Diet Change: Vegan to Grain-Free

I am an extremist. The simplicity of extremes is appealing as one avoids the complexities of grays. For the past two years or so, I have followed a rather strict vegan diet motivated by the health benefits claimed by The China Study, and not particularly by the idea that it is immoral to eat animals. Recently I have had a number of questions in my mind as to the evidence for and against such diets, and ultimately decided to add preferably lean, organic and non-feedlot meats back into my diet. At the same time, I am experimenting with removing grains from my diet. Here’s why:

Is the evidence for a vegan diet very strong?

The China Study presents a few lines of evidence to support that protein, probably by IGF-1, can increase cancer risks. However, upon reading The Protein Debate, it seems to me that Dr. Campbell believes all protein does this and a primary reason to go Vegan is that such a diet very likely limits total protein to less than 10%. If you are vegan and you eat enough legumes or vegan protein supplements to get that number to 20-30%, are you not violating the fundamental argument for the anti-cancer benefit?

Virtually none of the people studied in The China Study were vegan. An extrapolation is made that goes from low animal protein to zero should be helpful. Is that reasonable? As recently as 1998, new nutrients were recognized as essential. What essential nutrients have yet to be discovered? Perhaps even low levels of meat supplies something essential that is as of yet unknown, without which health is impaired. No population of humans that I am aware of have lived on vegan diets for their entire lives. I’d prefer to be conservative and adopt a diet with some consensus behind it, namely, what did groups of healthy and long-lived people eat? The Blue Zones project seeks to address this. They identified many groups of long-lived people. Only one of them had significant populations of vegetarians (Seventh-day Adventists), and even most of them consumed some fish and eggs. Granted, Adventists who ate more meat had higher cancer rates, but how controlled were the studies? Were those processed meats? A recent meta-analysis found processed meats increased heart disease and diabetes, but not red meat. Many studies lump all meats together, which may be throwing the baby out with the bathwater.

What will I eat?

If you are not on a tight budget, you have many options for food. My current experiment is to add meats back to my diet, but remove grains. Why am I removing grains? I was influenced by two arguments. The first being The Paleo Diet, the second being general low-carb diets that avoid grains such as rice, bread, pasta, and so on to reduce insulin production. The core idea is that there are some foods to which were are more adapted to eating than others, and grains are particularly bad. This is a reasonable hypothesis, but it needs to be substantiated by evidence before it should be treated as true. My ancestors have likely been farming for 10,000 years or more, and that may have been enough time to completely adapt to a grain-based diet. However, for this experiment, I’m removing grains. From a standpoint of nutrient density, grains are not so great. Take a look at the The World’s Healthiest Foods. Very few grains compare favorably against fruits, vegetables, and meats for nutrients per calorie. I am going to focus on very low glycemic index foods. The exception will be during or after longer running events or workouts. I will use bananas, watermelon, pineapple and sweet potatoes after workouts to get non-grain high-GI foods. I will also eat lentils and beans, which are low-GI, but not Paleo-approved. Some might say, this sounds like an Atkins diet, and that is not healthy. It appears to me concerns about lower carbohydrate diets seem to lack evidence. A recent 2-year study, sometimes called the ATOZ study, found Atkins dieters lost more weight and improved metabolic risk factors more than traditional, Ornish or Zone dieters. I can’t find any evidence that these diets are a risk. Can you?

Should you change your diet?

I believe humans are very metabolically flexible. If you have no problems with your health, athletic performance, or happiness that could plausibly be connected to diet, and you are pleased with your diet, I’m not sure there is strong evidence to change. If you are overweight, struggle to maintain your weight, are frequently injured, or feel that your workouts don’t go well, perhaps changing your diet is worth a try. I don’t think anyone can convincingly say much about diet other than if you are obese, it is harming your health. If your diet is not preventing obesity, you probably need a change.

Update 2/27/2011: I found this criticism of the China Study to make good points (and a few of the same ones I made). It would be interesting to see more a response to these questions and criticisms from Dr. Campbell.


5 Responses to Diet Change: Vegan to Grain-Free

  1. Rhett says:

    Do keep me posted. For the record, I’ve tried pretty much all of the diets you mentioned and found them to all work equivalently well for me as long as I continue to get heaping helpings of exercise (which is really the only thing that saves me from obesity in the long run). My nearly-vegan diet (vegan except for 1 meal each week) did seem to give me some trouble with muscle atrophy, but that’s not a very strong correlation, since I started Crossfit at the same time I dropped that diet.

    I am, by a BMI measurement, overweight, and getting down to “normal” weights is excessively difficult for me, but I’m really only a little over the line and I’m very active. I don’t win medals, but I am the statistical median runner in every event I enter, and I’ll take it. Honestly, I have massive leg muscles from a lifetime of soccer and cycling, and I’m sure I could hit that BMI target if I didn’t have them.

    I also think you have a healthy outlook on diets. I’ve been around the block on the literature and I can only conclude that it’s a wash and that it’s quite possible most long-lived populations pick it up from other lifestyle choices, not the least of which is abstinence from tobacco. Far too many of my friends have gone paleo mostly out of it appealing to their sense of “caveman originalism,” which is interesting when you consider most of them are computer engineers.

  2. Kylie says:

    I found your post very interesting. I am a health and lifestyle coach. Please check me out on my website and my blog I have been on a similar path and have recently thought a lot about removing grains. Here is what I found being on meat for one day. Meat sits in the digestive system too long and rots. This is not a bad thing, it’s just what happens and it doesn’t make me feel very good. The thing is that Paleo sounds good but I find that nothing really beats the benefits of veggies and fruit. Adding meat and fish is not a bad thing but I feel that the Paleo, Akins and such diets adds in too much meat/animal.

    I understand about what the caveman ate but then thing is that we are not cavemen and we have different digestive systems then they had. One thing you have to think about is digestion and ph levels. So check out these two topics on your journey. Digestion is really important because what ever you don’t fully digest sits in your body and causes toxic body which can lead to illness. Same thing with ph balance. Check out Natalia Rose’s The Raw Detox Diet Book and Kris Carr’s Crazy Sexy Diet.

    For myself I decided that adding meat back does not work for me and my current health issues. I have been gluten free and mostly vegan/vegetarian for several years. I don’t stick to things 100% because I like to keep a little wiggle room. I am going to attempt to continue being vegan but remove more grains. I a very into raw foods and I find that raw food diet is wonderful for my overall health. I do not practice 100% raw. Usually during the warmer months I am higher raw than the colder months.

    Too many grains are bad but so is too much meat. The thing I find is that you can never have too much fruits and vegetables. I wish you luck on your journey and can’t wait to read more about what you find.

  3. Jenny says:

    I’m grain-free and vegan, so it’s possible to do both 🙂
    I also avoid soy and potatoes.

  4. Zooko says:

    Who wrote that criticism of “The China Study”? It is unsigned and I can’t find an attributed copy of it by searching. Denise Minger has written a very effective criticism of The China Study in which she shows that the data are inconsistent with the conclusions. Ned Kock as done some related and supportive data analysis as well.

    Your hope that Dr. T. Colin Campbell will respond to these critiques is in vain. He had set up a web site to promote something or other of his, and when Denise Minger’s criticism was news he announced that he would use this site as a forum to engage in discussion with these critics, but then he abruptly cancelled that plan and has, as far as I know, remained mum on the topic since.

    I read everything that he posted on the topic up until that time, and it was truly a contemptible display on his part. It consisted almost entirely of evading the issues, lauding his own scientific credentials, and smearing his critic (Denise Minger) by suggesting that she might be a sock puppet invented by his enemies, the Weston Price Foundation.

    I have quite a lot of strong opinions on diet that are related to your speculations above, but I’ll spare you the full litany for now, except to say:

    > I can’t find any evidence that these diets are a risk. Can you?

    The claims that low-carb diets like Atkins are dangerous are a myth. There is no evidence that low-carb is dangerous, and plenty of evidence that it is healthy. Interestingly, those false claims have been strongly promulgated by many of the nutrition authorities of our time. Check out this list:

    (Curated by a vegan doc, by the way: Michael Greger.)

    Cheers! It was fun discovering your blog by way of you mentioning “Tahoe-LAFS” on twitter. Say hi to Boston McGravity who works with you at Twitter.



  5. Jeffg says:

    Have been following the Paleo diet for about 6 months. Initially difficult, but once I found some tasty recipes and rearranged my shopping habits, everything seems to be falling into place. Certainly my energy levels are up and mainly doing distance walking–I think this might just work out

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