I’m Dr. Michael Greger. The recovery of my grandmother from advanced heart disease with a plant-based diet and lifestyle changes inspired me to go into medicine and become a founding member and Fellow of the American College of Lifestyle Medicine. I started NutritionFacts.org, which features more than a thousand short videos on the latest in evidence-based nutrition. My new book How Not to Die hit stores this week.

Beyond my chronic disease work, I also have published on zoonotic (animal-to-human) infectious disease as the Director of Public Health and Animal Agriculture at The Humane Society of the United States. I was invited to testify as an expert witness in the defense of Oprah Winfrey in the infamous "meat defamation" trial and have testified before congressional committees on food safety as well.

I'm a graduate of Cornell University's School of Agriculture and Tufts University's School of Medicine.

I'm walking on my treadmill desk and ready to answer questions. Ask me anything!

Proof: https://twitter.com/nutrition_facts/status/674971230743756800

UPDATE: Thank you so much for all the amazing questions! Unfortunately I could only dedicate 5 hours to it, but hope to be back for another AMA soon! If you have any further questions please feel free to post in any of the comment sections on NutritionFacts.org

Comments: 375 • Responses: 40  • Date: 

Brusswole_Sprouts58 karma

Hi Dr. Greger! I almost worked for you during your first round of hiring, but had to finish college! Your word is pretty much law in my household.

My question is based on a lot of people who have studied science and are quick to call out 'bad science'. Even those in the vegan community are wary of some of your contents' more bold claims. How do you ensure that you don't merely 'look for the answers you want' in studies, that the studies themselves are good, and that you remain unbiased? A friend of mine's favorite science quote is 'remember, a bullet will kill cancer cells in a petri dish'.

P.S. just bought your book How Not to Die; can't wait to dig in!

MichaelGregerMD63 karma

Science today is indeed fraught with fraud, bias, sloppiness, and conflicts of interest. Quietly shelving and burying unfavorable outcomes, inappropriate interpretations, etc. but I figure it’s like that Winston Churchill quote “Democracy is the worst form of government—except for all the others." One could say the peer-reviewed scientific literature these days is the worst form of evidence... except all the others… How else can we make life or death decisions for ourselves, our families, and our patients but by the best available balance of evidence?

In terms of "my" claims, I really try not to make any on NutritionFacts.org, but rather let the science speak for itself. My videos are basically just showing all the original papers and include links to all the sources cited so people can make up their minds for themselves.

I hope that answers your question?

Hope you like the book!

magicmanfk39 karma

Do you have any general tips for people who are already vegan on how to make sure they stay healthy?

MichaelGregerMD67 karma

The most important thing vegans can do is to make sure to ensure a regular reliable source of vitamin B12. See, for example, my video Vitamin B12 Necessary for Arterial Health.

Probably the easiest way is to take one 2,500 mcg (µg) cyanocobalamin supplement once each week. Can cost less than $5 a year, but is absolutely critical (unless eating enough B12-fortified foods). Our fellow great apes get the B12 they need from bugs, dirt, and feces but I prefer supplements! :)

plantbasedmartin5 karma

Is it best to take the supplement before, during, or after a meal?

MichaelGregerMD19 karma

For vitamin B12 it doesn't matter timingwise, though to ensure adequate absorption (i.e. make sure it breaks down and doesn't just pass through you undigested) I would recommend a chewable, sublingual, or liquid B12 supplement.

MssDee3 karma

Isn't metacobalamin better option than cyanocobalamin? I've heard the later doesn't absorb well regardless the form.

MichaelGregerMD8 karma

As far as I'm aware, nearly all documented B12 deficiency reversal in those on plant based diets has been done on cyanocobalamin. In fact the only study I know of with methyl was one in which one out of the three treated didn't completely resolve! So better safe than sorry I say, until we have more data.

runnerdood37 karma

Why have you found plant-based eating to be healthier than diets heavy with meat?

MichaelGregerMD72 karma

I think that's what the balance of peer-reviewed scientific evidence shows. One can look at population studies, like seeing what the healthiest and most long-lived populations eat (the so-called "Blue Zones"). For example, my video The Okinawa Diet: Living to 100. Or go all the way to randomized controlled trials, like Dr. Dean Ornish's Lifestyle Heart Trial, that showed that a plant-based diet and other healthy lifestyle changes can reverse heart disease, our leading cause of death. In fact it's the only diet that has ever been proven to reverse heart disease in the majority of patients. So seems like maybe that should be the default diet until proven otherwise--after all, a cure for our #1 killer? And the fact that it has also been shown to reverse other chronic diseases like hypertension and type 2 diabetes would seem to make the case overwhelming.

coco_lani28 karma

Hello! Thanks for doing the AMA, I've been enjoying your work and although I started as a vegan for more political reasons, the change I've felt in my health has really inspired me to reach out to others I know that are struggling and that is seemingly a much easier way to approach it for most people.

My question is:

What do you think of the raw vegan movement? Do you think that it is worth it?

MichaelGregerMD43 karma

The reason I think one might see some benefits early on eating predominantly raw is that by definition it means you're cutting out processed food and junk. So compared to a vegan living off of french fries and vegan doughnuts, someone eat a raw vegan diet would do much better. The important thing is to try to eat lots of whole plant foods. I don't know of any data suggesting eating exclusively raw has benefits over a a diet composed of largely whole plant foods, both raw and cooked. I am concerned about AGEs, though, and so though I love them, in my own diet I've been roasting my nuts less. See, for example, my video Reducing Glycotoxin Intake to Prevent Alzheimer’s

ares_god_not_sign25 karma

Dr. Greger, what are your views on pseudoscience in the realm of nutrition and health? People like Vani Hari (the food babe) and Dr. Mercola have gotten extremely popular by manipulating, misusing, and misunderstanding basic science. Do you see that as a major problem in nutrition science? What do you think should be done?

MichaelGregerMD44 karma

Here's a quote from my new book that touches on this:

"Too much of the nutrition world is split into camps, each following their respective guru. What other field of serious scientific inquiry is like that? After all, 2 + 2 = 4 regardless of what your favorite mathematician thinks. This is because there isn’t a trillion-dollar industry that profits from confusing people about arithmetic. If you were getting conficting messages from all sides about basic math, in desperation, you might have to choose one authority to stick with, hoping that person will accurately represent the available research. Who has time to read and decipher all the original source material?

Early on in my practice, I decided that I didn’t want to rely on anyone else’s interpretation for what could ultimately be life-or-death decisions for my patients. I had the access, the resources, and the background to interpret the science on my own. When I initially began my annual reviews of the nutrition literature, it was really just to make myself a better doctor. But when I discovered such a treasure trove of information, I knew I couldn’t keep it to myself. My hope is to disseminate it in a way that removes me as much as possible from the equation. I don’t want to present the trademarked Dr. Greger Diet; I want to present the best-available-evidence diet. That’s why I show the original papers, charts, graphs, and quotes with links to all the primary sources in my Nutrition Facts.org videos. I try to keep my own interpretation to a minimum—though admittedly, I sometimes can’t help myself!

custerdome25 karma

Dr Greger,

First off, you are a hero to the vegan movement -- thank you!

1) How do you feel about the growing interest in cannabis as medicine, for everything from PTSD to glaucoma?

2) Have you made your mind up on the ever-changing research surrounding coffee?

MichaelGregerMD24 karma

There is very little clinical (i.e. human, not in a test-tube) research on cannabis, which is the reason I haven't covered it. But every year I renew my search to see if there's anything new out there and will report as soon as I find anything! If you ever run across a study you think I may have missed, please email me at [email protected].

I've got a bunch of videos on coffee, my two most recent are Coffee and Mortality and Coffee and Artery Function. Bottom-line: I don't recommend drinking coffee not because it's unhealthy but because of the opportunity cost. Every cup of coffee is a missed opportunity to drink something even healthier (like green tea).

jsr0esq4 karma

In your book you seem to recommend coffee saying that even the addictive nature of it may be a good thing, no?

Is there anything to worry about acidic drinks affecting gut bacteria? I remember hearing something like phosphoric acid in colas can be harmful. Is this true? Is the same true for coffee?

MichaelGregerMD13 karma

I refer to the potential beneficial effects of the addictive qualities of caffeine in my video Preventing Liver Cancer with Coffee, but coffee can exacerbate GERD (gastroesophageal reflux disease). I'm not aware of any research on the effects of coffee on the microbiome, but I do have a video coming up on the beneficial effects of tea on our gut flora. The phosphate additives in cola are indeed harmful because they are highly absorbable--see Phosphate Additives in Meat Purge and Cola but there are none in coffee.

TheBrit9025 karma

I have changed my diet quite considerably since I discovered your website and watched your videos, but I still can't kick my entire meat intake. Do you have any advice on how to make the transition easier into plant based foods? I have successfully cut out Milk and most other dairy (apart from fresh mozzarella). Also here is my favourite quote which helps me - A man can live and be healthy without killing animals for food; therefore, if he eats meat, he participates in taking animal life merely for the sake of his appetite. Leo Tolstoy

MichaelGregerMD28 karma

PCRM has a fantastic three-week kick-start program for plant-based eating. Check it out at 21DayKickstart.org. It's a free online program that starts the first of every month and offers a full meal plan, recipes, tips, resources, a restaurant guide, and a community forum. That's what I tell my medical colleagues who are like "I don't have enough time to talk to my patients about diet." I tell them to just give them that URL. Hope it helps!

PCRM (the Physicians Committee for Responsible Medicine) is a nonprofit nutrition research and policy advocacy organization in Washington, D.C. Disclaimer: the love of my life works there so I'm kinda biased :)

jsr0esq22 karma

I am almost finished listening to the audiobook! We need to get this book in the hands of Oprah and make it a bestseller. It needs to be assigned reading for everyone. Thank you for your work.

I have a few questions for you today.

First, egg whites. I am vegan, and family members aren't. I order the tofu scramble. They order an egg white scramble. They tell me there is nothing in egg whites other than protein. Moreover, the protein in egg whites is supposedly better absorbed. Is this correct? Who is eating the better breakfast?

MichaelGregerMD42 karma

Plant protein sources are generally preferable to animal sources because of the baggage animal foods tend to carry with them. Food is a package deal. As much as Burger King says you can have it your way, you can’t be like “I’d like the burger, hold the saturated fat and cholesterol.” Whereas what’s the “baggage” that accompanies plant protein? Many of the nutrients most Americans are lacking. A striking 97% of Americans don’t even reach the recommended minimum daily fiber intake. 98% of Americans suffer from potassium deficient diets. Most of our dietary deficiencies are due to inadequate intake of whole plant foods.

But egg whites and skim dairy products don't have saturated fat (and the cholesterol in eggs is only in the yolks). It's not just a matter of the opportunity cost, though (missing out on the fiber and phytonutrients you're getting in your tofu scramble). Because of the amino acid profile typical of animal proteins, the consumption of animal foods tends to increase the level of a cancer-promoting growth hormone in the body known as IGF-1. That is thought to be why those who eat more animal (but not plant) protein appear to die sooner and have higher cancer and diabetes mortality. See my 2015 year-in-review video starting at minute 6:36 for a discussion of animal vs. plant protein and IGF-1.

The effect on kidney function is another issue. See what happens within just a few hours after eating the same amount of protein in the form of tunafish versus tofu in my video Which Type of Protein is Better for Our Kidneys?. It's really pretty striking.

Now an egg white only scramble is certainly better than using whole eggs, because the saturated fat and cholesterol have been removed, but your tofu scramble would be expected to be even healthier (especially if you add turmeric!).

Astuague21 karma

Dear Dr. Greger, In 2013 and 2014, some studies were published that are not so positive on vitamin D supplementation(http://www.ncbi.nlm.nih.gov/pubmed/24703049 and http://www.ncbi.nlm.nih.gov/pubmed/23250508). The studies I'm talking about are also cited in this piece by Dr. McDougall (who himself is also not in favor of supplementing vitamin D): https://www.forksoverknives.com/vitamin-d-supplements-are-harmful-sunshine-and-food-determine-health/

If I am not mistaken, the videos on nutrionfacts.org dating from 3 to 4 years ago are quite positive on vitamin D supplementation. Do you think these most recent studies will require a re-evaluation on whether or not to supplement vit. D?

MichaelGregerMD41 karma

Great question! My current recommendations can be found here, but indeed I haven't reviewed the D literature for years. What I do (if you pay really close attention you can catch it :) is cycle through the alphabet, so you'll notice on NutritionFacts.org berry videos follow bean videos follow avocado videos, etc. Well I'm finally on V! An unprecedented 14,000 papers were published on nutrition in the medical literature last year and so I'm still catching up. But I just finished a slew of vinegar videos, and next up? Vitamin D! So I should have an answer soon, and indeed my recommendations may change if the science has indeed changed. Sorry I'm so far behind!

everlong4 karma

Somehow I got through your entire video backlog and never noticed them proceeding alphabetically. :/

Does this mean we'll get updates to supplant your older clips? I find the "Fact vs. Fiction", "Harmful/Harmless/Helpful?", and "Which is best—A, B, C, D, E...?" videos to be much more boring, and not the high-quality, information-dense snippets I'd like to refer to or share.

MichaelGregerMD15 karma

My dream is to one day replace all those old low quality videos. Still trying to just keep my head above water keeping up with posting new videos/blogs every day that I never seem able to get to the old stuff. Hopefully one day!

hlh220 karma

What are the pro's and cons of current "fad" diets such as Atkins, Paleo and the "bulletproof"? What are your top recommended foods to eat on a daily basis?

MichaelGregerMD18 karma

I couldn't have said it better myself Wombatmanchevre! :). You can see my daily dozen list (all the foods and in what quantities I recommend) in my book trailer video. You might have to pause, though, as it goes by fast. Please let me know if you have any questions on serving sizes, as they may be a bit unconventional (for example I recommend a quarter teaspoon of the spice turmeric a day).

sporesofdoubt18 karma

What do you think are the biggest problems with the current USDA Dietary Guidelines for Americans, and how would you change them if you had the power to do so?

MichaelGregerMD32 karma

The new (2015) guidelines have yet to be released, but may be out as soon! (the current 2010 guidelines were released in January 2011). I did, however, speak before the 2015 Dietary Guidelines Committee and then at a later hearing after their recommendations had been released. View My Testimony Before the 2015 Dietary Guidelines Committee. I just found my follow-up comments on-line here. Let me know if you have any further questions about them.

Thanks for your question--it's very timely!

AuntyVal12 karma

Do people beyond reproductive age need to worry about organophosphate pesticide residues on food? I eat a lot of kale and collards and they cost $3 a bunch organic and less than $1 non-organic. Thank you for all you do.

MichaelGregerMD29 karma

This year I did a 4-part video series on the latest on buying organic (5-part if you include How to Make Your Own Fruit and Vegetable Wash):

Basically I conclude that the benefits of eating fruits and vegetables (especially the healthiest--like greens) far outweigh the risks. From strictly a human health standpoint (I realize there are other reasons for choosing organic), I'd rather see you spend that $3 to eat three times as many greens, even if they are conventionally produced.

unahcoogin12 karma

Thank you for your website, i search it often and have made the transition to plant based eating 95% of the time. I bought your book in support, reading it now!

What are your thoughts on intermittent or alternate day fasting for long term weight loss?

MichaelGregerMD17 karma

Yes, yes, I agree with KolbeP--great question! There is a burst of new research on intermittent fasting (for a 2014 review to whet your appetite, check out this article). Studies like this, though, suggesting moves like skipping breakfast may increase blood cholesterol levels make me nervous. It's one of the topics I'm most excited about diving into--stay tuned!

Grandpa_Rob11 karma

Do you see the AMA moving to or away from lifestyle and diet as medicine given the huge influx of dollars from drug companies?

Huge fan, thanks for everything you do.

MichaelGregerMD22 karma

An AMA about the AMA--love it!

Sadly, the American Medical Association has a shameful history of being beholden to corporate interests at the expense of patient health. See for example starting around minute 1:04 in my annual year-in-review video, where I talk about the AMA withholding support from the Surgeon General's report on smoking after receiving a $10 million grant form the tobacco industry.

But slowly but surely, things are changing. There are now nutrition based medical conferences (here and here). The current President of the American College of Cardiology walks the walk (I use one of the quotes attributed to him in this article. When he was asked why he follows his own advice to patients to follow a plant-based diet, he reportedly answered: "I don’t mind dying. I just don’t want it to be my fault."). And look at what Kaiser Permanente put out in What Diet Should Physicians Recommend?. These are reasons to be optimistic!

weezerluva36910 karma

Dr. Greger, I'm a huge fan. I know that a lot of research into consuming meat has shown that it is bad for human health. My question is, how does this translate to other animals? Do you advocate feeding animals thought to be obligate carnivores (like cats) plant-based diets? Do you think that the health risks regarding meat consumption are limited to humans and other omnivores?

Along the same lines, what should we, as plant-based eaters, be feeding our pets?

Also, on a slightly different note, I've found that people are a lot more receptive to hearing about veganism if you approach it from a health perspective, instead of an ethical one. Do you find this to be true, and if so, do you think that this is how vegans should approach discussions with omnivores?

MichaelGregerMD23 karma

That's a great question, but alas, as a physician I'm a very narrow limited veterinarian in that I only know a single species :). I imagine this may be a very unsatisfying answer but I would recommend you ask your vet. Sorry!

evenode10 karma

Love your work on nutritionfacts.org :) Thanks for providing all the good info!

What is your favorit dinner recepie?

MichaelGregerMD26 karma

In my attempts to be as efficient as possible in all areas of my life, I like checking off as many boxes as possible of my Daily Dozen at one time, so in the book I include my "Eight Check-Mark Pesto" recipe:

  • 2 cups fresh basil leaves
  • 1⁄4 cup freshly toasted walnuts
  • 2 cloves fresh garlic
  • 1⁄4 of a peeled lemon
  • 1⁄4 teaspoon lemon zest
  • 1⁄4 inch of fresh turmeric root (or 1⁄4 teaspoon turmeric powder)
  • 1⁄4 cup pinto beans
  • 1⁄4 cup water or liquid from bean can
  • 1 tablespoon white miso
  • Pepper to taste

Combine all ingredients in a food processor. Blend until smooth. Scoop onto a cup and a half of cooked whole-grain pasta.

Ok, now you made my hungry :)

Bosonwit9 karma

Hello Dr. Greger! I hope you can answer something to my question even though its a bit of a stretch from medicine and nutrition. Climate change is not directly related to health and nutrition but in the grand scheme of things it is so of course very much. Therefore I would like to ask, how or if you or medical organizations you are a member of, are involved in the COP21 negotiations in Paris, to promote plant-based diets and to assure that the detrimental effects of animal agriculture and animal product consumption to human health and further to the environment are voiced clearly and are discussed openly? As far as I could follow, these issues are (as usual) not discussed very much or at all despite the huge impact.

If not, do you know who and how is involved in the negotiations in relation to the issues of animal product consumption?

Best, Boson

MichaelGregerMD11 karma

My favorite medical journal is probably The Lancet for the very reason that they address these kinds of broader issues related to human health. You don't see much about climate change in the American journals. It's not something I follow closely, but I did do a video on it a few months ago: Diet and Climate Change: Cooking Up a Storm. I'm sorry I can't answer your question about the COP21 negotiations, though. Anyone know out there?

plantbasedfooddotcom8 karma

Hi Dr Greger, I would like to cycle around London with a T-Shirt that says "Until Now"... any plans to do more promotional stuff in line with your book release? I'd buy my whole family everything :-)

MichaelGregerMD13 karma

That's hilarious! There's some company called Plant-Powered Clothing that made some NutritionFacts.org shirts. If you'd like a bumper sticker for your bike (yeah cycling!) email me your mailing address to [email protected] and I'll get one right out to you!

grayprog8 karma

Thank you for your amazing content and well-produced videos, Dr. Greger. I especially like the year-in-review talks. I identify as "mostly vegan". Why I'd prefer 100% vegan, I find it to be a difficult lifestyle in social settings and even in my otherwise non-vegan family.

My question is: how much of an occasional deviation from vegan diet is detrimental to one's health? Does an occasional salmon dish, or butter in the paste, or the eggs in a pastry negate all the benefits of otherwise whole-food vegan diet?

MichaelGregerMD18 karma

Fabulous question! There was a study involving four thousand participants that compared traditional Asian diets with and without occasional servings of meat. The researchers found that men who avoided meat altogether had only half the odds of diabetes compared to those eating a serving of meat every few days, and the vegetarian women had 75% lower odds of diabetes than women who were otherwise vegetarian but averaged a single serving of meat a week. We don’t know exactly where that dividing line is, but we do know based on the Adventist data that vegetarians who start to eat meat at least once a week appear to experience large increases in the risk of heart disease, stroke, diabetes, and weight gain. During the twelve years after the transition from vegetarian to omnivore, meat-eating was associated with a 3.6 year decrease in life expectancy.

From a nutrition standpoint, I’d much rather see people eat, for example, the traditional Okinawan diet, which is largely (but not exclusively) plant-based, than the strictest 100% vegan diet centered around french fries and vegan Doritos.

Unprocessed plant foods are the healthiest options, so the more we can squeeze into our daily diet the better. Health-wise it doesn’t really matter what we eat on holidays or special occasions; it’s our week-to-week choices that makes the most difference for our long-term health and longevity. Sounds like you're doing better than 99.99% of Americans so congratulations and keep it up!

IFuckingLoveB126 karma

What are your thoughts on the book The China Study by Dr. T. Colin Campbell? I read that book and was completely blown away by the information. I have been on a WFPB Vegan diet for 4 months now, and love it! Was his work influential in your own research at all?

MichaelGregerMD10 karma

Dr. Campbell is one of the reasons I went to study at Cornell! He's long been an inspiration to me. If you're interested, I quote a bit from his writings in my video China Study on Sudden Cardiac Death.

MichaelGregerMD6 karma

Dr. Campbell is one of the reasons I went to study at Cornell! He's long been an inspiration to me. If you're interested I quote a bit from his work in my video China Study on Sudden Cardiac Death.

MountainRose1006 karma

If I put broccoli sprouts in a green smoothie, do i have to chop them and let them sit 40 minutes before actually blending and drinking in order to get the cancer fighting benefit?

MichaelGregerMD8 karma

Ooh, that's a good question. For context for those unsure what we're talking about, check out my video Second Strategy to Cooking Broccoli. A goal in eating broccoli sprouts (and cruciferous vegetables in general) is to get at the compound sulforaphane which, like it's precursor, is heat-stable, but the enzyme that creates it is not. So by eating such vegetables raw, pre-chopping broccoli and waiting before cooking (thereby activating the enzyme and letting it do it's work before it's destroyed), or adding exogenous enzyme after cooking (in the form of mustard powder, grated radish, or raw cruciferous like shreds of purple cabbage) you can maximize sulforaphane production. The reason eating such veggies raw works even though our own stomach acid also deactivates the enzyme is that when we eat food it out it sits in our upper stomach long enough for sulforaphane to be created. But, to finally get to your question, when consuming cruciferous vegetables in blended form like a smoothie, it really would be better to blend and wait (no need to prechop--the blender blades will do that for you). So wait, or just drink is slow (as I recommend for other reasons in my video series on smoothies, for example Green Smoothies: What Does the Science Say?. I love these high level questions!

affenlehrer6 karma

Hi Dr. Greger,

I love your channel and I'm a vegan for more than a year now. However, even though I exercise, drastically limit salt and rarely eat any processed foods my blood pressure is still relatively high (about 130/90). Do you have any tips what I could do to "fix" that? I know you can give "real" medical advice this way but maybe you have an idea what I could get checked out or try...

Thank you!

Edit: I also supplement B12 and take freshly ground flax seeds daily

MichaelGregerMD18 karma

I'm so glad you wrote in! Although the average blood pressure of those eating strictly plant-based may come in down around an extraordinary 110/65 (see my video How to Treat High Blood Pressure with Diet), there's a bell curve. Sounds like you've already subtracted the stuff from your diet that may have been raising your blood pressure. If that's not enough, then the next step is to add foods that may help bring it down:

For example, check out my video Flax Seeds for Hypertension, in which a found prospective, double-blinded, placebo-controlled, randomized trial found that flaxseed "induced one of the most potent antihypertensive effects ever achieved by a dietary intervention."

And in terms of what to drink, see Hibiscus Tea vs. Plant-Based Diets for Hypertension, where two cups of strong hibiscus tea every morning (using a total of 5 tea bags for those two cups) effectively beat out a leading anti-hypertensive drug in a head-to-head challenge (by working just as well without the side-effects).

NOTE: If you are on anti-hypertensive medications, make sure to closely monitor your blood pressure along with your physician so they can wean you off the meds. People underestimate the power of dietary interventions, and if they remain on the same dose of blood pressure pills their pressures can drop too low and people can pass out and hurt themselves. The same goes with dietary reversal of diabetes for those on insulin and "sugar pills."

yungrabbit5 karma

I've never considered potatoes to be so controversial ... until now. Dr. John McDougall, for example, laudes the potato as one of the most healthful foods, while others such as yourself have a different idea, going as far as to say they are toxic. What's the verdict, doc - will potatoes, sweet potatoes, and possibly yams - boiled or baked - make me regret eating them regularly (say, three to four nights per week)? Thanks for all your kind work.

MichaelGregerMD9 karma

Sweet potatoes (which in the U.S. is synonymous with "yam") are one of the healthiest foods on the planet! Even better, purple sweet potatoes! That's actually one of my favorite snacks. After scrubbing some purple-fleshed potatoes I cut them into wedges, sprinkle some malt vinegar on them, dredge them in a mixture of blue cornmeal and powdered rosemary and bake them until they're mashed potato soft inside. Then dip them in hot sauce spiked ketchup--yum!

jbauer225 karma

Hi Dr. Greger, thanks for doing the AMA!

What's your research tell you about the gluten free craze? I feel like I see so many contradictory studies about gluten being the devil or gluten being benign, I'm not sure what to believe about it.

MichaelGregerMD8 karma

I did a 3-part video series within the last year summarizing where we stand:

The bottom line is that wheat intolerance (whether from celiac disease, formal wheat allergy or non-celiac manifestation) remains rare, but for sufferers gluten-free diets can be a life-saver. For the other 95% of us, though, gluten-free diets may do more harm than good (though I believe we should all try to minimize our intake of refined grain products such as white bread/bagels/pasta and stick to whole grains).

AlbertoAru5 karma

Hi, I'd love to know what do you think about what doctors and nutritionist currently think about veganism. I know you are a great advocate and I love it, but this is not what most physicians think and I'd like to know what's your impression? how are they receiving veganism? and if veganism is as good as we think it is, what's wrong with them, then? why don't they see it?

I have a friend whose doctor told him that he can't be vegetarian (nor vegan, of course) because of his blood type, what would you tell him?

Thanks so much!!

Kind regards, Alberto

PS. Do you have in mind coming to Spain?

MichaelGregerMD13 karma

Doctors have a severe nutrition deficiency--in education. Most doctors are just never taught the impact healthy nutrition on the course of illness and so they graduate lacking a powerful tool from their medical toolbox. That's one of the reasons I started NutritionFacts.org. There are also institutional barriers, such as time constraints and reimbursement schedules. In general, doctors simply aren't paid for counseling people on how to take care of themselves. Of course the drug companies also play a role in influencing medical education and practice. Ask your doctor when's the last time they were taken out to dinner by Big Broccoli :)

In terms of blood type, please ask your friend to refer their doctor to my video Blood Type Diet Debunked.

Me encantaría ir a España! So far I've only got 6 countries confirmed on my current book tour, but I'd love to add more. If you can find a hospital or other organization to host me, please have them fill out by Speaking Inquiries form.

Assmouthorboth3 karma

How do I get my kids to eat more vegetables?

horsec8z23 karma

Hiya Dr Greger Thanks for all your hard work. Since I very recently had a bout with a severe allergic reaction to mango, and have since found out that the sap from them is akin to poison oak, I was wondering if you have ever done a video about common food allergen's?

MichaelGregerMD7 karma

The closest I come is talking about the effects of diet on allergic-type diseases, for example Preventing Asthma With Fruits and Vegetables and Treating Asthma With Fruits and Vegetables but not much on food allergies per se. Sorry to hear about your mango allergy--it's one of my fave fruits!

romie__2 karma

Hi Dr. Greger, I have two questions. In a previous question dealing with B12 you recommended a weekly oral supplement. I have recently started using a B12 fortified toothpaste. Is that enough? What would your take be on that? My second question deals with migraines. I have migraine with aura, I can't really see for 40 minutes and it is followed by or accompanied by feeling queasy. I watched your video on migraine and have been using ginger to deal with the pain, but I was wondering if you have any dietary advice on dealing with visual disturbances or feeling nauseous. And if there are any foods which could make these migraines less frequent. I am 32, vegan and try to eat pretty healthy... Have a nice day!

MichaelGregerMD5 karma

I've never even heard of B12 fortified toothpaste! Sounds gimmicky. And since one doesn't typically swallow toothpaste, how do they expect people are going to get ahold of it. Since there's been no studies (that I'm aware of) that have shown B12-fortified toothpaste can reverse B12 deficiency (which is the gold standard) I'd recommend taking the supplement (though you could do both--you can't take too much oral B12--you just pee out the excess).

In terms of migraines the ginger remedy you note from Ginger for Migraines would presumably help with the nausea too (see my Nausea Remedy Recipe), though I'm not aware of any aura data.

Lavender is another natural option for treating migraines . I hope that helps!

VegIsGreat2 karma

Hello Dr. Greger, Great Book. Have a hard copy as well as audio book. I am a healthy lifelong vegetarian (last 3 years predominantly whole food plant based vegan). At age 46 now. While at age 35 I had glaucoma and cataract surgery and otherwise in great health. I still use eye drops for glaucoma for controlling eye pressure. Any plant focused food will help in my situation or reverse the condition? My daughter also has a high myopia greater than -10. Any help from plant based lifestyle? Or is this pretty genetic and ho hope?!

Thanks to your great service to the world

MichaelGregerMD6 karma

Nothing that I know of for myopia (darn it!), but I do have three videos that address glaucoma:

I hope those help!

0bel1sk2 karma

Hello Doctor. I am a huge fan. Thank you for doing this AMA. Have you considered sharing your personal diet as an example of what one should/could eat? I would be interested in a regularly updated diary of the food that you eat.

MichaelGregerMD5 karma

This is so much fun--I wish I had done an AMA earlier! Q&A are always my favorite part when I give presentations, and so it's like all the questions I can eat :). I go into detail about my daily diet in the new book but haven't kept a diary. Good idea for a blog post, though!

tenthtimesthecharm2 karma

Hello! I'm a big fan of your website and really appreciate your effort to report on what science says. I just recently received your new book (I pre-ordered) and am really enjoying what I've read so far!

My questions: What recommendations do you have for medical students who are interested in nutrition and other lifestyle factors affecting health, but receive very little formal training in that area? Do you think this is a change we will see in medical school curriculums in the future (more nutrition/prevention training)? How can we start making that change?

MichaelGregerMD5 karma

Very little indeed. Did you see my Physicians May Be Missing Their Most Important Tool video this year? Shameful! I'm afraid you're going to have to do a lot of self-learning, but there are more and more resources every day. For example, the American College of Preventive Medicine is launching a 30 hour online Lifestyle Medicine Core Competency program (I was lucky enough to be chosen to contribute some of the nutrition content). Hopefully by the time you're in practice programs like that will be a dime a dozen. In the meanwhile feel free to subscribe to my (free like everything on the ad-free, noncommercial, nonprofit site) daily nutrition updates.

Melvegan661 karma

Are there foods that will effectively address menopause symptoms?

MichaelGregerMD5 karma

Thank you so much for the question!

Though 80 to 85% of European and American women suffer from hot flashes, this figure may be as low as 15% in places like Japan. In fact there’s not even a word for it in the Japanese language. Maybe the phytoestrogens in soy are helping?

The association between soy product intake and the occurrence of hot flashes was examined by following a thousand Japanese women before they started menopause over time to see who developed hot flashes and who didn’t, and those women who were eating like 4 ounces of tofu a day appeared to cut their risk in half compared to women who only ate like an ounce or two a day, suggesting soy products are protective. But maybe soy intake is just a marker for a healthier diet over all?

A study in China found that the consumption of whole plant foods in general seemed to be associated with decreased menopausal symptoms, so to see if soy was something special you’d have to put it to the test. Studies using phytoestrogens in pill form have shown extraordinary results, a significant drop in hot flash presence, number, and severity. Over the last 20 years more than 50 clinical trials have evaluated the effects of soy foods and supplements on the alleviation of hot flashes. Compiling the best ones together, the placebo groups got about a 20% drop in hot flash severity, the soy groups achieved about a 45% drop, so on average the soy did about 25% better than control.

There have been two studies that compared soy phytoestrogens head to head against hormone replacement therapy and in one study they actually seemed pretty comparable, in terms of reducing hot flashes, muscle and joint pain, and vaginal dryness compared to placebo, though in the other, soy did better than placebo but estrogen and preogesterone therapy did better than them both. But, unlike hormone replacement therapy, the soy has the benefit of not increasing cancer, heart disease, and stroke risk.