Question:

Are there any medical conditions which require someone to eat flesh?
Are there any that prevent someone from being vegan?

Answer:

There are certainly people who feel like their health suffers when they don’t eat meat, unfortunately.

As I’ve posted about recently, there are some conditions which might make it difficult to eat a normal vegan diet, such as having herpes, being allergic or intolerant of soy or wheat, and having trouble absorbing iron.

And although research shows that a plant-based diet is a good way to treat early chronic kidney disease, once someone has to be on dialysis it can be difficult. This is because most plant foods are either high in phosphorus (as is dairy) or potassium. People on dialysis tend to need large amounts of protein and it’s hard to get it from plants without also getting phosphorus. You can take calcium tablets to try to prevent phosphorus absorption but this strategy is limited.

Vegetarian Diet for Kidney Disease Treatment, by Joan Brookhyser, RD, CSR, CD, is a book about how to be vegetarian or vegan while on dialysis. So, it can be done but I do not know how often it is done.

Finally, there might be some people whose bodies don’t make enough of a nutrient that can only be obtained, at this time, from animal foods.

I once corresponded with an animal advocate who thought his body did not produce enough cholesterol and it was causing him to pass out. He did have very low cholesterol (under 100 mg/dl) which may or may not have been the problem. He said that when he ate cheese, he felt much better and didn’t pass out. We tried to figure out what else it might be, such as not enough calories or fat, but we did not succeed. However, I do not think that cheese, or any other animal product, has magical properties. If the cheese really was solving his problem, then there must be some molecule(s) in the cheese that can be uncovered as the cause.

Eventually, we might be able to produce all such molecules without harming animals, particularly if in vitro meat becomes a reality.

Ginny Messina has sent me an update to the article, Is It Safe to Eat Soy?, which she and her husband Mark wrote for VeganHealth.org.

Quick summary: Soy does not appear to lower sperm count or testosterone levels.

More details can be found here.

I spoke with Beth Ragan at Archer Daniels Midland (ADM) on March 25. She told me that at this time, ADM sells 60 TVP products and two of the 60 have MSG added as part of the artificial beef flavoring.

With everyone talking about the latest study linking red meat to an early death, we almost missed the results of a paper published on March 18 reporting the mortality rates of vegetarians compared to meat-eaters in EPIC-Oxford!

Unfortunately, the news is not as exciting as the red meat study. Vegetarians had the same rates of heart disease, stroke, and all causes as meat eaters.

The following groups had higher rates of an early death:

* Smokers
* Those with very high or very low body weight
* Those who did not drink alcohol

Moderate drinkers had lower rates of an early death.

More details can be read at VeganHealth.org.

Common question I receive:

I just found out recently that I’m allergic to [insert five to ten common plant foods]. Can I still be vegan?

Answer:

Whenever I see that someone is allergic to so many different things, it makes me think they probably have leaky gut syndrome which can give the impression on some food allergy tests that someone is allergic to some foods when they actually are not. I hope to eventually write an article on treating a leaky gut, but do not have one at this time.

I would also be skeptical of food allergy tests as they can give false positives. If I really thought I had a food allergy, I’d go to an allopathic doctor and get a referral to someone who can use the most reliable tests for determining allergies. Click here for a decent article on food allergy testing.

In addition to food allergies, there are food intolerances which will not show up on food allergy tests. The best way to deal with these is to do an elimination diet in which you do not eat the offending food for two to four weeks, see if the symptoms abate, and then add the food back in and see if the symptoms return.

The Food Allergy Survival Guide is a book about eating a vegan diet for people with food allergies.

Comment:

While I was leafleting about vegetarianism, someone told me they tried to be vegetarian but got iron deficiency.

Answer:

When someone says this, you might want to ask them if a medical doctor diagnosed them. A lot of people diagnose their own iron deficiency and are likely wrong about it. It’s good to get people to reconsider whether they really had iron deficiency because my suspicion is that a lot of them actually didn’t.

And then you might suggest that they try eating spinach and oranges at the same meal, on a regular basis. The spinach for iron, and the orange for vitamin C which increases iron absorption. Other iron tips:

* Avoiding black or green tea and coffee at meals.
* Adding a source of vitamin C at meals.
* Increasing legume (peanuts, beans, lentils, peas) intake.
* Cooking foods (especially water based acidic foods like tomato sauce)
in cast iron skillets.

More info can be found on the Iron page of VeganHealth.org.

Question (from a woman who is not larger than average):

I have been vegan for over a year now and recently started to exercise on a regular basis! My personal trainer has told me that I need to significantly increase my protein intake. She wants me to get to close to 100 g of protein per day! I have been logging what I have been eating and have been finding my protein intake to be between 40 g and 60 g. How much plant-based protein is safe/healthy for me to eat? Is my trainer asking to much of me to get 100g of protein per day?

Answer:

Unless you are training to be a competitive bodybuilder, 100 g of protein is much more than you need. I would suggest getting a vegetarian protein powder (natural foods stores will have them) and making one drink (smoothie, or just putting it in soymilk and blending it) per day with a couple tablespoons of the powder. That will boost your protein intake by about 20 g which is plenty for someone who is starting a weightlifting program. That way, you can tell your trainer you’re increasing your protein intake, but without going to 100 g. Once your muscles are where you want them, you can probably drop the protein supplement and maintain them at that level with just normal foods.

This question has arisen a few times for me lately, and I thought the readers of this blog might be interested in the topic.

My personal opinion is that the evolution of apes and humans diverged long enough ago that significant differences in optimal nutrition have manifested themselves, and the value of looking at the diets of apes, in comparison to the nutrition research that has been performed on humans, is very minimal.

Even in regards to looking at our human ancestors, I would not assume that the most natural diet of humans (if that can even be defined or determined) is the optimal diet. Diets can be tweaked and improved in unnatural ways.

In their article Cooking as a Biological Trait, Richard Wrangham and NancyLou Conklin-Brittain, of the Department of Anthropology at Harvard, suggest that it only takes 5,000 years or less for the human body to adapt to different methods of eating. In some cases, some populations can adapt much more quickly, such as during periods of famine when only those whose bodies are most efficient at storing energy survive.

Some interesting articles about the diets of non-human primates and to what extent they are vegetarian can be found on BeyondVeg.com.

Many people commented on yesterday’s post, Cancer and Vegetarianism, saying they wished the researchers had separated vegans from vegetarians.

In the paper, the authors stated, “…because of the small number of cancers among vegans, in this article the vegans are included in the vegetarian category.”

All we really know from that statement is that vegans didn’t have an unusually large number of cancers – so much that they would have reached some sort of statistical significance. It could also be that vegans have less cancer, or even a lot less cancer, but there was not enough data to create any sort of statistical significance.

I think it’s reasonable to hold out some hope that vegans will eventually be shown to have less cancer than meat-eaters or lacto-ovo vegetarians.

It could also be that except for in cases of very high amounts of animal products and very low amounts of fruits and vegetables, diet might not affect cancer that much. In the more moderate amounts of these foods, your body may be getting enough antioxidants, or have enough other mechanisms, to deal with carcinogens introduced by food.

I didn’t include a citation to the study in the original post:

Key TJ, Appleby PN, Spencer EA, Travis RC, Roddam AW, Allen NE. Cancer incidence in vegetarians: results from the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford). Am J Clin Nutr 2009;89(suppl):1S-7S.

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On March 11, a study was released that measured the cancer incidence among British vegetarians. The study was part of European Prospective Investigation into Cancer and Nutrition–Oxford (EPIC-Oxford). I have updated the VeganHealth.org article Cancer, Vegetarianism, and Diet with the new findings.

(For this article to make sense you should take a minute to read this quick explanation of disease rate statistics if you are not already familiar with them.)

The participants in EPIC-Oxford were recruited from 1993 to 1999 and were followed through 2005. Previously, they had their overall cancer mortality through 2002 reported: Vegetarians had an 11% higher rate of death from cancer, but it was not statistically significant (1.11, .82 – 1.51).

The new findings reported the rates in two different ways:

1. Comparing vegetarians (including vegans) to all the meat-eaters.

2. Breaking the meat-eaters into two groups: regular and fish-eaters (no meat except fish).

The only statistically significant findings were:

• Vegetarians had higher rates of colorectal cancer than all meat-eaters (1.49, 1.09-2.03).
• Vegetarians had higher rates of colorectal cancer than the regular meat-eaters (1.39, 1.01-1.91).
• Fish-eaters had lower rates of all cancer than regular meat-eaters (.83, .71-.96).
• Vegetarians had borderline-significant, lower rates of all cancer than regular meat-eaters (.89, .80-1.00).

Rates for breast, prostate, lung, and ovarian cancer did not differ between groups.

When comparing this study population (including vegetarians and all meat eaters), their cancer rates were 28% lower than the overall population, their smoking rates were about half, and the meat-eating among the meat-eaters was “only moderate.” The authors hypothesized that, “Consumption of vegetables and fruit was higher among vegetarians than among nonvegetarians, but the differences were not large (< 20%). Thus, if high intakes of meat had an adverse effect and high intakes of fruit and vegetables had a beneficial effect, the relatively low meat intake and high fruit and vegetable intake of the nonvegetarians in this cohort could reduce the chance of observing lower cancer rates in the vegetarians than in the nonvegetarians." Although we consider cancer rates of 1.49 (1.09-2.03) and .83 (.71-.96) as being statistically significant, I'm starting to wonder how relevant measurements of this magnitude actually are. The studies on vegetarians that have shown statistical significance are pretty inconsistent, and most studies have not found statistical significance. On the other hand, if you look at how the smoking rates affected lung cancer in this study, heavy smokers had 87 times the amount of lung cancer (87.3, 37.8 – 202). Now that is statistical significance. Even light smokers (27.1, 11.1-66.4) and former smokers (6.54, 2.89-14.8) had many times the rates of lung cancer as nonsmokers.

If we include these latest findings of vegetarian cancer rates with the others that have been measured (listed in Cancer, Vegetarianism, and Diet), I think we start to get a fairly consistent picture:

Among vegetarians and people who eat moderate amounts of meat and don’t smoke, cancer rates are about the same, but lower than for people who do smoke and eat large amounts of meat. In other words, you can reduce your risk of cancer by not smoking, by limiting meat to moderate amounts (or abstaining entirely), and by eating plenty of fruits and vegetables. The evidence for stronger claims doesn’t seem to be there.

Similarly, the combined colon cancer rates to date seems to indicate that, in comparison to eating moderate amounts of meat, being vegetarian neither increases nor decreases your risk of colon cancer.