Do DHA Supplements Improve Brain Function?

The concept of vitamins was first described by none other than Dr. Funk. In his landmark paper in 1912, he discussed the notion that there were complex compounds our body couldn’t make from scratch, so we had to get them from our diet. By the mid-20th century, all the vitamins had been discovered and isolated, but it wasn’t until the 1960s that we realized that certain fats were essential, too.

In 1929, the necessity for fat was definitively settled… “in the diet (of the rat),” but when one of the researchers tried a 99 percent fat-free diet on himself for six months, ironically, he felt better. His high blood pressure went away, he felt more energetic, and his migraines disappeared. This one-man experiment “fortif[ied] the medical profession’s doubt that essential fatty acids had any relevance to humans,” until TPN—Total Parenteral Nutrition, meaning feeding someone exclusively through an IV—was developed in the 1960s. TPN was initially developed for babies born without working intestines. Because we didn’t think humans needed fat, “the first preparations were fat free, and they rapidly induced severe EFA [essential fatty acid] deficiencies, ultimately convincing the medical community” that some fats are indeed essential. They started out using safflower oil, but, as they discovered in a young girl given the oil after an abdominal gunshot wound, we don’t just need fat—we need specific fats like omega-3s. So, when they switched from safflower oil to soybean oil, she was restored to normal.

The fact it took so long and under such extreme circumstances to demonstrate the essential nature of omega-3s illustrates how hard it is to develop overt omega-3 deficiency. Of course, the amount required to avoid deficiency is not necessarily the optimal amount for health. The vitamin C in a spoonful of orange juice would be enough to avoid scurvy (the overt vitamin C deficiency disease), but no one considers that enough vitamin C for optimal health.

As I discuss in my video Should We Take DHA Supplements to Boost Brain Function?, what would optimal omega-3 status look like? Well, doubt has been cast on its role in heart health (see Is Fish Oil Just Snake Oil?), which appears to have been based on a faulty premise in the first place (see Omega-3s and the Eskimo Fish Tale), so taking extra omega-3s for our heart might not make any sense (see Should We Take EPA and DHA Omega-3 for Our Heart?). But what about for our baby’s brain (see Should Pregnant and Breastfeeding Women Take DHA?)? Extra DHA may not help pregnant or breast-feeding fish-eaters, but those who want to avoid the contaminants in fishes can take supplements of pollutant-free algae oil to get the best of both worlds for their babies (see Should Vegan Women Supplement with DHA During Pregnancy?). What about adults? There doesn’t appear to be any apparent psychological (see Fish Consumption and Suicide) or neurological (see Is Fish “Brain Food” for Older Adults?) benefit of DHA supplementation for the general public, but what about in those who don’t eat fish?

The famous Alpha Omega Trial randomized thousands of people over three years to get either long-chain omega-3s from fish, short-chain omega-3s from plants, or placebo. The result? The study found no significant benefits for any kind of omega-3 supplementation on global cognitive decline. However, most of the subjects were eating fish, thereby already getting pre-formed DHA in their diets. General population studies like this, that find no benefit, can’t fully inform us about the role of DHA in brain health. It would be akin to giving half these people oranges, finding no difference in scurvy rates (zero in both groups), and concluding vitamin C plays no role in scurvy.

In 2013, for the first time, DHA supplementation was found to improve memory and reaction time among young adults who rarely ate fish. Previous randomized, controlled trials failed to find such a benefit among18- to 45-year-olds, but they only lasted a few months at most, whereas the 2013 study lasted for six months. If all the studies showed either no effect or a positive effect, one might give it a try. But in one of those shorter trials, DHA supplementation didn’t just fail to show benefit—it appeared to make things worse. After 50 days, those who consumed the DHA had worse memory than those taking the placebo. So, out of the six randomized controlled trials for DHA supplementation, four showed nothing, one showed a benefit, and one showed a harm. If it were just about boosting brain function in the short term, I’d err on the side of caution and spend my money elsewhere.


What about the long term though? See Should Vegans Take DHA to Preserve Brain Function?.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

 

Why Did Doctors Keep Prescribing Cancer?

We’ve known about the role of estrogen in breast cancer going back to the 1800s, when surgical removal of the ovaries seemed to help in some cases. Ovaries were said to send out “mysterious” influences to the rest of the body, which were identified as estrogen in 1923. The medical profession jumped on this discovery and started injecting menopausal women by the thousands, and it was said that “[t]he ‘shot’ gives a ‘respectable’ hook on which to hang the visit to the doctor…” Soon, there were pills and patches, and medical journals like the Journal of the American Medical Association regaled doctors with ads I feature in my video How Did Doctors Not Know About the Risks of Hormone Therapy? on how they can “help the women to happiness by simply prescribing estrogen” and, “[w]hen women outlive their ovaries…,” there is Premarin.

As far back as the 1940s, concerns were raised that this practice might cause breast cancer, noting it would have been nice to figure this out before we started dosing women en masse. But breast cancer risk didn’t seem to matter as much, because heart disease was the number-one killer of women, reviews concluded, and because women taking hormones appeared to have lower heart attack rates, which would outweigh any additional breast cancer. However, women taking estrogen tended to be of a higher socioeconomic class, exercised more, and engaged in other healthy lifestyle changes like consuming more dietary fiber and getting their cholesterol checked. So, maybe that’s why women taking estrogen appeared to be protected from heart disease. Perhaps it had nothing to do with the drugs themselves. Despite the medical profession’s “enthusiasm for estrogen replacement therapy,” only a randomized clinical trial could really resolve this question. We would need to divide women into two groups, with half getting the hormones and half getting a placebo, and follow them out for a few years. There was no such study…until the 1990s, when the Women’s Health Initiative study was designed.

Wait a second. Why did it take the bulk of a century to decide to definitively study the safety of something prescribed to millions of women? Perhaps because there had never been a female director of the National Institutes of Health until then. “Just three weeks after being named NIH Director in 1991, [Bernadine Healy] went before Congress to announce, ‘We need a moon walk for women.’ That ‘moon walk’ took the form of the Women’s Health Initiative, the most definitive, far-reaching clinical trial of women’s health ever undertaken in the United States.”

The bombshell landed in summer 2002. There was so much more invasive breast cancer in the hormone users that they were forced to stop the study prematurely. What about heart disease? Wasn’t that supposed to balance things out? The women didn’t just have more breast cancer—they had more heart attacks, more strokes, and more blood clots to their lungs.

The news that women treated with hormone replacement therapy “experienced higher rates of breast cancer, cardiovascular disease, and overall harm has rocked women and physicians across the country.” Estrogen started out as the most prescribed drug in America before the study, but, after, the number of prescriptions dropped immediately and, within a year, so did the incidence of breast cancer in the United States.

The most important question about this story is why were we all so surprised? There had been “decades of repeated warnings” about the risks of cancer. In fact, the reason breast cancer patients had so much trouble suing the pharmaceutical company was that “the drugs have contained warning labels for decades.” And, with that disclosure, surely any reasonable physician would have included it in their risk and benefit discussions with their patients, right? It’s like the warning labels on packs of cigarettes. If you get lung cancer now, you should have known better. And, so, if you were on hormone replacement therapy and got breast cancer, don’t blame the drug company. They warned you about the risks, right there in the fine print.

Why didn’t more doctors warn their patients? Even after the study came out, millions of prescriptions continued to be dispensed. That’s a lot of cancer in our patients we caused, wrote one doctor. “How long will it take us to discard the financial gains, to admit that we are harming many of our patients, and to start changing our prescription habits?”

“Why did this practice continue in the face of mounting evidence of harm?” Well, it is a multibillion-dollar industry. “Despite an overwhelming amount of evidence to the contrary, many physicians still believe that estrogenic hormones have overall health benefits,” a “non-evidence-based perception [that] may be the result of decades of carefully orchestrated corporate influence on medical literature.” Indeed, “[d]ozens of ghostwritten reviews and commentaries published in medical journals and supplements were used to promote unproven benefits and downplay harms of menopausal hormone therapy…” PR companies were paid to write the articles that were then passed off as having been written by some expert.

What now? “Gynecologists must switch allegiance from eminence-based to evidence-based medicine.” In other words, they must consider what the science says and not just what some so-called expert says. It’s been said that the “current culture of gynecology encourages the dissemination of health advice based on advertising rather than science.”

“Women were placed in the way of harm by their physicians, who acted as unsuspecting patsies for the pharmaceutical companies.” If we really wanted to prevent heart attacks in women, simple lifestyle behaviors can eliminate more than 90 percent of heart attack risk. So, instead of being Big Pharma’s pawns, “recommending a healthful diet, increased exercise, and smoking cessation would truly benefit women’s health.”


The whole Premarin debacle speaks to the importance of putting purported therapies to the test (see, for example, Do Vitamin D Supplements Help with Diabetes, Weight Loss, and Blood Pressure?), as well as to the power of Big Pharma (Eliminating Conflicts of Interest in Medical Research), medical community collusion (American Medical Association Complicity with Big Tobacco), and my most series on mammograms.

What about Plant-Based Bioidentical Hormones and Soy Phytoestrogens for Menopause Hot Flashes? Check out the videos to find out.

In general, patients (and doctors) tend to wildly overestimate the efficacy of pills and procedures. See Why Prevention Is Worth a Ton of Cure and The Actual Benefit of Diet vs. Drugs.

Medical care, in general, may be the third leading cause of death in the United States. See How Doctors Responded to Being Named a Leading Killer.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Preorder How Not to Diet Now!

My new book How Not to Diet is now available for preorder! 

It’s hard to express how excited I am that it’s finally coming out. It’s the biggest single research project I’ve ever taken on. There are more than a half million papers published in the medical literature on obesity with 100 new ones every day. It’s no wonder no one has yet pulled together all the best science…until now!

In Part 1, I explain the cause of the obesity epidemic. What exactly happened in the late 1970’s that triggered the global crisis? In Part 2, I construct the ideal weight loss diet from the ground up, identifying 17 different ingredients for optimal weight control with a chapter on each. Then, in Part 3, I go through specific foods proven in randomized, controlled trials to enhance weight loss by acting as everything from fat blockers and burners to appetite suppressants and metabolic boosters. And it’s not just what you eat, but how and when. In the last twenty chapters, I dive into optimal meal and exercise timing and frequency, habit formation, negative calorie preloading, and more—all immortalized in my Twenty-One Tweaks to accelerate weight loss that will complement my Daily Dozen

Why Pre-Order?

The book comes out on December 10, 2019, in time for the holidays and the burst of New Year resolutions. We’re hoping to get on all the major media outlets so we can spread the idea of evidence-based nutrition far and wide, but that depends in part on whether I can get on the New York Times Best Seller List. The list is decided based on the number of sales we get in the first week—including all of the pre-order sales. Thanks to so many of you, when How Not to Die launched, there were already tens of thousands of orders queued up, so it debuted as an instant New York Times Best Seller starting out at #6 on the list. Ready to help me shoot for #1? Pre-order it now at https://nutritionfacts.org/how-not-to-diet.

I don’t receive a penny from the book. It’s right in my contract that all the money I would normally receive from the advance and sales and royalties instead goes to charity. But the faster the book sells, the more opportunity I may have to broadcast this message of dietary sanity to the world. Wouldn’t it be amazing if I could get on some of the big morning shows? With your help, we can reach many more millions. So please pre-order a copy for yourself, and however many copies you think you may be able to gift to friends and family to get them on the right track for the new year (and the rest of their long, healthy life!). And if you’re active on social media, help me get the word out by directing folks to the pre-order page. I’ll be using the hashtag #HowNotToDiet.

And Don’t Forget Your Signed Bookplates!

By pre-ordering the book now, not only will you help launch How Not to Diet onto the New York Times Best Seller list, but you’ll also be able to get a bookplate signed by me to insert in the book. Just make a donation of any amount with this form, and we’ll send you a signed bookplate in appreciation. It makes a great gift or a keepsake for yourself. Your tax-deductible donation helps keep NutritionFacts.org going and growing. There’s only 3,000 bookplates available, so don’t delay!

I end the Preface with these words:

“This has been a mammoth but joyful undertaking. People sometimes ask me why I don’t go on vacations or even ever take a day off. I have to explain that I feel as though my entire life is a holiday. I feel so blessed to be able to dedicate my time to helping people while doing what I love, learning and sharing. I can’t imagine doing anything else.”

New Webinar: Fasting for Disease Reversal

Last month, thousands of people joined me for my first webinar on fasting, something I knew next to nothing about… until I did this deep dive into the medical literature. By my count, there are 1,527 articles on fasting in English-language peer-reviewed scientific journals, and I read every single one of them so you… don’t have to!

I’ve compiled all the best science into 41 videos which I will drip out on NutritionFacts.org over the next few years, but for those who don’t want to wait, we have a series of webinars so I can share the information all at once and answer questions throughout.

Last month I had a blast covering all the latest and greatest research on intermittent fasting and time-restricted eating. You can stream all the videos I covered here. I also covered the safety and efficacy of water-only fasting for weight loss, but what about the use of fasting for the reversal of disease? That’s the focus of my next fasting webinar, where I will spend three hours covering fasting for blood pressure, diabetes, depression, autoimmune diseases, and more. To get the full list of topics and titles, visit the webinar page.

Webinar Date & Time: September 29th at 1pm ET

Registration Closes: Midnight on September 22nd

There was so much research regarding fasting and cancer, that we made its own separate webinar as the third and final installation of the webinar series. This 3-hour webinar will be October 25th (on my birthday!) and focus on fasting for cancer reversal and during chemotherapy. Make sure to mark your calendars now—registration will begin in September.

To join: Make a donation through this form and we will send you a link to register for the September 29th Fasting for Disease Reversal webinar as a gift. Your support helps keep NutritionFacts.org alive and thriving!

 

Seeking Spanish Volunteers

Spanish volunteers neededOur Spanish team is looking for a few experienced translators to work on translating and editing transcripts, blog posts, and video subtitles. Applicants should be proficient in both Spanish and English, with previous translation experience and a basic understanding of NutritionFacts.org content and medical terms. To apply, go to https://nutritionfacts.org/volunteer.   
 
 
 
 
 
 

Eating Guide Survey

Have you used our Evidence-Based Eating Guide? If so, please consider taking two minutes to complete our brief survey to help guide the future direction of our health resources. 

 

 

 

 

 

 

Plant-Based Diets Recognized by Diabetes Associations

Plant-based diets as the single most important, yet underutilized, opportunity to reverse the pending obesity and diabetes-induced epidemic of disease and death.

 

 

How to Stop Tooth Decay

If sugar consumption is considered the one and only cause of cavities, how much is too much?

 

 

 

The Best Diet for Colon Cancer Prevention

What would happen within just two weeks if you swapped the diets of Americans with that of healthier eaters?

 

 

 

Live Q&As – Sept 19

Live Q&AI won’t have a live Q&A this month, but I’ll be back at it on Sept 19:

  • Facebook Live: At 12:00 p.m. ET go to our Facebook page to watch live and ask questions.
  • YouTube Live Stream: At 1:00 p.m. ET go here to watch live and ask even more questions! 

You can now find links to all of my past live YouTube and Facebook Q&As right here on NutritionFacts.org. If that’s not enough, remember I have an audio podcast to keep you company at http://nutritionfacts.org/audio.

 

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations: