VEGETARIANISM VS, NON-VEGETARIANISM

Following my shoulder injury and surgery, I switched to a vegetarian diet consisting of dairy, eggs, vegetables and fruits for about 8 months. Every time I refused to eat meat at a gathering I would be asked two questions? Did you switch because a vegetarian diet is healthier? And did you switch to a vegetarian diet for weight loss? My answer to both would be, no!

Based on my literature search on carbohydrates and weight gain, I would expect neither would apply to a vegetarian diet, i.e., a vegetarian diet would neither be more healthy nor be less fattening than an omnivorous (meat and vegetable) diet. Even looking at the demographics of obesity and diabetes it’s hard to come to such a conclusion. For example the Indian subcontinent has the highest concentration of vegetarians in the world and yet at the same time they have the highest concentration of type II diabetes and the fastest growing obesity trend. So why has this notion that a vegetarian diet is healthier and less fattening than a comparable calorie omnivorous diet perpetuated throughout the western world? In the following discussion I plan on dispelling this myth along with evidence that an omnivorous diet is as healthy if not more, than a vegetarian diet and in fact an omnivorous diet incorporating fish is even superior to an all vegetarian diet in terms of overall mortality from heart disease and other factors.

We have to understand some of the motivational background for vegetarianism in the east vs. the west. In India for example, most Hindus, Buddhists and Jains are vegetarian by religion as animal slaughter is considered inhumane. In contrast to that, people in the industrialized nations of the west are vegetarian by lifestyle choice mostly motivated by a desire for good health (again perpetuated by the notion that vegetarianism is somehow healthier). So in studies (mostly done in the west) on the health merits of vegetarianism, the vegetarian group is already practicing a healthy lifestyle in terms of regular exercise, not smoking and not drinking alcohol and watching what they eat. That is the most fundamental flaw in these studies because one group of the control population is already working towards biasing the result in a direction that the study intends to find. In a controlled clinical trail, say for example, the trial for a new drug to lower blood sugar. There would be a control group that will be given the sugar pill and there will be a second group that will be given the trial drug. But what if the trial drug group was already working on an exercise plan to lower weight and hence the blood sugar? Would you call such a study fair? I think not! I would bet my farm (if I had one) that the results would be in favor of the trial drug group even if that drug did absolutely nothing. So keeping that in mind let’s look at what research has been done to correlate health to a particular type of diet.

There are 5 famous studies ^{[1, 2, 3]} done all the way back from 1982 up until now where 8,300 deaths were analyzed among 76,000 men and women with respect to their diet. Frequent meat eaters were defined as people that ate meat more than once a week and occasional meat eaters were defined as those eating less than once a week and furthermore another category in the meat eaters was the fish eaters that didn’t eat any meat except fish. The vegetarians were sub divided into the vegetarians that also ate eggs and dairy and vegans that ate no animal products. I am not going to go into the details of how the study was performed or how the data was analyzed but readers are welcome to go through the references if they are statistically inclined. The distribution of the subjects sampled is summarized in table 1 below.

Table 1. The distribution of sampled subjects with respect to lifestyle and dietary habits.

The first thing that strikes us is that the vegetarians in all the studies were following a healthier lifestyle compared to the non-vegetarians. The vegetarians smoked considerably less, drank considerably less alcohol and exercised more than the non-vegetarian population. The Body mass index (BMI) was similar in both groups so neither group was more obese than the other. The results are summarized in table 2 and graph 1 below.

Table 2. Percentage deaths in both groups from various causes.

Graph1. Graphical interpretation of table 1.

It’s worth noting that the number of vegans in the study is an order of magnitude lower than any of the other groups, so anyone that knows statistics would know that the results for this group are not as accurate as the other groups. For example there were no deaths from breast cancer or from prostate cancer in the vegan group but that should not be interpreted as something that is a benefit of the vegan diet. It just means that in the time period of these studies no one in the (small) vegan population died of these two factors. This doesn’t mean that if the sample population of vegans was as large as the other groups in this study there would still be no deaths from these factors.

The percentage of deaths from heart disease was similar in both the regular meat eaters and in the vegetarian and vegan group. The occasional meat eater’s percentage was slightly higher. The non-vegetarians that ate fish had the lowest heart disease deaths. There was no statistically significant difference between vegetarians and non-vegetarians in mortality from cerebrovascular disease, stomach cancer, colorectal cancer, lung cancer, breast cancer, prostate cancer, or all other causes combined. The fish eaters were the ones that fared the best in almost all the categories. The regular meat eaters and the vegetarians fared comparably in almost all the categories except lung cancer but remember the meat eaters were smoking considerably more than the vegetarians.

Final thoughts:

The general trend is that meat eaters eat too little vegetables and get too little fiber and also consume alcohol and smoke, where as vegetarians are more health conscious and so exercise regularly and watch what they eat. I believe that a healthy diet has to have a balance between animal sources of food and plant sources of food. The caveman diet, or the Paleolithic diet, that consists of vegetables, fruits, nuts and organic meats is the healthiest diet and that is the diet that the humans have evolved with for hundreds of thousands of years before the modern grain diet was invented few thousand years ago. If you are averse to eating meat then more power to you but do realize that being a vegetarian doesn’t offer any health benefits over an omnivorous diet. In fact a diet predominant in grains without much fruit or vegetables might be worse than a meat and vegetable diet due to the GI value of the diet and the resultant weight gain and the health problems that come with weight gain. And if you are not averse to eating meat than incorporating 2-3 servings of fish a week along with vegetables and fruits will be even better than an all vegetarian diet for both weight loss and general health.

So the next time you see a person tout a vegetarian diet ask them if they are doing it for good health or weight loss.

References:

1. Animal product consumption and mortality because of all causes combined, coronary heart disease, stroke, diabetes, and cancer in Seventh-day Adventists. American Journal of Clinical Nutrition 1988; 48(suppl):739–48.
2. Vegetarianism, dietary fiber, and mortality. American Journal of Clinical Nutrition, 1982; 36:873–7.
3. Chronic disease among Seventh-day Adventists, a low-risk group. Cancer 1989; 64:570–81.
4. 3)Mortality among German vegetarians: first results after five years of follow-up. Nutr Cancer 1988; 11:117–26.
5. The GLIM system release 4 manual. Oxford, United Kingdom: Oxford University Press, 1993.
6. Mortality pattern of German vegetarians after 11 years of follow-up. Epidemiology 1992; 3:395–401.