your cancer and your drug regimen.

If this study advanced our knowledge at all, it would be that:

  • The supplements most likely to interfere with chemotherapy appear to be high dose antioxidants, vitamin B12, and iron supplements.
  • Multivitamins, even multivitamins with iron when appropriate, are unlikely to interfere with chemotherapy.

The Bottom Line 

Recent headlines have warned, “Supplement Use During Chemotherapy May Be Risky”. Is that true?

However, when you analyze the study behind the headlines you realize that the evidence supporting the headlines is very weak.

So, that puts us back to where we were before the study was published. Simply put:

  • It is theoretically possible that supplements interfere with chemotherapy, but we don’t know for sure.
  • A pragmatic approach is to avoid supplementation for a day or two before to a day or two after each round of chemotherapy. This is a strategy designed to minimize the possibility that supplementation would interfere with chemotherapy and maximize the possibility that supplementation might aid in recovery between rounds of chemotherapy.

Note: This is generic advice. I am not a medical doctor, so it would be unethical for me to provide individualized advice on how to minimize interactions between supplements and the chemotherapy drugs you are on. What I recommend is that you ask your doctor whether my generic recommendations make sense for your cancer and your drug regimen.

If this study advanced our knowledge at all, it would be that:

  • The supplements most likely to interfere with chemotherapy appear to be high dose antioxidants, vitamin B12, and iron supplements.
  • Multivitamins, even multivitamins with iron when appropriate, are unlikely to interfere with chemotherapy.

For more details read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 

Are Carnitine Supplements Good For You Or Bad For You?

What Is The Truth About Carnitine And TMAO?

BodybuilderIf you are a weightlifter or bodybuilder, chances are you are taking an L-carnitine supplement or a protein shake fortified with L-carnitine. That is because L-carnitine has been promoted for increasing muscle mass and physical performance for so long that most people have come to believe it must be true. Is it true, or is it just another food myth?

If you visit Dr. Strangelove’s website, you may also be told that carnitine supplementation is beneficial for weight loss, migraines, baldness, ADHD and autism, chronic fatigue syndrome, and/or low energy, muscle loss, and cognitive decline in older adults. Are these claims fact or fiction?

On the flip side, recent studies have suggested that the carnitine in red meat might be bad for your heart. Could the same be true for carnitine supplements? Could they also be bad for your heart?

A recent systematic review (AG Sawicka et al, Journal of the International Society of Sports Nutrition, 17: 49, 2020) of L-carnitine supplementation answers these important questions. The authors called their study “The bright and dark sides of L-carnitine supplementation” because they set out to systematically investigate the benefits and potential risks of L-carnitine supplementation.

But before I share the results of this study, I need to give you a little background on L-carnitine. It is time for another Biochemistry 101 segment.

Biochemistry 101: What You Need To Know About Carnitine

professor owlCarnitine plays an essential role in human metabolism. It is required for transport of fatty acids into our mitochondria so they can be used to generate energy. Without carnitine we would be unable to utilize most of the fats in our diet as an energy source.

As you might expect, carnitine is essential for any tissues that have mitochondria, but it is particularly important for high energy tissues like skeletal and heart muscle.

For most of us, our liver and kidneys make all the carnitine we need. So, we don’t really need carnitine from food or supplements.

However, we do get significant amounts of carnitine from red meat, much smaller amounts of carnitine from other animal foods, and almost no carnitine from plant foods. Adults consuming diets with red meat and other animal foods get about 60-180 mg of carnitine a day from their diet, whereas vegans only get around 10-12 mg/day.

Uptake of carnitine from the blood into muscle tissues requires insulin. Thus, carnitine uptake into muscle is significantly less on a low-carbohydrate or keto diet than it is on a mixed diet containing carbohydrates.

Finally, our kidneys do an excellent job of regulating blood carnitine levels, with excess carnitine being excreted into the urine. Thus, total body carnitine levels are virtually the same with high-carnitine and low-carnitine diets.

Question MarkThis raises the question: “Are L-carnitine supplements good for you?”

Now, let’s talk about the dark side of carnitine. I have discussed this in a previous issue of “Health Tips From the Professor”. Here is a brief summary:

  • People who eat a lot of red meat harbor a species of bacteria in their intestine that converts carnitine to trimethylamine (TMA). We don’t know whether this species of gut bacteria is favored by the presence of red meat in the diet or the absence of certain fruits, whole grains, and legumes from the diet of meat eaters.
  • The TMA is reabsorbed into the bloodstream, and the liver converts TMA to TMAO (trimethylamine N-oxide).
  • TMAO is associated with an increased risk of heart attack, stroke, and heart failure.

When you think about it, this is a perfect example of double jeopardy. Red meat is high in carnitine, and red meat eaters have gut bacteria that result in carnitine being converted to a compound that may increase the risk of heart disease.

This raises the question: “Are L-carnitine supplements bad for you?”

Let’s look at these two questions. First, I will discuss the recent review. Then I will put the conclusions of that review into perspective by looking at what other health experts say.

Are Carnitine Supplements Good For You Or Bad For You?

good news bad newsMost previous studies of carnitine supplementation have lasted only two or three weeks, which may not be long enough to measure an effect of carnitine supplementation on performance. So, the authors of this review paper selected studies that lasted 11 weeks or more for their review.

The review included 11 studies. They lasted either 12 or 24 weeks. Participants received doses ranging from 1 gm to 4.5 gm of L-carnitine per day. Here are the conclusions of the review:

  • Participants receiving L-carnitine alone had no increase in muscle carnitine content.
  • Participants receiving L-carnitine + 80 grams of carbohydrate had around a 10% increase in muscle carnitine content. [To put that into perspective, 80 grams of carbohydrate is roughly equivalent to 2 cups of white rice or two medium potatoes.]
  • One study compared male vegetarians with male omnivores. The omnivores had no increase in muscle carnitine content, but the vegetarians did. [The study did not analyze the diets of the omnivores and vegetarians, but it is probably safe to assume that the carbohydrate content was higher on the vegetarian diet.]
  • There was no significant effect of L-carnitine on muscle mass or physical performance. [This is logical, given the minimal effect of L-carnitine supplementation on muscle carnitine levels.

Thus, this review found little evidence that L-carnitine supplementation was good for you. It resulted in little or no increase in muscle carnitine levels or in physical performance.

  • Two of the 11 studies measured plasma TMAO levels. These studies found that L-carnitine supplementation resulted in a significant increase in plasma TMAO levels.

Thus, this review found some evidence that L-carnitine supplementation might be bad for you.

What Is The Truth About Carnitine And TMAO?

the truth signIs carnitine good for you? With respect to this question, the conclusions of this review are similar to the conclusions of other health experts. For example, in their Fact Sheet On Carnitine For Health Professionals the NIH states “Some athletes take carnitine to improve performance. However, twenty years of research finds no consistent evidence that carnitine supplements can improve exercise or physical performance in healthy subjects—at doses ranging from 2–6 grams/day administered for 1 to 28 days. For example, carnitine supplements do not appear to increase the body’s use of oxygen or improve metabolic status when exercising, nor do they necessarily increase the amount of carnitine in muscle.”

The NIH fact sheet goes on to list some diseases causing muscle loss or muscle weakness, for which L-carnitine supplementation is appropriate. However, in these cases, the carnitine supplementation should be recommended by health professionals.

Is carnitine bad for you? The TMAO story is a bit more complicated. As I mentioned above, there is an association between red meat consumption and blood TMAO levels and an association between blood TMAO levels and heart disease.

Is it TMAO that increases the risk of heart disease or is it some other component (saturated fat, for example) of red meat that increases the risk of heart disease? Nobody knows. More research is needed.

There is also a “red herring” that complicates the TMAO story. It turns out that TMAO helps fish survive the high pressures they encounter in the deep ocean. Thus, many fish are high in TMAO, and fish consumption also increases blood TMAO levels.

Are the bad effects of TMAO in fish outweighed by the heart healthy components in fish (omega-3s, for example)? Nobody knows. More research is needed.

To summarize:

  • There is no reason to take L-carnitine supplements unless directed by your health professional. There is little evidence they will help your physical performance. There is also no good evidence to support the other benefits of L-carnitine you find listed on Dr. Strangelove’s blog or the website of your favorite supplement company.
  • L-carnitine supplements may be bad for your heart, but much more research will be needed to be sure. [Note: Based on what we know about the role of gut bacteria in TMAO production, vegans could probably take l-carnitine supplements without causing an increase in TMAO levels. However, that is probably a moot point. There is no evidence that L-carnitine is more effective for vegans than it is for omnivores.]

The Bottom Line 

If you are a weightlifter or bodybuilder, chances are you are taking an L-carnitine supplement or a protein shake fortified with L-carnitine. That is because L-carnitine has been promoted for increasing muscle mass and physical performance for so long that most people have come to believe it must be true. Is it true, or is it just another food myth?

On the flip side, recent studies have suggested that the carnitine in red meat might be bad for your heart. Could the same be true for L-carnitine supplements? Could they also be bad for your heart?

A recent review looked at these questions. Here are the conclusions of the review:

  • Participants receiving L-carnitine alone had no increase in muscle carnitine content.
  • Participants receiving L-carnitine + 80 grams of carbohydrate had around a 10% increase in muscle carnitine content. [To put that into perspective, 80 grams of carbohydrate is roughly equivalent to 2 cups of white rice or two medium potatoes.]
  • There was no significant effect of L-carnitine on muscle mass or physical performance. [This is logical, given the minimal effect of L-carnitine supplementation on muscle carnitine levels.

Thus, this review found little evidence that L-carnitine supplementation was beneficial. It resulted in little or no increase in muscle carnitine levels or in physical performance.

  • This review also found that L-carnitine supplementation resulted in a significant increase in plasma TMAO, a compound that has been associated with an increased risk of heart disease.

Thus, this review found some evidence that L-carnitine supplementation might be bad for you.

The NIH has also issued a fact sheet for health professionals summarizing research on L-carnitine over the past 20 years. The conclusions from their fact sheet can be best summarized as:

  • There is no reason to take L-carnitine supplements unless directed by your health professional. There is little evidence they will help your physical performance. There is also no good evidence to support the other benefits of L-carnitine you find listed on Dr. Strangelove’s blog or the website of your favorite supplement company.
  • L-carnitine supplements may be bad for your heart, but much more research will be needed to be sure.

For more details read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Do Antioxidants Reduce Diabetes Risk?

What Diet Is Best For Reducing Your Risk Of Diabetes?

ConfusionI don’t need to tell you that nutrition is confusing. The headlines change day to day. One day antioxidants are good for you. The next day they are worthless. What are you to believe?

That is why I knew you would be skeptical when you saw recent headlines saying things like, “Antioxidants reduce your risk of diabetes” or “An antioxidant-rich diet may prevent diabetes”. You are probably waiting for the other shoe to drop.

You are waiting for the next headline telling you to ignore the previous headlines.

That is why I decided to analyze the study (FM Mancini et al, Diabetologia, 61: 308-316, 2018) behind the headlines and tell you whether the headlines were true or false. More importantly, I wanted to put the study into perspective so you could apply the findings to your life.

How Was The Study Done?

Clinical StudyThe data for this paper came from the Interaction of Genetic and Lifestyle Factors on the Incidence of Type 2 Diabetes (InterAct) study. French women born between 1925 and 1950 were enrolled in the study beginning in 1990.

Women were excluded from the study if they had pre-existing cardiovascular disease, diabetes, or cancer.

In June of 1993 a very extensive dietary questionnaire was mailed to all participants. The antioxidant capacity of each of the foods in the diet was estimated using an existing database, and the total antioxidant content of each woman’s diet was calculated.

A total of 64,223 women (average age = 52) completed the questionnaire and were followed for 15 years. During that time 1751 of the women developed type 2 diabetes.

The study correlated the total antioxidant content of the diet with the risk of developing type 2 diabetes. Coffee was excluded from the analysis because the antioxidants found in coffee are high molecular weight compounds, and it is not clear how well they are absorbed.

The major sources of antioxidants in the French diet were fruits (23%), vegetables (19%), wine (15%), tea (10%), and chocolate (2%). Whole grains and beans are also good sources of antioxidants, but the French (and Americans) don’t eat enough of them to influence their total antioxidant intake.

In case you were wondering why wine and chocolate were among the five top sources of antioxidants, remember this is the French diet we are talking about.

Do Antioxidants Reduce Diabetes Risk?

Diabetes and healthy die The authors of the study divided the women into 5 groups (quintiles) based on the antioxidant content of their diets. Quintile one had the lowest antioxidant intake, and quintile five had the highest antioxidant intake.

Compared to the women in quintile one (lowest antioxidant intake), the risk of developing type 2 diabetes was decreased by:

  • 15% for women in quintile two.
  • 30% for women in quintile three.
  • 38% for women in quintile four.
  • 39% for women in quintile five (highest antioxidant intake).
  • As you might guess from the data above, there was an inverse association between total antioxidant content of the diet and type 2 diabetes up until somewhere between the third and fourth quintiles.
  • Above that antioxidant level, the relationship between dietary antioxidant content and risk of developing type 2 diabetes plateaued.

The authors concluded, “Our findings suggest that the total antioxidant capacity of the diet may play a role in reducing the risk of type 2 diabetes in middle-aged women. As type 2 diabetes represents a high disease burden worldwide, our results may have important public health implications.”

What Diet Is Best For Reducing Your Risk Of Type 2 Diabetes?

While most of the headlines talked about the effect of antioxidant intake on the risk of developing type 2 diabetes, we need to remember that the study was done with antioxidant-rich foods. That raises 3 important questions.

#1: Is it the antioxidants or the foods that decrease the risk of developing type 2 diabetes?

Diabetes-&-Vitamin-CThis was a diet rich in fruits, vegetables, and tea with moderate amounts of wine and chocolate. Although they didn’t make it to the top 5 in this study, whole grains and beans are also a good source of dietary antioxidants. In short, this was a very healthy diet.

That represents a complicating factor. For example, fruits and vegetables are also good sources of non-antioxidant phytonutrients that appear to have health benefits. They are also a good source of fiber and the healthy gut bacteria that eat the fiber.

In short, this study shows that healthy foods reduce the risk of developing type 2 diabetes. Since oxidative stress is thought to play a role in the development of diabetes, it is logical that antioxidants in these foods may help prevent diabetes. However, in reality, we don’t know how much of the risk reduction is due to the antioxidant content of the foods and how much is due to other components of the foods.

#2: Is it healthy foods that decrease the risk of type 2 diabetes, or is it due to decreased intake of unhealthy foods?

food choiceThe skeptic in me wants to ask, “Is the diabetes risk reduction due to the healthy foods included in the diet or does it derive from the fact that those foods displaced unhealthy foods from the diet?” It is also legitimate to ask whether people who eat healthier foods also followed a healthier lifestyle.

Fortunately, the data from this study puts those questions to rest. Compared to women in the lowest quintile of antioxidant intake, women in the highest quintile of antioxidants intake from diet:

  • Drank more sugar-sweetened and artificially sweetened beverages.
  • Ate more processed meat.
  • Ate more calories.
  • Smoked more.
  • Were just as likely to be overweight.

These women were more physically active, but in other ways their diet and lifestyle were no better than women with much less antioxidant intake.

However, we do need to remember that these are French women. Their overall diet and lifestyle is much better than American women. For example, at their worst:

  • 30% were overweight or obese compared to >60% for American women.
  • Intake of processed meat was less than ½ serving/day.
  • Intake of sugar-sweetened beverages was less than 1 ounce/day and intake of artificially sweetened beverages was 1.3 ounces/day.

#3: How much healthy foods do your need to include in your diet to reduce the risk of type 2 diabetes?

fruits and vegetablesThe fact that the beneficial effect of adding antioxidant-rich foods to your diet reduced the risk of developing type 2 diabetes up to a point and then plateaued has important implications. It means you don’t need to be a vegan to reduce your risk of type 2 diabetes. You just need to include enough healthy foods in your diet.

“How much healthy foods”, you might ask. If we look at the point at which the benefit of eating antioxidant-rich foods plateaued in this study, the women were eating:

  • 5-6 servings of fresh fruits and vegetables per day.
  • 4 cups of tea/day.
  • 7 pieces of chocolate/day.
  • 1 glass of wine/day.

If you are an American who is consuming less tea, chocolate, and wine than the French, you will probably want to aim for 6 or more servings of fresh fruits and vegetables per day and include whole grains and beans in your diet.

In a previous issue of “Health Tips From the Professor” I reviewed a study that looked at the optimal intake of fruits and vegetables for various other diseases. That study reported:

  • 10 servings per day is optimal for reducing the risk of heart disease, stroke, and premature death.
  • 6 servings per day is optimal for reducing the risk of cancer.

This study suggests 6 servings of fruits and vegetable per day is likely to also be optimal for reducing the risk of developing type 2 diabetes.

The bad news is that the average American eats one serving of fruit and less than 2 servings of vegetables a day. The good news is that each added serving of fruits and vegetables reduces your risk of disease and premature death. The same is probably true for whole grains and beans, but they weren’t specifically included in these studies.

What About Supplementation?

vitamin COf course, some of you will be tempted to say, “Changing my diet is hard. I’ll just take antioxidant supplements.” Will that work. If we are talking about individual antioxidant supplements, the answer is a clear, “No”. Numerous clinical studies have shown that.

However, one study looked at a holistic approach to supplementation and found that it significantly decreased the risk of developing type 2 diabetes over a 20-year period. That is encouraging, but you need to know that the people in that study were not just consuming antioxidant supplements. They were also consuming:

  • Supplements containing B vitamins, calcium, magnesium, and trace minerals.
  • Plant-based protein supplements that replaced some of the animal protein in their diet.
  • Omega-3 supplements.
  • Probiotic supplements.

So, just as was true for the diet study discussed above, antioxidant supplements may be beneficial in reducing the risk of developing type 2 diabetes. However, it is not possible to separate the benefits of antioxidant supplements from the other supplements included in the study.

The Bottom Line

You may have seen recent headlines claiming, “Antioxidants reduce your risk of diabetes”. The study behind those headlines was actually looking at the effect of antioxidant-rich foods like fruits and vegetables at decreasing the risk of developing type 2 diabetes.

The study did show that increasing the amount of antioxidant-rich foods in your diet decreases your risk of developing type 2 diabetes.

Since oxidative stress is thought to play a role in the development of diabetes, it is logical that antioxidants in those foods may help prevent diabetes. However, in reality we don’t know how much of the risk reduction is due to the antioxidant content of the foods and how much is due to the phytonutrient and fiber content of the foods.

There was an inverse association between total antioxidant content of the diet and type 2 diabetes up until somewhere between the 5 and 6 servings per day of fresh fruits and vegetables. At that point. the beneficial effect of eating antioxidant-rich foods plateaued. Eating 6 servings per day of fresh fruits and vegetables appears to be optimal for reducing the risk of developing type 2 diabetes.

To put that into perspective, a previous study that looked at the optimal intake of fruits and vegetables for various other diseases reported:

  • 10 servings per day is optimal for reducing the risk of heart disease, stroke, and premature death.
  • 6 servings per day is optimal for reducing the risk of cancer.

The bad news is that the average American eats one serving of fruit and less than 2 servings of vegetables a day. The good news is that each added serving of fruits and vegetables reduces your risk of disease and premature death. The same is probably true for whole grains and beans, but they weren’t specifically included in these two studies.

Of course, if you really wish to prevent or reverse type 2 diabetes, a holistic approach including weight control, exercise, diet, and supplementation is best.

For more details, including a more detailed discussion of supplementation, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

 

Finally, you should also never think of supplementation as a replacement for a healthy diet. If you wish to reduce your risk of developing type 2 diabetes, I recommend a holistic approach that includes weight control, exercise, diet, and supplementation.

Does Poverty Affect Nutritional Status?

How Can We Improve Nutrition In Disadvantaged Communities?

Calcium FoodsRecently there has been increased focus on health disparities in disadvantaged communities. In our discussions of the cause of these health disparities, two questions seem to be ignored.

1. Does poverty play a role in poor nutrition?

2. Does poor nutrition play a role in the health disparities we see in disadvantaged communities?

The study (K Marshall et al, PLoS One 15(7):e0235042) I discuss in this week’s “Health Tips From The Professor” attempts to address both of these questions.

Before, I start, let me put this study into context.

  • Osteoporosis is a major health problem in this country. Over 2 million osteoporosis-related fractures occur each year, and they cost our health care system over 19 billion dollars a year. Even worse, for many Americans these osteoporosis-related fractures often cause:
    • A permanent reduction in quality of life.
    • Immobility, which can lead to premature death.
  • Inadequate calcium and vitamin D intakes increase the risk of osteoporosis.

While most studies simply report calcium and vitamin D intakes for the general population, this study breaks them down according to ethnicity and income levels. The results were revealing.

How Was The Study Done?

Clinical StudyThis study drew on data from the 2007-2010 and 2013-2014 National Health and Nutrition Examination Surveys (NHANES). These surveys are conducted by the National Center for Health Statistics, which is part of the CDC. They are designed to assess the health and nutritional status of adults and children in the United States and are used to produce health statistics for the nation.

The NHANES interview includes demographic, socioeconomic, dietary, and health-related questions. The examination component consists of medical, dental, and physiological measurements, as well as laboratory tests administered by highly trained medical personnel. All participants visit a physician. Dietary interviews and body measurements are included for everyone.

This study measured calcium intake, vitamin D intake, and osteoporosis for adults 50 and older. The data were separated by gender, ethnic group and income level. Four different measures of poverty were used. For purposes of simplicity, I will only use one of them, income beneath $20,000, for this article.

Does Poverty Affect Nutritional Status?

The Effect of Ethnicity And Gender On Calcium And Vitamin D Intake: 

FriendsWhen the authors looked at the effect of ethnicity and gender on calcium and vitamin D intake, in people aged 50 and older the results were (Note: I am using the same ethnic nomenclature used in the article):

Hispanics:

    • 66% (75% for women and 56% for men) were getting inadequate calcium intake.
    • 47% (47% for women and 47% for men) were getting inadequate vitamin D intake.

Non-Hispanic Blacks:

    • 75% (83% for women and 64% for men) were getting inadequate calcium intake.
    • 53% (51% for women and 54% for men) were getting inadequate vitamin D intake.

Non-Hispanic Whites:

    • 60% (64% for women and 49% for men) were getting inadequate calcium intake.
    • 33% (30% for women and 37% for men) were getting inadequate vitamin D intake.

For simplicity, we can generalize these data by saying:

Gender:

    • Women are more likely to be calcium-deficient than men.
    • Men are more likely to be vitamin D-deficient than women.

Ethnicity: For both genders and for both calcium and vitamin D:

    • The rank order for deficiency is Non-Hispanic Blacks > Hispanics > Non-Hispanic Whites.

The Effect Of Poverty On Calcium Intake, Vitamin D Intake, And Osteoporosis:

PovertyWhen looking at the effect of poverty, the authors asked to what extent poverty (defined as income below $20,000/year) increased the risk of calcium and vitamin D deficiency in adults over 50. Here is a summary of the data

Hispanics:

    • For both Hispanic women and Hispanic men, poverty had little effect on the risk of calcium and vitamin D deficiency.

Non-Hispanic Blacks:

    • For Non-Hispanic Black women, poverty had little effect on the risk of calcium deficiency, and vitamin D deficiency.
    • For Non-Hispanic Black men, poverty increased the risk of both calcium and vitamin D deficiency by 32%.

Non-Hispanic Whites:

    • For Non-Hispanic White women, poverty had little effect on the risk of calcium deficiency but increased the risk of vitamin D deficiency by 30%.
    • For Non-Hispanic White men, poverty increased the risk of both calcium deficiency and vitamin D deficiency by 18%.

For simplicity, we can generalize these data by saying:

    • Poverty increased the risk of both calcium and vitamin D deficiency for Non-Hispanic Black men, Non-Hispanic White women, and Non-Hispanic White men.

Other statistics of interest:

  • The SNAP program (formerly known as Food Stamps) had little effect on calcium and vitamin D intake. There are probably two reasons for this:
    • In the words of the authors, “While the SNAP program has been shown to decrease levels of food insecurity, the quality of the food consumed by SNAP participants does not meet the standards for a healthy diet.” In other words, the SNAP program ensures that participants have enough to eat, but SNAP participants are just as likely to prefer junk and convenience foods as the rest of the American population. The SNAP program provides no incentive to eat healthy foods.
    • We also need to remember that dairy foods are a major source of calcium and vitamin D in the American diet and that Hispanics and Non-Hispanic Blacks are more likely to be lactose-intolerant than the rest of the American population. There are other sources of calcium and vitamin D in the American diet. But without some nutrition education, most Americans are unaware of what they are.
  • An increased risk of osteoporosis was found in Non-Hispanic Black men, and Non-Hispanic Whites with incomes below $20,000/year.
    • This increased risk of osteoporosis was seen primarily for the individuals in each group who were deficient in calcium and vitamin D. There were other factors involved, but I will focus primarily on the effect of poverty on calcium and vitamin D intake in the discussion below.

How Can We Improve Nutrition In Disadvantaged Communities?

Questioning WomanLet’s start with the two questions I posed at the beginning of this article:

1. Does poverty play a role in poor nutrition?

2. Does poor nutrition play a role in the health disparities we see in disadvantaged communities?

In terms of calcium intake, vitamin D intake, and the risk of osteoporosis, the answer to both questions appears to be, “Yes”. So, the question becomes, “What can we do?”

It is when we start to ask what we can do to increase calcium and vitamin D intake and decreased the risk of osteoporosis in disadvantaged communities that we realize the complexity of the problem. There are no easy answers. Let’s look at some of the possibilities.

[Note: I am focusing on what we can do to prevent osteoporosis, not to detect or treat osteoporosis. The solutions for those issues would be slightly different.]

1. We could increase funding for SNAP. That would increase the quantity of food available for low income families, but, as noted above, would do little to improve the quality of the food eaten.

2. We could improve access to health care in disadvantaged communities. But unless physicians started asking their patients what they eat and start recommending a calcium and vitamin D supplement when appropriate, this would also have little impact on diet quality.

3. We could improve nutrition education. A colleague of mine in the UNC School of Public Health ran a successful program of nutrition education through churches and community centers in disadvantaged communities for many years. The program taught people how to eat healthy on a limited budget. Her program improved the health of many people in disadvantaged communities.

However, the program was funded through grants. When she retired, federal and state money to support the program eventually dried up. The program she started is a model for what we should be doing.

4. The authors suggested food fortification as a solution. In essence, they were suggesting that junk and convenience foods be fortified with calcium and vitamin D. That might help, but I don’t think it is a good idea.

If we want to improve the overall health of disadvantaged communities, we need to find ways to replace junk and convenience foods with healthier foods. Adding a few extra nutrients to unhealthy foods does not make them healthy.

5. The authors also said that a calcium and vitamin D supplement would be a cheap and convenient way to eliminate calcium and vitamin D deficiencies. Unfortunately, supplements are currently not included in the SNAP program. Unless that is changed, even inexpensive supplements are a difficult choice for families below the poverty line.

As I said at the beginning of this section, there are no easy answers. It is easy to identify the problem. It would be easy to throw money at the problem. But finding workable solutions that could make a real difference are hard to identify.

Yes, we should make sure every American has enough to eat. Yes, we should make sure every American has access to health care. But, if we really want to improve the health of our disadvantaged communities, we also need to:

  • Change the focus of our health care system from treatment of disease to prevention of disease.
  • Train doctors to ask their patients what they eat and to instruct their patients how simple changes in diet could dramatically improve their health.
  • Provide basic nutrition education to disadvantaged communities at places where they gather, like churches and community centers. This would cover topics like eating healthy, shopping healthy on a limited budget, and cooking healthy.

We don’t necessarily need another massive federal program. But those of us with the knowledge could each volunteer to share that knowledge in disadvantaged communities.

  • Cover basic supplements, like multivitamins, calcium and vitamin D supplements, and omega-3 supplements in food assistance programs like SNAP.

The Bottom Line

Osteoporosis is a major health problem in this country. Over 2 million osteoporosis-related fractures occur each year, and they cost our health care system over 19 billion dollars a year. Even worse, for many Americans these osteoporosis-related fractures often cause:

  • A permanent reduction in quality of life.
  • Immobility, which can lead to premature death.

We know that inadequate calcium and vitamin D intakes increase the risk of osteoporosis. But most studies simply report calcium and vitamin D intakes for the general population. At the beginning of this article, I posed two questions.

  1.  Does poverty play a role in poor nutrition?

2. Does poor nutrition play a role in the health disparities we see in disadvantaged communities?

A recent study looked at the effect of gender, ethnicity and income levels on calcium intake, vitamin D intake, and the risk of developing osteoporosis. The results of this study shed some light on those two questions.

When looking at the effect of gender and ethnicity on the risk of inadequate calcium and vitamin D intake, the study found:

  • Women are more likely to be calcium-deficient than men.
  • Men are more likely to be vitamin D-deficient than women.
  • For both genders and for both calcium and vitamin D, the rank order for deficiency is Non-Hispanic Blacks > Hispanics > Non-Hispanic Whites. [Note: Note: I am using the same ethnic nomenclature used in the study.]
  • Poverty (defined as incomes below $25,000/year) significantly increased the risk of both calcium and vitamin D deficiency for Non-Hispanic Black men, Non-Hispanic White women, and Non-Hispanic White men.
  • An increased risk of osteoporosis was also found in Non-Hispanic Black men, and Non-Hispanic White men and women with incomes below $20,000/year.
  • This increased risk of osteoporosis was seen primarily for the individuals in each group who were deficient in calcium and vitamin D.

In short, this study suggests that the answer to both questions I posed at the beginning of the article is, “Yes”.

For more information and a discussion of what we could do to correct this health disparity in disadvantaged communities, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Does Maternal Vitamin D Affect Childhood ADHD?

Can ADHD Be Prevented?

vitamin dIf you are pregnant, or of childbearing age, should you be supplementing with vitamin D? Increasingly, the answer appears to be yes.

1) Based on blood 25-hydroxy vitamin D levels (considered the most accurate marker of vitamin D status):

    • 8-11% of pregnant women in the US are deficient in vitamin D (<30 nmol/L).
    • 25% of pregnant women have insufficient vitamin D status (30-49 nmol/L).

In short, that means around 1/3 of pregnant women in the US have insufficient or deficient levels of vitamin D. The effect of inadequate vitamin D during pregnancy is not just an academic question.

2) The Cochrane Collaboration (considered the gold standard for evidence-based medicine) has recently concluded that supplementation with vitamin D reduces the risk of significant complications during pregnancy.

3) Another recent study found that inadequate vitamin D status during pregnancy delayed several neurodevelopmental milestones in early childhood, including gross motor skills, fine motor skills, and social development.

If neurodevelopmental milestones are affected, what about ADHD? Here the evidence is not as clear. Some studies have concluded that vitamin D deficiency during pregnancy increases the risk of ADHD in the offspring. Other studies have concluded there is no effect of vitamin D deficiency on ADHD.

Why the discrepancy between studies?

  • Most of the previous studies have been small. Simply put, there were too few children in the study to make statistically reliable conclusions.
  • Most of the studies measured maternal 25-hydroxyvitamin D levels in the third trimester or in chord blood at birth. However, it is during early pregnancy that critical steps in the development of the nervous system take place.

Thus, there is a critical need for larger studies that measure maternal vitamin D status in the first trimester of pregnancy. This study (M Sucksdorff et al, Journal of the American Academy of Child & Adolescent Psychiatry, 2020, in press) was designed to fill that need.

How Was The Study Done?

Clinical StudyThis study compared 1,067 Finnish children born between 1998 and 1999 who were subsequently diagnosed with ADHD and 1,067 matched controls without ADHD. There were several reasons for choosing this experimental group.

  • Finland is among the northernmost European countries, so sun exposure during the winter is significantly less than for the United States and most other European countries. This time period also preceded the universal supplementation with vitamin D for pregnant women that was instituted in 2004.

Consequently, maternal 25-hydroxyvitamin D levels were significantly lower than in most other countries. This means that a significant percentage of pregnant women were deficient in vitamin D, something not seen in most other studies. For example:

    • 49% of pregnant women in Finland were deficient in vitamin D (25-hydoxyvitamin D <30 nmol/L) compared to 8-11% in the United States.
    • 33% of pregnant women in Finland had insufficient vitamin D status (25-hydroxyvitamin D 30-49.9 nmol/L) compared to 25% in the United States.
  • Finland, like many European countries, keeps detailed health records on its citizens. For example:
    • The Finnish Prenatal Study collected data, including maternal 25-hydroxyvitamin D levels during the first trimester), for all live births between 1991 and 2005.
    • The Care Register for Health Care recorded, among other things, all diagnoses of ADHD through 2011.

Thus, this study was ideally positioned to compare maternal 25-hydroxyvitamin D levels during the first trimester of pregnancy with a subsequent diagnosis of ADHD in the offspring. The long-term follow-up was important to this study because the average age of ADHD diagnosis was 7 years (range = 2-14 years).

Does Maternal Vitamin D Affect Childhood ADHD?

Child With ADHDThe answer to this question appears to be a clear, yes.

If you divide maternal vitamin D levels into quintiles:

  • Offspring of mothers in the lowest vitamin D quintile (25-hydroxyvitamin D of 7.5-21.9 nmol/L) were 53% more likely to develop ADHD than offspring of mothers in the highest vitamin D quintile (49.5-132.5 nmol/L).

When you divide maternal vitamin D levels by the standard designations of deficient (<30 nmol/L), insufficient (30-49.9 nmol/L), and sufficient (≥50 nmol/L):

  • Offspring of mothers who were deficient in vitamin D were 34% more likely to develop ADHD than children of mothers with sufficient vitamin D status.

The authors concluded: “This is the first population-based study to demonstrate an association between low maternal vitamin D during the first trimester of pregnancy and an elevated risk for ADHD diagnosis in offspring. If these findings are replicated, they may have public health implications for vitamin D supplementation and perhaps changing lifestyle behaviors during pregnancy to ensure optimal maternal vitamin D levels.”

Can ADHD Be Prevented?

Child Raising HandI realize that this is an emotionally charged title. If you have a child with ADHD, the last thing I want is for you to feel guilty about something you may not have done. So, let me start by acknowledging that there are genetic and environmental risk factors for ADHD that you cannot control. That means you could have done everything right during pregnancy and still have a child who develops ADHD.

Having said that, let’s examine things that can be done to reduce the risk of giving birth to a child who will develop ADHD, starting with vitamin D. There are two aspects of this study that are important to keep in mind.

#1: The increased risk of giving birth to a child who develops ADHD was only seen for women who were vitamin D deficient. While vitamin D deficiency is only found in 8-11% of pregnant mothers in the United States, that is an average number. It is more useful to ask who is most likely to be vitamin D deficient in this country. For example:

  • Fatty fish and vitamin D-fortified dairy products are the most important food sources of vitamin D. Fatty fish are not everyone’s favorite and may be too expensive for those on a tight budget. Many people are lactose intolerant or avoid milk for other reasons. If you are not eating these foods, you may not be getting enough vitamin D from your diet. This is particularly true for vegans.
  • If you have darker colored skin, you may have trouble making enough vitamin D from sunlight. If you are also lactose intolerant, you are in double trouble with respect to vitamin D sufficiency.
  • Obesity affects the distribution of vitamin D in the body. So, if you are overweight, you may have low 25-hydroxyvitamin D levels in your blood.
  • The vitamin D RDA for pregnant and lactating women is 600 IU, but many multivitamin and prenatal supplements only provide 400 IU. If you are pregnant or of childbearing age, it is a good idea to look for a multivitamin or prenatal supplement that provides at least 600 IU, especially if you are in one of the high risk groups listed above.
  • Some experts recommend 2,000 to 4,000 IU of supplemental vitamin D. I would not recommend exceeding that amount without discussing it with your health care provider first.
  • Finally, for reasons we do not understand, some people have a difficult time converting vitamin D to the active 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D in their bodies. If you are pregnant or of childbearing age, it is a good idea to have your blood 25-hydroxyvitamin D levels determined and discuss with your health care provider how much vitamin D you should be taking. Many people need more than 600 IU to reach vitamin D sufficiency status.

#2: Maternal vitamin D deficiency has a relatively small effect (34%) on the risk of the offspring developing ADHD. That means assuring adequate vitamin D status during pregnancy should be part of a holistic approach for reducing ADHD risk. Other factors to consider are:

  • Low maternal folate and omega-3 status.
  • Smoking, drug, and alcohol use.
  • Obesity.
  • Sodas and highly processed foods.

Alone, each of these factors has a small and uncertain influence on the risk of your child developing ADHD. Together, they may play a significant role in determining your child’s risk of developing ADHD.

In closing, there are three take-home lessons I want to leave you with:

1) The first is that there is no “magic bullet”. There is no single action you can take during pregnancy that will dramatically reduce your risk of giving birth to a child who will develop ADHD. Improving your vitamin D, folate, and omega-3 status; avoiding cigarettes, drugs, and alcohol; achieving a healthy weight; and eating a healthy diet are all part of a holistic approach for reducing the risk of your child developing ADHD.

2) The second is that we should not think of these actions solely in terms of reducing ADHD risk. Each of these actions will lead to a healthier pregnancy and a healthier child in many other ways.

3) Finally, if you have a child with ADHD and would like to reduce the symptoms without drugs, I recommend this article.

The Bottom Line

A recent study looked at the correlation between maternal vitamin D status during the first trimester of pregnancy and the risk of ADHD in the offspring. The study found:

  • Offspring of mothers who were deficient in vitamin D were 34% more likely to develop ADHD than children of mothers with sufficient vitamin D status.

The authors concluded: “This is the first population-based study to demonstrate an association between low maternal vitamin D during the first trimester of pregnancy and an elevated risk for ADHD diagnosis in offspring. If these findings are replicated, they may have public health implications for vitamin D supplementation and perhaps changing lifestyle behaviors during pregnancy to ensure optimal maternal vitamin D levels.”

In the article above I discuss what this study means for you and other factors that increase the risk of giving birth to a child who will develop ADHD.

For more details read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

 

Does Vitamin D Prevent Type 1 Diabetes?

Does Genetics Influence Supplementation Benefits?

diabetesThe cause of type 1 diabetes is a mystery. If you go to an authoritarian source like the Mayo Clinic, you will discover that:

  • Type 1 diabetes is an autoimmune disease that selectively attacks the insulin-producing islet cells of the pancreas.
  • Certain genetic variants predispose individuals to type 1 diabetes.
  • The autoimmune response may be triggered by a viral infection or other unknown environmental factors in genetically susceptible individuals.
  • The incidence of type 1 diabetes increases as you travel away from the equator, which suggests that vitamin D may be involved.

The idea that vitamin D may be involved is an important concept because it suggests that vitamin D supplementation might reduce the risk of developing type 1 diabetes. This idea was reinforced by a Finnish study (E Hyponnen et al, Lancet, 358: 1500-1503, 2001) published in 2001 showing the vitamin D supplementation of newborn infants reduced the incidence of type 1 diabetes at age 1.

However, subsequent studies in other parts of the world have had mixed results. Some have confirmed the results of the Finnish study. Others have come up empty.

Similarly, some studies have shown a correlation between low 25-hydroxyvitamin D levels in the blood and the development of type 1 diabetes in children, while other studies have found no correlation.

Why the discrepancy between studies? Some of the differences can be explained by differences in the populations studied or differences in study design. But what if there were another variable that none of the previous studies has considered?

The study (JM Norris et al, Diabetes, 67: 146-154, 2018) I review this week describes just such a variable. The authors of the study hypothesized that the association between 25-hydroxyvitamin D levels and the risk of developing type 1 diabetes is influenced by mutations that affect the way vitamin D works in the body. Previous studies have not taken these mutations into account. If the author’s hypothesis is true, it might explain why these studies have produced conflicting results.

In this article, I will answer 3 questions:

  • Does vitamin D prevent type 1 diabetes?
  • If so, is supplementation with vitamin D important?
  • Who will benefit most from vitamin D supplementation?

But, before I answer those questions, I should begin by providing some background. I will start by reviewing the how diet, increased need, disease, and genetics influence the likelihood that we will benefit from supplementation. Then I will review vitamin D metabolism.

Does Genetics Influence Supplementation Benefits?

need for supplementsThe reason so many studies find no benefit from supplementation is that they are asking the wrong question. They are asking “Does supplementation benefit everyone?” That is an unrealistic expectation.

I have proposed a much more realistic model (shown on the left) for when we should expect supplementation to be beneficial. Simply put, we should ask:

  • Is the diet inadequate with respect to the nutrient that is being studied?
  • Is there an increased need for that nutrient because of age, gender, activity level, or environment?
  • Is there a genetic mutation that affects the metabolism or need for that nutrient?
  • Is there an underlying disease state that affects the need for that nutrient?

When clinical studies are designed without taking this paradigm into account, they are doomed to fail. Let me give you some specific examples.

  • The Heart Outcomes Prevention Evaluation study concluded supplementation with folate and other B vitamins did not reduce heart disease risk. The problem was that 70% of the people in the study were getting adequate amounts of folate from their diet at the beginning of the study. For those individuals not getting enough folate in their diet, B vitamin supplementation decreased their risk of heart disease by 15%. This is an example of poor diet influencing the need for supplementation.

The other three examples come from studies on the effect of vitamin E supplementation on heart disease that I summarized in an article in “Health Tips From The Professor” a few years ago. Here is a brief synopsis.

  • The Women’s Health Study concluded that vitamin E did not decrease heart disease risk in the general population. However, the study also found that in women over 65 (who are at high risk of heart disease), vitamin E supplementation decreased major cardiovascular events and cardiovascular deaths by 25%. This is an example of increased need because of age and gender influencing the need for supplementation.
  • The Women’s Antioxidant Cardiovascular Study” concluded that vitamin E did not decrease heart disease risk in the general population. However, when they looked at women who already had cardiovascular disease at the beginning of the study, vitamin E supplementation decreased risk of heart attack, stroke, and cardiovascular death by 23%. This is an example of an underlying disease affecting the need for supplementation.
  • The HOPE study concluded that vitamin E did not decrease heart disease risk in the general population. However, when they looked at individuals with a mutation that increases the risk of heart disease, vitamin E supplementation significantly decreased their risk of developing heart disease. This is an example of genetics affecting the need for supplementation.

These are just a few of many examples. When you ask whether supplementation benefits everyone, the answer is often no. However, when you look at people with inadequate diet, increased need, underlying disease, and/or genetic predisposition, the answer is often yes.

This background sets the stage for the current study. Of course, to understand the author’s hypothesis that mutations in genes involved in vitamin D metabolism might influence the effect of vitamin D on the risk of developing type 1 diabetes, you need to know a little about vitamin D metabolism.

Biochemistry 101: Vitamin D Metabolism

Vitamin D MetabolismWhen sunlight strikes a metabolite of cholesterol in our skin, it is converted to a precursor that spontaneously isomerizes to form vitamin D3. Because this series of reactions is usually not sufficient to provide all the vitamin D3 our bodies require, we also need to get vitamin D3 from diet and supplementation.

However, vitamin D3 is not active by itself. It first needs to be converted to 25-hydroxyvitamin D by our liver and then to the active 1,25-dihydroxyvitamin D. 1,25-dihydroxyvitamin D is an important hormone that regulates many cells in our body.

Some of the 1,25-dihydroxyvitamin D is synthesized by our kidneys and released into the bloodstream. This 1,25-dihyroxyvitamin D binds to vitamin D receptors on the surface of many cells and initiates regulatory pathways that affect metabolism inside the cell.

Other cells take up 25-hydroxyvitamin D and convert it to 1,25-dihydroxyvitamin D themselves. In these cells both the synthesis and regulatory effects of 1,25-dihydroxyvitamin D occur entirely inside the cell.

In both cases, it is 1,25-dihydroxyvitamin D that regulates cellular metabolism. The only difference is the way this regulation is accomplished.

There are two additional points that are relevant to this study.

  • The efficiency of conversion of vitamin D to 25-hydroxyvitamin D varies from person to person.
    • Thus, blood levels of 25-hydroxyvitamin D are considered a more reliable measure of vitamin D status than dietary intake of vitamin D or sun exposure.
    • Blood levels of 25-hydroxyvitamin D levels ≥50 nmol/L are considered optimal, while levels of 30 to <50 nmol/L are considered suboptimal, and levels <30 nmol/L are considered deficient.
  • 1,25-dihydroxyvitamin D binds to the vitamin D receptor on immune cells. This initiates a series of reactions that decrease the risk of autoimmune responses by our immune system.

How Was This Study Done?

Clinical StudyThis study was called TEDDY (The Environmental Determinants Of Type 1 Diabetes in the Young). Between September 2004 and February 2010, 424,788 newborn infants from 6 medical centers in Colorado, Georgia, Washington, Finland, Germany, and Sweden were screened for genes that predispose to type 1 diabetes.

The investigators identified 21,589 high-risk infants, and 8,676 of them were enrolled in this study before age 4 months. Clinic visits for the children occurred every 3 months between 3 and 48 months of age and every 6 months thereafter.

  • A DNA sample was taken at the time they entered the study and analyzed for mutations in genes involved in vitamin D metabolism.
  • 25-hydroxy vitamin D levels were obtained at each office visit. Because some studies have suggested the vitamin D status during the first year of life is important, the data were analyzed in two ways.
    1. An average of all 25-hydroxyvitamin D levels (referred to as “childhood 25-hydroxyvitamin D levels”).
    1. An average of 25-hydroxyvitamin D levels during the first 12 months (referred to as “early infancy 25-hydroxyvitamin D levels”).
  • Serum autoantibodies to pancreatic islet cells were measured at each office visit as a measure of an autoimmune attack on those cells. Persistent autoimmune response was defined as positive autoantibodies on two consecutive office visits.

While this study did not directly measure type 1 diabetes, children with an autoimmune response to their pancreatic islet cells are highly likely to develop type 1 diabetes. Thus, for purposes of simplicity I will refer to “risk of developing type 1 diabetes” rather than “persistent autoimmune response” in describing these results.

    1. 418 children developed persistent autoantibodies to their pancreatic islet cells during the study. The onset of this autoimmune response ranged from 2 months to 72 months with an average of 21 months.
    1. These children were compared to 3 matched controls from their medical center who did not develop an autoimmune response.

This study was remarkable for two reasons:

1) It was much larger than previous studies. This gave it greater power to detect an effect of vitamin D status on the risk of developing type 1 diabetes.

2) This was the first study to ask whether mutations in genes controlling the metabolism of vitamin D influenced the effect of vitamin D on the risk of developing type 1 diabetes.

Does Vitamin D Prevent Type 1 Diabetes?

Vitamin DThe study compared the risk of developing type 1 diabetes in children whose 25-hydroxyvitamin D levels were optimal (≥50 nmol/L) to children whose 25-hydroxyvitamin D levels were suboptimal (30 to <50 nmol/L). The results were:

  • Optimal vitamin D status during childhood was associated with a 31% decrease in the risk of developing type 1 diabetes.
  • Optimal vitamin D status during early infancy (first 12 months) was associated with a 40% decrease in the risk of developing type 1 diabetes.

In other words, having optimal vitamin D status significantly reduces the likelihood of developing of type 1 diabetes in childhood.

  • 25-hydroxyvitamin D levels >75 nmol/L provided no additional benefit.

In other words, you need sufficient vitamin D, but higher levels provide no additional benefit.

  • They tested 5 genes involved in vitamin D metabolism to see if they influenced the effect of vitamin D on the risk of developing type 1 diabetes. Only the VDR (vitamin D receptor) gene had any influence.
    • When the VDR gene was fully functional, optimal vitamin D status had no effect on the risk of developing type 1 diabetes. This means that even suboptimal (30 to <50 nmol/L) levels of 25-hydroxyvitamin D were sufficient to prevent type 1 diabetes when the vitamin D receptor was fully functional.
    • Only 9% of the children in this study were vitamin D deficient (<30 nmol/L 25-hydroxyvitamin D). Presumably, these children would be at high risk of developing type 1 diabetes even with a fully functional VDR gene. However, there were not enough children in that category to test this hypothesis.
  • When they looked at children with mutations in the VDR gene:
    • Optimal vitamin D status during childhood was associated with a 59% decrease in the risk of developing type 1 diabetes.
    • Optimal vitamin D status during early infancy (first 12 months) was associated with a 67% decrease in the risk of developing type 1 diabetes.

In short, the need for optimal vitamin D levels to reduce the risk of developing type 1 diabetes is only seen in children with a mutation in the VDR (vitamin D receptor) gene.

  • This is a clear example of genetics affecting the need for a nutrient.
    • For children with a fully functional VDR gene, even 30-50 nmol/L 25-hydroxyvitamin D was sufficient to reduce the risk of developing type 1 diabetes.
    • However, children with mutations in the VDR gene required ≥50 nmol/L 25-hydroxyvitamin D to reduce their risk of developing type 1 diabetes.
  • This is also an example of genetics affecting the need for supplementation with vitamin D.
    • 42% of the children in this study had suboptimal levels of 25-hydroxyvitamin D. Those who also have a mutation in the VDR gene would require supplementation to bring their 25-hydroxyvitamin D up to the optimal level to reduce their risk of developing type 1 diabetes.
    • Other studies have estimated that up to 61% of children in the US may have suboptimal 25-hydroxyvitamin D levels.

What Does This Study Mean For You?

Questioning WomanLet’s start with the three questions I proposed at the beginning of this article.

1) Does vitamin D prevent type 1 diabetes? Based on this study, the answer appears to be a clear yes. However, this is the first study of this kind. We need more studies that into account the effect of mutations in the VDR gene.

2) If so, is supplementation with vitamin D important? If we think in terms of supplementation with RDA levels of vitamin D or sufficient vitamin D to bring 25-hydroxyvitamin D into the optimal range, the answer is also a clear yes. However, there is no evidence from this study that higher doses of vitamin D provide additional benefits.

3) Who will benefit most from vitamin D supplementation? Based on this study, the children who will benefit the most from vitamin D supplementation are those who have a suboptimal vitamin D status and have a mutation in the VDR (vitamin D receptor) gene. To put this into perspective:

    • Up to 60% of children and adults in this country have suboptimal vitamin D levels.
    • The percentage of suboptimal vitamin D levels is highest for people who are obese, have pigmented skin, are institutionalized (eg, elderly in nursing homes), and/or live far from the equator.
    • Supplementation with a multivitamin containing the RDA for vitamin D reduces the risk of having suboptimal vitamin D status by 2.5 to 5-fold depending on the person’s ethnicity.
    • This study may be just the tip of the iceberg. The vitamin D receptor is also found on many other cells that control important biological functions.

Finally, if you are a parent or parent-to-be, you probably have several questions. Here are the ones I have New Parentsanticipated:

#1: Is my child at risk for developing type 1 diabetes? If you or a close family member has type 1 diabetes, you can assume your child is genetically predisposed to developing type 1 diabetes. Other factors that increase your child’s risk of developing type 1 diabetes are obesity, non-White ethnicity, and geographical location far from the equator.

#2: Should I have my baby tested for genetic predisposition to type 1 diabetes? That is not currently recommended. Just be aware of the risk factors listed above.

#3: Should I have my baby tested for VDR mutations? That is unnecessary. If your child has a VDR mutation, they just need sufficient vitamin D, not mega doses of vitamin D. And there are lots of other reasons for making sure your child gets sufficient vitamin D.

#4: How much vitamin D should my child be getting? The recommendation is 400 IU up to age 1 and 600 IU over age 1.

#5: Should I give my child vitamin D supplements? It is a good idea. For children over age 1, I recommend a multivitamin supplying 600 IU of vitamin D.

For infants, the American Association of Pediatrics recommends 400 IU vitamin D drops, regardless of whether the infants are breast or formula fed. That is because studies during the first year of life show that less than one-fifth of all infants get the recommended 400 IU/d from any source, and fewer than one out of 10 breast-fed infants meet the requirement – even if the mother is getting adequate vitamin D in their diet.

One Caution: I do not recommend exceeding 400 IU for infants or 600 IU for children unless directed by your health care provider. In terms of the risk of developing type 1 diabetes, your child needs sufficient vitamin D, and more is not better.

#6: Should I have my child tested for 25-hydroxyvitamin D levels? That is not done routinely at the present time. However, if your child has one or more of the risk factors listed above, it is a conversation you should have with your health care provider.

The Bottom Line

While it is widely accepted that vitamin D helps reduce the risk of developing type 1 diabetes in childhood, that has been difficult to prove. Clinical studies have provided conflicting results. The authors of a recent study postulated that the discrepancies between studies may have arisen because the studies neglected the effect of mutations in genes controlling vitamin D metabolism which may affect the ability of vitamin D to reduce the risk of developing type 1 diabetes.

This study found that:

1) Infants and children with optimal vitamin D status (25-hydroxyvitamin D levels ≥50 nmol/L) were 31-40% less likely to develop type 1 diabetes than children with suboptimal vitamin D status (25-hydroxyvitamin D = 30 to <50 nmol/L).

2) However, the effect of vitamin D on the risk of developing type 1 diabetes was only seen in children with one or more mutations in the VDR (vitamin D receptor) gene. To interpret this observation, you need to know that:

    • Type 1 diabetes is caused by an autoimmune attack on the pancreatic islet cells that release insulin.
    • 1,25-dihydroxyvitamin D promotes immune tolerance and decreases the risk of autoimmune responses.
    • 1,25-dihydroxyvitamin D exerts this effect by binding to the vitamin D receptor on the surface of immune cells.

3) Thus, mutations in the VDR gene modify the effect of vitamin D on the risk of developing type 1 diabetes. Specifically:

    • When the VDR gene is fully active, even suboptimal levels of vitamin D appear to be sufficient to prevent the development of type 1 diabetes in childhood.
    • However, when the VDR gene has mutations that reduce its activity, suboptimal levels of vitamin D no longer prevent type 1 diabetes. Optimal levels of vitamin D are required to reduce the risk of developing type 1 diabetes.

This is an example of genetics increasing the need for a nutrient (vitamin D) and increasing the need for supplementation to make sure that optimal levels of that nutrient are achieved.

While this study focused on the effect of vitamin D on the development of type 1 diabetes, this may just be the tip of the iceberg. The vitamin D receptor is also found on many other cells that control important biological functions.

For more details, read the article above. You will probably want to read the section “What Does This Mean For You?”, including my recommendations for parents of young children

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Health Tips From The Professor