Unsaturated Fats

The Seed Oil Myths

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The Truth About Seed Oils 

Author: Dr. Stephen Chaney 

The Seed Oil Myths

You’ve seen the claims. “You should avoid all seed oils. They are toxic.”

Any time you see claims like, “Avoid all…[add the food villain of the day]” or “[a certain food] is toxic” your “truth-meter” should go on high alert. Claims like that are more likely to be hype than truth.

More specifically, the claims about seed oils are:

  • They are heavily processed.
  • They contain toxic ingredients.
  • They are genetically modified.
  • They cause inflammation and oxidative damage.
  • They increase your risk of inflammatory diseases, heart disease, and cancer.
  • A healthier option is to replace seeds oils with animal foods high in saturated fats.

Like any good food myth, there is a kernel of truth to each of these claims. In this article I will describe the kernel of truth associated with each of these claims, put them into perspective, and give practical guidelines for incorporating seed oils into your diet.

The topics I will cover are:

  • The truth about fats.
  • The truth about omega-6 fats.
  • The truth about saturated fats.
  • The truth about canola oil.
  • The truth about seed oils.

The Truth About Fats

The health authorities and media must think the American public is stupid. They oversimplify everything. They tell us:

  • Animal fats are saturated fat.
  • Olive oil is monounsaturated fat.
  • Vegetable oils are omega-6 polyunsaturated fat.
  • Fish oil is omega-3 polyunsaturated fat.

The truth is that every naturally occurring fat and oil is a mixture of all four kinds of fat. And each food contains a unique mixture of fats. The kernel of truth is:

  • Animal fats have a higher percentage of saturated fat than other fats and oils.
  • Olive oil has a higher percentage of monounsaturated fat than other oils.
  • Vegetable oils have a higher percentage of omega-6 polyunsaturated fat than other oils.
  • Fish oil has a higher percentage of omega-3 polyunsaturated fat than other oils.

But the full truth is that each food contains a unique mixture of fats. For example,

  • Meat and butter from grass-fed animals contain a greater percentage of omega-3 fats than meat and butter from animals which were fattened on corn.
  • Flaxseed oil has a higher percentage of omega-3 fats than other seed oils.
  • High-oleic sunflower oil has the highest percentage of monounsaturated fat than other seed oils.
    • Other vegetable oils with high monounsaturated fat content include olive oil, avocado oil, and canola oil. [Note: Although olive oil is the source of monounsaturated fat that we hear about most, avocado oil is equally high in monounsaturated fat and has a higher smoke point, which makes it a better choice for high-heat cooking.]
  • Walnuts have a higher percentage of omega-3 fats than other nuts.
  • Macadamia nuts and almonds have the highest percentage of monounsaturated fats than other nuts, with cashews and peanuts not far behind. Nut butters, of course, reflect the fat composition of the nuts.

The point I am making is that while myths are simple, the truth is much more complex.

Take Home Lesson: Every vegetable oil and every seed oil has a unique composition of fats. Each has its unique benefits and unique drawbacks.

That is something you will want to think about the next time you read an article about the dangers or the benefits of all seed oils. Every seed oil is unique. No generalization applies to all of them.

Biochemistry 101 – Essential Fats

ProfessorLet’s start with the most important point.

  • Omega-6 fats and omega-3 fats are essential. Simply put, that means:
  • We can’t make them.
  • They are essential for life.
  • We must get them from our diet.

If they are essential, the next question is, “Why do we need them?” Let me start with a little “Biochemistry 101” and talk about their role in cell membranes and cellular regulation.

Cell Membranes:

  • You might think of cell membranes as a solid protective armor around the cells, but nothing could be farther from the truth. A better analogy would be the ocean that covers vast areas of our planet. Our membranes are quite fluid.
  • And that membrane fluidity is important. Our cell membranes contain receptors like the cholesterol receptor and insulin receptor that must cluster together for cholesterol and insulin to be transported into the cell. Those receptors cluster best when cell membranes are very fluid.
  • Our membranes are most fluid when they contain high levels of polyunsaturated fats (For membrane fluidity it doesn’t matter if they are omega-6 or omega-3). Conversely, our membranes are less fluid when they contain high levels of saturated fats.
  • And here is the most important point. Because our bodies cannot make omega-6 and omega-3 polyunsaturated fats, this is the one time it is literally true that, “We are what we eat”. If our diets are high in saturated fats, our membranes are high in saturated fats. If our diets are high in polyunsaturated fats, our membranes are high in polyunsaturated fats. And the ratio of omega-6 and omega-3 polyunsaturated fats in our membranes reflects the ratio of omega-6 and omega-3 polyunsaturated fats in our diet.

Take Home Lesson: Diets high in omega-6 and/or omega-3 fats help lower cholesterol levels and improve blood sugar regulation.

Cellular Regulation:

  • Our cells also use the polyunsaturated fats in our cell membrane to make hormone-like substances called prostaglandins and leukotrienes that exert profound effects on nearby tissues. [Note: For the sake of simplicity, I will just talk about prostaglandins for the rest of this article, but what I say applies equally to leukotrienes.]
  • The enzymes that make prostaglandins do not distinguish between omega-6 and omega-3 polyunsaturated fats. They just use whatever polyunsaturated fat they come across.
  • That’s important because the effects of omega-6 and omega-3 prostaglandins are often different and are sometimes opposite.
  • Here’s where the “We are what we eat” principle comes into play. The ratio of omega-6 and omega-3s in our diet determines the omega-6 and omega-3 content of our membranes. And that determines the type of prostaglandins our cells produce.

Take Home Lessons:

  • Some of the benefits of omega-6s are unique because they are dependent on omega-6 prostaglandins. These benefits cannot be duplicated by diets high in omega-3s.
  • Because some effects of omega-6 and omega-3 prostaglandins are opposite, we need to look closely at the omega-6 to omega-3 ratio in the diet to optimize the health benefits of these two essential polyunsaturated fats.

Now, with Biochemistry 101 behind us, we are ready to look at the truth about omega-6 fats.

The Truth About Omega-6 Fats

Let’s start by looking at the pros and cons of omega-6 fats. 

Pros Of Omega-6 Fats

Cellular Health: Omega-6 and fats are important for maintaining proper membrane fluidity. And omega-6 prostaglandins also regulate cell metabolism and cellular repair mechanisms.

Heart Health: Omega-6s are associated with lower risk of heart disease. This is caused by:

  • Lower cholesterol levels due to proper membrane fluidity which allows clustering of cholesterol receptors.
  • More flexible endothelial cells lining our arteries, which helps lower blood pressure and prevent blockage of the arteries by blood clots. This is most likely due to more fluid cell membranes and the production of beneficial prostaglandins.
  • Some of these benefits are duplicated by omega-3 fats, but the American Heart Association stated in a recent Health Advisory (WS Harris et al, Circulation, 119, 902-907, 2009) that omega-6 fats are essential for some heart health benefits. They cannot be replaced by omega-3s.

Brain Health: Omega-3s get most of the press here, but experts feel that omega-6s play an important and independent role as well.

Fetal Growth and Development: Omega-6 fats are essential for normal neural development and growth. The mechanism(s) for this benefit are ill-defined.

Other Benefits:

  • Omega-6 fats support healthy skin, hair, and bones. The mechanisms for these effects are unknown, but most experts feel they are independent of omega-3 fats.
  • Omega-6 fats are also important for reproductive health. Most experts think this is due to the production of omega-6 prostaglandins.

Take Home Lesson: Omega-6 fats are essential for a healthy heart, a healthy brain, and normal fetal growth and development.

Cons Of Omega-6 Fats

Oxidation: Omega-6 (and omega-3) fats are very susceptible to oxidation, especially at high temperatures. This can lead to free radical formation, which can promote the formation of cancer cells.

You may have seen the statement that omega-6 fats cause cancer. This is an oversimplification. A more accurate statement would be, “Improperly used, any polyunsaturated fat may increase cancer risk. But this is largely avoidable. Here are the precautions I recommend:

  • Choose your source carefully.
    • For seeds and nuts look for freshness. If they look or taste funny, throw them out.
    • For oils choose reputable brands and choose ones that use low-heat processing. Also, look for ones with minimal processing. They may be cloudy rather than clear, but they will also contain naturally occurring antioxidants and polyphenols.
  • Don’t overheat them.
    • Most vegetable oils are only suitable for use as salad dressings and other room temperature cooking.
    • The exceptions are vegetable oils with high smoke points – for example, olive oil for stir fries and avocado oil for higher temperature cooking.
  • Store them safely. Don’t give them a chance to become oxidized.
    • We store sunflower seeds and almonds in our refrigerator and walnuts in our freezer.
    • We buy unsaturated vegetable oils in small quantities (so they are used up quickly) and store them in the refrigerator.

Take Home Lesson: Improperly used, omega-6 fats, like any unsaturated fat, can become oxidized and form free radicals (the kernel of truth). Choose your source carefully. Don’t overheat them. Store them safely.

FlamesInflammation: This is the one you hear the most about. You have been told that omega-6 vegetable oils (seed oils) cause inflammation. As a blanket statement, it is mostly untrue. But it does have a kernel of truth.

Let’s start with the kernel of truth:

  • Omega-6 fats are inflammatory only when compared to omega-3 fats. You have also been told that omega-6 fats are inflammatory when compared to saturated fats. This is false, as I will discuss below.

Let me elaborate on the first statement with a little more Biochemistry 101 (If you haven’t guessed, that’s my favorite topic. Once a professor, always a professor).

  • Omega-6 fats are converted into one inflammatory prostaglandin. Omega-3 fats are converted into several anti-inflammatory prostaglandins (This is an example of some omega-6 and omega-3 prostaglandins having opposite effects).
  • Because of their opposite effects on inflammation, some experts say that the optimal ratio of omega-6 to omega-3 fats is in the range of 1:1 to 4:1. But the typical American diet is around 15:1.

If the omega-6 to omega-3 ratio is important (and not every expert agrees that it is), the statement that we should avoid omega-6-containing vegetable oils (seed oils) because they are inflammatory is mostly untrue.

    • Every omega-6 oil has a different omega-6 to omega-3 ratio. For example,
    • Corn oil has a 50:1 ratio and sesame oil has a 42:1 ratio. If you are just going by omega-6 to omega-3 ratios, you might want to avoid these.
    • Soybean oil has a 7:1 ratio and extra virgin olive oil has a 5:1 ratio. They are almost in the optimal range.
    • Canola oil has a 2:1 ratio. It’s in the optimal range.
    • And flaxseed oil is the clear winner with a 1:4 ratio.

But the truth is also much more complex than you have been led to believe.

  • The kernel of truth is that omega-6 fats can be converted to an inflammatory prostaglandin.
  • But omega-6 fats can also be converted to anti-inflammatory prostaglandins. And some omega-6 fats such as GLA are anti-inflammatory.
  • Human clinical studies find that omega-6 fats either have no effect on inflammation or decrease it slightly (A Poli et al, International Journal of Molecular Sciences, 24, 4567, 2023).

Take Home Lesson: Omega-6 fats are converted into one inflammatory prostaglandin (the kernel of truth). But they are also converted to anti-inflammatory prostaglandins. The net effect in the human body is a slight anti-inflammatory effect.

The Truth About Saturated Fats

Saturated fats on tables. Raw meat, sausages, cheese, butter. Bad food concept. Top view

You have been told that saturated fats are anti-inflammatory and decrease the risk of heart disease. For many Americans those claims are enticing because it means they don’t have to change their diet. But are the claims true?

You have been told that these claims are based on science. There are clinical studies behind them. Is that true?

The problem is that there are a lot of bad studies on saturated fats in the literature, and the Dr. Strangeloves of the world cherry pick the ones that support their beliefs.

If you want to compare the effect of different kinds of fat on either inflammation or heart health, you must make sure that all other components of the diet are the same. Too many of these studies have compared a whole food diet high in saturated fat with the typical American diet high in omega-6 fats. The results are predictable. Anything is better than the typical American diet.

In a previous issue of “Health Tips From The Professor” I discussed the criteria for a good study of fats. High quality studies must:

  • Show the subjects stick with the new diet for the duration of the study. Subjects find it difficult to adhere to a diet to which they are not accustomed long term and often revert to their more familiar diet. This requires either very close monitoring of what the subjects are eating or measurement of fat membrane composition to verify diet adherence, or both.
  • Carefully control or measure what the saturated fats are replaced with. In good studies only the fat composition of the diet changes. All other components of the diet remain the same.
  • Last two years or more. The fats we eat determine the fat composition of our cell membranes, and that is what ultimately determines both inflammation in our bodies and our risk of dying from heart disease. While it is true to say, “We are what we eat”, changing the fat composition of our cell membranes does not occur overnight. It takes 2 years or more to achieve a 60-70% change in the fat composition of cell membranes.
  • Measures multiple markers of inflammation or actual cardiovascular end points such as heart attack, stroke, and deaths due to heart disease.

When studies are done that meet these criteria the results are as follows:

Inflammation (A Poli et al, International Journal of Molecular Sciences, 24: 4567, 2023):

  • Replacing saturated fats with omega-6 fats reduces inflammation by 8%.
  • Replacing saturated fats with omega-3 fats reduces inflammation by 48%

Heart Disease (FM Sacks et al, Circulation, 136, Number 3, 2017):

  • Replacing saturated fats with omega-6 from decreased the risk of heart disease by 24%.
  • Replacing saturated fats with a mixture of both omega-6 and omega-3 fats decreased the risk of heart disease by 29%. This is equivalent to statin therapy, without the side effects.
  • When the replacement of saturated fats with omega-6 and omega-3 fats occurred in the context of a heart healthy diet such as the Mediterranean diet, heart disease risk was reduced by 47%.

The Food and Nutrition Board of the Institute of Medicine recommends that Americans not exceed 10% of calories from saturated fat.

  • Two thirds of Americans exceed this limit.

The Food and Nutrition Board recommends that omega-6 fats be around 5-6% of calories. Because omega-6 fats play an important role in heart health, the American Heart Association recommends they be at 5-10% of calories.

  • Americans get around 6.5% of their calories from omega-6 fats.

Take Home Lesson: Replacing saturated fat with omega-6 fats reduces both inflammation and heart disease risk. Adding omega-3 fats reduces both even more. So, bringing omega-6 and omega-3 into a better balance is a good idea. But omega-6 fats are essential and are at the recommended intake for most Americans, so don’t do this by cutting back on healthy omega-6 fats. Instead, add some more omega-3s.

The Truth About Canola Oil

There are a lot of things t like about canola oil:

  • It is an excellent source of healthy omega-6 fats.
  • It has a good omega-6 to omega-3 ratio (2:1), which makes it anti-inflammatory.
  • It is also a good source of monounsaturated fats and has a moderate smoke point, which makes it suitable for low heat cooking.

So, why is it so unpopular? Unfortunately, it suffers from a lot of undeserved myths. Each has a kernel of truth. But like a secret passed around the room, the myths have grown with each repetition, and the truth has become unrecognizable.

So, let’s try to separate the myths from the truth.

Myth: Canola oil is genetically engineered.

Truth: It was created by old-fashioned plant breeding.

Myth: Canola oil contains toxic ingredients.

Truth:

  • Rapeseed oil comes from the oilseed rape plant (a relative of mustard).
  • Rapeseed oil contains erucic acid and glucosinolates, both of which can be toxic in large amounts (the kernel of truth).
  • Baldur Stefansson from the University of Manitoba bred a “double low” variety the oilseed rape plant which produces an oil that contains <2% of both erucic acid and glucosinolates and is safe for human consumption. This new oil was named canola oil (from Canada and ola for oil).
  • Both cultivars of the oilseed rape plant are still grown. Rapeseed oil is used for industrial purposes, and canola oil is used for human consumption.
  • Canola oil is tightly regulated in Canada, the US, and the EU to <2% erucic acid.
  • 98% of the canola oil sold in the US is grown in Canada and the northern US.

Myth: Canola oil is unhealthy.

Truth: Because it is one of the least expensive omega-6 oils, canola oil is often found as an ingredient in unhealthy, highly processed, food (the kernel of truth). The solution is simple. Avoid unhealthy foods. Adding a different kind of fat to unhealthy foods is not going to make them healthier.

The Truth About Seed Oils

Myth Versus FactsBy now I have covered most of the myths about seed oils in my sections on omega-6 fats and canola oil, but here is a quick review.

Myth: All seed oils are…[add your favorite derogatory term here].

Truth: Every seed oil has a unique composition of fats. Each has its unique benefits and unique drawbacks.

Myth: Seed oils are genetically modified.

Truth: The plants producing canola oil and high oleic sunflower oil have been modified (the kernel of truth), but they were modified by conventional plant breeding rather than genetic engineering.

Myth: Seed oils contain toxic ingredients. This myth is most often directed at canola oil.

Truth: Rapeseed oil contains components that can be toxic at high levels (the kernel of truth). However, the rapeseed plant has been bred to produce canola oil with safe levels of those components.

Myth: Seed oils are inflammatory, which increases your risk of inflammatory diseases and heart disease.

Truth: Seed oils contain omega-6 fats which can be converted into one inflammatory prostaglandin (the kernel of truth). But they are also converted to anti-inflammatory prostaglandins. The net effect in well done human clinical trials is a slight anti-inflammatory effect.

Myth: Seed oils cause oxidative damage, which increases your risk of cancer.

Truth: Seed oils (like any polyunsaturated fat) are susceptible to oxidation, especially at high temperatures. This can lead to free radical formation and oxidative damage (the kernel of truth). But this is only true when you use them improperly. The solution is to store them safely and to not overheat them when cooking. 

Myth: Saturated fats are healthier than seed oils. Replacing saturated fat with the omega-6 fats found in seed oils increases inflammation and heart disease risk.

Truth: Many studies in this area of research are poorly designed. Well-designed studies show that replacing saturated fat with the omega-6 fats found in seed oils reduces both inflammation and heart disease risk.

Myth: Omega-3 fats are healthier than the omega-6 fats found in seed oils, so we should replace seed oils with omega-3 fats.

Fact: Omega-3 fats are more effective than omega-6 fats at reducing inflammation and heart disease risk (the kernel of truth). However, omega-6 fats are essential for a healthy heart, a healthy brain, and normal fetal growth and development. We can’t make them, so we must get them from our diet. Americans are currently consuming the recommended amount of omega-6 fats. So, we should not decrease the amount of omega-6 fats in our diet. Instead, we would benefit from adding more omega-3s to our diet.

Myth: Seed oils are highly processed. High heat processing alters the oils. Processing also removes beneficial antioxidants and polyphenols from the oils.

Truth: This is mostly true. The solution is to choose your brands carefully.

  • For oils choose reputable brands and choose ones that use low-heat processing. Also, look for ones with minimal processing. They may be cloudy rather than clear, but they will also contain naturally occurring antioxidants and polyphenols.
    • It’s not easy to choose your source carefully. But this difficulty is not unique to seed oils. For example:
      • The term EVO is supposed to mean extra virgin olive oil was used, but cheaper oils are sometimes blended into the olive oil to save money.
      • If a company wishes to use the term “grass fed” on their product, they must file a certification with the USDA, but the USDA does not inspect to determine whether the certification is accurate.
  • Seed oils are also found as an ingredient in unhealthy, highly processed foods. The solution here is simple. Avoid unhealthy foods. Adding a different kind of fat to unhealthy foods is not going to make them healthier.

For more details about each of these Truth statements, read the article above.

The Bottom Line

There are many myths about seed oils. Each myth has a kernel of truth but is mostly false. In this week’s “Health Tips From the Professor” I discuss the myths and truths about seed oils. Because this is a complex subject, I have broken it down into individual topics that address one or more seed oil myths before talking about seed oil myths directly.

The topics I covered are:

  • The truth about fats.
  • The truth about omega-6 fats.
  • The truth about saturated fats.
  • The truth about canola oil.
  • The truth about seed oils.

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.

 ______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance 

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.

Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

 

Does Olive Oil Help You Live Longer?

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Which Fat Is Healthiest?

Author: Dr. Stephen Chaney

If you believe the headlines, olive oil is a superfood. It is often described as the star of the Mediterranean diet. It is referred to as the healthiest of dietary fats. Is this true, or is it hype?

Olive oil’s resume is impressive:

  • It is rich in monounsaturated fatty acids, which…
    • Are less susceptible to oxidation than polyunsaturated oils.
    • Make our arteries more flexible, which lowers blood pressure.
    • Lower LDL-cholesterol levels, which reduces the risk of heart disease.
  • Extra-virgin olive oil contains phytonutrients and tocopherols (various forms of vitamin E), which…
    • Have anti-inflammatory properties.
    • Improve insulin sensitivity and blood sugar control.
  • Olive oil consumption is also associated with healthier gut bacteria, but it is not clear whether this is due to olive oil or to the fact that a Mediterranean diet is also richer in fresh fruits, vegetables, and whole grains.

Several recent studies have shown that olive oil consumption is associated with a lower risk of heart disease. However, these studies were conducted in Mediterranean countries where the average intake of olive oil (3 tablespoons/day) is much greater than in the United States (0.3 tablespoons/day).

The current study (M Guasch-Ferré et al, Journal of the American College of Cardiology, 79: 101-112, 2022) was designed to test whether:

  • The amount of olive oil Americans consume decreases the risk of heart disease.
  • Whether olive oil consumption had benefits beyond a reduction in heart disease risk.

How Was This Study Done? 

Clinical StudyThis study combined data from 60,582 women enrolled in the Nurses’ Health Study and 31,801 men enrolled in the Health Professionals Follow-Up Study). The participants:

  • Were free of heart disease and diabetes at the start of the study.
  • Were 56 at the start of the study with an average BMI of 25.6 (Individuals with BMIs in the 25-30 range are considered overweight, so they were at the lowest end of the overweight range).

The Nurses’ Health Study and Health Professional Follow-Up Study are both association studies, meaning they looked at the association between olive oil consumption and health outcomes. They cannot directly prove cause and effect. However, they are very strong association studies because:

  • Every 2 years, participants filled out a questionnaire that updated information on their body weight, smoking status, physical activity, medications, multivitamin use, and physician-diagnosed diseases.
  • Every 4 years, participants filled out a comprehensive food frequency questionnaire.
  • In other words, this study did not just rely on the participant’s lifestyle, dietary intake, and health at the beginning of the study, as so many association studies do. It tracked how each of these variables changed over time.

The participants were followed for an average of 28 years and their average olive oil intake over those 28 years was correlated with all-cause mortality and mortality due to specific diseases.

  • Deaths were identified from state vital statistics, the National Death index, reports by next of kin, or reports by postal authorities.
  • Causes of death were determined by physician review of medical records, medical reports, autopsy reports, or death certificates.

Does Olive Oil Help You Live Longer?

During the 28 years of this study:

  • Olive oil consumption in the United States increased from an average of ~1/3 teaspoon/day to ~1/3 tablespoon/day.
  • Margarine consumption decreased from 12 g/day to ~4 g/day.
  • The consumption of all other fats and oils remained about the same.

As I mentioned above, olive oil consumption was averaged over the life of the study for each individual. When the investigators compared people consuming the highest amount of olive oil (>0.5 tablespoon/day) with people consuming the least olive oil (0 to 1 teaspoon/day):

  • Mortality from all causes was decreased by 35% for the group consuming the most olive oil.

However, the group consuming the most olive oil also was more physically active, had a healthier diet, and consumed more fruits and vegetables than the group who consumed the least olive oil.

  • After correcting for all those factors, mortality from all causes was decreased by 19% for the group consuming the most olive oil.

The authors concluded, “We found that greater consumption of olive oil was associated with lower risk of total…mortality… Our results support current dietary recommendations to increase the intake of olive oil…to improve overall health and longevity.” (I will fill in the blanks in this statement once I have covered other aspects of this study)

The authors also said, “Of note, our study showed that benefits of olive oil can be observed even when consumed in lower amounts than in Mediterranean countries.”

Are There Other Benefits From Olive Oil Consumption?

Mediterranean dietThe study didn’t stop there. The investigators also looked at the effect of olive oil consumption on the major killer diseases in the United States and other developed countries. When they compared the effect of olive oil consumption on cause-specific mortality, they found that the group who consumed the most olive oil reduced their risk of dying from:

  • Cardiovascular disease by 19%.
  • Cancer by 17%
  • Respiratory disease by 18%.
  • Neurodegenerative disease (cognitive decline and Alzheimer’s disease) by 29%.
    • The reduction in neurodegenerative disease was much greater for women (34% decrease) than for men (19% decrease).

With this information I can fill in one of the blanks in the author’s conclusions: “We found that greater consumption of olive oil was associated with lower risk of total and cause-specific mortality… Our results support current dietary recommendations to increase the intake of olive oil…to improve overall health and longevity.”

Which Fats Are Healthiest?

Good Fat vs Bad FatThe sample size was large enough and the dietary information complete enough for the investigators to also estimate the effect of substituting olive oil for other dietary fats and oils.

They found that every ¾ tablespoon of olive oil substituted for an equivalent amount of:

  • Margarine decreased total mortality by 13%.
  • Butter decreased total mortality by 14%.
  • Mayonnaise deceased total mortality by 19%
  • Dairy fat decreased total mortality by 13%.
    • The same beneficial effects of substituting olive oil for other fats were seen for cause-specific mortality (cardiovascular disease, cancer, respiratory disease, and neurodegenerative disease).
    • There was a linear dose-response. This means that substituting twice as much olive oil for other dietary fats doubled the beneficial effects on total and cause-specific mortality.
  • However, substituting olive oil for polyunsaturated vegetable oils had no effect on total and cause-specific mortality.

Now I can fill in the remaining blanks in the author’s conclusion: “We found that greater consumption of olive oil was associated with lower risk of total and cause-specific mortality. Replacing other types of fat, such as margarine, butter, mayonnaise, and dairy fat, with olive oil was also associated with a lower risk of mortality. Our results support current dietary recommendations to increase the intake of olive oil and other unsaturated vegetable oils in place of other fats to improve overall health and longevity.”

What Does This Study Mean For Us?

ConfusionAs I said above, this is an association study, and association studies do not prove cause and effect. However:

1) This is a very strong association study because:

    • It is a very large study (92,383 participants).
    • It followed the participants over a long time (28 years).
    • It utilized a very precise dietary analysis.
    • Most importantly, it tracked the participant’s lifestyle, dietary intake, and health at regular intervals throughout the study. Most association studies only measure these variables at the beginning of the study. They have no idea how they change over time.

2) This study is consistent with several previous studies showing that olive oil consumption decreases the risk of dying from heart disease.

3) This study draws on its large population size and precise dietary analysis to strengthen and extend the previous studies. For example:

    • The study showed that increased olive oil consumption also reduced total mortality and mortality due to cancer, respiratory disease, and neurodegenerative disease.
    • The study measured the effect of substituting olive oil for other common dietary fats.
    • The study showed that increased olive oil consumption in the context of the American diet was beneficial.

I should point out that the headlines you have seen about this study may be misleading.

  • While the headlines may have depicted olive oil as a superfood, this study did not find evidence that olive oil was more beneficial than other unsaturated vegetable oils. Again, this is consistent with many previous studies showing that substituting vegetable oils for other dietary fats reduces the risk of multiple diseases.
  • The headlines focused on the benefits of increasing olive oil consumption. However, they neglected the data showing that increasing olive oil (and other vegetable oils) was even more beneficial (35% reduction in total mortality) in the context of a healthy diet – one with increased intake of fruits, vegetables, whole grains, nuts, legumes, and long-chain omega-3s and decreased intake of red & processed meats, sodium, and trans fats.

So, my recommendation is to follow a whole food, primarily plant-based diet and substitute extra-virgin olive oil and cold pressed vegetable oils for some of the animal fats in your diet.

Some vegan enthusiasts recommend a very low-fat whole food plant-based diet. They point to studies showing that such diets can actually reverse atherosclerosis. However:

  • Those studies are very small.
  • The overall diet used in those studies is a very healthy plant-based diet.
  • The studies did not include a control group following the same diet with olive oil or other vegetable oils added to it, so there is no comparison of a healthy vegan diet with and without vegetable oils.

If you have read my book, “Slaying the Food Myths”, you know that my recommendations encompass a variety of whole food, primarily plant-based diets ranging all the way from very-low fat vegan diets to Mediterranean and DASH diets. Choose the one that best fits your food preferences and the one you will be most able to stick with long term. You will be healthier, and you may live longer.

The Bottom Line

A recent study looked at the effect of olive oil consumption on the risk dying from all causes and from heart disease, cancer, respiratory disease, and neurodegenerative diseases. When the study compared people consuming the highest amount of olive oil (>0.5 tablespoon/day) with people consuming the least olive oil (0 to 1 teaspoon/day):

  • Mortality from all causes was decreased by 19% for the group consuming the most olive oil.

They also found that the group who consumed the most olive oil reduced their risk of dying from:

  • Cardiovascular disease by 19%.
  • Cancer by 17%
  • Respiratory disease by 18%.
  • Neurodegenerative disease (cognitive decline and Alzheimer’s disease) by 29%.

They also found that every ¾ tablespoon of olive oil substituted for an equivalent amount of:

  • Margarine decreased total mortality by 13%.
  • Butter decreased total mortality by 14%.
  • Mayonnaise deceased total mortality by 19%
  • Dairy fat decreased total mortality by 13%.
  • However, substituting olive oil for polyunsaturated vegetable oils had no effect on total and cause-specific mortality.

The authors concluded, “We found that greater consumption of olive oil was associated with lower risk of total and cause-specific mortality. Replacing other types of fat, such as margarine, butter, mayonnaise, and dairy fat, with olive oil was also associated with a lower risk of mortality. Our results support current dietary recommendations to increase the intake of olive oil and other unsaturated vegetable oils in place of other fats to improve overall health and longevity.”

For more details and a summary of what this study means 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.

Is Dairy Bad For Your Heart?

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Is Dairy Right For You? 

Author: Dr. Stephen Chaney

dairy foodsWe have been told for years that dairy foods are good for us. They are part of the USDA five food groups. In fact, they are part of the dietary recommendations of every government and most health organizations across the world.

And dairy foods are nutritious. They are excellent sources of calcium, potassium, protein, and vitamins A and B12. And if they are fortified, they are also an excellent source of vitamin D. Many health experts consider them essential for healthy bones. So, you might be saying, “Case closed. We should all be eating more dairy foods”.

But, not so fast. Many dairy foods are high in saturated fats. In fact, 65% of the fat in dairy foods is saturated. We have known for years that when saturated fats replace polyunsaturated fats in the diet, LDL cholesterol levels increase. And, as I reported in a previous issue of “Health Tips From the Professor” there is excellent evidence that replacing polyunsaturated fats with saturated fats substantially increases the risk of dying from heart attack, stroke, and other forms of heart disease.

The widely accepted message from these studies is that saturated fats raise LDL cholesterol levels and increases our risk of dying from heart disease. If we accept this message, it poses a dilemma. Dairy foods are nutritious. But they are high in saturated fat. What should we do?

The answer from the American Heart Association and most other health organizations is simple. We should eat low-fat dairy foods.

But this is where it gets really confusing. Dairy foods are composed of much more than saturated fats. And you have probably seen the claims that full fat dairy foods don’t increase the risk of heart disease.

So, what is the truth about full-fat dairy foods and heart health? In this issue of “Health Tips From The Professor” I review three recent studies and the recommendations of the Heart Foundation because they shed light on this question.

Is Dairy Bad For Your Heart?

dairy products and heart disease cheeseBefore I answer this question, I should point out that there are two ways of looking at it.

  • As I said above, the studies proving that saturated fats increase the risk of heart disease, substituted saturated fats for polyunsaturated fats and controlled every other aspect of the diet. That has led the American Heart Association and other organizations to recommend that we eat low-fat dairy foods.
  • However, when most people hear that recommendation, they simply substitute low-fat dairy for full-fat dairy foods without changing any other aspect of their diet or lifestyle. The first two studies were designed to see if that approach was effective for reducing heart disease risk.

The first study (KA Schmidt et al, American Journal of Clinical Nutrition, 114: 882-892, 2021) was a randomized controlled trial that compared the effect of low-fat dairy foods and full-fat dairy foods on heart health parameters.

The participants in this study were:

  • Average age = 62
  • 56% male
  • 75% white
  • Average weight = 214 pounds
  • All of them were prediabetic

All participants were told to stick with their usual diets (probably typical American diets) except for the amount and type of dairy foods added to their diet. During the first four weeks they restricted dairy consumption to 3 servings of nonfat dairy/week so they would all be starting with the same amount of dairy consumption. Then they were divided into 3 groups for the 12-week study:

  • Group 1 continued with 3 servings of nonfat dairy/week.
  • Group 2 added 3 servings of low-fat dairy/day to their usual diet.
  • Group 3 added 3 servings of high-fat dairy/day to their usual diet.

At the beginning of the study and again at the end of the 12-week study LDL cholesterol, HDL cholesterol, triglycerides, free fatty acids, and blood pressure were measured. The results were:

  • There was no difference in LDL cholesterol, HDL cholesterol, triglycerides, free fatty acids, or blood pressure in the three groups at the end of 12 weeks.
  • There was no also significant change in LDL cholesterol, HDL cholesterol, triglycerides, free fatty acids, or blood pressure during the study in any of the three groups.

The authors concluded, “A diet rich in full-fat dairy had no effect on fasting lipid profile or blood pressure compared with diets limited in dairy or rich in low-fat dairy. Therefore, dairy fat, when consumed as part of complex whole foods does not adversely affect these classic cardiovascular disease risk factors.”

[Note: The last sentence is key. Remember the “proof” that saturated fats increase LDL levels and increase the risk of heart disease come from studies in which saturated fats were substituted for polyunsaturated fats and every other aspect of the diet was carefully controlled.

In this study, and others like it, the effects of saturated fats are studied in a complex food (dairy) in the presence of an even more complex diet containing many foods that influence the risk of heart disease.]

The second study (J Guo et al, European Journal of Epidemiology 32: 269-287, 2017) was a meta-analysis of Healthy Heart29 studies with 938,465 participants looking at the association of full-fat dairy consumption with the risk of dying from heart disease.

Seven of the 29 studies were conducted in the United States. Of the remaining studies 3 were from Japan and Taiwan, 2 were from Australia, and 17 were from Europe.

The results of the study were:

  • There was no association between full-fat dairy, low-fat dairy, and total dairy consumption and risk of dying from heart disease.

When the results were broken down into individual dairy foods.

  • There was no association between milk consumption and risk of dying from heart disease.
  • Consumption of one serving/day of fermented dairy foods was associated with a 2% decreased risk of dying from heart disease.

The authors concluded, “The current meta-analysis of 29 prospective cohort studies suggested no association of total, high and low-fat dairy and milk with risk of cardiovascular disease. In addition, a possible role of fermented dairy was found in cardiovascular disease prevention, but the result was driven by a single study.” [I would add that this effect, if confirmed by subsequent studies, is extremely small (2%).]

The first two studies do not say that full-fat dairy foods are heart healthy for everyone, as some headlines would have you believe. Instead, these studies show fairly convincingly that simply switching from full-fat to low-fat dairy foods, without changing any other aspect of your diet and lifestyle, is not as effective at decreasing your risk of heart disease as some experts would have you believe.

balance scaleThe third publication (WC Willett and DS Ludwig, New England Journal of Medicine 382: 644-654, 2020) was a review of the effect of dairy foods on our health. One of the authors, Walter C Willett, is one of the top experts in the field. The review covered many topics, but I will focus on the section dealing with the effect of dairy foods on heart health.

This review took a more nuanced look at full-fat dairy foods and examined the effect of substituting full-fat dairy for other protein foods.

The review concludes, “The association of milk with the risk of cardiovascular disease depends on the comparison foods. In most cohort studies [such as the studies described above], no specific comparison was made; by default, the comparison was everything else in the diet – typically large amounts of refined grains, potato products, sugar, and meat.”

The review went on to say that previous studies have shown:

  • “Both full-fat and low-fat dairy foods…were associated with a lower risk [of cardiovascular disease and stroke] than…the same number of servings of red meat but with a higher risk than seen with the same number of servings of fish or nuts.”
  • “Dairy fat…was associated with a higher risk of cardiovascular disease than was polyunsaturated or vegetable fat.”
  • “For persons living in low-income countries where diets are very high in starch, moderate intake of dairy foods may reduce cardiovascular disease by providing nutritional value and reducing glycemic load [the amount of easily digestible carbohydrate in the diet].”

Is Dairy Right For You?

dairy products and heart disease questionsNow I am ready to answer the question posed at the beginning of this article, “Is dairy bad for your heart?” The answer is, “It depends”.

  • As described above, the effect of dairy on heart health depends on our overall diet. It also depends on our lifestyle, our weight, and our health.
  • In addition, clinical studies report averages, and none of us are average. We all have unique diets, lifestyles, health status, and genetic makeup.

So, what does this mean for you? Perhaps it is best summed up by the recommendations of Australia’s Heart Foundation which take health status, lifestyle, and genetic differences into account:

  • A heart healthy diet can include dairy, but it is not essential [with careful planning and/or supplementation you can get your calcium and protein elsewhere].
  • Milk, yogurt, and cheese are considered neutral for heart health, meaning they neither increase nor decrease the risk of heart disease for the average person. However, the recommendations vary depending on health status, genetics, and lifestyle:
    • Low-fat milk, yogurt, and cheese are recommended for people with heart disease or high cholesterol because the fat in dairy foods can raise cholesterol more for these people. [Note: If cholesterol is elevated, it usually means that individual has a hard time regulating blood cholesterol levels because of obesity, genetics, or pre-existing disease. For these individuals, diets high in saturated fat are more likely to increase LDL cholesterol and risk of heart disease.]
    • Full-fat milk, yogurt, and cheese can be part of a heart healthy diet for healthy people provided most of the fat in the diet comes from fish, nuts, seeds, and healthy oils. [Note: Overall diet is important.]
  • Choosing unflavored milk, yogurt, and cheese helps limit the amount of sugar in your diet.
  • Ice cream, cream, and dairy desserts should be eaten only sometimes and in small amounts because they have more sugar and fat, and less protein, vitamins, and minerals than other dairy foods.
  • Butter raises LDL cholesterol levels, especially in people who already have elevated cholesterol.
    • There is no evidence that butter can be part of a heart healthy diet, so you should consider healthier options such as olive oil, avocado, nut butters, and spreads made with healthier oils, such as olive oil.

The Bottom Line

We have been told for years that dairy foods are good for us. They are part of the USDA five food groups. In fact, they are part of the dietary recommendations of every government and most health organizations across the world.

However, dairy foods have been controversial in recent years. Some experts claim that only low-fat dairy products can be heart healthy. Others claim that full-fat dairy foods are just as healthy as low-fat dairy foods.

I shared three recent publications and dietary recommendations from The Heart Foundation that shed light on these controversies.

The first study found that full-fat dairy foods did not increase LDL cholesterol, triglycerides, and other heart disease risk factors.

The second study was a meta-analysis of 29 clinical studies with almost one million people. It found that full-fat dairy foods did not increase the risk of dying from heart disease.

“Case closed”, you might say. However, these studies do not say that full-fat dairy foods are heart healthy for everyone, as some headlines would have you believe. Instead, these studies show fairly convincingly that simply switching from full-fat to low-fat dairy foods, without changing any other aspect of your diet and lifestyle, is not as effective at decreasing your risk of heart disease as some experts would have you believe.

Moreover, these studies do not account for the effect of overall diet, lifestyle, health status, and genetics on the risk of heart disease.

That is why I included the third study in my review. It took the overall diet into account and concluded the effect of full-fat dairy foods on heart disease risk depends on the overall diet.

  • For some diets full-fat dairy increases heart disease risk.
  • For other diets full-fat dairy has no effect on heart disease risk.
  • And for some diets full-fat dairy may even decrease heart disease risk.

Finally, I included recommendations of the Australian Heart Foundation because they included the effect of health status, lifestyle, and genetics in their recommendations.

For more details on the findings of the third study and the recommendations of the Heart Foundation, read the article above.

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

What Is An Anti-Inflammatory Diet?

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Can Diet Douse The Flames?

Author: Dr. Stephen Chaney

InflammationIf you have arthritis, colitis, bursitis, or any of the other “itis” diseases, you already know that inflammation is the enemy. Chronic, low level inflammation is also a contributing factor to heart disease, cancer, and many other diseases. Clearly, inflammation is a bad actor. It is something we want to avoid.

Obesity and diabetes are two of the biggest contributors to inflammation, but does diet also play a role? With all the anti-inflammation diets circulating on the internet, you would certainly think so. How good is the evidence that certain foods influence inflammation, and what does an anti-inflammatory diet look like?

The Science Behind Anti-Inflammatory Diets

ScientistLet me start by saying that the science behind anti-inflammatory diets is nowhere near as strong as it is for the effect of primarily plant-based diets on heart disease and diabetes. The studies on anti-inflammatory diets are mostly small, short duration studies. However, the biggest problem is that there is no standard way of measuring inflammation.

There are multiple markers of inflammation, and they do not change together. That means that in every study some markers of inflammation are altered, while others are not. There is no consistent pattern from one study to another.

In spite of these methodological difficulties, the studies generally point in the same direction. Let’s start with the strongest evidence and work our way down to the weakest evidence. 

Omega-3 fats are anti-inflammatory (I. Reinders et al, European Journal of Clinical Nutrition, 66: 736-741, 2011). The evidence is strongest for the long chain omega-3s found in fish and fish oil, but the shorter chain omega-3s found in foods like walnuts, flaxseeds, chia seeds and flaxseed oil, soybean oil, and canola oil also appear to be anti-inflammatory. 

Inflammation is directly correlated with glycemic index (L. Qi and F.B. Lu, Current Opinion in Lipidology, 18: 3-8, 2007). This has a couple of important implications.

The most straightforward is that refined carbohydrates and sugars (sodas, pastries, and desserts), which have a high glycemic index, increase inflammation. In contrast, complex carbohydrates (whole grains, most fruits and vegetables) decrease inflammation. No surprise there. The second implication is that it is the glycemic index, not the sugar, that is driving the inflammatory response.

That means we need to look more closely at foods than at sugars. Sodas, pastries and desserts are likely to cause inflammation, but sugar-containing foods with a low glycemic index are unlikely to be inflammatory. 

Fruits and vegetables are anti-inflammatory. This has been shown in multiple studies. At this point most of the research is centered on identifying the nutrients and phytonutrients from fruits and vegetables that are responsible for the reduction in inflammation. I suspect the investigators are hoping to design an anti-inflammatory supplement and make lots of money. I will stick with the fresh fruits and vegetables. 

Saturated fats are inflammatory. At face value, the data on saturated fats appear to be contradictory. Some Fatty Foodsstudies say that saturated fats increase inflammation, while others say they do not. However, similar to my earlier discussion on saturated fats and heart disease), the outcome of the study depends on what the saturated fats are replaced with.

When saturated fats are replaced with refined carbohydrates, sugar and highly processed foods (the standard American low-fat diet), inflammation doesn’t change. This doesn’t mean that a diet high in saturated fat is healthy. It just means that both diets are bad for you. Both are inflammatory.

However, when saturated fat is replaced with omega-3 polyunsaturated fats (J.A. Paniagua et al, Atherosclerosis, 218: 443-450, 2011) or monounsaturated fats (B. Vessby et al, Diabetologia, 44: 312-319, 2001), markers of inflammation decrease. Clearly, saturated fats are not the best fat choice if you wish to keep inflammation in check.

I would be remiss if I did not address the claims by the low-carb diet proponents that saturated fats do not increase inflammation in the context of a low-carb diet. I want to remind you of two things we have discussed previously:

  • The comparisons in those studies are generally with people consuming a diet high in simple carbohydrates and sugars.
  • These studies have mostly been done in the short-term when the participants are losing weight on the low-carb diets. Weight loss decreases inflammation, so the reduction in inflammation on the low-carb diet could be coming from the weight loss.

The one study (M. Miller et al, Journal of the American Dietetic Association, 109: 713-717, 2009) I have found that compares a low-carb diet (the Atkins diet) with a good diet (the Ornish diet, which is a low-fat, lacto-ovo vegetarian diet) during weight maintenance found that the meat based, low-carb Atkins diet caused greater inflammation than the healthy low-fat Ornish diet.

Red meat is probably pro-inflammatory. Most, but not all, studies suggest that red meat consumption is associated with increased inflammation. If it is pro-inflammatory, the inflammation is most likely associated with its saturated fat, its heme iron content, or the advanced glycation end products formed during cooking.

What Is An Anti-Inflammatory Diet?

Colorful fruits and vegetablesAnti-inflammatory diets have become so mainstream that they now appear on many reputable health organization websites such as Harvard Health, WebMD, the Mayo Clinic, and the Cleveland Clinic. Each have slightly different features, but there is a tremendous amount of agreement. 

Foods an anti-inflammatory diet includes: In a nutshell, an anti-inflammatory diet includes fruits and vegetables, whole grains, plant-based proteins (like beans and nuts), fatty fish, and fresh herbs and spices. Specifically, your diet should emphasize:

  • Colorful fruits and vegetables. Not only do they help fight inflammation, but they are a great source of antioxidants and other nutrients important for your health.
  • Whole grains. They have a low glycemic index. They are also a good source of fiber, and fiber helps flush inflammatory toxins out of the body.
  • Beans and other legumes. They should be your primary source of protein. They are high in fiber and contain antioxidants and other anti-inflammatory nutrients.
  • Nuts, olive oil, and avocados. They are good sources of healthy monounsaturated fats, which fight inflammation.
  • Fatty fish. Salmon, tuna, and sardines are all great sources of long chain omega-3 fatty acids, which are fish and fish oilincorporated into our cell membranes. Those long chain omega-3s in cell membranes are, in turn, used to create compounds that are powerful inflammation fighters.

Walnuts, flaxseeds, and chia seeds are good sources of short chain omega-3s. The efficiency of their conversion to long chain omega-3s that can be incorporated into cell membranes is only around 2-5%. If they fight inflammation, it is probably because they replace some of the saturated fats and omega-6 fats you might otherwise be eating.

  • Herbs and spices. They add antioxidants and other phytonutrients that fight inflammation.

Foods an anti-inflammatory diet excludes: In a nutshell, an anti-inflammatory diet should exclude highly processed, overly greasy, or super sweet foods, especially sodas and other sweet drinks. Specifically, your diet should exclude:

  • Refined carbohydrates, sodas and sugary foods. They have a high glycemic index, which is associated with inflammation. They can also lead to weight gain and high blood sugar, both of which cause inflammation.
  • Foods high in saturated fats. This includes fatty and processed meats, butter, and high fat dairy products.
  • Foods high in trans fats. This includes margarine, coffee creamers, and any processed food containing partly hydrogenated vegetable oils. Trans fats are very pro-inflammatory.
  • French fries, fried chicken, and other fried foods. They used to be fried in saturated fat and/or trans fat. Nowadays, they are generally fried in omega-6 vegetable oils. A little omega-6 in the diet is OK, but Americans get too much omega-6 fatty acids in their diet. Most studies show that a high ratio of omega-6 to omega-3 fatty acids is pro-inflammatory.
  • Foods you are allergic or sensitive to. Eating any food that you are sensitive to can cause inflammation. This comes up most often with respect to gluten and dairy because so many people are sensitive to one or both. However, if you are not sensitive to them, there is no reason to exclude whole grain gluten-containing foods or low-fat dairy foods from your diet.

Can Diet Douse The Flames?

FlamesIn case you didn’t notice, the recommendations for an anti-inflammatory diet closely match the other healthy diets I have discussed previously. It should come as no surprise then that both the Mediterranean (L. Gallard, Nutrition in Clinical Practice, 25: 634-640, 2010; L. Schwingshackl and G. Hoffmann, Nutrition Metabolism and Cardiovascular Diseases, 24: 929-939, 2014) and DASH (D.E. King et al, Archives of Internal Medicine, 167: 502-506, 2007) diets are anti-inflammatory.

Vegan and vegetarian diets also appear to be anti-inflammatory as well. The anti-inflammatory nature of these diets undoubtedly contributes to their association with a lower risk of heart disease, diabetes, and cancer.

As for the low-carb diets, the jury is out. There are no long-term studies to support the claims of low-carb proponents that their diets reduce inflammation. The few long-term studies that are available suggest that low-carb diets are only likely to be anti-inflammatory if vegetable proteins and oils replace the animal proteins and fats that are currently recommended.

What does this mean for you if you have severe arthritis or other inflammatory diseases? An anti-inflammatory diet is unlikely to “cure” your symptoms by itself. However, it should definitely be a companion to everything else you are doing to reduce inflammation.

The Bottom Line 

If you have arthritis, colitis, bursitis, or any of the other “itis” diseases, you already know that inflammation is the enemy. Chronic, low level inflammation is also a contributing factor to heart disease, cancer, and many other diseases. Clearly, inflammation is a bad actor. It’s something we want to avoid.

Obesity and diabetes are two of the biggest contributors to inflammation, but does diet also play a role? With all the anti-inflammation diets circulating on the internet, you would certainly think so. In this article I review the evidence that certain foods influence inflammation and describe what an anti-inflammatory diet looks like.

For more details read the article above.

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

What’s Worse Saturated Fat or Sugar?

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What Causes Fatty Liver Disease?

Author: Dr. Stephen Chaney

 

what is worse saturated fats or sugarThe great American food fight continues. The low fat enthusiasts tell you saturated fat is going to kill you. The low carb enthusiasts tell you saturated fat is fine. It’s sugar that’s going to kill you.

You can find studies that support either viewpoint. And the story keeps changing. One day the headlines proclaim: “The latest study shows…” A few weeks later you see a headline saying: “Wait. That’s wrong. Science now shows…” It’s no wonder you are confused and perhaps a bit cynical.

So, what’s worse saturated fat or sugar?

Perhaps we should step back and ask how we got to this point.

 

Why Is the Saturated Fats and Sugar Dilemma So Confusing?

saturated fats or sugar dilemmaTo understand why the literature around saturated fats and sugar is so confusing, we need to go back to the 1950s. The first studies implicating saturated fats as a risk factor for heart disease replaced saturated fats with unsaturated fats. Everything else in the diet was kept the same. When you do that, the answer is clear-cut. Saturated fats increase heart disease risk and unsaturated fats decrease heart disease risk.

When the American Heart Association first recommended a low-fat diet, they had in mind replacing saturated fats with fresh fruits, vegetables, whole grains, and beans. The remaining fat would be mostly unsaturated. Today, we would call that a Mediterranean diet, which, by the way, has been shown to reduce both diabetes and heart disease risk.

Big Food Inc. took one look at that and panicked. They make their money from processed foods, not from fresh fruits and vegetables. If the American people made the changes the American Heart Association recommended, Big Food Inc. would go bankrupt.

They sprang into action. They had their laboratories whip up processed foods that replaced fat with sugar, white flour, and a witch’s brew of chemicals. Then they told the American people: “Never fear. You don’t have to give up your favorite foods. We have created low fat versions of the foods you love.”

That became the diet that most Americans adopted. Even worse, most Americans continued eating foods high in saturated fats. We ended up with the worst of all possible worlds – a diet high in saturated fat and high in sugar. This became the Standard American Diet (SAD).

This shift has corrupted most of the recent research studies on saturated fat and sugar. Most of the studies on saturated fat or sugar have compared them with the Standard American Diet, not with a healthy diet. When you do that, your results are going to be skewed. Almost anything is better that the Standard American Diet.

Why Was This Study Done?

fatty liver disease causesWhen we think of obesity, we think of the excess fat we can see. But what we have learned in recent years is that the fat you can’t see is far more damaging to our health. I am talking about fat stores in the liver, something called fatty liver disease.

Fatty liver disease has serious consequences. It causes insulin resistance and inflammation, and that increases the risk of diabetes and heart disease. Even worse, it can lead to cirrhosis and liver failure.

Excess sugar is converted to saturated fat in the liver. Therefore, the popular literature attributes the epidemic of fatty liver disease to increased intake of simple sugars. But is it true? Saturated fats require no conversion. They can simply be deposited in the liver as is. Shouldn’t they be at least as damaging to the liver as sugar?

It turns out that no studies have actually compared the effect of excess calories in the form of saturated fat, unsaturated fat, and simple sugars on fat accumulation in the liver. This study (PK Luukkonen et al, Diabetes Care, 41: 1732-1739, 2018) was designed to fill that gap.

How Was The Study Done?

saturated fats or sugar studyThe authors enrolled 38 middle aged (average age = 48), overweight (average BMI = 31) adults for the study. The participants were divided into three groups and were fed an extra 1,000 calories per day of saturated fat (SAT group), unsaturated fat (UNSAT group), or sugar (SUGAR group) for 3 weeks. The composition of those extra 1,000 calories was as follows:

  • The SAT group ate an extra 30 g coconut oil, 40 g butter, and 100 g blue cheese
    • Macronutrient composition = 1% carbohydrate, 86% fat, 13% protein, 0% simple sugars.
    • Fat composition = 76% saturated fats, 21% monounsaturated fats, 3% polyunsaturated fats
  • The UNSAT group ate an extra 36 g olive oil, 26 g pesto, 54 g pecans, and 20 g butter
    • Macronutrient composition = 2% carbohydrate, 91% fat, 7% protein, 0% simple sugars.
    • Fat composition = 21% saturated fats, 57% monounsaturated fats, 22% polyunsaturated fats
  • The SUGAR group ate an extra 9.5 ounces of orange juice, 16 ounces of sugar-sweetened beverages, and 200 g of candy.
    • Macronutrient composition = 100% simple sugars.

Compliance to these dietary additions was confirmed by measuring the fat composition of serum triglycerides. As expected, the triglycerides were primarily composed of saturated fat in the SAT and SUGAR groups and unsaturated fats in the UNSAT group.

None of the participants had diabetes or other diseases, pre-existing liver disease, excessive consumption of alcohol (which can also lead to fatty liver disease). They were also not taking any drugs that could influence glucose or lipid metabolism.

Upon entry into the study, the three groups were comparable with respect to age, sex, BMI (a measure of obesity), amount and type of fat stores in the liver, and insulin sensitivity.

The baseline diet to which the extra calories were added was also comparable between the three groups and did not change during the study. That meant that the only difference between groups was the composition of the extra calories they consumed.

 

What Causes Fatty Liver Disease?

fatty liver disease dietsAt the end of three weeks:

  • All 3 groups gained weight, but the weight gain was slightly larger (0.6 pounds) for the SAT and SUGAR groups than for the UNSAT group (0.4 pounds).
  • Fat stores in the liver increased by 55% in the SAT group, 33% in the SUGAR group, and 15% in the UNSAT group.
  • The fat stores were primarily saturated fat in the SAT and SUGAR groups and primarily unsaturated fat in the UNSAT group.
  • Insulin resistance was increased in the SAT group, but not in the SUGAR and UNSAT groups.

Previous studies have suggested that the effect of liver fat stores on insulin resistance might be mediated by fat metabolites called ceramides. Therefore, they also measured plasma ceramide levels.

  • Plasma ceramides were increased in the SAT group, but not in the SUGAR and UNSAT groups.

Previous studies have also suggested that the effect of saturated fat on insulin resistance might be mediated by a change in gut bacteria that produce endotoxins which end up in the bloodstream.

  • A change in gut bacteria and an increase in plasma endotoxins was observed in the SAT group, but not in the SUGAR and UNSAT groups.

 

What is Worse Saturated Fat Or Sugar?

sugar cubesThe authors of this study concluded: “Saturated fat induced the greatest increase in fat stores in the liver, insulin resistance, and harmful ceramides. Decreased intakes of saturated fat could be beneficial in reducing fat stores in the liver and the associated risk of diabetes.”

Is that statement true? This study was well designed. However, this is a very small study. It needs to be replicated by larger studies. In the meantime, we can ask if the findings are consistent with previous studies.

You may have noticed, the authors included three variables in their study (saturated fats, unsaturated fats, and simple sugars), but I focused only on the comparison between saturated fats and simple sugars in this article. That is because the damage caused by saturated fats versus simple sugars is controversial in the popular literature. In contrast, most (but not all) experts agree that saturated fats are worse for you than unsaturated fats.

Let’s start with the relatively non-controversial comparison (saturated fats versus unsaturated fats) before turning to the comparison between saturated fats and simple sugars. When comparing saturated fats and unsaturated fats, the author’s conclusion that saturated fats are worse for you is probably true.

  • In this study saturated fats caused greater fat accumulation in the liver than unsaturated fats, and these differences were statistically significant.
  • The fat stores in the liver mirrored the fat composition of the diet. Saturated fat caused saturated fat stores. Unsaturated fat caused unsaturated fat stores.
  • Saturated fats increased insulin resistance while unsaturated fats did not.
  • This is consistent with several previous studies that have shown:
  • Saturated fats cause greater fat accumulation in the liver than polyunsaturated fats in younger, normal weight individuals.
  • High saturated fat intake is associated with fatty liver disease and insulin resistance.
  • Saturated fat increases heart disease risk, while unsaturated fat decreases heart disease risk.

However, the differences between saturated fats and sugar were less clear.

  • In this study saturated fats caused greater fat accumulation in the liver and more insulin resistance than simple sugars.
  • The conclusion that saturated fats are worse for you than simple sugars was strengthened by the following:
  • Saturated fat caused insulin resistance, while simple sugars did not.
  • Saturated fat caused a change to gut bacteria which resulted in increased endotoxin levels in the bloodstream, while simple sugars did not.
  • The conclusion that saturated fats are worse for you than simple sugars was weakened by the following:
  • The difference in fat accumulation in the liver was not statistically significant. A larger study may have provided a more definitive answer.
  • Previous studies have suggested that saturated fats and simple sugars may be equally bad for you. They both increase the risk of diabetes and heart disease.

Clearly, this study does not end the debate about whether saturated fats or simple sugars are worse for you. However, it does provide a new perspective.

Previous studies have not compared the effects of saturated fat and sugar on fatty liver disease when all other aspects of the diet were identical. If the observations of this study are confirmed in subsequent studies, it could influence how we evaluate the relative risks of saturated fats and sugars in the future.

What Does This Study Mean For You?

When you strip away all the noise, there are three obvious conclusions from this and most previous studies:

  • Excess calories in any form are bad for us. We don’t just store fat in the liver, and fat stores in other parts of our body have bad effects on our health as well.
  • Unsaturated fats are better for us than saturated fats. They reduce the risk of heart disease. This study suggests they also reduce the risk of fatty liver disease, insulin resistance, and possibly diabetes.
  • The jury is still out on the health consequences of saturated fats versus simple sugars. This study suggests that simple sugars may be less likely to cause fatty liver disease. While fatty liver disease can lead to diabetes and heart disease, so can fat stores anywhere else in the body. Other studies suggest that excess calories as saturated fats and simple sugars are equally likely to lead to obesity, diabetes and heart disease.

My recommendation is to avoid both saturated fats and simple sugars. Don’t focus on low fat diets or low carb diets. Instead focus on whole food diets with healthy fats and healthy carbs.

 

The Bottom Line

 

Fatty liver disease has serious consequences. It causes insulin resistance and inflammation, and that increases the risk of diabetes and heart disease. Even worse, it can lead to cirrhosis and liver failure.

Excess sugar is converted to saturated fat in the liver. Therefore, the popular literature attributes the epidemic of fatty liver disease to increased intake of simple sugars. But is it true? Saturated fats require no conversion. They can simply be deposited in the liver as is. Shouldn’t they be at least as damaging to the liver as sugar?

A recent study compared the effect of diets high in saturated fats (SAT group), unsaturated fats (UNSAT group), or simple sugars (SUGAR group) on fat accumulation in the liver. The results were:

  • Fat stores in the liver increased by 55% in the SAT group, 33% in the SUGAR group, and 15% in the UNSAT group.
  • The fat stores were primarily saturated fat in the SAT and SUGAR groups and primarily unsaturated fat in the UNSAT group.
  • Insulin resistance was increased in the SAT group, but not in the SUGAR and UNSAT groups.

The authors of this study concluded: “Saturated fat induced the greatest increase in fat stores in the liver and insulin resistance. Decreased intakes of saturated fat could be beneficial in reducing fat stores in the liver and the associated risk of diabetes.”

My recommendation is to avoid both saturated fats and simple sugars. Don’t focus on low fat diets or low carb diets. Instead focus on whole food diets with healthy fats and healthy carbs.

For more details on the study and what it means 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.

Health Tips From The Professor