Do Omega-3s Reduce Cognitive Decline?

Should You Supplement With Omega-3s?

Author: Dr. Stephen Chaney 

Cognitive-DeclineDo omega-3s reduce cognitive decline, or is this another nutrition myth?

There is certainly good reason to believe that the long chain omega-3s EPA and DHA are good for brain health.

  • DHA is an essential part of the membrane that coats our neurons. As such, it is a major component of our brains and plays an important role in its structural integrity.
  • While EPA is not found in the brain it reduces inflammation and improves blood flow to the brain, both of which are important for brain health.

But the role of DHA and EPA in reducing cognitive decline remains controversial. Some studies strongly support their role in slowing cognitive decline while other studies find no effect.

So, the question remains, “Do omega-3s reduce cognitive decline or not?”

The study (B-Z Wei et al, American Journal of Clinical Nutrition, 117: 1096-1109, 2023) I will review today was designed to answer that question.

This study supports the hypothesis that omega-3s, especially DHA and EPA, reduce cognitive decline and Alzheimer’s disease. But it also raises several questions that need to be resolved by future studies.

Why Is The Effect Of Omega-3s On Cognitive Decline Controversial?

ArgumentWhy is it so difficult to come up with definitive answers about whether omega-3s reduce cognitive decline? It is probably because the relationship between omega-3s and brain health is complex. For example:

  • Because omega-3’s beneficial effects are widely publicized, many people are already consuming adequate amounts of omega-3s. A supplement study that does not measure the omega-3 status of participants at the beginning of the study and does not focus on participants with inadequate omega-3 status is doomed to failure.
  • Omega-3s may benefit older people more than younger people. A study that is not large enough to measure the effect of omega-3s on both groups is doomed to failure.
  • The APOE ɛ4 genotype is associated with an increased risk of cognitive decline and Alzheimer’s. Some studies suggest omega-3s are more beneficial for people with the APOE ɛ4 genotype, while other studies come to the opposite conclusion. This is a critical variable that needs to be resolved.
  • The ability of DHA to cross the blood-brain barrier and accumulate in our brain may be influenced by our genetics, especially our APOE ɛ4 status, and adequate levels of other nutrients, especially B vitamins. Unless studies are large enough to separate out these variables, they are doomed to failure. This study suggests accumulation of DHA in the brain is a critical variable that needs to be resolved.
  • Multiple studies suggest that higher doses of omega-3s are more effective at reducing cognitive decline than low doses of omega-3s. This study confirms that effect and identifies a threshold dose that is needed to provide measurable benefits. Studies providing supplemental omega-3s at doses below that threshold are likely to fail. And meta-analyses that combine low dose studies with high dose studies are also likely to come up empty.
  • Finally, people who take omega-3s for years are likely to benefit more than those who take omega-3s for just a few months. Again, this study confirms that effect, which means that studies involving short-term supplementation with omega-3s are likely to fail. And meta-analyses that combine short-term and long-term studies are likely to come up empty.

With so many potential pitfalls, it is easy to understand why many studies come up empty, and the effect of omega-3s on cognitive decline remains controversial.

How Was This Study Done?

clinical studyThis study consisted of two parts:

Part 1 used data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI). The ADNI study is a multicenter study designed to develop clinical, imaging, genetic, and biochemical markers for early detection and tracking of Alzheimer’s Disease.

Participants undergo standardized neuroimaging, psychological assessments, in-person interviews for medical history, and cognitive evaluations on entry into the study and at the end of the study.

This study followed a cohort of 1135 participants (average age = 73, 46% females) without dementia at entry into the study for 6 years.

Omega-3 supplement use was determined based on a questionnaire at the beginning of the study. Participants who used omega-3 supplements for over a year were considered omega-3 users. They were further divided into medium-term users (1-9 years) and long-term users (>10 years).

Alzheimer’s Disease was diagnosed by neurologists based on brain scans, cognitive scores, and the ability to live independently.

Part 2 was a meta-analysis of 31 studies with 103,651 participants. The studies included in the meta-analysis all:

  • Measured the relationship of omega-3 intake with the risk of Alzheimer’s Disease, all-cause dementia, or cognitive decline.
  • Were cohort studies (studies that follow a group of people over time) or case control studies (studies that compare people who develop a disease with those who do not).
  • Provided risk estimates or data that could be used to calculate risk.
  • Were original publications, not reviews or meta-analyses.

Do Omega-3s Reduce Cognitive Decline?

omega 3 supplementsThe results from Part 1 (data from the ADNI study) were as follows:

  • Omega-3 supplement users had a 37% lower risk of developing Alzheimer’s Disease than non-users.
  • Long-term (>10 years) omega-3 supplement users fared even better. They had a 64% lower risk of developing Alzheimer’s Disease than non-users.
  • When they broke the results for long-term omega-3 supplement users into subgroups:
    • Males (67% risk reduction) benefitted more than females (50% risk reduction).
    • People over 65 (65% risk reduction) benefited more than those under 65 (22% risk reduction).
    • People with the APOE ɛ4 genotype (71% risk reduction) benefitted more than those who were APOE ɛ4 negative (55% risk reduction).

The results from Part 2 (data from the meta-analysis) were as follows:

  • Dietary omega-3 intake lowered the risk of cognitive decline by 9%.
    • People with the APOE ɛ4 genotype fared better (17% risk reduction).
    • Their data suggested that a threshold of 1 gm/day omega-3s was needed before significant risk reduction was seen.
  • Dietary DHA intake lowered the risk of dementia by 27% and Alzheimer’s Disease by 24%.
  • Each 100 mg/day increase in DHA and EPA was associated with a significant reduction in the risk of cognitive decline (8% for DHA and 9.9% for EPA).

The authors concluded that,

1) “Long-term omega-3 supplementation may reduce risk of Alzheimer’s Disease; and

2) Dietary omega-3 fatty acid intake, especially DHA, may lower risk of dementia or cognitive decline…

3) However, further investigation is needed to understand the gene environment interactions involved in…[these effects of omega-3 fatty acids].”

Should You Supplement With Omega-3s?

QuestionsThis study provides strong support for the hypothesis that omega-3 supplementation reduces the risk of cognitive decline, dementia, and Alzheimer’s Disease as we age. It also suggests that a dose of 1 gram/day may be needed to obtain a significant benefit.

However, it also highlights the difficulty in designing definitive experiments to test this hypothesis. This study shows that gender, age, genetics (especially the APOE ɛ4 genotype), type of omega-3s, dosage, and duration of supplementation all exert a significant influence on the effect of omega-3s on cognitive decline.

It is extremely difficult to design a study that optimizes all these variables, which almost guarantees that the effect of omega-3s on cognitive decline will remain controversial for the foreseeable future.

However, omega-3s lower blood pressure, lower triglycerides, reduce inflammation and are heart-healthy. And the threshold for all these effects is around 1 gram/day or more. If omega-3s also reduce cognitive decline, you can consider that a side-benefit.

The Bottom Line 

The role of omega-3s in reducing cognitive decline remains controversial. Some studies strongly support their role in slowing cognitive decline while other studies find no effect.

So, the question remains, “Do omega-3s reduce cognitive decline or not?”

A recent study was designed to answer that question. Among other things the study showed:

  • Omega-3 supplement users had a 37% lower risk of developing Alzheimer’s Disease than non-users.
  • Long-term (>10 years) omega-3 supplement users fared even better. They had a 64% lower risk of developing Alzheimer’s Disease than non-users.
  • Dietary DHA intake lowered the risk of dementia by 27% and Alzheimer’s Disease by 24%.
  • Each 100 mg/day increase in DHA and EPA was associated with a significant reduction in the risk of cognitive decline (8% for DHA and 9.9% for EPA).
  • The threshold for observing a significant effect of omega-3s on cognitive decline was around 1 gram/day.

This study provides strong support for the hypothesis that omega-3 supplementation reduces the risk of cognitive decline, dementia, and Alzheimer’s Disease as we age. It also suggests that a dose of 1 gram/day may be needed to obtain a significant benefit.

However, it also highlights the difficulty in designing definitive experiments to test this hypothesis. This study shows that gender, age, genetics (especially the APOE ɛ4 genotype), type of omega-3s, dosage, and duration of supplementation all exert a significant influence on the effect of omega-3s on cognitive decline.

It is extremely difficult to design a study that optimizes all these variables, which almost guarantees that the effect of omega-3s on cognitive decline will remain controversial for the foreseeable future.

However, omega-3s lower blood pressure, lower triglycerides, reduce inflammation and are heart-healthy. And the threshold for all these effects is around 1 gram/day or more. If omega-3s also reduce cognitive decline, you can consider that a side-benefit.

For more information on this study 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

 

 

Can Healthy Eating Help You Lose Weight?

Who Benefits Most From A Healthy Diet?

Author: Dr. Stephen Chaney 

fad dietsFad diets abound. High protein, low carb, low fat, vegan, keto, paleo – the list is endless. They all claim to be backed by scientific studies showing that you lose weight, lower your cholesterol and triglycerides, lower your blood pressure, and smooth out your blood sugar swings.

They all claim to be the best. But any reasonable person knows they can’t all be the best. Someone must be lying.

My take on this is that fad diet proponents are relying on “smoke and mirrors” to make their diet look like the best. I have written about this before, but here is a brief synopsis:

  • They compare their diet with the typical American diet.
    • Anything looks good compared to the typical American diet.
    • Instead, they should be comparing their diet with other weight loss diets. That is the only way we can learn which diet is best.
  • They are all restrictive diets.
    • Any restrictive diet will cause you to eat fewer calories and to lose weight.
    • As little as 5% weight loss results in lower cholesterol & triglycerides, lower blood pressure, and better control of blood sugar levels.

Simply put, any restrictive diet will give you short-term weight loss and improvement in blood parameters linked to heart disease, stroke, and diabetes. But are these diets healthy long term? For some of them, the answer is a clear no. Others are unlikely to be healthy but have not been studied long term. So, we don’t know whether they are healthy or not.

What if you started from the opposite perspective? Instead of asking, “Is a diet that helps you lose weight healthy long term?”, what if you asked, “Can healthy eating help you lose weight?” The study (S Schutte et al, American Journal of Clinical Nutrition, 115: 1-18, 2022) I will review this week asked that question.

More importantly, it was an excellent study. It compared a healthy diet to an unhealthy diet with exactly the same degree of caloric restriction. And it compared both diets to the habitual diet of people in that area. This study was performed in the Netherlands, so both weight loss diets were compared to the habitual Dutch diet.

How Was The Study Done?

clinical studyThis was a randomized controlled trial, the gold standard of clinical studies. The investigators recruited 100 healthy, abdominally obese men and women aged 40-70. At the time of entry into the study none of the participants:

  • Had diabetes.
  • Smoked
  • Had a diagnosed medical condition.
  • Were on a medication that interfered with blood sugar control.
  • Were on a vegetarian diet.

The participants were randomly assigned to:

  • A high-nutrient quality diet that restricted calories by 25%.
  • A low-nutrient-quality diet that restricted calories by 25%.
  • Continue with their habitual diet.

The study lasted 12 weeks. The participants met with a dietitian on a weekly basis. The dietitian gave them the foods for the next week and monitored their adherence to their assigned diet. They were advised not to change their exercise regimen during the study.

At the beginning and end of the study the participants were weighed, and cholesterol, triglycerides, and blood pressure were measured.

Can Healthy Eating Help You Lose Weight?

Vegetarian DietTo put this study into context, these were not healthy and unhealthy diets in the traditional sense.

  • Both were whole food diets.
  • Both included fruits, vegetables, low-fat dairy, and lean meats.
  • Both restricted calories by 25%.

The diets were designed so that the “high-nutrient quality” diet had significantly more plant protein (in the form of soy protein), fiber, healthy fats (monounsaturated and omega-3 fats), and significantly less fructose and other simple sugars than the “low-nutrient-quality” diet.

At the end of 12 weeks:

  • Participants lost significant weight on both calorie-restricted diets compared to the group that continued to eat their habitual diet.
    • That is not surprising. Any diet that successfully restricts calories will result in weight loss.
  • Participants on the high-nutrient quality diet lost 33% more weight than participants on the low-nutrient-quality diet (18.5 pounds compared to 13.9 pounds).
  • Participants on the high-nutrient quality diet lost 50% more inches in waist circumference than participants on the low-nutrient-quality diet (1.8 inches compared to 1.2 inches).
    • This is a direct measure of abdominal obesity.

When the investigators measured blood pressure, fasting total cholesterol levels, and triglyceride levels:Heart Healthy Diet

  • These cardiovascular risk factors were significantly improved on both diets.
    • Again, this would be expected. Any diet that causes weight loss results in an improvement in these parameters.
  • The reduction in total serum cholesterol was 2.5-fold greater and the reduction in triglycerides was 2-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.
  • The reduction in systolic blood pressure was 2-fold greater and the reduction in diastolic blood pressure was 1.67-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.

The authors concluded, “Our results demonstrate that the nutrient composition of an energy-restricted diet is of great importance for improvements of metabolic health in an overweight, middle-aged population. A high-nutrient quality energy-restricted diet enriched with soy protein, fiber, monounsaturated fats, omega-3 fats, and reduced in fructose provided additional health benefits over a low-nutrient quality energy-restricted diet, resulting in greater weight loss…and promoting an antiatherogenic blood lipid profile.”

In short, participants in this study lost more weight and had a better improvement in risk factors for heart disease on a high-nutrient-quality diet than on a low-nutrient-quality diet. Put another way, healthy eating helped them lose weight and improved their health.

Who Benefits Most From A Healthy Diet?

None of the participants in this study had been diagnosed with diabetes when the study began. However, all of them were middle-aged, overweight, and had abdominal obesity. That means many of them likely had some degree of insulin resistance.

Because of some complex metabolic studies that I did not describe, the investigators suspected that insulin resistance might influence the relative effectiveness of the two energy-restricted diets.

To test this hypothesis, they used an assay called HOMA-IR (homeostatic model assessment of insulin resistance). Simply put, this assay measures how much insulin is required to keep your blood sugar under control.

They used a HOMA-IR score of 2.5 to categorize insulin resistance among the participants.

  • Participants with a HOMA-IR score >2.5 were categorized as insulin-resistant. This was 55% of the participants.
  • Participants with a HOMA-IR score ≤2.5 were categorized as insulin-sensitive. This was 45% of the participants.

When they used this method to categorize participants they found:

  • Insulin-resistant individual lost about the same amount of weight on both diets.
  • Insulin-sensitive individuals lost 66% more weight on the high-nutrient-quality diet than the low-nutrient-quality diet (21.6 pounds compared to 13.0 pounds).

The investigators concluded, “Overweight, insulin-sensitive subjects may benefit more from a high- than a low-nutrient-quality energy-restricted diet with respect to weight loss…”

What Does This Study Mean For You?

Questioning WomanSimply put this study confirms that:

  • Caloric restriction leads to weight loss, and…
  • Weight loss leads to improvement in cardiovascular risk factors like total cholesterol, triglycerides, and blood pressure.
    • This is not new.
    • This is true for any diet that results in caloric restriction.

This study breaks new ground in that a high-nutrient quality diet results in significantly better:

  • Weight loss and…
  • Reduction in cardiovascular risk factors…

…than a low-nutrient quality diet. As I said above, the distinction between a “high-nutrient-quality” diet and a “low-nutrient-quality” diet may not be what you might have expected.

  • Both diets were whole food diets. Neither diet allowed sodas, sweets, and highly processed foods.
  • Both included fruits, vegetables, grains, and lean meats.
  • Both reduced caloric intake by 25%.
    • If you want to get the most out of your weight loss diet, this is a good place to start.

In this study the investigators designed their “high-nutrient-quality” diet so that it contained:

  • More plant protein in the form of soy protein.
    • In this study they did not reduce the amount of animal protein in the “high-nutrient-quality” diet. They simply added soy protein foods to the diet. I would recommend substituting soy protein for some of the animal protein in the diet.
  • More fiber.
    • The additional fiber came from substituting whole grain breads and brown rice for refined grain breads and white rice, adding soy protein foods, and adding an additional serving of fruit.
  • More healthy fats (monounsaturated and omega-3 fats).
    • The additional omega-3s came from adding a fish oil capsule providing 700mg of EPA and DHA.
  • Less simple sugars. While this study focused on fructose, their high-nutrient-quality diet was lower in all simple sugars.

ProfessorAll these changes make great sense if you are trying to lose weight. I would distill them into these 7 recommendations.

  • Follow a whole food diet. Avoid sodas, sweets, and highly processed foods.
  • Include all 5 food groups in your weight loss diet. Fruits, vegetables, whole grains, dairy, and lean proteins all play an important role in your long-term health.
  • Eat a primarily plant-based diet. My recommendation is to substitute plant proteins for at least half of your high-fat animal proteins. And this study reminds us that soy protein foods are a convenient and effective way to achieve this goal.
  • Eat a diet high in natural fibers. Including fruits, vegetables, whole grains, beans, nuts, seeds, and soy foods in your diet is the best way to achieve this goal.
  • Substitute healthy fats (monounsaturated and omega-3 fats) for unhealthy fats (saturated and trans fats) in your diet. And this study reminds us that it is hard to get enough omega-3s in your diet without an omega-3 supplement.
  • Reduce the amount of added sugar, especially fructose, from your diet. That is best achieved by eliminating sodas, sweets, and highly processed foods from the diet. I should add that fructose in fruits and some healthy foods is not a problem. For more information on that topic, I refer you to a previous “Health Tips” article .
  • Finally, I would like to remind you of the obvious. No diet, no matter how healthy, will help you lose weight unless you cut back on calories. Fad diets achieve that by restricting the foods you can eat. In the case of a healthy diet, the best way to do it is to cut back on portion sizes and choose foods with low caloric density.

I should touch briefly on the third major conclusion of this study, namely that the “high-nutrient quality diet” was not more effective than the “low-nutrient-quality” diet for people who were insulin resistant. In one sense, this was not news. Previous studies have suggested that insulin-resistant individuals have more difficulty losing weight. That’s the bad news.

However, there was a silver lining to this finding as well:

  • Only around half of the overweight, abdominally obese adults in this study were highly insulin resistant.
    • That means there is a ~50% chance that you will lose more weight on a healthy diet.
  • Because both diets restricted calories by 25%, insulin-resistant individuals lost weight on both diets.
    • That means you can lose weight on any diet that successfully reduces your caloric intake. That’s the good news.
    • However, my recommendation would still be to choose a high-nutrient quality diet that is designed to reduce caloric intake, because that diet is more likely to be healthy long term.

The Bottom Line 

A recent study asked, “Can healthy eating help you lose weight?” This study was a randomized controlled study, the gold standard of clinical studies. The participants were randomly assigned to:

  • A high-nutrient quality diet that restricted calories by 25%.
  • A low-nutrient-quality diet that restricted calories by 25%.
  • Continue with their habitual diet.

These were not healthy and unhealthy diets in the traditional sense.

  • Both were whole food diets.
  • Both included fruits, vegetables, low-fat dairy, and lean meats.
  • Both restricted calories by 25%.

The diets were designed so that the “high-nutrient quality” diet had significantly more plant protein (in the form of soy protein), fiber, healthy fats (monounsaturated and omega-3 fats), and significantly less fructose and other simple sugars than the “low-nutrient-quality” diet.

At the end of 12 weeks:

  • Participants on the high-nutrient quality diet lost 33% more weight than participants on the low-nutrient-quality diet (18.5 pounds compared to 13.9 pounds).

When the investigators measured cardiovascular risk factors at the end of 12 weeks:

  • The reduction in total serum cholesterol was 2.5-fold greater and the reduction in triglycerides was 2-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.
  • The reduction in systolic blood pressure was 2-fold greater and the reduction in diastolic blood pressure was 1.67-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.

The authors concluded, “Our results demonstrate that the nutrient composition of an energy-restricted diet is of great importance for improvements of metabolic health in an overweight, middle-aged population. A high-nutrient quality energy-restricted diet enriched with soy protein, fiber, monounsaturated fats, omega-3 fats, and reduced in fructose provided additional health benefits over a low-nutrient quality energy-restricted diet, resulting in greater weight loss…and promoting an antiatherogenic blood lipid profile.”

In short, participants in this study lost more weight and had a better improvement in risk factors for heart disease on a high-nutrient-quality diet than on a low-nutrient-quality diet. Put another way, healthy eating helped them lose weight and improved their health.

For more details on this study, what this study means for you, and my 7 recommendations for a healthy weight loss diet, 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.

Can Diet Protect Your Mind?

Which Diet Is Best?

Author: Dr. Stephen Chaney 

can diet prevent alzheimer'sAlzheimer’s is a scary disease. There is so much to look forward to in our golden years. We want to enjoy the fruits of our years of hard work. We want to enjoy our grandkids and perhaps even our great grandkids. More importantly, we want to be able to pass on our accumulated experiences and wisdom to future generations.

Alzheimer’s and other forms of dementia have the potential to rob us of everything that makes life worth living. What is the use of having a healthy body, family, and fortune if we can’t even recognize the people around us?

Alzheimer’s and other forms of dementia don’t happen overnight. The first symptoms of cognitive decline are things like forgetting names, where you left things, what you did last week. For most people it just keeps getting worse.

Can diet protect your mind? Recent studies have given us a ray of hope. For example, several meta-analyses have shown that adherence to the Mediterranean diet was associated with a 25-48% lower risk of cognitive decline and dementia.

However, there were several limitations to the studies included in these meta-analyses. For example:

  • For most of the studies the diet was assessed only at the beginning of the study. We have no idea whether the participants followed the same diet throughout the study. This means, we cannot answer questions like:
    • What is the effect of long-term adherence to a healthy diet?
    • Can you reduce your risk of cognitive decline if you switch from an unhealthy diet to a healthy diet?
  • These studies focused primarily on the Mediterranean diet. This leaves the question:
    • What about other healthy diets? Is there something unique about the Mediterranean diet, or do other healthy diets also reduce the risk of cognitive decline?

This study (C Yuan et al, American Journal of Clinical Nutrition, 115: 232-243, 2022) was designed to answer those questions.

How Was The Study Done?

clinical studyThe investigators utilized data from The Nurse’s Health Study. They followed 49,493 female nurses for 30 years from 1984 to 2014. The average age of the nurses in 1984 was 48 years, and none of them had symptoms of cognitive decline at the beginning of the study.

The nurse’s diets were analyzed in 1984, 1986, and every 4 years afterwards until 2006. Diets were not analyzed during the last 8 years of the study to eliminate something called “reverse causation”. Simply put, the investigators were trying to eliminate the possibility that participants in the study might change their diet because they were starting to notice symptoms of cognitive decline.

The data from the dietary analyses were used to calculate adherence to 3 different healthy diets:

  • The Mediterranean diet.
  • The DASH diet. The DASH diet was designed to reduce the risk of high blood pressure. But you can think of it as an Americanized version of the Mediterranean diet.
  • The diet recommended by the USDA. Adherence to this diet is evaluated by something called the Alternative Healthy Eating Index or AHEI.

Adherence to each diet was calculated by giving a positive score to foods that were recommended for the diet and a negative score for foods that were not recommended for the diet. For more details, read the article.

In 2012 and 2014 the nurses were asked to fill out questionnaires self-assessing the early stages of cognitive decline. They were asked if they had more trouble than usual:

  • Remembering recent events or remembering a short list of items like a grocery list (measuring memory).
  • Understanding things, following spoken instructions, following a group conversation, or following a plot in a TV program (measuring executive function).
  • Remembering things from one second to the next (measuring attention).
  • Finding ways around familiar streets (measuring visuospatial skills).

The extent of cognitive decline was calculated based on the number of yes answers to these questions.

Can Diet Protect Your Mind?

Vegan FoodsHere is what the investigators found when they analyzed the data:

At the beginning of the study in 1984 there were 49,493 female nurses with an average age of 48. None of them had symptoms of cognitive decline.

  • By 2012-2014 (average age = 76-78) 46.9% of them had cognitive decline and 12.3% of them had severe cognitive decline.

Using the data on dietary intake and the rating systems specific to each of the diets studied, the investigators divided the participants into thirds based on their adherence to each diet. The investigators then used these data to answer two important questions that no previous study had answered:

#1: What is the effect of long-term adherence to a healthy diet? To answer this question the investigators averaged the dietary data obtained every 4 years between 1984 and 2006 to obtain cumulative average scores for adherence to each diet. When the investigators compared participants with the highest adherence to various healthy diets for 30 years to participants with the lowest adherence to those diets, the risk of developing severe cognitive decline was decreased by:

  • 40% for the Mediterranean diet.
  • 32% for the DASH diet.
  • 20% for the USDA-recommended healthy diet (as measured by the AHEI score).

#2: Can you reduce your risk of cognitive decline if you switch from an unhealthy diet to a healthy diet? To answer this question, the investigators looked at participants who started with the lowest adherence to each diet and improved to the highest adherence by the end of the study. This study showed that improving from an unhealthy diet to a healthy diet over 30 years decreased the risk of developing severe cognitive decline by:

  • 20% for the Mediterranean diet.
  • 25% for the DASH diet.

There were a few other significant observations from this study.

  • The inverse association between healthy diets and risk of cognitive decline was greater for nurses who had high blood pressure.
    • This is an important finding because high blood pressure increases the risk of cognitive decline.
  • The inverse association between healthy diets and risk of cognitive decline was also greater for nurses who did not have the APOE-ɛ4 gene.
    • This illustrates the interaction of diet and genetics. The APOE-ɛ4 gene increases the risk of cognitive decline. Healthy diets reduced the risk of cognitive decline in nurse with the APOE-ɛ4 gene but not to the same extent as for nurses without the gene.

This study did not investigate the mechanism by which healthy diets reduced the risk of cognitive decline, but the investigators speculated it might be because these diets:

  • Were anti-inflammatory.
  • Supported the growth of healthy gut bacteria.

The investigators concluded, “Our findings support the beneficial roles of long-term adherence to the [Mediterranean, DASH, and USDA] dietary patterns for maintaining cognition in women…Further, among those with initially relatively low-quality diets, improvement in diet quality was associated with a lower likelihood of developing severe cognitive decline. These findings indicate that improvements in diet quality in midlife and later may have a role in maintenance of cognitive function among women.”

Which Diet Is Best?

Mediterranean Diet FoodsIn a sense this is a trick question. That’s because this study did not put the participants on different diets. It simply analyzed the diets the women were eating in different ways. And while the algorithms they were using were diet-specific, there was tremendous overlap between them. For more specifics on the algorithms used to estimate adherence to each diet, read the article.

That is why the investigators concluded that all three diets they analyzed reduced the risk of cognitive decline rather than highlighting a specific diet. However, based on this and numerous previous studies the evidence is strongest for the Mediterranean and DASH diets.

And I would be remiss if I didn’t also mention the MIND diet. While it was not included in this study, the MIND diet:

  • Was specifically designed to reduce cognitive decline.
  • Can be thought of as a combination of the Mediterranean and DASH diets.
  • Includes data from studies on the mind-benefits of individual foods. For example, it recommends berries rather than all fruits.

The MIND diet has not been as extensively studied as the Mediterranean and DASH diets, but there is some evidence that it may be more effective at reducing cognitive decline than either the Mediterranean or DASH diets alone.

Which Foods Are Best?

AwardThe authors of this study felt it was more important to focus on foods rather than diets. This is a better approach because we eat foods rather than diets. With that in mind they analyzed their data to identify the foods that prevented cognitive decline and the foods increased cognitive decline. This is what they found:

  • Fruits, fruit juices, vegetables, fish, nuts, legumes, low-fat dairy, and omega-3 fatty acids (fish oil) reduced the risk of cognitive decline.
  • Red and processed meats, omega-6 fatty acids (most vegetable oils), and trans fats increased the risk of cognitive decline.

While this study did not specifically look at the effect of processed foods on cognitive decline, diets high in the mind-healthy foods listed above are generally low in sodas, sweets, and highly processed foods.

What Does This Study Mean For You?

Question MarkThe question, “Can diet protect your mind”, is not a new one. Several previous studies have suggested that healthy diets reduce the risk of cognitive decline, but this study breaks new ground. It shows for the first time that:

  • Long-term adherence to a healthy diet can reduce your risk of cognitive decline by up to 40%.
    • This was a 30-year study, so we aren’t talking about “diet” in the traditional sense. We aren’t talking about short-term diets to drop a few pounds. We are talking about a life-long change in the foods we eat.
  • If you currently have a lousy diet, it’s not too late to change. You can reduce your risk of cognitive decline by switching to a healthier diet.
    • This is perhaps the best news to come out of this study.

Based on current evidence, the best diets for protecting against cognitive decline appear to be the Mediterranean, DASH, and MIND diets.

And if you don’t like restrictive diets, my advice is to:

  • Eat more fruits, fruit juices, vegetables, fish, nuts, legumes, low-fat dairy, and omega-3 fatty acids (fish oil).
  • Eat less red and processed meats, omega-6 fatty acids (most vegetable oils), and trans fats.
  • Eat more plant foods and less animal foods.
  • Eat more whole foods and less sodas, sweets, and processed foods.

And, of course, a holistic approach is always best. Other lifestyle factors that help reduce your risk of cognitive decline include:

  • Regular exercise.
  • Weight control.
  • Socialization.
  • Memory training (mental exercises).

The Bottom Line 

Alzheimer’s is a scary disease. What is the use of having a healthy body, family, and fortune if we can’t even recognize the people around us?

A recent study looked at the effect of diet on cognitive decline in women. The study started with middle-aged women (average age = 48) and followed them for 30 years. The investigators then used these data to answer two important questions that no previous study had answered:

#1: What is the effect of long-term adherence to a healthy diet? When the investigators compared participants with the highest adherence to various healthy diets for 30 years to participants with the lowest adherence to those diets, the risk of developing severe cognitive decline was decreased by:

  • 40% for the Mediterranean diet.
  • 32% for the DASH diet.
  • 20% for the USDA recommendations for a healthy diet.

#2: Can you reduce your risk of cognitive decline if you switch from an unhealthy diet to a healthy diet? This study showed that improving from an unhealthy diet to a healthy diet over 30 years decreased the risk of developing severe cognitive decline by:

  • 20% for the Mediterranean diet.
  • 25% for the DASH diet.

The investigators concluded, “Our findings support the beneficial roles of long-term adherence to the [Mediterranean, DASH, and USDA] dietary patterns for maintaining cognition in women…Further, among those with initially relatively low-quality diets, improvement in diet quality was associated with a lower likelihood of developing severe cognitive decline. These findings indicate that improvements in diet quality in midlife and later may have a role in maintenance of cognitive function among women.”

For more details on the study, which diets, and which foods are best for protecting your mind, and 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.

The Omega-3 Pendulum

Who Benefits Most From Omega-3s? 

Author: Dr. Stephen Chaney

Pendulum
Pendulum

If you were around in the 60’s, you might remember the song “England Swings Like a Pendulum Do”. It was a cute song, but it had nothing to do with pendulums. This week I am talking about something that really does resemble a pendulum – the question of whether omega-3s reduce heart disease risk.

There is perhaps nothing more confusing to the average person than the “truth” about omega-3s and heart disease risk. The headlines and expert opinion on the topic swing wildly between “omega-3s reduce heart disease risk” to “omega-3s have no effect on heart disease risk” and back again. To me these swings resemble the swings of a pendulum – hence the title of this article.

Part of the reason for the wild swings is that journalists and most “experts” tend to rely on the latest study and ignore previous studies. Another contributing factor is that most journalists and experts read only the main conclusions in the article abstract. They don’t read and analyze the whole study.

So, in today’s “Health Tips From the Professor” I plan to:

  • Analyze 3 major studies that have influenced our understanding of the relationship between omega-3 intake and heart disease risk. I will tell you what the experts missed about these studies and why they missed it.
  • Summarize what you should know about omega-3 intake and your risk of heart disease.

Why Is The Role Of Omega-3s In Preventing Heart Disease So Confusing?

SecretsIn answering that question, let me start with what I call “Secrets Only Scientists Know”.

#1: Each study is designed to disprove previous studies. That is a strength of the scientific method. But it guarantees there will be studies on both sides of every issue.

Responsible scientists look at all high-quality studies and base their opinions on the weight of evidence. Journalists and less-responsible “experts” tend to “cherry pick” the studies that match their opinions.

#2: Every study has its flaws. Even high-quality studies have unintended flaws. And I have some expertise in identifying unintended flaws.

I published over 100 papers that went through the peer review process. And I was involved in the peer review of manuscripts submitted by other scientists. In the discussion below I will use my experience in reviewing scientific studies to identify unintended flaws in 3 major studies on omega-3s and heart disease risk.

Next, let me share the questions I ask when reviewing studies on omega-3s and heart disease. I am just sharing the questions here. Later I will share examples of how these questions allowed me to identify unintended flaws in the studies I review below.

#1: How did they define heart disease? The headlines you read usually refer to the effect of omega-3s on “heart disease”. However, heart disease is a generic term. In layman’s terms, it encompasses angina, heart attacks, stroke due to blood clots, stroke due brain bleeds, congestive heart failure, impaired circulation, and much more.

Omega-3s have vastly different effects on different forms of heart disease, so it is important to know which form(s) of heart disease the study examined. And if the study included all forms of heart disease, it is important to know whether they also looked at the forms of heart disease where omega-3s have been shown to have the largest impact.

#2: What was the risk level of the patients in the study? If the patients in the study are at imminent risk of a heart attack or major cardiovascular event, it is much easier to show an effect than if they are at low risk.

For example, it is easy to show that statins reduce the risk of a second heart attack in someone who has just suffered a heart attack. These are high-risk patients. However, if you look at patients with high cholesterol but no other risk factors for heart disease, it is almost impossible to show a benefit of statins. These are low-risk patients.

If it is difficult to show that statins benefit low-risk patients, why should we expect to be able to show that omega-3s benefit low-risk patients?

[Note: I am not saying that statins do not benefit low-risk patients. I am just saying it is very difficult to prove they do in clinical studies.]

#3: How much omega-3s are the patients getting in their diet? The public reads the headlines. When the headlines say that omega-3s are good for their hearts, they tend to take omega-3 supplements. When the headlines say omega-3s are worthless, they cut back on omega-3 supplements. So, there is also a pendulum effect for omega-3 intake.

Omega-3s are fats. So, omega-3s accumulate in our cell membranes. The technical term for the amount of omega-3s in our cellular membranes is something called “Omega-3 Index”. Previous studies have shown that:

    • An omega-3 index of 4% or less is associated with high risk of heart disease, and…
    • An omega-3 index of 8% or more is associated with a low risk of heart disease.

When the omega-3 index approaches 8%, adding more omega-3 is unlikely to provide much additional benefit. Yet many studies either don’t measure or ignore the omega-3 index of patients they are enrolling in the study.

#4: How many and what drugs were the patients taking? Many heart disease patients are taking drugs that lower blood pressure, lower triglycerides, reduce inflammation, and reduce the risk of blood clot formation. These drugs do the same things that omega-3s do. This decreases the likelihood that you can see any benefit from increasing omega-3s intake.

The Omega-3 Pendulum

With all this in mind let’s examine three major double-blind, placebo-controlled studies that looked at the effect of omega-3s on heart disease risk and came to different conclusions. Here is a summary of the studies.

GISSI Study ASCEND Study VITAL Study
11,000 participants 15,480 participants 25,871 participants
Followed for 3.5 years Followed for 7.4 years Followed for 5.3 years
Europe USA USA
Published in 1999 Published in 2018 Published in 2019
Dose = 1 gm/day Dose = 1 gm/day Dose = 1 gm/day
20% ↓ in heart disease deaths No effect on fatal or non-fatal heart attack or stroke Significant ↓ in some forms of heart disease
45% ↓ in fatal heart attack or stroke – as effective as statins Significant ↓ in heart disease risk for some patients

heart attacksAt first glance the study designs look similar, so why did these studies give such different results. This is where the unintended flaws come into play. Let’s look at each study in more detail.

The GISSI Study:

  • The patients enrolled in this study all had suffered a heart attack in the previous 3 months. They were at very high risk of suffering a second heart attack within the next couple of years.
  • Omega-3 intake was not measured in this study. But it was uncommon for Europeans to supplement with omega-3s in the 90’s. And European studies on omega-3 intake during that period generally found that omega-3 intake was low.
  • Patients enrolled in this study were generally taking only 2 heart disease drugs, a beta-blocker and a blood pressure drug.

The ASCEND Study:

  • The patients enrolled in this study had diabetes without any evidence of heart disease. Only 17% of the flawspatients enrolled in the study were at high risk of heart disease. 83% were at low risk. Remember, it is difficult to show a benefit of any intervention in low-risk patients.
  • The average omega-3 index of patients enrolled in this study was 7.1%. That means omega-3 levels were near optimal at the beginning of the study. Adding additional omega-3s was unlikely to show much benefit.
  • Most of the patients in this study were on 3-5 heart drugs and 1-2 diabetes drugs which duplicated the effects of omega-3s.

That means this study was asking a very different question. It was asking whether omega-3s provided any additional benefit for patients who were already taking multiple drugs that duplicated the effects of omega-3s.

However, you would have never known that from the headlines. The headlines simply said this study showed omega-3s were ineffective at preventing heart disease.

Simply put, this study was doomed to fail. However, despite its many flaws the authors reported that omega-3s did reduce one form of heart disease, namely vascular deaths (primarily due to heart attack and stroke). Somehow this observation never made it into the headlines.

The VITAL Study:

  • This study enrolled a cross-section of the American population aged 55 or older (average age = 67). As you might suspect for a cross-section of the American population, most of the participants in this study were at low risk for heart disease. This limited the ability of the study to show a benefit of omega-3 supplementation in the whole population.

However, there were subsets of the group who were at high risk of heart disease (more about that below).

  • This study excluded omega-3 supplement users The average omega-3 index of patients enrolled in this study was 2.7% at the beginning of the study and increased substantially during the study. This enhanced the ability of the study to show a benefit of omega-3 supplementation.
  • Participants in this study were only using statins and blood pressure medications. People using more medications were excluded from the study. This also enhanced the ability of the study to show a benefit of omega-3 supplementation.

The authors reported that “Supplementation with omega-3 fatty acids did not result in a lower incidence of major cardiovascular events…” This is what lazy journalists and many experts reported about the study.

good newsHowever, the authors designed the study so they could also:

  • Look at the effect of omega-3s on heart disease risk in high-risk groups. They found that 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 of heart disease.
  • Look at the effect of omega-3s on heart disease risk in people with low omega-3 intake. They found that omega-3 supplementation reduced major cardiovascular events by:
    • 19% in patients with low fish intake.
  • Look at the effect of omega-3s on the risk of different forms of heart disease. They found that omega-3 supplementation reduced:
    • Heart attacks by 28% in the general population and by 70% for African Americans.
    • Deaths from heart attacks by 50%.
    • Deaths from coronary heart disease (primarily heart attacks and ischemic strokes (strokes caused by blood clots)) by 24%.

In summary, if you take every study at face value it seems like the pendulum is constantly swinging from “omega-3s reduce heart disease risk” to “omega-3s are worthless” and back again. There appears to be no explanation for the difference in results from one study to the next.

However, if you remember that even good studies have unintended flaws and ask the four questions I proposed Question Markabove, it all makes sense.

  • How is heart disease defined? Studies looking at heart attack and/or ischemic stroke are much more likely to show a benefit of omega-3s than studies that include all forms of heart disease.
  • Are the patients at low-risk or high-risk for heart disease? Studies in high-risk populations are much more likely to show a benefit than studies in low-risk populations.
  • What is the omega-3 intake of participants in the study? Studies in populations with low omega-3 intake are more likely to show a benefit of omega-3 supplementation than studies in populations with high omega-3 intake.
  • How many heart drugs are the patients taking? Studies in people taking no more than one or two heart drugs are more likely to show a benefit of omega-3 supplementation than studies in people taking 3-5 heart drugs.

When you view omega-3 clinical studies through the lens of these 4 questions, the noise disappears. It is easy to see why these studies came to different conclusions.

Who Benefits Most From Omega-3s?

omega 3s and heart diseaseThe answers to this question are clear:

  • People at high risk of heart disease are most likely to benefit from omega-3 supplementation.
  • People with low omega-3 intake are most likely to benefit from omega-3 supplementation.
  • Omega-3 supplementation appears to have the biggest effect on heart attack and ischemic stroke (stroke due to blood clots). Its effect on other forms of heart disease is less clear.
  • Omega-3 supplementation appears to be most effective at preventing heart disease if you are taking no more than 1 or 2 heart drugs. It may provide little additional benefit if you are taking multiple heart drugs. However, you might want to have a conversation with your doctor about whether omega-3 supplementation might allow you to reduce or eliminate some of those drugs.

What about the general population? Is omega-3 supplementation useful for patients who are at low to moderate risk of heart disease?

  • If we compare omega-3 studies with statin studies, the answer would be yes. Remember that statins cannot be shown to reduce heart attacks in low-risk populations. However, because they are clearly effective in high-risk patients, the medical community assumes they should be beneficial in low-risk populations. The same argument could be made for omega-3s.
  • We also need to recognize that our ability to recognize those who are at high risk of heart disease is imperfect. For too many Americans, the first indication that they have heart disease is sudden death!

When I was still teaching, I invited a cardiologist to speak to my class of first year medical students. He told the students, only partly in jest, that he felt statins were so beneficial they “should be added to the drinking water”.

I feel the same way about omega-3s:

  • Most Americans do not get enough omega-3s in our diet.
  • Our omega-3 index is usually much closer to 4% (high risk of heart disease) than 8% (low risk of heart disease).
  • Many of us may not realize that we are at high risk of heart disease until it is too late.
  • And omega-3s have other health benefits.

For all these reasons, omega-3 supplementation only makes sense.

The Bottom Line

There is perhaps nothing more confusing to the average person than the “truth” about omega-3s and heart disease risk. The headlines and expert opinion on the topic swing wildly between “omega-3s reduce heart disease risk” to “omega-3s have no effect on heart disease risk” and back again. To me these swings resemble the swings of a pendulum – hence the title of this article.

If you take every study at face value, there appears to be no explanation for the difference in results from one study to the next. However, if you recognize that even good studies have unintended flaws and ask four simple questions to expose these flaws, it all makes sense.

For the four questions you should ask when reviewing any omega-3 study and my recommendations for who benefits the most from omega-3 supplementation, read the article above.

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

Do Omega-3s Oil Your Joints?

Fish Oil And Osteoarthritis

Author: Dr. Stephen Chaney

Osteoarthritis is not just painful. It is one of the leading causes of disability in this country. And because the joint pain associated with osteoarthritis limits activity levels, it is linked to:

  • Obesity
  • The diseases associated with obesity (diabetes and heart disease).
    • Osteoarthritis increases the risk of heart disease by 50%.
  • Premature death associated with the increased prevalence of obesity, diabetes, and heart disease.
    • Osteoarthritis increases the risk of all-cause mortality by 55%.

If osteoarthritis were rare, these statistics would just be an interesting side note. But osteoarthritis is the most common form of arthritis. It affects more than 32 million Americans. And it is costly. It costs the American economy:

  • $65 billion in health care costs.
  • $17 billion in lost wages.
  • $136 billion in total costs.

Conventional therapy for osteoarthritis is treatment with anti-inflammatory drugs, but they have side effects. They may even increase the risk of premature death in some individuals.

What about natural anti-inflammatory nutrients and phytonutrients? Two that have received a lot of press in recent years are omega-3s (fish oil) and curcumin.

A recent meta-analysis (NK Senftleber et al, Nutrients, 9: 42, 2017) of 42 clinical studies on the effects of omega-3s on various types of arthritis found that:

  • There is moderate quality evidence that omega-3s reduce the pain associated with rheumatoid arthritis. Basically, this means that there is strong, but not definitive, evidence that omega-3s reduce the pain of rheumatoid arthritis. Other general conclusions with respect to rheumatoid arthritis were:
    • The best results were obtained from fish oil preparations with an EPA/DHA ratio of >1.5, suggesting that EPA is more beneficial than DHA.
    • Early studies suggested that the optimal dose of omega-3s was ≥2.6 g/day for ≥12 weeks.
  • There was low quality evidence for an effect of omega-3s on osteoarthritis. Only 5 clinical trials have been published on the topic and the results of those studies are conflicting.

The data for an effect of curcumin on osteoarthritis pain are even more limited. There is some evidence it might be beneficial, but the studies are small and are conflicting.

In this week’s issue of “Health Tips From the Professor” I discuss an exploratory study (JC Kuszewski et al, Rheumatology Advances In Practice 4: 1-9, 2020) on the effect of omega-3s and curcumin on osteoarthritis pain.

How Was The Study Done?

Clinical StudyYou are probably wondering, “What is an “exploratory study?” Let me start by providing you with a little perspective from my years of heading a cancer research laboratory at the University of North Carolina:

Clinical studies are expensive. And if you are trying to study an approach that has not already proven to be successful, the money needed to fund the study can be hard to come by. It is a “Catch 22” situation. You need to conduct an “exploratory study” to show your project is likely to succeed before the funding agency will give you money to fund your project.

But where do you get the money to fund your exploratory project? One way that investigators overcome that barrier is to use data from a previous study that was originally designed for a different purpose. The study I will describe today is an example of that approach.

The study utilized data collected from a clinical trial designed to measure the effect of omega-3s and curcumin on brain function in older adults. The study recruited 152 older adults (average age = 65) who were overweight to obese (average BMI = 31) and sedentary (˂55 min/week of physical activity) from New South Wales, New Australia.

The participants were randomly divided into 4 groups:

  • Placebo group. [Note: The fish oil placebo contained 20 mg of fish oil so it would match the odor of the fish oil supplement, and the curcumin placebo contained yellow food dye so it would match the color of the curcumin supplement.]
  • Fish oil group (2,000 mg DHA & 400 mg EPA per day).
  • Curcumin group (160 mg/day curcumin).
  • Fish oil + curcumin group.

Participants were followed for 16 weeks. At the beginning and end of the study participants filled out questionnaires assessing (among other things):

  • The severity of their chronic osteoarthritis pain.
  • Disabilities caused by osteoarthritis in the participant’s daily life (physical distress, sleep disturbances, psychological distress, loss of productivity, physical limitations, physical deconditioning due to reduction in physical activity, and financial hardship).
  • Their physical and mental wellbeing during the past 4 weeks.
  • Their mood during the past 7 days.

Do Omega-3s Oil Your Joints?

fish and fish oilThe results were as follows:

  • Omega-3 supplementation reduced chronic osteoarthritis pain by 42%.
  • Omega-3 supplementation reduced disability associated with osteoarthritis by 40%.
    • The reduction in pain and disability in participants supplemented with fish oil was greatest in those who reported the highest pain/disability at the beginning of the study.
    • The reduction in pain was associated with an improved perception of physical and mental wellbeing.
    • The reduction in pain was also associated with a decrease in depression and other mood disturbances.
  • Curcumin did not affect pain or osteoarthritis burden either alone or paired with omega-3s.

The authors concluded, “Our findings indicate potential for fish oil supplementation to reduce mild osteoarthritis pain and burden in sedentary overweight/obese older adults…,which was associated with improved wellbeing.”

What Are The Pros And Cons Of This Study?

pros and consPros:

The results for the effects of omega-3s on osteoarthritis were highly significant. In addition, the questionnaires used were well designed to capture the intensity and location of pain, mood, and feelings of wellbeing.

Cons:

This was an exploratory study using data collected from a study designed to measure the effect of omega-3s and curcumin on brain health in older adults. It was not ideally designed to measure the effect of omega-3s and curcumin on osteoarthritis.

If the original study had been intended for investigating the effect of these supplements on osteoarthritis, it would have been designed differently:

  • Participants would have been recruited into the study based on the presence and intensity of osteoarthritis pain.
  • The diagnosis of osteoarthritis would have been confirmed by X-rays.
  • Participants would have been admitted into the study only if they had moderate to severe osteoarthritis pain. Most of the participants in this study had only mild osteoarthritis pain. That may have limited the ability of this study to find an effect of curcumin on osteoarthritis pain.
  • The design of the omega-3 supplement would have been different.
    • Because the original study was designed to determine the effect of omega-3s on brain health, the omega-3 supplement chosen had more DHA than EPA.
    • Had the study been designed to determine the effect on omega-3s on an inflammatory disease like osteoarthritis, the omega-3 supplement would have had more EPA than DHA.
  • The curcumin supplement was also not ideally designed for this study. The curcumin supplement used in this study contained only 160 mg of curcumin and contained no other ingredients. Well-designed curcumin supplements usually contain around 500 mg curcumin standardized to 95% curcuminoids plus piperine to enhance the absorption of the curcumin.

In the words of the authors, “Further studies are warranted to evaluate the benefits of fish oil, alone or as an adjunct to pharmacotherapy, in patients diagnosed with osteoarthritis who suffer moderate-to-severe pain…” In other words, they now intend to use the data from this exploratory study to apply for funds to conduct a larger study specifically designed to measure the effects of omega-3s on osteoarthritis pain.

The study limitations described above, severely restricted the ability of the study to detect any beneficial effect of curcumin on osteoarthritis pain. The effect of curcumin on osteoarthritis pain is probably less than the effect of omega-3s, but it would be premature to conclude that it has no benefit. However, they obtained no data from their “exploratory study” to justify a follow-up study on the effect of curcumin on osteoarthritis pain.

Fish Oil And Osteoarthritis

omega-3 fish oil supplementThis study suggests that 2.4 grams/day of omega-3s may be equally effective at reducing osteoarthritis pain and the effects that osteoarthritis pain has on both physical health and psychological health. However, because this study has several limitations, the evidence cannot be considered definite.

If you have either rheumatoid or osteoarthritis, I recommend trying omega-3 supplementation. Based on the studies described above, you might want to aim for 2-3 g/day of omega-3s with an EPA/DHA ration of 1.5 or greater.

As with any natural approach, this will work better for some people that for others. However, don’t forget that omega-3s are also important for heart health, healthy blood pressure, brain health, and a healthy pregnancy (https://chaneyhealth.com/healthtips/omega-3s-during-pregnancy-are-healthy/). If they also happen to reduce your arthritis pain, that is an extra benefit.

As usual, I recommend a holistic approach. You should also:

  • Keep active.
  • Aim for a healthy weight.
  • Add antioxidant and polyphenol supplements.

These lifestyle changes should allow you to reduce or eliminate any pain medication you may be taking.

Finally, if you are on blood thinners, consult with your physician before adding omega-3 supplements to your diet. My preference is to incorporate omega-3s and reduce other medications, but that is a discussion you need to have with your doctor.

The Bottom Line

A recent meta-analysis has concluded there is moderate quality evidence that omega-3s reduce the pain associated with rheumatoid arthritis. Basically, this means that there is strong, but not definitive, evidence that omega-3s reduce the pain of rheumatoid arthritis. Other general conclusions with respect to rheumatoid arthritis were:

  • The best results were obtained from fish oil preparations with an EPA/DHA ratio of >1.5, suggesting that EPA is more beneficial than DHA.
  • Earlier studies suggested that the optimal dose of omega-3s was ≥2.6 g/day for ≥12 weeks.

However, there have been few studies on the effect of omega-3s on osteoarthritis. A new exploratory study looked at the effect of 2.4 g/day of omega-3s for 16 weeks on the pain and disability associated with osteoarthritis. It found:

  • Omega-3 supplementation reduced chronic osteoarthritis pain by 42%.
  • Omega-3 supplementation reduced disability associated with osteoarthritis by 40%.
    • The reduction in pain and disability in participants supplemented with fish oil was greatest in those who reported the highest pain/disability at the beginning of the study.
    • The reduction in pain was associated with an improved perception of physical and mental wellbeing.
    • The reduction in pain was also associated with a decrease in depression and other mood disturbances.

The authors concluded, “Our findings indicate potential for fish oil supplementation to reduce mild osteoarthritis pain and burden in sedentary overweight/obese older adults. Further studies are warranted to evaluate the benefits of fish oil, alone or as an adjunct to pharmacotherapy, in patients diagnosed with osteoarthritis who suffer moderate-to-severe pain…”

If you have either rheumatoid or osteoarthritis, I recommend trying omega-3 supplementation. Based on the studies described above, you might want to aim for 2-3 g/day of omega-3s with an EPA/DHA ration of 1.5 or greater.

As with any natural approach, this will work better for some people that for others. However, don’t forget that omega-3s are also important for heart health, healthy blood pressure, brain health, and a healthy pregnancy. If they also happen to reduce your arthritis pain, that is an extra benefit.

As usual, I recommend a holistic approach. You should also:

  • Follow an anti-inflammatory diet.
  • Keep active.
  • Aim for a healthy weight.
  • Add antioxidant and polyphenol supplements.

These lifestyle changes should allow you to reduce or eliminate any pain medication you may be taking.

Finally, if you are on blood thinners, consult with your physician before adding omega-3 supplements to your diet. My preference is to incorporate omega-3s and reduce other medications, but that is a discussion you need to have with your doctor.

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.

How Much Omega-3s Do You Need?

Can You Get The Omega-3s You Need From Diet Alone?

Author: Dr. Stephen Chaney

how much omega-3s do you need prevent heart attackTwo recent studies have provided strong evidence that omega-3s reduce the risk of heart attacks. However, both studies used high doses of omega-3s and did not do a dose-response analysis. That leaves you with several unanswered questions:

  • How much omega-3s do you need to significantly reduce your risk of heart attack?
  • Will that amount of omega-3s provide other health benefits?
  • Can you get that amount of omega-3s from diet alone?
  • Can you get that amount of omega-3s from supplementation alone?

Fortunately, a recent study (KH Jackson et al, Prostaglandins, Leukotrienes and Essential Amino Acids, 142: 4-10, 2019) has answered those questions. But, before we consider that article, we should look at a biomarker called “Omega-3 Index.”

 

What Is Omega-3 Index And Why Is It Important?

how much omega-3s do you need fish oilThe Omega-3 Index is a measure of the ratio between the heart-healthy omega-3 fats (EPA + DHA) and all the other fats in red blood cell membranes. It is considered an excellent measure of our omega-3 status.

Dr. William S Harris, one of the top experts in the omega-3 field, first proposed the Omega-3 Index as a biomarker for cardiac health back in 2007. Based on multiple clinical and population studies, he proposed that an Omega 3 Index of 4% was associated with high heart attack risk, and an Omega-3 Index of 8% was associated with low heart attack risk. This has been supported by a recent meta-analysis of 10 clinical studies showing that an Omega-3 Index of 8% was associated with a 35% reduction in cardiovascular death compared to an Omega-3 Index of 4%.

Other studies suggest that an Omega-3 Index of 8% is associated with:

  • A slower rate of telomere shortening.
  • A lower risk of death from any cause.
  • Reduction in symptoms of depression.
  • Improved recovery from a heart attack.
  • Reduction in arthritis symptoms.
  • Reduced age-related brain shrinkage in B-vitamin treated subjects. (I have written about the synergistic relationship between omega-3s and B vitamins with respect to brain health in a previous issue  of “Health Tips From the Professor.”

(Note: You will find references to these studies in the paper I have cited.)

For reference, most Americans have an Omega-3 Index between 4 and 6%. In contrast, in Japan, where the incidence of heart disease is much lower, the Omega-3 Index ranges from 6.8% to 9%.

How Was The Study Designed?

how much omega-3s do you need studyThe data for this study were derived from 3458 individuals who 1) sent in a dried blood spot to a commercial laboratory for determination of Omega-3 Index between March 30, 2017 and January 15, 2018, 2) filled out a short questionnaire about fish intake and omega-3 supplement use, and 3) were older than 18.

With respect to fish intake, the possible responses were “none per week,” “every other week,” “every week,” “2 times per week,” and “3 or more times per week.”

With respect to omega-3 supplement use, those who reported taking an omega-3 supplement were asked what kind of omega-3 supplement they were taking. Those who said they were taking a flaxseed oil supplement were excluded from the analysis because flaxseed oil contains no EPA or DHA.

The characteristics of the population studied were as follows:

  • 84% came from the United States. The remaining 16% came from 27 other countries.
  • The average age was 51 years and 40% of the respondents were male.
  • 62% ate little or no fish. The exact breakdown of fish consumption was:
    • 5% ate no fish.
    • 9% ate fish every other week.
    • 6% ate fish weekly.
    • 2% ate fish twice a week.
    • 8% ate fish three or more times a week.
  • 52% took omega-3 supplements. Of those taking omega-3 supplements, 84% were taking fish oil supplements.

 

How Much Omega-3s Do You Need?

how much omega-3s do you need supplementsThe correlation between omega-3 intake and Omega-3 Index in these individuals was:

  • No fish = 4.5%.
    • No fish + supplementation = 6.6%.
  • Bi-weekly = 4.8%
    • Bi-weekly + supplementation = 6.9%
  • Weekly = 5.1%
    • Weekly + supplementation = 7.3%
  • Twice weekly = 5.7%
    • Twice weekly + supplementation = 7.8%
  • 3+ times per week = 6.5%
    • 3+ times per week + supplementation = 8.6%

The authors said: “We found that those with the best chance of achieving a desirable Omega-3 Index were reporting the consumption of at least 3 fish meals per week and were taking an EPA + DHA-containing omega-3 supplement.”

The authors further concluded that an EPA + DHA intake of around 835 mg per day or higher would be required to achieve an average Omega-3 Index of 8%. This was based on two assumptions:

  • A 4 once serving of oily fish provides around 1,200 mg of EPA + DHA.
  • The average omega-3 supplement provides around 300 mg of EPA + DHA.

 

What Are The Limitations Of The Study?

The two biggest limitations of the study are the assumptions that a serving of fish provides 1,200 mg of EPA + DHA and a fish oil supplement provides 300 mg of EPA + DHA.

  • Their dietary survey did not ask what kind of fish the respondents were consuming. Some fish provide much less than 1,200 mg of EPA + DHA per serving. This could have caused the authors to overestimate the contribution that fish intake made to the Omega-3 Index in their study.
  • Some omega-3 supplements provide more than 300 mg EPA + DHA, and some people take more than the recommended number of omega-3 capsules. This could have caused the authors to underestimate the contribution of omega-3 supplements to the Omega-3 Index in their study.

The major implication of these limitations comes when we look at the standard deviation of the correlations between omega-3 intake and Omega-3 Index.

  • Some people consuming 3 or more servings of fish per week had an Omega-3 Index of well above 8%. This suggests that diet alone can allow you to reach an optimal Omega-3 Index. This conclusion is also supported by dietary studies in Japan (see below).
  • Some people taking omega-3 supplements had an omega-3 index of above 8% even in the group consuming no fish. This suggests that supplementation alone can allow you to reach an optimal Omega-3 Index as long as your total EPA + DHA intake is 835 mg/day or greater.

These limitations may also affect the calculation of how much EPA + DHA we need to reach an optimal Omega-3 Index. For example, the most widely used omega-3 calculator estimates that you would need 950 mg of EPA + DHA to increase your Omega-3 Index from 4% to 8%.

 

What Does This Study Mean For You?

how much omega-3s do you needAt the beginning of this article I said that this study answered 4 questions:

  • How much omega-3s do you need to significantly reduce your risk of heart attack?
    • This study estimated that around 835 mg/day of EPA + DHA is needed to reach an Omega-3 Index of 8%, which previous studies have shown to be associated with low heart disease risk.
    • This is similar to the 950 mg/day estimate from a widely used omega-3 calculator.
    • There is considerable individual variability, but 835 – 950 mg/day is a good target for most people. If in doubt, I recommend that you get your Omega-3 Index tested.
  • Will that amount of omega-3s provide other health benefits?
    • The evidence is strongest for heart health, but this paper lists other studies suggesting that a high Omega-3 Index is associated with reduced risk of depression, arthritis, age-related brain shrinkage & cognitive decline, and death from all causes.
  • Can you get that amount of omega-3s from diet alone?
    • In this study an optimal Omega-3 Index was achieved only in the group that consumed 3 or more servings of fish per week and took an omega-3 supplement. However, not all those fish were rich in EPA + DHA.
    • Previous studies have shown that Japanese who consume 3 or more servings per week of oily fish, rich in EPA + DHA, have an Omega-3 Index of 6.8% to 9%. This shows us it is possible to reach an optimal Omega-3 Index from diet alone.
  • Can you get that amount of omega-3s from supplementation alone?
    • Here the answer is clearly yes. Based on this and other studies, it would require in the range of 835-950 mg/day from supplementation to reach an optimal Omega-3 Index for most people.

 

Here are some other conclusions from the authors of the study:

  • “The average Omega3 Index in Japan ranges from 6.8 to 9.0%…So, yes, an Omega-3 Index of >8% is achievable by diet alone. But Japan is fairly unique…The average Omega-3 Index for Americans ranges from 4 to 6%. So, short of adopting the Japanese diet for a lifetime, it appears that taking an EPA + DHA supplement could be an important strategy for achieving a cardioprotective Omega-3 Index.”
  • They consider current recommendations for omega-3 intake to be inadequate. Their recommended intake of 835 mg of EPA + DHA per day is:
    • “>3 times the EPA + DHA recommended by the Dietary Guidelines for Americans (250 mg/day).”
    • “1.7 times the amount recommended by the Academy of Nutrition and Dietetics (500 mg/day).”
    • “8 times higher than the typical EPA + DHA intake in the US (~100 mg/day).”
  • The American Heart Association currently recommends the consumption of 1-2 seafood meals per week.
  • The authors commented: “We do recognize that public health recommendations must balance what is ideal vs. what is practical for the public and must also take into consideration…potentially hazardous components of fish (mercury, PCBs) and the sustainability of the world’s fish supply.”
  • However, they considered the recommendation of the American Heart Association to be woefully inadequate. Based on their data, they concluded: “To achieve an Omega-3 Index of >8%, either adding an EPA + DHA supplement or increasing to 4-5 servings of fish/week would be necessary.”

Because of the high level of contamination of the world’s fish supply, my personal preference would be to add a high purity omega-3 supplement to my diet rather than consuming fish multiple times a week. I love salmon, but I try to limit myself to a salmon dinner no more than once a month.

 

The Bottom Line

 

A recent study looked at how much EPA + DHA you would need to achieve an optimal omega-3 status. The investigators used a measurement called Omega-3 Index, which has been shown to be an excellent measurement of omega-3 status. They asked how much EPA + DHA from diet plus supplementation was required to achieve an Omega-3 Index of 8%, which is associated with a low risk for heart disease. The key findings from this study were:

  • Around 835 mg/day of EPA + DHA is needed to reach an Omega-3 Index of 8%.
  • This is similar to the 950 mg/day estimate from a widely used omega-3 calculator.
  • There is considerable individual variability, but 835 – 950 mg/day is a good target for most people. If in doubt, I recommend that you get your Omega-3 Index tested.
  • The Japanese eat EPA + DHA-rich fish 3 or more times per week and have an Omega-3 Index of 6.9 to 9.0%, so it is clearly possible to achieve an optimal Omega-3 Index from diet alone. However, the American diet is so different from the Japanese diet that the authors concluded: “Short of adopting the Japanese diet for a lifetime, it appears that taking an EPA + DHA supplement could be an important strategy for achieving a cardioprotective Omega-3 Index.”
  • The American Heart Association currently recommends the consumption of 1-2 seafood meals/week. The authors consider this recommendation to be woefully inadequate. They said: “To achieve an Omega-3 Index of >8%, either adding an EPA + DHA supplement or increasing to 4-5 servings of fish/week would be necessary.”

Because of the high level of contamination of the world’s fish supply, my personal preference is to add a high purity omega-3 supplement to my diet rather than consuming fish multiple times a week. I love salmon, but I try to limit myself to a salmon dinner no more than once a month.

 

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.

DHA During Pregnancy; Yes or No?

Are Pregnant Women Deficient In Omega-3s?

Author: Dr. Stephen Chaney

 

dha during pregnancyDo women need DHA during pregnancy?  Most experts agree that omega-3 fatty acids, especially DHA, are essential for fetal development during pregnancy and for brain development through at least the first two years of a child’s life. That’s because DHA is an important component of the myelin sheath that coats and protects our brain neurons.

During the last two trimesters of pregnancy and the first two years of a child’s life, their brains are growing and maturing at a remarkable rate. The need for DHA during this critical period is huge, and most of that DHA comes from the mom. That’s why the mom’s intake of DHA during pregnancy and breastfeeding is so important.

For example, higher intakes of omega-3s during pregnancy and breastfeeding have been associated with:

  • Decreased maternal depression.
  • Increased birth weight.
  • Reduced risk of preterm birth.
  • Reduction in ADHD symptoms.
  • Reduction in allergies and asthma.
  • Improved developmental and cognitive outcomes such as:
    • Increased visual acuity.
    • Better problem-solving skills.

I do wish to acknowledge that there is still debate in the scientific literature about the strength of some of these associations. However, there is enough cumulative evidence for the beneficial effects of omega-3s especially DHA during pregnancy and breastfeeding that virtually all experts agree adequate maternal omega-3 intake is important during this crucial period in a child’s life.

 

How Much DHA During Pregnancy & Breastfeeding Is Needed?

fish oil dha during pregnancyThe National Academies of Science have not yet set a Daily Value for omega-3s. However, a group of experts met in 1999 to recommend adequate dietary intake of omega-3s (Simopoulos et al, Prostaglandins, Leukotrienes & Essential Fatty Acids, 63: 119-121, 2000 ). They concluded that an adequate intake of omega-3 fatty acids in adults was at least 650 mg/day with at least 440 mg/day of that coming from EPA + DHA (220 mg/day each of EPA and DHA). They further recommended that DHA intake in pregnant and lactating women should be at least 300 mg/day.

However, because of concerns about seafood contamination with heavy metals and PCBs (both of which are neurotoxins), the FDA recommended in 2004 that pregnant and lactating women limit seafood consumption to two servings a week, which amounts to about 200 mg/day of DHA. This has been subsequently adopted by the American College of Obstetricians and Gynecologists and the European Union as the recommended amount of DHA during pregnancy and lactation (Coletta et al, Reviews in Obstetrics & Gynecology, 3, 163-171, 2010 ).

How Was The Study Done?

The authors of this study (Nordgren et al, Nutrients, 2017, 9, 197; doi:10.3390/nu9030197 ) utilized a nationwide database called NHANES (National Health and Nutrition Examination Survey). NHANES data are based on an annual survey conducted by the National Center for Health Statistics (NCHS) to assess the health and nutritional status of adults and children in the United States, and to track changes over time.

Dietary intake of nutrients is based on two interviewer-administered, 24-hour dietary recalls conducted 3-10 days apart. Omega-3 intake was calculated based on the USDA database of nutrient composition of foods.

The investigators combined NHANES data from the years 2003 to 2012. This included 6478 women of childbearing years (14-45 years old), of which 788 were pregnant at the time of the survey.

Are Pregnant Women Deficient In Omega-3s?

omega3 deficiency in pregnant womenThe results of this study were alarming:

  • Mean EPA + DHA intake was only 89 mg/day with no difference between pregnant and non-pregnant women of childbearing age.
  • This contrasts to the expert committee’s recommendation of at least 440 mg/day for EPA + DHA (220 mg/day each from EPA and DHA).
  • Mean DHA intake was only 66 mg/day in pregnant and 58 mg/day in non-pregnant women of childbearing status.
  • This contrasts to the recommendations of 200 – 300 mg/day for pregnant women.
  • These intakes did not include dietary supplements, but only 1.8% of non-pregnant and 9% of pregnant women in this survey took supplements containing EPA and/or DHA.

The authors concluded “Our results demonstrate that omega-3 fatty acid intake is a concern in pregnant women and women of childbearing age…” They went on to say: ‘Strategies to increase omega-3 fatty acid intake in these populations could have the potential to improve maternal and infant health outcomes.”

What Do Other Studies Show?

This study is not an outlier. In a previous issue  Do Women Get Enough Omega-3 During Pregnancy of “Health Tips From the Professor” I reported on a study showing that 90% of Canadian women were not getting enough DHA in their diet. A similar study in Germany concluded that 97% of middle-aged women had suboptimal omega-3 status (Gellert et al, Prostaglandins, Leukotrienes and Essential Fatty Acids, doi: 10.1016/j.plefa.2017.01.009 ).

More importantly, these omega-3 deficiencies matter. In another issue DHA Supplements During Pregnancy of “Health Tips From the Professor” I reported on a study showing that DHA supplementation significantly reduced preterm births. Based on that effect alone, the authors concluded that DHA supplementation during pregnancy could save the US healthcare system close to $6 billion/year.

Women do need DHA during pregnancy.

The Bottom Line

  • Optimal intake of omega-3s during pregnancy and breastfeeding is associated with:
    • Decreased maternal depression.
    • Increased birth weight.
    • Reduced risk of preterm birth.
    • Reduction in ADHD symptoms.
    • Reduction in allergies and asthma.
    • Improved developmental and cognitive outcomes such as:
      • Increased visual acuity.
      • Better problem-solving skills.
  • In 1999, a panel of experts met to set standards for omega-3 intake. They recommended:
    • At least 650 mg/day for adults with at least 440 mg/day coming from EPA + DHA (220 mg/day each of EPA and DHA).
    • At least 300 mg/day of DHA for pregnant and breastfeeding women.
  • Because of concerns about seafood contamination with heavy metals and PCBs (both of which are neurotoxins), the FDA reduced the recommendation for pregnant and breastfeeding women to 200 mg/day of DHA. That recommendation has been subsequently adopted by the American College of Obstetricians and Gynecologists and the European Union.
  • A recent study has found:
    • Mean EPA + DHA intake was only 89 mg/day with no difference between pregnant and non-pregnant women of childbearing age.
      • This contrasts to the expert committee’s recommendation of at least 440 mg/day (with 220 mg/day each from EPA and DHA).
    • Mean DHA intake was only 66 mg/day in pregnant and 58 mg/day in non-pregnant women of childbearing status.
      • This contrasts to the recommendations of 200 – 300 mg/day for pregnant and breastfeeding women.
    • These intakes did not include dietary supplements, but only 1.8% of non-pregnant and 9% of pregnant women in this survey took supplements containing EPA and/or DHA.
    • This study is in line with recent studies in Canada and Germany. Clearly pregnant and Breastfeeding women in developed countries like the US are getting suboptimal amounts of omega-3s in their diet.
    • This is alarming because these findings come amidst mounting evidence that optimal omega-3 intake during pregnancy and breastfeeding is important for the health of both mother and child.

     

    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 Some Omega-3 Fish Oil Supplements Better Than Others?

Author: Dr. Stephen Chaney

truth about omega-3 fish oil supplementThe ethyl ester form of omega-3 fatty acids from fish oil has been the industry standard for high purity omega-3 fish oil supplements for many years. It is very stable, easily purified, and well absorbed by the body. What’s not to like?

If you believe some recent advertisements, there is a lot not to like about the ethyl ester form of omega-3s. These ads each claim that their particular form of omega-3s is more natural, better absorbed, and more efficiently incorporated into cell membranes, or some combination of those features. They each cite clinical studies “proving” that their products are superior. These advertisements seem so plausible and so compelling.

However, most of these advertisements come from relatively new companies that are trying to make a name for themselves in a very profitable and competitive product niche. Are the advertisements true, or is it all just smoke and mirrors? Most of these advertisements rate at least one Pinocchio.

However, it is almost impossible to tell you why I consider these advertisements omega-3 fish oil supplements to be misleading without getting a little “techie”, so let’s start with some basic definitions. I call this section “Omega-3s 101.”

 

Omega-3s 101

 

Let’s start with some basic definitions:

  • Free fatty acids (FFA) are long chain hydrocarbons with a single acid group at the end. They are only slightly water soluble. They are important intermediates in metabolism, but they are almost always combined with something else in the body.
  • Saturated fatty acids contain no double bonds, monounsaturated fatty acids contain one double bond, and polyunsaturated fatty acids contain multiple double bonds. The number of double bonds primarily affects whether they are liquids (polyunsaturated) or solids (saturated) at room temperature.
  • omega-3 fatty acidsThere are two classes of polyunsaturated fatty acids that are essential because the body cannot make them. Those with a double bond 3 carbons from the end are called omega-3s(If you think about the Greek alphabet, omega is at the end). Those with a double bond 6 carbons from the end are called omega-6s.
  • When 3 fatty acids are combined with a single molecule of glycerol they form very water insoluble compounds commonly referred to as fats or triglycerides. The proper chemical name is triacylglycerol, which is abbreviated TAG.
  • If one of the fatty acids on the glycerol chain is replaced by a compound containing phosphate and other charged residues, the resulting complex is called a phospholipid (PL). Because these compounds have a hydrocarbon surface that is attracted to fats and a highly charged surface that is attracted to water, they are good at emulsifying fats and are an important part of membrane structure. One phospholipid that is a major component of membranes is called phosphatidylcholine (PC), also known as lecithin.

Next, let’s look at how omega-3 fatty acids are metabolized:

  • The omega-3s in fish oil are primarily in the form of triglycerides, with small amounts of phospholipids. The omega-3s in most omega-3 supplements are in the form of ethyl esters for the reasons stated above.
  • Before the omega-3s leave the intestine they are hydrolyzed to free fatty acids.
  • In the cells that line the intestine the omega-3s are reconverted back into triglycerides and phospholipids and incorporated into special lipid-protein complexes for transport through the blood.
  • Once these lipid-protein complexes reach our cells, their contents are delivered to the cell where they can be stored as fat (TAG), used for energy (FFA), or incorporated into membranes (PL). It is primarily the omega-3s incorporated in cellular membranes that are thought to be responsible for the beneficial effects of omega-3s.

Finally, we should ask how one measures the bioavailability of the various forms of omega-3s:

While there are some nuances that I did not cover, the basic mechanisms of absorption and metabolism of omega-3s are remarkably similar regardless of whether they start out in the ethyl ester, triglyceride, phospholipid, or free fatty acid form. The questions then become, how does one test how efficiently the various forms are utilized by the body and how much do these individual test actually tell us?

  • When we look at what happens in the bloodstream, we need to be aware that we are looking at a combination of two effects – how rapidly the substance enters the bloodstream and how rapidly it leaves from the bloodstream. There are three important parameters we can measure when looking at delivery of omega-3s to the bloodstream:
    • The maximum concentration achieved (Cmax)
    • How rapidly that maximum concentration was achieved (Tmax)
    • The total amount in the bloodstream over time (AUC)
  • When you look at some of the ads touting specialized forms of omega-3s, they are usually based on studies looking at either the maximum levels of omega-3s in the bloodstream (Cmax) or how rapidly those maximum levels were achieved (Tmax). (One suspects the ads may have selectively featured whichever parameter made their product look best). However, the parameter that really matters is the total concentration of omega-3s achieved over time (AUC).
  • Finally, the most important question is how much of the omega-3 is actually incorporated into cellular membranes. Once again, there is more than one parameter that can be measured.
  • One can measure the level of omega-3s found in cellular membranes in a short term study (a few hours) or in a long term study following many weeks of supplementation.
  • The short term studies only measure the rate of incorporation. The long term studies measure the steady state levels attained over time, which is a much more relevant measure.
  • Once again, the ads touting specialized products are usually based on short term studies which are really measuring an initial rate of incorporation of omega-3s into cellular membranes, not on long term studies that measure the steady state level of omega-3s achieved over time.

 

Are Some Omega-3 Fish Oil Supplements Better Than Others?

omega-3 fish oil supplementThere has been a lot of confusion in the literature about whether the form of omega-3 supplements matters. Various studies have been published supporting the superiority of one form or another of omega-3s. Most of these studies have been supported by manufacturers who have a particular form of omega-3s they want to sell, and, as I mentioned above, the parameters tested seem to have been selected to make their supplement look good.  So, are some omega-3 fish oil supplements better than others?

 

Finally, someone has designed a comprehensive study to clear up all the confusion and provide answers that can be trusted (West et al, British Journal of Nutrition, 116: 788-797, 2016). Interestingly, this research was supported by a pharmaceutical company (Vifor Pharma) that does not appear to sell an omega-3 product currently. Perhaps they simply wanted to find out what worked best before designing their own product. What a novel concept!

The authors tested 4 different forms of omega-3 fish oil supplements:

  • Unmodified fish oil containing the omega-3s primarily in triglyceride form (uTAG).
  • An omega-3 supplement in which the omega-3s in the fish oil had been hydrolyzed to free fatty acids (FFA).
  • An omega-3 supplement in which the omega-3s in the fish oil had been hydrolyzed to free fatty acids and converted back to triglycerides (TAG)
  • An omega-3 supplement in which the omega-3s in the fish oil had been hydrolyzed to free fatty acids and converted to ethyl esters (EE)

All 4 supplements contained 1.1 grams of EPA and 0.37 grams of DHA.

The authors conducted two studies:

  • One was a cross-over study where healthy men consumed each of the supplements in random order on different days with 14 days between tests. Blood samples were collected over the next 6 hours and levels of EPA and DHA in the blood and cellular membranes was determined.
  • The other was a long term study in which a randomized group of healthy men and women consumed one of the supplements for 12-weeks and incorporation of the EPA and DHA into cellular membranes was measured.

The results were pretty clear cut:

  • In the short term study there were no significant differences between the various supplements in the rate of uptake, maximum concentration achieved, or the total concentration over time when uptake of omega-3s into plasma triglycerides and phospholipids was measured.
  • The ethyl ester form was less efficiently incorporated into plasma free fatty acids than the other forms as reported in some previous studies, but this is perhaps the least important parameter measured, and there was large variability from subject to subject.
  • In the long term study, no significant differences were seen between the various supplements in omega-3 incorporation into cellular membranes.

The authors concluded: “Together, these findings show that in healthy individuals neither the lipid structure nor the overall fatty acid composition of supplements influence their bioavailability during dietary supplementation, despite the apparent lower postprandial availability [in short term studies] of EPA + DHA ethyl esters compared with triglycerides or free fatty acids.”

What Do These Studies Mean For You?

You can forget all those ads hyping the newest, greatest form of omega-3 fish oil supplements. Objective research has shown there is not a dimes worth of difference between the various forms of omega-3 supplements.

A far more important question is the purity of the omega-3 supplement you are using. Purity of omega-3 supplements is a huge issue. You need to remember that the EPA + DHA supplements you purchase come from polluted fish. Unfortunately, many manufacturers have inadequate purification and quality control standards. In other words, neither you nor they know whether their omega-3 products are pure. You need to make sure that the omega-3 supplement you purchase is made by a manufacturer with stringent quality control standards.

Sustainability is also an issue, so you should choose manufacturers who source their omega-3s in a sustainable manner. There are two comments I will make about sustainability so you won’t be misled.

  • Krill oil is marketed as a more sustainable source of omega-3s. Krill reserves are quite large, but they are not infinite. Krill is also the very foundation of the food chain that supports a large percentage of our ocean’s fish. We need to be very cautious about depleting our krill reserves.
  • Omega-3s derived from algae are also marketed as a more sustainable source of omega-3s. Algae-derived omega-3s have purity issues of their own, but may become an important source of omega-3s once those issues have been resolved.

 

The Bottom Line

  • The ethyl ester form of omega-3 fatty acids from fish oil has been the industry standard for high purity fish oil supplements for many years. It is very stable, easily purified, and well absorbed by the body.
  • However, in recent years, some manufacturers have been claiming that their omega-3 fish oil supplements were better utilized by the body because their supplements contained the omega-3s in triglyceride or free fatty acid forms.
  • Unfortunately, the clinical studies supporting those claims have been supported by the manufacturers making the products. There is reason to suspect that the data has been “cherry picked” to support the conclusions that support the manufacturer’s claims.
  • Finally, an independent and comprehensive study has compared the various forms of omega-3 fatty acids. It found that neither the lipid structure nor the overall fatty acid composition of omega-3 supplements influenced their bioavailability during long term dietary supplementation.
  • A far more important question is the purity of the omega-3 supplement you are using. Purity of omega-3 supplements is a huge issue. You need to remember that the EPA + DHA supplements you purchase come from polluted fish. Unfortunately, many manufacturers have inadequate purification and quality control standards. In other words, neither you nor they know whether their omega-3 products are pure. You need to make sure that the omega-3 supplement you purchase is made by a manufacturer with stringent quality control standards.
Health Tips From The Professor