Dr. Greger on Avocados and Lectins

My new DVD starts streaming today 

My new DVD is out today and is available as a streaming video so you can start watching it immediately. In this new volume, I take on guacamole and explore the best foods for autism, fibroids, lowering cholesterol, and preventing common childhood infections. I start out, though, with an analysis of a new book people have been emailing me about: The Plant Paradox. The title of the first video (see below) kind of gives it away, but I thought folks might appreciate a deeper dive into the lectins issue and so I did that too. All of these videos will eventually be available for free online over the next few months, but if you don’t want to wait, you can watch them all streaming right now. You can also order it as a physical DVD.

Here’s the full list of chapters from the new volume—a preview of what’s to come over the next few months on NutritionFacts.org:

  1. Dr. Gundry’s “The Plant Paradox” is Wrong
  2. How to Avoid Lectin Poisoning
  3. Are Lectins in Food Good or Bad for You?
  4. Benefits of Turmeric for Arsenic Exposure
  5. Fever Benefits for Autism in a Food
  6. Fighting Autism Brain Inflammation with Food
  7. Best Foods for Autism
  8. Is Sodium Lauryl Sulfate Safe?
  9. Is CABP in SLS-Free Toothpaste Any Better?
  10. Does Cell Phone Radiation Cause Cancer?
  11. Cell Phone Brain Tumor Risk?
  12. Is it Worth Getting Annual Health Check-Ups?
  13. Is it Worth Getting an Annual Physical Exam?
  14. Eczema Treatment with Evening Primrose Oil, Borage Oil vs. Hempseed Oil
  15. Eczema Treatment with Coconut Oil, Mineral Oil, vs. Vaseline
  16. The Best Diet for Fibroids
  17. The Best Food for Fibroids
  18. Are Avocados Healthy?
  19. Culture Shock: Questioning the Efficacy and Safety of Probiotics
  20. The Best Food for High Cholesterol
  21. Amla vs. Drugs for Cholesterol, Inflammation, and Blood-Thinning
  22. Lycopene Supplements vs. Prostate Cancer
  23. Tomato Sauce vs. Prostate Cancer
  24. Saffron vs. Memantine (Namenda) for Alzheimer’s
  25. Best Food to Prevent Common Childhood Infections
  26. Lead Contamination in Fish and Game

DVD Subscription

If you were a regular supporter, you’d already be an avocado expert, a lectin lexicon, having already received a link to the new DVD. New DVDs are released every nine weeks. If you’d like to automatically receive them before they’re even available to the public, please consider becoming a monthly donor.

Anyone signing up on the donation page to become a $25 monthly contributor will receive the next three downloads for free, and anyone signing up as a $50 monthly contributor will get a whole year’s worth of new DVDs (as physical DVDs, downloads, streaming, your choice). If you signed up for physical copies, you should have already received this volume, but if not please email DVDhelp@NutritionFacts.org and we’ll make everything all better.

Live Q&A Today

Every month now I do Q&As live from my treadmill, and this month, today (August 31st) is the day.

  • 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! 

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:

How to Design a Misleading Study to Show Diet Doesn’t Work

A study out of the University of North Carolina found no association between dietary fiber intake and diverticulosis. They compared those who ate the highest amount of fiber, 25 grams, to those who ate the smallest amount, which was three times lower at only 8 grams. Finding no difference in disease rates, researchers concluded that a low-fiber diet was not associated with diverticulosis.

The university sent out a press release entitled: “Diets high in fiber won’t protect against diverticulosis.” The media picked it up and ran headlines such as “High-fiber diet may not protect against diverticulosis, study finds.” It went all over the paleo blogs and even medical journals, publishing such statements as an “important and provocative paper…calls into question” the fiber theory of the development of diverticulosis. Other editorials, though, caught the study’s critical flaw. To understand this, let’s turn to another dietary deficiency disease: scurvy.

Medical experiments on prisoners at Iowa State Penitentiary showed that clinical signs of scurvy start appearing after just 29 days without vitamin C. Experiments on pacifists during World War II showed that it takes about 10 mg of vitamin C a day to prevent scurvy. Imagine going back a few centuries when they were still trying to figure scurvy out. Dr. James Linde had this radical theory that citrus fruits could cure scurvy. What if an experiment was designed to test this crazy theory, in which sailors were given the juice of either one wedge of lemon or three wedges of lemon each day? If a month later on the high seas there was no difference in scurvy rates, one might see headlines from printing presses touting that a low-vitamin C diet is not associated with scurvy.

Well, a wedge of lemon only yields about 2 mg of vitamin C, and it takes 10 mg to prevent scurvy. They would have been comparing one vitamin C-deficient dose to another vitamin C-deficient dose. No wonder there would be no difference in scurvy rates. We evolved eating so many plants that we likely averaged around 600 mg of vitamin C a day. That’s what our bodies are biologically used to getting.

What about fiber? How much fiber are we used to getting? More than 100 grams a day! The highest fiber intake group in the North Carolina study was only eating 25 grams, which is less than the minimum recommended daily allowance of about 32 grams. The subjects didn’t even make the minimum! The study compared one fiber-deficient diet to another fiber-deficient diet—no wonder there was no difference in diverticulosis rates.

The African populations with essentially no diverticulosis ate diets consisting in part of very large platefuls of leafy vegetables—similar, perhaps, to what we were eating a few million years ago. They were eating plant-based diets containing 70 to 90 grams of fiber a day. Most vegetarians don’t even eat that many whole plant foods, although some do. At least vegetarians tend to hit the minimum mark, and they have less diverticulosis to show for it. A study of 47,000 people confirmed that “[c]onsuming a vegetarian diet and a high intake of dietary fiber were both associated with a lower risk of admission to hospital or death from diverticular disease.” They had enough people to tease it out. As you’ll see in my video Does Fiber Really Prevent Diverticulosis?, compared to people eating a single serving of meat a day or more, those who ate less than half a serving appeared to have a 16% lower risk and pescatarians (eating no meat except fish) had a risk down around 23%. Both of these results weren’t in and of themselves statistically significant, but eating vegetarian was. Vegetarians had 35% lower risk, and those eating strictly plant-based appeared to be at 78% lower risk.

As with all lifestyle interventions, it only works if you do it. High-fiber diets only work if they’re actually high in fiber.

There’s more great information in my video Diverticulosis: When Our Most Common Gut Disorder Hardly Existed.

This reminds me of an ancient video I did: Flawed Study Interpretation.

People commonly ask Do Vegetarians Get Enough Protein?, but maybe they should be more concerned where everyone else is getting their fiber. Ninety-seven percent of Americans don’t even reach the recommended daily minimum.

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:

9 out of 10 That Die From it Never Knew They Even Had This Preventable Disease

Diverticula are out-pouchings of our intestine. Doctors like using a tire analogy: high pressures within the gut can force the intestines to balloon out through weak spots in the intestinal wall like an inner tube poking out through a worn tire tread. You can see what they actually look like in my video, Diverticulosis: When Our Most Common Gut Disorder Hardly Existed. These pockets can become inflamed and infected, and, to carry the tire analogy further, can blow out and spill fecal matter into the abdomen, and lead to death. Symptoms can range from no symptoms at all, to a little cramping and bloating, to “incapacitating pain that is a medical emergency.” Nine out of ten people who die from the disease never even knew they had it.

The good news is there may be a way to prevent the disease. Diverticular disease is the most common intestinal disorder, affecting up to 70% of people by age 60. If it’s that common, though, is it just an inevitable consequence of aging? No, it’s a new disease. In 1907, 25 cases had been reported in the medical literature. Not cases in 25% of people, but 25 cases period. And diverticular disease is kind of hard to miss on autopsy. A hundred years ago, in 1916, it didn’t even merit mention in medical and surgical textbooks. The mystery wasn’t solved until 1971.

How did a disease that was almost unknown become the most common affliction of the colon in the Western world within one lifespan? Surgeons Painter and Burkitt suggested diverticulosis was a deficiency disease—i.e., a disease caused by a deficiency of fiber. In the late 1800s, roller milling was introduced, further removing fiber from grain, and we started to fill up on other fiber-deficient foods like meat and sugar. A few decades of this and diverticulosis was rampant.

This is what Painter and Burkitt thought was going on: Just as it would be easy to squeeze a lump of butter through a bicycle tube, it’s easy to move large, soft, and moist intestinal contents through the gut. In contrast, try squeezing through a lump of tar. When we eat fiber-deficient diets, our feces can become small and firm, and our intestines have to really squeeze down hard to move them along. This buildup of pressure may force out those bulges. Eventually, a low-fiber diet can sometimes lead to the colon literally rupturing itself.

If this theory is true, then populations eating high­-fiber diets would have low rates of diverticulosis. That’s exactly what’s been found. More than 50% of African Americans in their 50s were found to have diverticulosis, compared to less than 1% in African Africans eating traditional plant-based diets. By less than 1%, we’re talking zero out of a series of 2,000 autopsies in South Africa and two out of 4,000 in Uganda. That’s about one thousand times lower prevalence.

What, then, do we make of a new study concluding that a low-fiber diet was not associated with diverticulosis. I cover that in my video Does Fiber Really Prevent Diverticulosis?

For more on bowel health, see:

What if your doctor says you shouldn’t eat healthy foods like nuts and popcorn because of your diverticulosis? Share with them my Diverticulosis & Nuts video.

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: