Dr. Steve Chaney, Author at Health Tips From The Professor

The Truth About Vitamin D

December 11, 2018 by Dr. Steve Chaney

Does Vitamin D Reduce Risk Of Heart Disease & Cancer?

Author: Dr. Stephen Chaney

You have every right to be confused. One day you are told that vitamin D reduces your risk of heart disease and cancer. The next day you are told vitamin D makes has no effect on those diseases. You are told vitamin D is a waste of money. What should you believe? What is the truth about vitamin D?

In mid-November a major clinical study called VITAL was published. It examined the effect of vitamin D and omega-3s on heart disease and cancer risk. Last week I wrote about the omega-3 portion of the study. This week I will cover the vitamin D portion of the study.

Once again, if you rely on the media for your information on supplementation, you are probably confused. Headlines ranged from “Vitamin D Is Ineffective For Preventing Cancer And Heart Disease to “Vitamin D Lowers Odds Of Cancer Death.” What is the truth?

The problem is that reporters aren’t scientists. They don’t know how to interpret clinical studies. What they report is filtered through their personal biases. That is why I take the time to carefully evaluate the clinical studies, so I can provide you with accurate information. Let me sort through the dueling headlines and give you the truth about vitamin D, cancer, and heart disease.

How Was The Study Designed?

The VITAL study (JE Manson et al, New England Journal of Medicine, DOI: 10.1056/NEJMoa1811403) enrolled 25,871 healthy adults (average age = 67) in the United States. The study participants were 50% female, 50% male, and 20% African American. None of the participants had preexisting cancer or heart disease. The characteristics of the study group were typical of the American population at that age, namely:

The average BMI was 28, which means that most of the participants were significantly overweight.
7% of them had diabetes.

Study participants were given questionnaires on enrollment to assess clinical and lifestyle factors including dietary intake. Blood samples were taken from about 65% of the participants to determine 25-hydroxyvitamin D levels (a measure of vitamin D status) at baseline and at the end of the first year. The participants were given either 2,000 IU of vitamin D/day or a placebo and followed for an average of 5.3 years.

There were two important characteristics of the participants in this study that may have influenced the outcome.

The average 25-hydroxyvitamin D level of participants at the beginning of the study was 31 ng/ml (78 nmol/L). The NIH considers 20-50 ng/ml (50-125 nmol/L) to be the optimal level of 25-hydroxyvitamin D for most physiological functions. This means that study participants started in the middle of the optimal range with respect to vitamin D status.

[Note: The NIH defines the 20-50 ng/ml range as “adequate.” However, I know many of my readers like to aim beyond adequate to reach what they consider to be “optimal.” In the case of vitamin D, that might not be a good idea. The NIH considers anything above 50 ng/ml as associated “with potentially adverse effects.” For that reason, I will refer to the 20-50 ng/ml range as optimal for this article. I wouldn’t want to encourage my readers to be aiming for above 50 ng/ml.]

Only 12.7% of participants had 25-hydroxyvitamin D levels below 20 ng/ml, which the NIH considers to be inadequate. The results with this group were not statistically different from the study participants with optimal vitamin D status, but it is not clear that there were enough people in this subgroup for a statistically valid comparison with participants starting with an optimal vitamin D status.
At the end of the first year, 25-hydroxyvitamin D levels in the treatment group increased to 42 ng/ml (105 nmol/L), which is near the upper end of the optimal range. Thus, for most of the participants, the study was evaluating whether there was a benefit of increasing vitamin D status from the middle to the upper end of the optimal range.
The study allowed subjects to continue taking supplements that contained up to 800 IU of vitamin D. While the authors tried to correct for this statistically, it is a confounding variable.

Does Vitamin D Reduce The Risk Of Cancer?

You may remember from last week that omega-3s were more effective for reducing heart disease risk than for reducing cancer risk. What is the truth about vitamin D and cancer risk? The results are reversed for vitamin D, so I will discuss cancer first.

The study reported that vitamin D supplementation did not reduce a diagnosis of invasive cancer of any type, breast cancer, prostate cancer, or colon cancer during the 5.3-year time-period of this study. This was the result that was reported in the abstract and was what lazy journalists, who never read past the abstract, reported.

However, the rest of the study was more positive. For example, occurrence of invasive cancer of any type was reduced by:

23% in African-Americans.
24% in patients with a healthy body weight.

Several previous studies have suggested that vitamin D may be more effective at preventing cancer in people with a healthy body weight, but the mechanism of this effect is currently unknown.

Most previous studies have not included enough African-Americans to determine whether they respond more favorably to vitamin D supplementation. However, African-Americans have a higher risk of cancer, so this finding deserves follow-up.

In addition, when the study looked at deaths from cancer, the results were very positive. For example:

Cancer deaths during the 5.3-year study period were reduced by 17%.
The longer vitamin D supplementation was continued the more effective it became at reducing cancer deaths. For example,
When the authors excluded cancer deaths occurring during the first year of supplementation, vitamin D reduced cancer deaths by 21%.
When the authors excluded cancer deaths occurring during the first two years of supplementation, vitamin D reduced cancer deaths by 25%.

Finally, no side effects were noted in the vitamin D group.

Does Vitamin D Reduce The Risk Of Heart Disease?

The VITAL study also looked at the effect of vitamin D on heart disease risk. What is the truth about vitamin D and heart disease? The results from this study were uniformly negative. There was no effect of vitamin D supplementation on all major cardiovascular events combined, heart attack, stroke, or death from heart disease. Does that mean vitamin D has no role in reducing heart disease risk? That’s not clear.

The authors had a thought-provoking explanation for why the results were negative for heart disease, but positive for cancer. Remember that the participants in this trial started with a 25-hydroxyvitamin D level of 31 ng/ml and increased it to at least 42 ng/ml with vitamin D supplementation.

The authors stated that previous studies have suggested the 25-hydroxyvitamin D level associated with the lowest risk for heart disease is between 20 and 25 ng/ml. If that is true, most of the participants in this trial were already in the lowest possible risk for heart disease with respect to vitamin D status before the study even started. There would be no reason to expect additional vitamin D to further reduce their risk of heart disease.

In contrast, the authors said that previous studies suggest the 25-hydroxyvitamin D level associated with the lowest risk of cancer deaths is above 30 ng/ml. If that is true, it would explain why vitamin D supplementation in this study was effective at reducing cancer deaths.

However, previous placebo-controlled clinical studies have also been inconclusive with respect to vitamin D and heart disease. My recommendation would be to think of adequate vitamin D status as part of a holistic approach to reducing heart disease – one that includes a heart-healthy diet and a heart-healthy lifestyle – rather than a “magic bullet” that decreases heart disease risk by itself.

As for heart-healthy diets, I discuss the pros and cons of various diets in my book, “Slaying The Food Myths.” As I discuss in my book, the weight of scientific evidence supports primarily plant-based diets that include omega-3s as heart healthy. As an example, the Mediterranean diet is primarily plant-based and is rich in healthy oils like olive oil and omega-3s. It is associated with reduced risk of both heart disease and cancer.

What Is The Truth About Vitamin D?

There is a lot of confusion around the question of whether vitamin D reduces the risk of cancer. This study strengthened previous observation suggesting that vitamin D supplementation decreases cancer deaths. However, it is also consistent with previous studies that have failed to find an effect of vitamin D on cancer development. How can we understand this apparent discrepancy? The authors provided a logical explanation. They pointed out that:

Cancer development takes 20-30 years while this clinical study lasted only 5.3 years. That means that vitamin D supplementation only occurred at the tail end of the cancer development process. In fact, the cancer was already there in most of the patients in the study who developed cancer. It just had not been diagnosed yet. In the words of the authors: “Given the long latency for cancer development, extended follow-up is necessary to fully ascertain potential effects [of vitamin D supplementation].”
In contrast, none of the patients had been diagnosed with cancer when they entered the trial. That means that the patients were diagnosed with cancer during the 5.3-year study period. They were receiving extra vitamin D during the entire period of cancer treatment. Thus, the effect of vitamin D on reducing cancer deaths was easier to detect.

What Does This Study Mean For You?

Vitamin D Is Likely To Decrease Your Risk Of Dying From Cancer: When you combine the results of this study with what we already know about vitamin D and cancer, the results are clear. Vitamin D appears to reduce your risk of dying from cancer. More importantly, the longer you have been supplementing with vitamin D, the greater your risk reduction is likely to be.

Vitamin D May Decrease Your Risk Of Developing Cancer: Association studies suggest that optimal vitamin D status is associated with decreased cancer risk, especially colon cancer risk. However, the long time for cancer development means that we may never be able to prove this effect through double-blind, placebo-controlled clinical trials.

Holistic Is Best: When you combine the VITAL study results with what we already know about vitamin D and heart disease, it appears that supplementing with vitamin D is unlikely to reduce your risk of developing heart disease unless you are vitamin D deficient. However, a holistic approach that starts with a healthy, primarily plant-based diet and makes sure your vitamin D status is adequate is likely to be effective.

The same is likely true for cancer. While the latest study suggests that vitamin D supplementation reduces your risk of dying from cancer, those vitamin D supplements are likely to be even more effective if you also adopt a healthy diet and lifestyle.

How Much Vitamin D Do You Need? The optimal dose of vitamin D is likely to be different for each of us. One of the things we have learned in recent years is that there are significant differences in the efficiency with which we convert vitamin D from diet and/or sun exposure into the active form of vitamin D in our cells. Fortunately, the blood test for 25-hydroxyvitamin D is readily available and is widely considered to be an excellent measure of our vitamin D status.

I recommend that you have your blood level of 25-hydroxyvitamin D tested on an annual basis. Based on the best currently available data, I recommend you aim for >20 ng/ml (50 nmol/L) if you wish to minimize your risk of heart disease and >30 ng/ml (75 nmol/L) if you wish to minimize your risk of cancer. If you can achieve those levels through diet and a multivitamin supplement, that is great. If not, I would recommend adding a vitamin D supplement until those levels are achieved.

Finally, you shouldn’t think of vitamin D as a magic bullet. If you are a couch potato and eat sodas and junk food, don’t expect vitamin D to protect you from cancer and heart disease. You should think of maintaining adequate 25-hydroxyvitamin D levels as just one component of a holistic approach to healthy, disease-free living.

The Bottom Line

There is a lot of confusion around the question of whether vitamin D reduces the risk of cancer and heart disease. A major clinical study has just been published that sheds light on these important questions. It reported:

Vitamin D did not decrease the risk of developing cancer during the 5.3-year study duration. The authors pointed out that cancer takes 20-30 years to develop, which means their study was probably too short to detect an effect of vitamin D on the risk of developing cancer.
Vitamin D did decrease the risk of dying from cancer, and the longer people were supplementing with vitamin D the bigger the protective effect of vitamin D was.
Vitamin D did not decrease the risk of heart disease. However, most study participants had a level of 25-hydroxyvitamin D that was optimal for reducing the risk of heart disease at the beginning of the study. There was no reason to expect that extra vitamin D would provide additional benefit.
With respect to both cancer and heart disease the best advice is to:
- Get your 25-hydroxyvitamin D levels tested on an annual basis and supplement, if necessary, to keep your 25-hydroxyvitamin D levels in what the NIH considers to be an adequate range (20-50 ng/ml).
- We do not have good dose response data for the beneficial effects of vitamin D on heart disease and cancer. However, according to this article, previous studies suggest you may want to am for 25-hydroxyvitamin D levels above 20 ng/ml to reduce the risk of heart disease and above 30 ng/ml to reduce your risk of cancer.
- Consider vitamin D as just one component of a holistic approach to healthy, disease-free living.

For more details about the interpretation of these studies and what they mean 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.

Are Omega-3 Supplements Good For You?

December 4, 2018 by Dr. Steve Chaney

Do Omega-3s Reduce Risk Of Heart Disease & Cancer?

Author: Dr. Stephen Chaney

Are omega-3 supplements good for you?

You have every right to be confused. In the late 1990s and early 2000s several major clinical studies showed that omega-3 supplements reduced the risk of heart attacks and stroke. In contrast, a few months ago a major study called ASCEND was published that failed to find any benefit of omega-3s at reducing heart disease risk. The headlines said “Omega-3 Supplements Don’t Protect Against Heart Disease”. You were told that omega-3 supplements were worthless. I pointed out the weakness of that study in a previous issue of “Health Tips From the Professor”.

In mid-November two more major clinical studies were published. However, if you rely on the media for your information on supplementation, you are probably still confused. Headlines ranged from “Omega-3 Supplements Do Not Prevent Cancer Or Heart Disease” to “Eating More Fish Or Taking Omega-3 Fish Oil Supplements Can Cut Heart Attack Risk.” What is the truth?

Note: One of the clinical studies looked at the effect of omega-3s on both cancer and heart disease risk. I will discuss the cancer results briefly, but most of my focus will be on the heart disease findings.

How Were The Studies Designed?

The VITAL STUDY (JE Manson et al, New England Journal of Medicine, DOI: 10.1056/NEJMoa1811403 )in the United States. The study participants were 50% female, 50% male, and 20% African American. None of the participants had pre-existing heart disease. The characteristics of the study group were typical of the American population at that age, namely:

The average BMI was 28, which means that most of the participants were significantly overweight.
7% of them had diabetes.
38% were on cholesterol-lowering medications.
50% had high blood pressure treated by medication.

Study participants were given questionnaires on enrollment to assess clinical and lifestyle factors including dietary intake. Blood samples were taken from about 50% of the participants to determine omega-3 index at baseline and at the end of the first year. The participants were given a high purity omega-3 supplement (1 gram capsules containing 840 mg of total omega-3s, 460 mg of EPA, and 380 mg of DHA as the ethyl esters) or a placebo and followed for an average of 5.3 years.

There were two important characteristics of this study that distinguished it from the negative ASCEND study.

This study specifically excluded cardiovascular drugs other than statins and blood pressure medications because many of those drugs provide the same benefits as omega-3s. Patients in the ASCEND study were on 3-5 heart medications
The omega-3 status of participants at the beginning of this study was very low. The omega-3 status of participants in the ASCEND study was near optimal at the beginning of the study.

The REDUCE-IT study (DL Bhatt et al, New England Journal Of Medicine, DOI:10.1056/NEJMoa1812792 ): This study enrolled 8,179 participants (average age = 64) from several countries. The study participants were 70% male and 90% white. The average BMI was 31, which is considered obese. This study differed from the VITAL study in that all the patients were at high risk of heart disease.

70% of them had preexisting heart disease.
The remaining 30% had diabetes plus at least one additional risk factor for heart disease.
In addition, all of them had elevated triglycerides, which is an independent risk factor for heart disease.

The participants were given a high purity EPA supplement (4 grams of EPA as the ethyl ester) or a placebo and followed for an average of 4.9 years.

Do Omega-3s Reduce The Risk Of Heart Disease?

The VITAL Study: The primary end point for this study was something called “major cardiovascular events”, which was a composite every cardiovascular end point measured in the study. For this end point the results were negative. Omega-3 supplementation did not cause a significant decrease in major cardiovascular events compared to the placebo.

This was the result that was reported in the abstract and was what lazy journalists, who never read past the abstract, reported.

However, the rest of the study was very positive. For example, major cardiovascular events were reduced by:

26% in African-Americans.
26% in patients with diabetes.
17% in patients with a family history of heart disease.
19% in patients with two or more risk factors for heart disease.
19% in patients with low fish intake.

In other words, omega-3 supplementation caused a significant decrease in heart disease risk for high risk patients and for patients with a poor diet (low intake of omega-3s).

In addition, several individual cardiovascular events were significantly reduced by omega-3 supplementation. For example:

Heart attacks were reduced by 28% in the general population and by 70% for African-Americans.
Death from heart attacks was reduced by 50%.
Total coronary heart disease was reduced by 17%.
Death from coronary heart disease was reduced by 24%.

In short, headlines saying that omega-3 supplementation can decrease heart attack risk appear to be accurate. Saying that eating more fish can reduce heart attack risk is stretching it a bit. The study was not done with fish, and you would need to eat 2-4 servings of omega-3-rich fish a week to get an equivalent amount of omega-3s. That’s a lot of fish.

The authors attributed the positive results obtained in this study compared to the negative results obtained in several recent studies to four factors:

Many of the previous studies had fewer participants, used lower doses of omega-3s, and were shorter. There may not have been enough statistical power to demonstrate a benefit of omega-3s in those studies.
Participants in many of the previous studies were on multiple medications that mimicked the beneficial effects of omega-3s, making it more difficult to show a positive effect of omega-3 supplementation.
Most of the previous studies either did not measure the omega-3 status of participants or had a study population that started the study with near optimal omega-3 status. The VITAL study showed that omega-3s had a stronger beneficial effect for people who seldom ate fish.
African-Americans were underrepresented in most previous studies. The VITAL study showed that omega-3s were more beneficial for African-Americans than for other ethnic groups.

As for side effects, there was no increased risk of bleeding or any other serious side effect from omega-3 supplementation.

The REDUCE-IT Study: This study of high-risk patients was even more positive than the VITAL study.

The composite of all cardiovascular end points was reduced by 25%.
The risk reduction was greatest for men, non-whites, and people over 65.
The risk reduction was also greatest for people with pre-existing heart disease, very high triglyceride levels, and people who required high-dose statin therapy to keep their cholesterol under control.

In other words, everyone benefited from omega-3 supplementation in this study because they were all at high risk, but those at the highest risk benefitted the most.

When they looked at individual cardiovascular events:

Fatal and non-fatal heart attacks were reduced by 31%.
Cardiovascular death was reduced by 20% and death from any cause was reduced by 23%.
Fatal and non-fatal stroke was reduced by 28%.
Hospitalization for unstable angina was reduce by 32%.

However, this very high dose of EPA was not completely without risk:

1% of patients in the EPA group were hospitalized for atrial fibrillation versus 2.1% in the placebo group.
7% of patients in the EPA group experienced a serious bleeding event compared to 2.1% in the placebo group.

Do Omega-3s Reduce The Risk Of Cancer?

The VITAL Study: The VITAL study also looked at the effect of omega-3s on cancer risk. The results from this study were uniformly negative. There was no effect of omega-3 supplementation on invasive cancer of any type, breast cancer, prostate cancer, colon cancer, or death from cancer. Does that mean omega-3s have no role in reducing cancer risk? That’s not clear.

If we look at previous animal studies and human association studies, reduced cancer risk is seen when omega-3s replaced saturated fats, trans fats, and/or omega-6 fats in the diet. The subjects in the VITAL study ate a typical American diet, and the study made no effort to change what they were eating. It just added an omega-3 supplement. There is relatively little evidence that you can eat burgers and fries and expect omega-3s to reduce cancer risk.

The VITAL study merely confirms what previous studies have suggested. You can’t continue to eat a typical American diet and expect omega-3s to make cancer go away. Omega-3s should be thought of as part of a holistic approach to reducing cancer risk. If they have any role in reducing cancer risk, it is likely to be as part of a primarily plant-based diet that substitutes omega-3s for the bad fats in the American diet.

For example, the Mediterranean diet is primarily plant-based and is rich in healthy oils like olive oil and omega-3s. It is associated with reduced risk of several cancers, especially cancers of the breast and colon.

Are Omega-3 Supplements Good For You?

There is a lot of confusion around the question of whether omega-3s are good for the heart. Some studies say yes. Others say no. If you average all the studies together, as some recent meta-analyses have done, it is easy to throw up your hands and conclude there is no definitive evidence that omega-3s reduce heart disease risk. However, if you look at why the studies differ a clear pattern emerges.

If the study subjects are on multiple heart medications that duplicate the beneficial effects of omega-3s, the studies tend to be negative. If the subjects are only on one or two medications, the studies tend to be positive. Since most people I know would prefer to minimize the number of medications they are on, the negative studies with multiple medications are simply not relevant to them.
If the study subjects are at low risk of heart disease, the studies tend to be negative. If the subjects are at high risk, the studies tend to be positive. This does not mean that omega-3s are of no benefit if you are at low risk of heart disease. It simply reflects the fact it is easier to show a beneficial effect of any intervention when you have a pool of high-risk patients who are likely to experience some sort of cardiovascular event during the time-period of the study.

For example, as discussed in my recent book, “Slaying The Supplement Myths,” this the same pattern you see with statin clinical studies. If patients are at high risk, statin drugs clearly save lives. If they are at low risk, it is almost impossible to show any benefit of statin drugs. Cardiologists extrapolate from the high-risk studies and prescribe statins to low-risk patients. I think it is time to take a similar approach with omega-3s.

If the subjects have a good omega-3 status at the beginning of the study, additional omega-3 supplementation usually has no benefit. If their omega-3 status is poor at the beginning of the study, the results of omega-3 supplementation tend to be positive. This is just common sense. Supplementation is meant to fill gaps in the diet – not to provide a surplus of nutrients. Of course, the reality is many Americans do not get enough omega-3s in their diet.

What Do These Studies Mean For You?

Omega-3s Are Good For Your Heart: When you combine the latest studies with what we already know about omega-3s and heart disease, the results are clear-cut.

If you are at high risk of heart disease, don’t eat many omega-3-rich fish, and/or don’t want to be on a handful of heart medications, the evidence is strong that omega-3s reduce your risk of heart disease.
On the other hand, if you are at low risk of heart disease, eat 2-4 servings of omega-3-rich fish a week, and/or are happy taking multiple heart medications with all their side effects, it is difficult to prove that omega-3s have any benefits. That doesn’t mean that omega-3s don’t have benefits. It just means we can’t prove they do.

If you are still having trouble making up your mind whether omega-3 supplements are the right choice for you, I might remind you:

If you are like millions of Americans, the first sign you are at risk of heart disease might be sudden death.
If you are like most Americans, you are probably not getting enough omega-3s in your diet.
If you prefer taking drugs, you are probably not interested in supplements anyway.

Holistic Is Best: When you combine the VITAL study results with what we already know about omega-3s and cancer, it appears that adding omega-3s to a bad diet is unlikely to reduce your risk of cancer. However, a holistic approach that starts with a healthy, primarily plant-based diet and substitutes omega-3s for the bad fats in the American diet is likely to substantially reduce your cancer risk. The Mediterranean diet might be considered an example of that approach.

The same is likely true for heart health. While the latest two studies suggest that adding omega-3 supplements to your regular diet reduces your heart disease risk, those omega-3 supplements are likely to be even more effective if you also adopt a heart-healthy diet and lifestyle.

Omega-3 Supplements vs Omega-3 Drugs: The Omega-3 preparations used in this study are pharmaceutical-grade omega-3 preparations and are marketed as drugs. Thus, it is likely that many doctors will recommend them rather than less expensive omega-3 supplements. Which choice is best for you?

The preparation used in the VITAL study is similar in composition to many commercially available omega-3 supplements. The main difference is that it is high purity and is subject to the quality control standards required for pharmaceutical drugs. Many omega-3 supplements do not meet these standards, but some do. If you wish to use an omega-3 supplement, do your research. Inquire about their quality control standards and only buy high purity supplements.

The preparation used in the REDUCE-IT study used ultra-pure EPA only. That preparation did not contain any other omega-3s, so a commercially available omega-3 supplement would not be comparable. However, I do not recommend an EPA-only supplement for three reasons.

The results for high risk patients in the REDUCE-IT study were similar to those for high risk patients in the VITAL study. This suggests that removing DHA and other omega-3s may not provide additional protection against heart disease. A head to head comparison of the two supplements would be required to prove the superiority of an EPA-only supplement.
I have the same concern for this high-dose EPA supplement as I have for any high-dose single nutrient supplement. DHA and other omega-3s provide benefits such as cognitive health that EPA does not. Very high dose EPA is likely to interfere with the uptake and utilization of the other omega-3s.
The EPA only supplement used in the REDUCE-IT study had side effects that were not seen with the mixed omega-3 supplement used in the VITAL study. It is not clear whether those side effects were due to differences in dose or differences in formulation.

Omega-3 Ethyl Esters vs Omega-3 Triglycerides: There has been a lot of hype about the superiority of omega-3 triglyceride preparations recently. These studies were both done with omega-3 ethyl esters and proved to be very effective. Until someone shows that omega-3 triglyceride preparations provide better results at reducing heart disease risk than omega-3 ethyl esters, I would leave omega-3 triglyceride supplements on the shelf.

How Much Omega-3s Do You Need? We have too few dose-response studies to reliably predict how much omega-3s are optimal for reducing heart disease risk. The 1 gram/day dose used in the VITAL study gave good results, so that is an excellent starting point. The 4 gram/day dose used in the REDUCE-IT study seemed to provide little additional benefit.

Of course, the optimal dose is likely to be different for each of us. Once the omega-3 index blood test becomes more widely available I would recommend getting your omega-3 index determined on an annual basis and aiming for an omega-3 index of 8 or above, since that is the level associated with a low risk of heart disease.

The Bottom Line

However, two recent studies support the effectiveness of omega-3s for reducing heart disease risk. When you combine the latest studies with what we already know about omega-3s and heart disease, the results are clear-cut.

If you are at high risk of heart disease, don’t eat many omega-3-rich fish, and/or don’t want to be on a handful of heart medications, the evidence is strong that omega-3s reduce your risk of heart disease.
On the other hand, if you are at low risk of heart disease, eat 2-4 servings of omega-3-rich fish a week, and/or are happy taking multiple heart medications with all their side effects, it is difficult to prove that omega-3s have any benefits. That doesn’t mean that omega-3s don’t have benefits. It just means we can’t prove they do.

If you are still having trouble making up your mind whether omega-3 supplements are the right choice for you, I might remind you:

If you are like millions of Americans, the first sign you are at risk of heart disease might be sudden death.
If you are like most Americans, you are probably not getting enough omega-3s in your diet.
If you prefer taking drugs, you are probably not interested in supplements anyway.

In addition, one of the studies confirmed what we already know about omega-3s and cancer. Adding omega-3s to a bad diet is unlikely to reduce your risk of cancer. However, a holistic approach that starts with a healthy, primarily plant-based diet and substitutes omega-3s for the bad fats in the American diet is likely to substantially reduce your cancer risk. The Mediterranean diet might be considered an example of that approach.

For more details read the article above. In addition, the article covers topics like omega-3 supplements versus omega-3 drugs, omega-3 ethyl esters versus omega-3 triglycerides, and how much omega-3s we need. It also discusses why several recent studies have failed to find a benefit of omega-3s for reducing heart disease risk.

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 Organic Foods Decrease Cancer Risk?

November 27, 2018 by Dr. Steve Chaney

Is Eating Organic Worth The Cost?

Author: Dr. Stephen Chaney

Millions of Americans choose organic foods whenever possible. However, organic foods are expensive, and some experts claim they are a waste of money. That is why recent headlines claiming that eating organic foods decrease cancer risk have created such a stir. I will look at the study behind the headlines below, but first let me summarize what we do know about organic foods.

I discussed a study comparing organic and conventionally-grown produce in a recent issue, Organic Foods Healthier, of “Health Tips From the Professor”. It was a major study that combined the results from 343 of the best-designed previous studies. The study found that pesticide and herbicide residues were 4-fold lower in organically-raised produce than in conventionally-raised produce. It also found that the polyphenol content of organically-raised produce was slightly higher than in conventionally-raised produce.

Neither of these findings automatically mean that eating organic produce will improve your health. However, there is increasing evidence that pesticide exposure is linked to increased risk of cancer. Thus, it seems logical that eating organic might decrease cancer risk. It is that hypothesis that the current study (J Baudry et al, JAMA Internal Medicine, doi: 10.1001/jamainternmed.2018.4357 ) was designed to test.

How Was The Study Designed?

This study is part of a major French study called NutriNet-Santé that was launched in 2009. The NutriNet-Santé study is web-based study designed to investigate associations between nutrition and health.Volunteers with access to the internet were recruited from the general population. After agreeing to participate in the study, the volunteers were asked to complete a battery of online assessment forms.

The baseline data for the NutriNet-Santé study included age, sex, occupational status, education level, marital status, income, number of children, smoking status, physical activity, and diet. Dietary intake was assessed using three 24-hour dietary recalls collected over a 2-week period. Two of the 24-hour dietary recalls were on weekdays and one was on a weekend.

The dietary recalls were used to create a “score” of diet quality. Without going into detail, diets that favored animal protein, animal fats, sweets, and highly processed foods were considered “poor quality diets.” Diets that favored plant proteins, vegetable oils & and omega-3 fats, fruits, vegetables, and whole grains were considered “good quality diets.”

This portion of the NutriNet-Santé was designed to measure the correlation between organic food consumption and cancer risk. Two months after enrollment in the study, the participants were asked to provide information on the frequency with which they chose the organic version of 16 different types of food. From this information each participant was assigned an “organic food score” ranging from 0 to 32 points.

The participants in this study were also asked to complete a yearly health status questionnaire online. If they reported a cancer diagnosis, they were asked to provide their medical records, and the study physicians contacted the patient’s physician to confirm details of the diagnosis.

A total of 68,946 French adults completed the study (78% female, mean age 44.2 years). They were followed for an average of 4.56 years. During this time period there were 1340 new cancer diagnoses in this population.

Do Organic Foods Decrease Cancer Risk?

The participants were divided into four groups based on their organic food score. When participants with the highest organic food score were compared to those with the lowest organic food score there was a:

25% reduction in total cancer risk.
86% reduction in non-Hodgkin lymphoma risk. This is not a novel finding. A previous study has also suggested eating organic might reduce the risk of non-Hodgkin lymphoma.
76% reduction in all lymphoma risk.
34% reduction in postmenopausal breast cancer risk.

The authors concluded “A higher frequency of organic food consumption was associated with a reduced risk of cancer. Although the study findings need to be confirmed, promoting organic food consumption in the general population could be a promising preventive strategy against cancer.”

These are the results and conclusions that made the headlines. However, the scientists who designed the study were aware of previous data showing that people who eat organic are also more likely to eat a healthy diet and follow a healthy lifestyle. Thus, their statistical analysis of the data considered all factors that might influence cancer risk. This analysis provided a much more nuanced interpretation of the data. They found that the association between increased organic food consumption and decreased cancer risk:

Was significant for women, older adults, individuals with a family history of cancer, individuals who had a poor diet, and former smokers.
Was seen for people of all weights but was greatest for individuals who were obese.
Was non-significant for men, younger adults, individuals with no family history of cancer, individuals who had a good diet, never-smokers, and current smokers.
Was non-significant for other types of cancer.

You are probably wondering “Does this mean organic foods are beneficial for some people, but not for others?” A superficial interpretation of these data might lead to that conclusion, but let’s dig a little deeper.

What Does This Study Mean For You?

In interpreting a study of this type, it is important to ask whether enough people will develop cancer during the study for the results to be statistically significant. That depends on 3 factors:

The number of people enrolled in the study.
The duration of the study.
The probability that participants will develop cancer during the duration of the study.

When you look at the whole study population, all three criteria have been met. There were 68,949 participants who were followed for 4.56 years. During that time 1340 of them developed cancer, of which 459 were breast cancer, 47 were non-Hodgkin lymphomas, and 15 were other lymphomas. A higher frequency of organic food consumption was associated with a decreased in the risk of all these cancers, and that decreased risk was statistically significant. This is the main take-home lesson of the study.

However, when you start to break the study down into subgroups, the number of people in each subgroup and the duration of the study become limiting factors. For example:

We don’t really know whether eating organic foods are unimportant for men or whether there were too few men in the study for any benefit to be statistically significant.
Colon cancer and many other cancers develop gradually over a 10 to 20-year period. We don’t know whether choosing organic foods is unimportant for these cancers or whether 4.56 years is too short a time to show a significant benefit.
The same is true for several of the other variables in this study. For example, if you are an older adult, have a family history of cancer, have a bad diet, and/or have smoked in the recent past, your probability of developing cancer over a 4.56-year time period is relatively high. On the other hand, if you are younger, have no family history of cancer, have a good diet, and have never smoked, your probability of developing cancer during that same time period is very low.

So, how do we interpret the data with these subgroups? We could conclude that eating organic foods in unimportant for people who are young, have no family history of cancer, have a good diet, and have never smoked. A more likely interpretation, however, is that people in these groups have such a low risk of cancer that 4.56 years is too short to demonstrate a benefit of organic foods. It might require a 10, 20, or 30-year study to show benefit of organic foods for these people.

Let me close with three important observations:

People often say too me: “I can’t afford organic fruits and vegetables, but I am concerned about pesticide exposure. Does that mean I should avoid fruits and vegetables?” The data from this study provide a clear answer. Eating lots of fruits and vegetables is beneficial even if you can’t afford organic.

[I also let them know about “The Dirty Dozen” ( Rank Produce Items By Pesticide Level ). This is a list of the fruits and vegetables most likely to be contaminated with pesticides. If your budget for organic foods is limited, these are the most important fruits and vegetables to spend it on.]

I find it ironic that people who consume a poor diet are the ones most likely to experience an immediate benefit from choosing organic foods. This is, of course, the group that is least likely to eat organic.
If you smoke, eating organic probably isn’t going to help you much. Your best bet is to stop smoking.

The Bottom Line

A recent study looked at the association between organic food consumption and cancer risk. When participants who consumed organic foods frequently were compared to those who almost never consumed organic foods there was a:

25% reduction in total cancer risk.
86% reduction in non-Hodgkin lymphoma risk. This is not novel. A previous study has also suggested eating organic might reduce the risk of non-Hodgkin lymphoma.
76% reduction in all lymphoma risk.
34% reduction in postmenopausal breast cancer risk.

These are the results and conclusions that you have seen in the headlines. However, the scientists who designed the study were aware of previous data showing that people who eat organic are also more likely to eat a healthy diet and follow a healthy lifestyle. Thus, their statistical analysis of the data considered all factors that might influence cancer risk. This analysis provided a much more nuanced interpretation of the data, which I have discussed in the article above.

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.

Warm Up Before Stretching

November 20, 2018 by Dr. Steve Chaney

Avoid Muscle Pain Before It Starts

Author: Julie Donnelly, LMT –The Pain Relief Expert

Editor: Dr. Steve Chaney

Happy Thanksgiving!

November is the month that reminds us to be grateful for all the blessings we enjoy because we are Americans. Of course, we should be grateful every day for the freedoms we have in this beautiful country! Have you thought about the freedom you enjoy the most? For me it’s the freedom to worship however I choose because we don’t have a particular religion forced on us. I also love the fact that I can own my business and move it anywhere I like in the entire country.

I hope you’ll give some thought to what you are grateful for as this happy holiday draws near.

Should we warm up before stretching?

Avoid Muscle Pain Before It Starts

Now that the weather has turned cooler in all parts of the USA, more people are exercising outdoors. Are you? Be sure to warm up your muscles before you go running or cycling. One good way to gently and effectively warm up your joints is to bring them into their full range-of-motion. This is also a great morning routine when you first get up.

You have been told to stretch before you exercise. However, stretching while a muscle is tied up with spasms that shorten its fibers may cause the muscle fibers to get micro-tears. You could be creating muscle pain rather than avoiding muscle pain.

As an analogy, think about what happens if you tie a rope in knots and then try to stretch it to its original length without first untying the knots. That is exactly what happens when you try to stretch a muscle that is tight or has spasms. Release the spasms by warming up first, and then stretch. It works great and will assure that you don’t hurt worse after stretching than you did before you stretched.

Warm Up Before Stretching

The key here is not attempting to stretch your muscles, but to just gently move your joints. Here is a whole-body warm-up procedure I recommend.

First, bring your arm all the way across the front of your body, then slowly help the movement by linking your opposite arm across your elbow and pull your arm toward your chest. Repeat this with your opposite arm, loosening the back of your shoulders. Only go to the point of “feels so good,” never to a point of pain.

Then bring both arms as far back as you can, releasing the front of your shoulders. While you’re there, move your head and neck down toward your chest and around to the side, moving the top of your shoulders and neck.

Next, with your arms still out to the side, rotate your arms forward several times, and then backwards several times. Your intention is to move your shoulder joint in as many directions as possible, always doing the movement gently and slowly.

Warm up your waist and lower back by keeping your hips still and rotating your upper body as far to the left as you comfortably can, and then as far to the right. The goal here is to gently move all the joints from your mid-back to your hips.

To loosen your hip joint, you’ll want to easily swing your leg back and forth. If you are standing with your foot on the floor, you’ll need to hold your foot up, so it clears the floor.

When possible, it’s good to be standing on a step or some books so the foot on your swinging leg will be relaxed. Below I am demonstrating by standing on two packs of copy paper.

Stand with your right leg on a step, and then slowly and gently swing your left leg back and forth. Let your leg drop, giving an easy stretch to your hip joint. Then reverse so you can do the same to your right leg & hip. Then hold on to something and swing your leg in front of you, going from side-to-side.

This entire program will take from 5-10 minutes of your time, and its goal is to just get your joints moving. It should always feel good, like you are waking up your joints to prepare for the day. There are many good morning routines to loosen up joints that stiffen while sleeping.

After you have released the knots in your muscles, you can stretch safely. Now you are ready to start your day!

How to Untie the Spasms that are Knotting Up Your Muscles

If your muscles have painful knots, this gentle warm-up procedure is not always enough. I also teach people how to untie the knots (spasms) that form in muscles. Those knots shorten the fibers and put a strain on the joints. I always recommend that you apply direct pressure on the knots, holding the pressure for 30 seconds to press toxins out of the fibers and draw blood into the muscle.

If you have been to see me at my office, you know that I always teach how to do two or three of the Julstro Method self-treatments that will help you stop pain. I’ve been doing this for years, and it works.

Back in 2001 I wrote my first self-treatment book titled The Pain-Free Triathlete. At the time most of my clients were either serious athletes or Ironman triathletes. That ultimately expanded to become a book for the general public and in 2010 I wrote Treat Yourself to Pain-Free Living. Thanks to print-on-demand that book was constantly updated and revised, with the latest version being done in 2018. Then I wrote the updated book for athletes titled: The Pain-Free Athlete.

I also have a DVD stretching program that combines all the self-treatments with a safe Yoga stretching routine. That DVD program is titled Focused Flexibility Training, although it started out as Trigger Point Yoga (only the name was changed).

The 15 Minute Back Pain Solution was another book added to the collection. This book focuses on the muscles that specifically cause low back pain, and hip/groin/knee pain, as well as sciatica. Originally it was only available as a Kindle book, but it is now being printed and will be ready soon.

It’s not difficult to release the tight muscle spasms that are causing you pain, it just takes a bit of direction to know how to find the point and how to treat it. Each of these books and DVD programs show you how to do that quickly and easily.

You can look at each of these books and programs by going to www.JulstroMethod.com/shop

Wishing you well,

Julie Donnelly

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.

About The Author

Julie Donnelly is a Deep Muscle Massage Therapist with 20 years of experience specializing in the treatment of chronic joint pain and sports injuries. She has worked extensively with elite athletes and patients who have been unsuccessful at finding relief through the more conventional therapies.

She has been widely published, both on – and off – line, in magazines, newsletters, and newspapers around the country. She is also often chosen to speak at national conventions, medical schools, and health facilities nationwide.

Are High Fat Dairy Foods Good For You?

November 13, 2018 by Dr. Steve Chaney

Can You Have Your Cream And Eat It Too?

Author: Dr. Stephen Chaney

Dairy foods can play an important role in helping us get enough calcium in our diet and may provide some other benefits (discussed below). However, many dairy foods contain a lot of saturated fat. Thus, we have been told to select low-fat dairy foods. So, what should we make of the recent headlines and blogs telling us that high-fat dairy foods are good for us?

Are high fat dairy foods good for us?

To answer that question, I picked a recent article (F. Imamura et al, PLOS Medicine, doi: 10.1371/journal.pmed.1002670 ) claiming that dairy fats lower the risk of type 2 diabetes and did an in-depth analysis of the data behind the headlines.

Fat Chemistry 101

Before I get started, let me cover what I call “Fat Chemistry 101”. Sorry, professors never fully retire.

Fat Nomenclature: Let me briefly describe some of the nomenclature that chemists and biochemists use when they describe fats. Fats, or triglycerides, are generally defined as three fatty acids attached to a molecule of glycerol. The chemical nomenclature for fatty acids consists of a “C” followed by the number of carbons in that fatty acid. That, in turn, is followed by a colon (:) and the number of doubles bonds (0 for a saturated fatty acid, 1 for a monounsaturated fatty acid, and 2 or more for a polyunsaturated fatty acid). Let me give some examples, specifically the examples I will refer to in this article.

Saturated fatty acids:

C15:0 (pentadecanoic acid)
C16:0 (palmitic acid)
C17:0 (heptadecanoic acid)
C18:0 (stearic acid)

Monounsaturated fatty acids:

C18:1 (oleic acid)

C16:0, and C18:0 are referred to as even-chain fatty acids (They have an even number of carbon atoms). C15:0 and C17:0 are referred to as odd-chain fatty acids (They have an odd number of carbon atoms).

C16:0 (palmitic acid) is the most abundant saturated fatty acid in meats and dairy food. C18:0 (stearic acid) is the second most abundant saturated fatty acid in these foods. The odd-chain fatty acids C15:0 and C17:0 are primarily found in dairy fat although small amounts can also be found in meat and fish.

All saturated fats raise LDL cholesterol. However, the effect is not equally strong for all saturated fats. The effect on LDL cholesterol is strongest for palmitic acid (C16:0). It is weaker for stearic acid, possibly because stearic acid (C18:0) can be metabolized to oleic acid (C18:1), which has no effect on LDL cholesterol.

Foods Are A Complex Mixture Of Fats: We generally think of saturated fats coming from meat and dairy, monounsaturated fats coming from olive oil and avocados, and polyunsaturated fats as coming from vegetable oils, seeds, and nuts. However, that is an oversimplification. Meats also contain monounsaturated and polyunsaturated fats. Olive oil contains some saturated and polyunsaturated fats. Vegetable oils also contain monounsaturated and saturated fats.

Why do I even mention this? It is important because we tend to label a food “good” or “bad” based on its most abundant fat. Perhaps we would be better served if we considered all the major fats in that food before deciding whether it is good or bad for us.

How Was The Study Designed?

With that background in mind, let us turn our attention to the current study. The authors wished to test the hypothesis that high-fat dairy foods might decrease the risk of type 2 diabetes. The results of previous studies had been mixed, but the authors hypothesized that might have been due to the limitations of using dietary recalls to assess intake of high-fat dairy foods. Specifically, they theorized that dietary recalls tend to underestimate the less apparent sources of dairy fats such as creams, sauces, cheeses, and butter used as part of meal preparation or in prepared foods.

They postulated that blood and tissue concentrations of the odd-chain fatty acids (C15:0 and C17:0) would be a much better biomarker of dairy fat consumption than dietary recalls. They performed a meta-analysis of all studies that measured blood or tissue levels of odd-chain fatty acids and looked at type 2 diabetes as an outcome.

Their meta-analysis included 16 studies from 12 countries with a total of 63,682 participants (age range: 49 to 76 years). The participants were slightly overweight, but none of them had type 2 diabetes at the beginning of the studies. The participants were followed for an average of 9 years. By the end of the studies 15,180 (24%) had developed type 2 diabetes.

Are High Fat Dairy Foods Good For You?

When the authors compared the highest versus the lowest levels of odd-chain fatty acids in the subjects, the results of the study were as follows:

The highest level of C15:0 fatty acids was associated with a 20% lower incidence of type 2 diabetes.
The highest level of C17:0 fatty acids was associated with a 35% lower incidence of type 2 diabetes. This is consistent with several previous studies that have suggested C17:0 fatty acids are a better predictor of type 2 diabetes than C15:0 fatty acids.
When these data were combined the overall effect was a 29% lower incidence of type 2 diabetes.

The authors concluded: “These novel findings support the need for additional clinical and molecular research to elucidate the potential effects of [odd-chain] fatty acids on glucose-insulin metabolism and the potential role of selected [high-fat] dairy products for the prevention of type 2 diabetes.”

What Does This Study Mean For You?

On the surface, this looks like a very strong study. It is, after all, a meta-analysis with over 68,000 subjects. It also used biomarkers for dairy fat consumption rather than relying on less accurate dietary recalls. Finally, it is consistent with several earlier studies suggesting that high-fat dairy foods decrease the risk of type 2 diabetes and heart disease. What could go wrong?

The answer is “Plenty.”

Studies looking at the effect of high-fat dairy foods on the risk of heart disease and type 2 diabetes have been inconsistent. Some have shown benefit, but others have come up empty. Despite the inconsistent results, the idea that high-fat dairy foods might be good for us has gotten a lot of media attention. I suspect that is because this is the kind of news we really want to be true. After all, wouldn’t it be great news if we could eat all the cheese, cream, and butter we wanted?
Some studies have concluded that high-fat and low-fat dairy products were equally effective at decreasing the risk of heart disease and type-2 diabetes. If these studies are correct, they would suggest something else in dairy foods is protective, not the kind of fat.
The odd-chain saturated fatty acids are very minor constituents of dairy fat. Together, they represent 1.3% of the fatty acids in dairy fat. In contrast, even-chain saturated fatty acids make up 68% of the fatty acids in dairy fat. Palmitic acid (C16:0) makes up 30% or 23 times the concentration of odd-chain fatty acids. Stearic acid (C18:0) makes up 12% or 9 times the concentration of odd-chain fatty acids.
This study, and most previous studies, have just looked at the association between odd-chain fatty acids and type 2 diabetes. They do not prove cause and effect.
No mechanism has been proposed that would account for the proposed beneficial effects of odd-chain saturated fatty acids, especially in the presence of much higher concentrations of even-chain saturated fatty acids.
A study published last year (BJ Jenkins et al, Scientific Reports, 7:44845, doi: 10.1038/srep44845 ) reported that blood levels of C15:0 were dependent on intake of dairy foods, but that blood levels of C17:0 were independent of dairy intake. These authors presented evidence showing C17:0 in the human body resulted from metabolism of C18:0 (stearic acid) in our diet rather than coming from dairy fats.

In other words, the odd-chain fatty acid (C15:0) that comes from dairy foods is the one that has only a weak association with the risk of developing type 2 diabetes. The odd-chain fatty acid with a strong association with diabetes risk is synthesized in our bodies from stearic acid (C18:0), a fatty acid that is also found at high levels in meat.

So, are high fat dairy foods good for you? More studies are needed.

The Bottom Line

A recent study has reported that high-fat dairy products may reduce the risk of type 2 diabetes. This is consistent with a few other studies that have suggested high-fat dairy products may reduce the risk of diabetes and heart disease.

The idea that high-fat dairy foods might be good for us has gotten a lot of media attention. I suspect that is because this is the kind of news we really want to be true. After all, wouldn’t it be great news if we could eat all the cheese, cream, and butter we wanted?

However, the clinical results have been inconsistent. Some have shown benefit, but others have come up empty. Most of the studies also had significant limitations. I have discussed the limitations of the current study in the article above.

We can remain hopeful that high-fat dairy foods will eventually be shown to be good for us, but until we have stronger evidence for the proposed benefits of dairy fats, my recommendation is to consume high-fat dairy products sparingly.

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.

Is Our Microbiome Affected By Exercise?

November 6, 2018 by Dr. Steve Chaney

Microbiome Mysteries

Author: Dr. Stephen Chaney

In a recent post, What is Your Microbiome and Why is it Important, of “Health Tips From The Professor” I outlined how our microbiome, especially the bacteria that reside in our intestine, influences our health. That influence can be either good or bad depending on which species of bacteria populate our gut. I also discussed how the species of bacteria that populate our gut are influenced by what we eat and, in turn, influence how the foods we eat are metabolized.

I shared that there is an association between obesity and the species of bacteria that inhabit our gut. At present, this is a “chicken and egg” conundrum. We don’t know whether obesity influences the species of bacteria that inhabit our gut, or whether certain species of gut bacteria cause us to become obese.

Previous studies have shown that there is also an association between exercise and the species of bacteria that inhabit our gut. In particular, exercise is associated with an increase in bacteria that metabolize fiber in our diets to short chain fatty acids such as butyrate. That is potentially important because butyrate is a primary food source for intestinal mucosal cells (the cells that line the intestine). Butyrate helps those cells maintain the integrity of the gut barrier (which helps prevent things like leaky gut syndrome). It also has an anti-inflammatory effect on the immune cells that reside in the gut.

However, associations don’t prove cause and effect. We don’t know whether the differences in gut bacteria were caused by differences in diet or leanness in populations who exercised regularly and those who did not. This is what the present study (JM Allen et al, Medicine & Science In Sports & Exercise, 50: 747-757, 2018 ) was designed to clarify. Is our microbiome affected by exercise?

How Was The Study Designed?

This study was performed at the University of Illinois. Thirty-two previously sedentary subjects (average age = 28) were recruited for the study. Twenty of them were women and 12 were men. Prior to starting the study, the participants filled out a 7-day dietary record. They were asked to follow the same diet throughout the 12-week study. In addition, a dietitian designed a 3-day food menu based on their 7-day recall for the participants to follow prior to each fecal collection to determine species of gut bacteria.

The study included a two-week baseline when their baseline gut bacteria population was measured, and participants were tested for fitness. This was followed by a 6-week exercise intervention consisting of three supervised 30 to 60-minute moderate to vigorous exercise sessions per week. The exercise was adapted to the participant’s initial fitness level, and both the intensity and duration of exercise increased over the 6-week exercise intervention. Following the exercise intervention, all participants were instructed to maintain their diet and refrain from exercise for another 6 weeks. This was referred to as the “washout period.”

VO_2max (a measure of fitness) was determined at baseline and at the end of the exercise intervention. Stool samples for determination of gut bacteria and concentrations of short-chain fatty acids were taken at baseline, at the end of the exercise intervention, and again after the washout period.

In short, this study divided participants into lean and obese categories and held diet constant. The only variable was the exercise component.

Is Our Microbiome Affected By Exercise?

The results of the study were as follows:

Fitness, as assessed by VO_2max, increased for all the participants, and the increase in fitness was comparable for both lean and obese subjects.
Exercise induced a change in the population of gut bacteria, and the change was comparable in lean and obese subjects.
Exercise increased fecal concentrations of butyrate and other short-chain fatty acids in the lean subjects, but not in obese subjects.
The exercise-induced changes in gut bacteria and short-chain fatty acid production were largely reversed once exercise training ceased.

The authors concluded: “These findings suggest that exercise training induces compositional and functional changes in the human gut microbiota that are dependent on obesity status, independent of diet, and contingent on the sustainment of exercise.” [Note: To be clear, the exercise-induced changes in both gut bacteria and short-chain fatty acid production were independent of diet and contingent on the sustainment of exercise. However, only the production of short-chain fatty acids was dependent on obesity status.]

What Does This Study Mean For You?

There are two important take home lessons from this study.

With respect to our gut bacteria, I have consistently told you that microbiome research is an emerging science. This is a small study, so you should regard it as the beginning of our understanding of the effect of exercise on our microbiome rather than conclusive by itself. It is consistent with previous studies showing an association between exercise and a potentially beneficial shift in the population of gut bacteria.

The strength of the study is that it shows that exercise-induced changes in beneficial gut bacteria are probably independent of diet. However, it is the first study to look at the interaction between obesity, exercise and gut bacteria, so I would interpret those results with caution until they have been replicated in subsequent studies.

With respect to exercise, this may be yet another reason to add regular physical activity to your healthy lifestyle program. We already know that exercise is important for cardiovascular health. We also know that exercise increases lean muscle mass which increases metabolic rate and helps prevent obesity. There is also excellent evidence that exercise improves mood and helps prevent cognitive decline as we age.

Exercise is also associated with decreased risk of colon cancer and irritable bowel disease. This effect of exercise has not received much attention because the mechanism of this effect is unclear. This study shows that exercise increases the fecal concentrations of butyrate and other short-chain fatty acids. Perhaps, this provides the mechanism for the interaction between exercise and intestinal health.

The Bottom Line

A recent study has reported that:

Exercise induces a change in the population of gut bacteria, and the change was comparable in lean and obese subjects.
Exercise causes an increase in the number of gut bacteria that produce butyrate and other short-chain fatty acids that are beneficial for gut health.
These effects are independent of diet, but do not appear to be independent of obesity because they were seen in lean subjects but not in obese subjects.
The exercise-induced changes in gut bacteria and short-chain fatty acid production are largely reversed once exercise training ceases.

For more details and my interpretation of the data, 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 Vitamin D Supplements Worthless?

October 30, 2018 by Dr. Steve Chaney

Are We Asking The Right Question?

Author: Dr. Stephen Chaney

We have been told that vitamin D is a miraculous “must have” vitamin. We have been told it’s not just important for healthy bones. It’s also important for a strong immune system, heart health, protection from cancer, and many other health benefits. We have been told that we should get our 25-hydroxy vitamin D levels tested and supplement with extra vitamin D if they are low.

Now, the latest headlines are saying all of that is wrong. They are telling us vitamin D supplements do not improve bone density or protect against falls and bone fractures. They are telling us to forget all the other claimed benefits of vitamin D. Those claims have been disproved. Forget about the 25-hydroxy vitamin D tests. They are a waste of money.

What is the truth? Why is it so confusing? Are vitamin D supplements worthless? Let me guide you through the claims and counterclaims so you can discover the truth for yourself.

How Did Vitamin D Become So Popular?

Let’s start with a brief history of vitamin D. It all started with the industrial revolution in Northern Europe. Suddenly, children and adults in the large cities were spending the bulk of their waking hours in dark factories rather than outdoors on the farm. They were already living in northern latitudes where sunlight was weak during the winter months. To make matters worse pollution from the factories was creating a haze that blocked the sunlight.

That lead directly to the discovery that sunlight was crucial to our body’s ability to synthesize vitamin D and that vitamin D was essential for building strong bones. The solution to the public health crisis of rickets and osteomalacia was to fortify dairy products with vitamin D. The almost universal adaptation of vitamin D fortification virtually eliminated rickets and osteomalacia except in association with certain rare diseases. The two important lessons learned from this experience were:

Vitamin D is essential for healthy bone formation.
Vitamin D supplementation improves bone health for individuals who are deficient in vitamin D

As we discuss the latest findings, we need to keep in mind that these fundamental principles have not changed.

In the late 20^th century our understanding of vitamin D took another leap with the discovery that vitamin D receptors were not restricted to bone cells. Almost every cell in our body contained vitamin D receptors. That lead to studies showing that people with low vitamin D intakes were more likely to experience heart disease, cancer, some autoimmune diseases, and infectious diseases such as flu than people with high vitamin D intakes.

The final leap in our understanding of vitamin D took place when the medical profession started routinely testing blood levels of 25-hydroxy vitamin D. That is when we discovered that some people who appeared to have adequate intake of vitamin D and/or adequate exposure to sunlight had low blood levels of 25-hydroxy vitamin D. Furthermore, follow-up studies showed that low 25-hydroxyvitamin D levels correlated with an increased risk of heart disease, cancer, and infectious disease. The important lessons learned from these experiments were:

Vitamin D deficiency is associated with increased risk of multiple diseases.
25-hydroxy vitamin D tests are the best way to measure vitamin D deficiency.

Once again, these fundamental principles have not changed.

What Did The Study Show?

The study (MJ Bolland et al, Lancet Diabetes Endocrinology 2018) behind the headlines was a meta-analysis of 81 randomized, placebo-controlled studies with a total of 53,537 subjects that looked at the effect of vitamin D supplementation in elderly populations on bone mineral density, bone fractures, and falls.

The meta-analysis only included studies in which vitamin D intake was the sole variable. In many cases the subjects were not taking a calcium supplement. If they were taking a calcium supplement, both the vitamin D group and placebo group were taking the same amount of calcium.

The results were unequivocal. In this study vitamin D supplementation had no effect on bone mineral density, bone fractures, or falls in elderly populations. The authors concluded “There is little justification to use vitamin D supplements to maintain or improve musculoskeletal health.”

Is this conclusion justified? Let’s put the findings of this study into a broader perspective.

Are We Asking The Right Questions?

Before throwing out our vitamin D supplements let’s ask whether this study is asking the right question. I have covered this topic in detail in my new book “Slaying The Supplement Myths” (https://slayingthesupplementmyths.com) with respect to similar studies that had called into question the value of calcium supplements for bone health. Let me cover the highlights here.

In my book I created the graphic on the right to put the question of who benefits from supplementation into perspective. For the purposes of this discussion, I will just focus on poor diet (or, in the case of vitamin D, poor exposure to sunlight). As I discussed above, science shows that people who are not getting enough vitamin D from diet and sunlight benefit from vitamin D supplementation. Unfortunately, vitamin D enthusiasts and some supplement companies have muddied the waters by going beyond what good science shows and suggesting or implying that everyone will benefit from vitamin D supplementation.

This is part of the problem. Once you have created a paradigm that everyone will benefit from vitamin D supplementation, that paradigm is easy to disprove. If someone already has adequate, or nearly adequate, levels of 25-hydroxy vitamin D, would we expect additional vitamin D to make a difference? Of course not, but that is exactly the question the most recent study was asking.

In discussing the limitations of their study, the authors said: “It is possible that trials of populations with low baseline 25-hydroxy vitamin D might produce different results because only 4 trials, involving 831 participants (1.6% of all participants), reported mean baseline 25-hydroxy vitamin D levels lower than 25 nmol/L (the level indicating vitamin D deficiency).

In other words, the study did not measure the effect of vitamin D supplementation for people who were vitamin D deficient. The only take-home lesson from this study is that people with adequate, or near adequate, vitamin D status do not benefit from vitamin D supplementation. That is a “no-brainer.”

Vitamin D And A Bone Healthy Lifestyle

The other glaring deficiency of this study is that it was only measuring the effect of vitamin D on bone health. They purposely excluded any other factor that might influence bone health. That was a fatal flaw because healthy bone requires a holistic approach, not individual nutrients. In my book Slaying the Supplement Myths I refer to this as a “bone healthy lifestyle.”

The most important feature of a “bone healthy lifestyle” is this:

Calcium, vitamin D, and resistance (weight bearing) exercise are all essential for healthy bones.
However, none of them is sufficient by itself. You need all three. You need a holistic approach if you wish to build strong bones.

Simply put, that means unless you include adequate calcium and exercise there is no reason to expect vitamin D supplementation to help build strong bones. Unfortunately, none of the studies included in the recent meta-analysis took a holistic approach to bone health. Some included calcium, but many didn’t. Resistance exercise was never considered. The studies were doomed to failure.

When you include flawed studies in your meta-analysis, you have what computer programmers call “Garbage in. Garbage out.” A meta-analysis can never be stronger than the individual studies it includes.

Other features of a “bone healthy lifestyle” include:

We need more than calcium and vitamin D for strong bones. We need magnesium, zinc, copper, manganese, vitamin C and vitamin K. If we are deficient in any of these, calcium will not be utilized as efficiently.
The foods we eat are also important. Our bones serve as a buffer system to keep our bodies slightly alkaline. Every time we eat acid-forming foods a little bit of bone is dissolved to neutralize the acid. For optimal bone health we need to minimize acid-forming foods and eat more alkaline-forming foods. That means we need to avoid sodas, sweets and refined grains. We also need to minimize meats, eggs, and dairy. Instead, we should focus on fruits, vegetables, peas, beans, lentils, seeds, and nuts.
Beware of drugs. The list of common medications that dissolve bones is a long one. Some of the worst offenders are anti-inflammatory steroids such as cortisone and prednisone, drugs to treat depression, drugs to treat acid reflux, and excess thyroid hormone. I am not suggesting that you should avoid properly prescribed medications. I would suggest you ask your doctor or pharmacist whether the drugs you are taking adversely affect bone density. If they do, you should pay a lot more attention to the other aspects of a “bone healthy lifestyle.”

Are Vitamin D Supplements Worthless?

Now we can come back to the question “Are vitamin D supplements worthless?” as the recent headlines have suggested. If you phrase the question as “Does everyone benefit from vitamin D supplementation?” or “Is vitamin D supplementation alone sufficient to build strong bones?” the answer is a clear no.

However, those are the wrong questions. If you ask: “Does vitamin D supplementation benefit people who are vitamin D-deficient?” the answer is a clear yes. If you ask: “Does a holistic approach that includes resistance exercise, adequate calcium, and adequate vitamin D improve bone health?” the answer is likely to be yes as well.

What about the headlines claiming that vitamin D is also worthless for strengthening the immune system and reducing the risk of heart disease, cancer, and auto-immune diseases? The studies on which these claims are based suffer from the same flaws. They are asking the same wrong questions.

My recommendations:

Have your blood levels of 25-hydroxy vitamin D tested on a regular basis. I have them tested each year when I get my physical.
If your blood levels of 25-hydroxy vitamin D are below 25 nmol/L (which the NIH considers deficient), you are likely to benefit from vitamin D supplementation. If they are above 50 nmol/L (which the NIH considers sufficient), vitamin D supplementation is unlikely to provide additional benefit. However, that level of vitamin D doesn’t guarantee that you will have strong bones. You also need sufficient calcium and resistance exercise.
If your blood levels are in the insufficient range (between 25 nmol/L and 50 nmol/L), the situation is more complicated. If you are close to 50 nmol/L, you may benefit slightly from adding a vitamin D supplement, but the benefit will be too small to show up in a clinical study such as the one that resulted in the recent headlines. My advice is to look at your diet and medication use. If they put you at risk for low bone density, my recommendation would be to add a vitamin D supplement – along with adequate calcium and resistance exercise, of course. If you are closer to 25 nmol/L, you will likely benefit from a vitamin D supplement along with adequate calcium and exercise.
Don’t think of vitamin D supplementation as a “magic bullet” that will solve all your ills. Instead, think of it as just one component of a holistic approach to a bone healthy lifestyle.

The Bottom Line

A recent meta-analysis concluded that vitamin D supplementation did not improve bone mineral density, reduce bone fractures, or reduce falls in the elderly. While this conclusion was definitive, the study was asking the wrong questions.

We know that vitamin D improves bone health for people who are vitamin D-deficient. However, only 1.6% of the people in this study were vitamin D-deficient at the beginning of the study. That means the study was really asking: “If people have adequate, or near adequate, vitamin D status, does vitamin D supplementation provide any additional benefit?” The answer to that question is a “no-brainer.” There is no reason to expect that additional vitamin D would provide benefit.
We know that while vitamin D is essential for building strong bones, it is not sufficient by itself. Strong bones require a holistic approach that includes resistance exercise, adequate calcium, and adequate vitamin D. However, this study only looked at the effect of vitamin D on bone health. Calcium and exercise were excluded from consideration. That means the study was really asking: “Is vitamin D a “magic bullet” that can build strong bones by itself?” Again, there is no reason to expect vitamin D to provide much benefit under those conditions.

My recommendations:

Have your blood levels of 25-hydroxy vitamin D tested on a regular basis. I have them tested each year when I get my physical.
If your blood levels of 25-hydroxy vitamin D are low, you are likely to benefit from vitamin D supplementation. If they are already optimal, vitamin D supplementation is unlikely to provide additional benefit.
Don’t think of vitamin D supplementation as a “magic bullet” that will keep your bones strong by itself. Instead, think of it as just one component of a holistic “bone healthy lifestyle.”

For more details and to see my detailed recommendations, 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.

How Long Do the Benefits of Supplements Last?

October 23, 2018 by Dr. Steve Chaney

Can Supplements Set You On A Path Towards A Healthier Life?

Author: Dr. Stephen Chaney

A recent study (U Alehagen et al, PLOS One, April 11, 2018, 1-15 ) reported that the heart benefits of supplementation with coenzyme Q10 and selenium persisted for 12 years after supplementation ended. You would have thought a story like that would have made the headlines. Nope. Hardly a mention. Perhaps it did not match the narrative of the media and health professionals that supplements are worthless.

This study broke new ground. Most studies last a year or two and report whether there were any benefits of supplementation. A few studies have been extended a few years beyond the original supplementation period and have reported continued benefits of supplementation. However, in those studies the intervention group was still taking supplements. The intervention period was simply extended.

However, this study was unique in that supplementation was discontinued after 4 years. However, the positive effects of supplementation during that four-year period persisted for another 12 years without additional supplementation.

How Was The Study Done?

In this study 443 elderly individuals (average age =78) were recruited from a rural village in Sweden. They were given either supplements providing 200 mg/day of coenzyme Q10 and 200 mcg/day of selenium yeast or placebo pills. They were followed for four years. At this point the intervention phase of the trial ended, and the participants were followed for another 12 years without supplementation.

Cardiovascular deaths and all-cause mortality were recorded at 4 years (the end of the original intervention period), 10 years, and 12 years. The Swedish health care system is incredibly efficient. None of the participants were lost to follow-up.

Note on study design: Both coenzyme Q10 and selenium have heart health benefits and they compliment each other. Coenzyme Q10 was included in this study because our bodies lose the ability to make coenzyme Q10 as we age. By the time we reach age 80, we only make around half the coenzyme Q10 we made when we were younger. Selenium was included in the study because most Swedes are selenium deficient.

This study measured selenium levels and confirmed that all participants were selenium deficient at the beginning of the study. Selenium levels increased to near optimal in the supplemented group during the 4-year intervention period. In contrast, the placebo group remained selenium deficient.

How Long Do the Benefits of Supplements Last?

The results of the study were truly amazing.

When you compared the group that had received coenzyme Q10 and selenium during the first 4 years of the study with the placebo group:

Cardiovascular mortality was 38% less and all-cause mortality was 24% less 12 years later in the supplement group.
The decrease in cardiovascular mortality lessened slightly with time (53% lower at 4 years, 46% lower at 10 years, and 38% lower at 12 years.
In contrast, the decrease in all-cause mortality remained relatively constant.
The effect was greater for women (who have lower coenzyme Q10 levels than men) than it was for men.
The decrease in cardiovascular mortality was 57% for women and 22% for men.
Cardiovascular mortality was decreased by 40-50% for people at high risk of cardiovascular death because of atherosclerosis, diabetes, high blood pressure, or impaired heart function.

Putting This Study Into Perspective

I don’t want to read too much into this study. It has multiple limitations:

It is a very small study.
It is the first study I am aware of that has followed study participants years after supplementation has ended. More studies like this are clearly needed before any firm conclusions can be drawn.
It may be unique to Sweden where selenium deficiency is widespread. Selenium deficiency is much less prevalent in some other countries such as the United States.
It is possible that once the study population heard about the results of the initial 4-year study they started self-supplementing with coenzyme Q10 and selenium. However, since the participants did not know whether they were in the supplement or placebo group, that would likely affect both groups equally.

However, it is the implications of the study that fascinate me.

The authors of the study speculated that the improvement in endothelial cell function (Endothelial cells line the arteries and play an important role in arterial health) and/or decreased inflammation may have persisted long after supplementation stopped.
A more interesting idea is that supplementation (or the effects of supplementation) caused modifications to the DNA that were persistent (something we refer to as epigenetics). Moreover, those DNA modifications may have altered gene expression in a manner that reduced heart disease risk.

Much more work needs to be done before we know whether epigenetic modifications were responsible for the persistent benefit of supplementation in this, or any other, study. However, the ramifications of this idea are substantial. We think of supplementation as something that provides benefit only while we are taking the supplement. What if, under the right conditions, supplementation could send us down an entirely different path to better health? That would be worth major headlines.

The Bottom Line

A recent study in Sweden looked at the effects of supplementation with coenzyme Q10 and selenium on heart health 12 years after supplementation had ended.

The study reported that cardiovascular mortality was 38% less and all-cause mortality was 24% less 12 years later in the group that supplemented during the first 4 years.

The study has multiple limitations and needs to be repeated before drawing any definite conclusions. However, if true, it has interesting implications. What if the benefits of supplementation didn’t stop when you stopped supplementing? What if supplementation sent you down an entirely different path, a path towards better health?

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.

High Protein Diets and Weight Loss

October 16, 2018 by Dr. Steve Chaney

Do High Protein Diets Reduce Fat And Preserve Muscle?

Author: Dr. Stephen Chaney

Are high protein diets your secret to healthy weight loss? There are lots of diets out there – high fat, low fat, Paleolithic, blood type, exotic juices, magic pills and potions. But recently, high protein diets are getting a lot of press. The word is that they preserve muscle mass and preferentially decrease fat mass.

If high protein diets actually did that, it would be huge because:

It’s the fat – not the pounds – that causes most of the health problems.

Muscle burns more calories than fat, so preserving muscle mass helps keep your metabolic rate high without dangerous herbs or stimulants – and keeping your metabolic rate high helps prevent both the plateau and yo-yo (weight regain) characteristic of so many diets.

When you lose fat and retain muscle you are reshaping your body – and that’s why most people are dieting to begin with.

So let’s look more carefully at the recent study that has been generating all the headlines (Pasiakos et al, The FASEB Journal, 27: 3837-3847, 2013).

The Study Design:

This was a randomized control study with 39 young (21), healthy and fit men and women who were only borderline overweight (BMI = 25). These volunteers were put on a 21 day weight loss program in which calories were reduced by 30% and exercise was increased by 10%. They were divided into 3 groups:

One group was assigned a diet containing the RDA for protein (about 14% of calories in this study design).
The second group’s diet contained 2X the RDA for protein (28% of calories)
The third group’s diet contained 3X the RDA for protein (42% of calories)

In the RDA protein group carbohydrate was 56% of calories, and fat was 30% of calories. In the other two groups the carbohydrate and fat content of the diets was decreased proportionally.

What Did The Study Show?

Weight loss (7 pounds in 21 days) was the same on all 3 diets.

The high protein (28% and 42%) diets caused almost 2X more fat loss (5 pounds versus 2.8 pounds) than the diet supplying the RDA amount of protein.

The high protein (28% and 42%) diets caused 2X less muscle loss (2.1 pounds versus 4.2 pounds) than the diet supplying the RDA amount of protein.

In case you didn’t notice, there was no difference in overall results between the 28% (2X the RDA) and 42% (3X the RDA) diets.

Pros And Cons Of The Study:

The con is fairly obvious. The participants in this study were all young, healthy and were not seriously overweight. If this were the only study of this type one might seriously question whether the results were applicable to middle aged, overweight coach potatoes. However, there have been several other studies with older, more overweight volunteers that have come to the same conclusion – namely that high protein diets preserve muscle mass and enhance fat loss.

The value of this study is that it defines for the first time the upper limit for how much protein is required to preserve muscle mass in a weight loss regimen. 28% of calories is sufficient, and there appear to be no benefit from increasing protein further. I would add the caveat that there are studies suggesting that protein requirements for preserving muscle mass may be greater in adults 50 and older.

The Bottom Line:

1) Forget the high fat diets, low fat diets, pills and potions. High protein diets (~2X the RDA or 28% of calories) do appear to be the safest, most effective way to preserve muscle mass and enhance fat loss in a weight loss regimen.

2) That’s not a lot of protein, by the way. The average American consumes almost 2X the RDA for protein on a daily basis. However, it is significantly more protein than the average American consumes when they are trying to lose weight. Salads and carrot sticks are great diet foods, but they don’t contain much protein.

3) Higher protein intake does not appear to offer any additional benefit – at least in young adults.

4) Not all high protein diets are created equal. What some people call high protein diets are laden with saturated fats or devoid of carbohydrate. The diet in this study, which is what I recommend, had 43% healthy carbohydrates and 30% healthy fats.

5) These diets were designed to give 7 pounds of weight loss in 21 days – which is what the experts recommend. There are diets out there promising faster weight loss but they severely restrict calories and/or rely heavily on stimulants, they do not preserve muscle mass, and they often are not safe. In addition they are usually temporary. I do not recommend them.

6) This level of protein intake is safe for almost everyone. The major exception would be people with kidney disease, who should always check with their doctor before increasing protein intake. The only other caveat is that protein metabolism creates a lot of nitrogenous waste, so you should drink plenty of water to flush that waste out of your system. But, water is always a good idea.

7) The high protein diets minimized, but did not completely prevent, muscle loss. Other studies suggest that adding the amino acid leucine to a high protein diet can give 100% retention of muscle mass in a weight loss regimen – but that’s another story for another day.

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 Probiotics Bad For You?

October 9, 2018 by Dr. Steve Chaney

Are Probiotics Worthless?

Author: Dr. Stephen Chaney

Probiotics (friendly gut bacteria) are all the rage. There is big money to be made, so the internet is ablaze with all the amazing things probiotics can do for you. Of course, most of those articles are posted by companies wanting to sell you their miracle mixture of probiotic bacteria.

In the last few weeks, you may have seen headlines proclaiming that probiotics are worthless. You just poop them out. Even worse, they may be upsetting the natural balance of bacteria in your gut. Are probiotics bad for you? They may be.

As usual, the truth is somewhere in the middle. Before I start sorting out fact from fiction, let me remind you of some important facts about gut bacteria that I covered in a recent article of “Health Tips From The Professor”:

The composition of bacteria in our gut is influenced by what we eat. For example, meat eaters have a completely different composition of gut bacteria than vegetarians.
Fiber from whole plant foods is a major food source for healthy gut bacteria.
Each plant-based food group and each food within that group has a unique blend of fibers. We should probably aim for a wide variety of whole plant foods in our diet.

Are Probiotics Worthless?

Let’s start with the study (N. Zmora et al, Cell 174, 1388-1405, 2018 ) that generated the headlines proclaiming that probiotics were worthless.

The characteristics of the study with my comments are as follows:

The study had 15 subjects who were given either a commercially available probiotic supplement or a placebo containing cellulose. It was a very small study.
The probiotic supplement contained 25 billion colony forming units of 11 commonly used strains of bacteria. Its manufacturer claimed the bacteria survived stomach acid and colonized the intestine, but no references were given for published clinical studies backing up that claim. It is buyer beware in the supplement industry. I would not believe any claims about a probiotic supplement that were not backed up by published clinical studies.
The investigators measured bacterial colonization of the mucosal cells lining the intestine rather than the population of bacteria that ended up in the feces. This is the “gold standard” for measuring colonization of the intestine by probiotic bacteria. However, it requires a colonoscopy before the study started and a second colonoscopy 3 weeks later. As any of you who have had a colonoscopy can attest, this is a very invasive procedure. It probably accounts for the small size of the study. In fact, the study started with 28 subjects and 13 dropped out, one after suffering a serious adverse reaction to the first colonoscopy. My point is simply that I don’t expect to see a lot of this type of study.

The results of the study with my comments are as follows:

Overall, the particular probiotic supplement used in this study didn’t work very well. There was minimal colonization of the intestinal mucosal cells by the bacteria in the probiotic supplement. Some did better than others, but the net colonization was small. We don’t know whether the results would have been the same with other probiotic supplements, but this is the finding that generated all the headlines. However, it is the rest of the study that is interesting.
The probiotic supplement worked better for some subjects than for others. Some of the subjects in the study were “permissive.” The probiotic cells colonized their intestinal mucosal cells with high efficiency. Other subjects were “resistant.” Probiotic bacteria had a great deal of difficulty colonizing their intestinal mucosal cells. This doesn’t surprise me. Most clinical studies report an average result. They don’t report individual variations. This is one of the first studies to report on individual variation of probiotic colonization. As such, it has important implications. It means that even though you may be taking a probiotic supplement that has been “clinically proven” to survive stomach acid and colonize the intestine, it may not work well for you. But, wait, the study gets even more interesting.
How well the probiotic supplement worked depended on the population of bacteria in the intestine to begin with. “Permissive” and “resistant” subjects had very different species of bacteria in their intestine at the beginning of the trial. There was a characteristic grouping of bacteria in “permissive” subjects and a different characteristic grouping of bacteria in “resistant” subjects. This is the part of the study that should have generated headlines. Let’s put this part of the study into perspective.

We each have around 38 trillion bacteria in our intestines. Let’s assume that all 25 billion bacteria in the probiotic supplement make it into the intestine intact. You have just dropped them into hostile territory where they are outnumbered 1,000 to 1. We know that some bacteria secret substances that support the growth of “like-minded” bacteria. That’s why certain species of bacteria tend to cluster together. We also know that bacteria secret toxins, so they can out-compete bacteria they don’t like. So, it is no wonder the survival of the probiotic bacteria depends on which species of bacteria are already populating the intestine when they arrive on the scene.

This study leaves a lot of unanswered questions:

What determined the original population of gut bacteria? Was it the genetics or health of the subject? Or, was it the food they were eating? We simply don’t know.
We were sending these probiotic bacteria into hostile territory. Were we giving them the food they needed to survive? Would the results have been different for the “resistant” subjects if they had been eating a different kind of fiber-rich foods, or taken a prebiotic supplement? Again, we just don’t know.

If we want to optimize the results of probiotic supplementation, these are the questions we should be asking.

Are Probiotics Bad For You?

Now, let’s turn to the study (J. Suez et al, Cell 174, 1406-1423, 2018) generating the headlines saying that probiotic supplements may be bad for you. This study was looking specifically at the use of probiotics following antibiotic use.

The study reported when probiotics are used following antibiotic use, they delay, rather than enhance, the recovery of intestinal bacteria back to the same number and type of bacteria that existed prior antibiotic use. That’s the finding that generated all the headlines. Let’s put that into perspective.

Both the headlines and interpretation of the data were inaccurate.

Probiotics actually had a relatively small effect on the ability to regain your “normal” population of intestinal bacteria. The headlines made it sound as if the delay was significant and that you never regained your “normal” population of intestinal bacteria. In fact by one measure, the population of intestinal bacteria was 70% normal by 5 days, 80% normal by 20 days, and 95% normal by 90 days.
Poop pills work better but will probably never be popular. When the investigators extracted intestinal bacteria from the subject’s poop and put them into pills prior to the study, the poop pills restored the “normal” population of intestinal bacteria much more quickly. However, I doubt that poop pills will become popular any time soon.
Your “normal” population of intestinal bacteria may not be the optimal population of intestinal bacteria. The headlines implied that the fact you never recovered your “normal” population of intestinal bacteria was a bad thing. That assertion assumes that all of us have the optimal population of intestinal bacteria to begin with, an assertion that almost any expert in the field would find absurd. The last time I checked, one of the major reasons for taking probiotic supplements was to change our population of intestinal bacteria for the better.

The study ignores the major reasons for taking a probiotic supplement after antibiotic use. Most people are not taking the probiotic supplement to restore their original population of intestinal bacteria. They are taking it to:

Prevent “bad guys” like yeast from filling the void caused by the antibiotics.
Improve digestion. Some strains of intestinal bacteria play an important role in digestion. Because antibiotics wipe out those bacteria, they often cause gas, diarrhea, and bloating. After antibiotic use, people are taking probiotic bacteria with digestive benefits to eliminate those digestive issues as quickly as possible.
Strengthen the immune system. People are generally taking antibiotics to fight some sort of infection. Some strains of intestinal bacteria play an important role in immunity. Because antibiotics wipe out those bacteria, they weaken the immune system. After antibiotic use, people are taking probiotics to strengthen the immune system as quickly as possible

In short, taking probiotic supplements that are proven to improve digestion and strengthen the immune system play an important role in minimizing the side effects of antibiotic use.

What Does This Mean For You?

At the beginning of this article I said; “The truth lies somewhere in between.” The first study is a perfect example.

It was valuable in that it challenged the assertion by some manufacturers that their probiotics survive stomach acid and work equally well for everyone. At the very least, it suggests that we should demand clinical proof that any probiotic supplement colonizes the intestine and provides a health benefit before we use it.
The most interesting finding from the first study is that probiotics work much better for some people than for others, and how well they work depends on the population of bacteria in our gut prior to taking the antibiotic. We have much more to learn about this individual variability, and how to control it.

Until we know more, my best advice is to eat a fiber-rich, primarily plant-based diet with as many different varieties of fruits, vegetables, whole grains, and legumes as possible. Providing a variety of fibers is important because at least some of them will likely support the growth of the bacteria in the probiotic supplement. Prebiotics may be of some help, but only if they have been shown to be effective for the particular strains of probiotic bacteria they are paired with.

The second study was much less enlightening. It reported that taking a probiotic after antibiotic use slowed the return to the original population of intestinal bacteria. My response to that is: “So what?”

The effect was minimal.
The purpose of probiotics is to improve on the population of intestinal bacteria, not to return to the same population of bacteria you had prior to antibiotic use.
Probiotics are taken after antibiotic use for reasons that have nothing to do with restoring the original population of intestinal bacteria.

The Bottom Line

Two recent studies have challenged the benefits of probiotic use.

The first study provided some valuable insights.

It reported that a particular probiotic supplement did a very poor job of colonizing the intestine. We have no idea whether that would apply to other probiotic supplements, but that was the result that generated all the headlines. At the very least, it suggests that we should demand clinical proof that any probiotic supplement colonizes the intestine and provides a health benefit before we use it.
However, the most interesting finding from the first study is that probiotics work much better for some people than for others, and how well they work depends on the population of bacteria in our gut prior to taking the antibiotic. We have much more to learn about this individual variability, and how to control it.

The second study was much less enlightening. It reported that taking a probiotic after antibiotic use slowed the return to the “normal” population of intestinal bacteria that were present before antibiotic use. My response to that is: “So what?”

The purpose of probiotics is to improve on the population of intestinal bacteria, not to return to the same population of intestinal bacteria you had prior to taking an antibiotic.
Probiotics are taken after antibiotic use for reasons that have nothing to do with restoring the original population of intestinal bacteria.

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.