This post is part of an on-going review of the recommendations of celebrity doctor Joseph Mercola, D.O. For an overview, see Monday's post.
As I have explained over the last few days, see The Meat and Butter Diet. I believe Dr. Mercola is aggressive beyond reason in recommending meat as a health food.
There is, however, some reasonable evidence in the scientific literature to support the idea that people should include some animal products in their diet. There are primarily three weaknesses of a vegan diet, they are:
- Plant foods do not contain B12 (all vegans should take B12).
- Some people have a need for more taurine, and may not get optimal amounts with a vegan diet. (Some vegans need to take a taurine supplement, or they could get a blood test to assure adequacy).
- Some vegans may not produce ideal levels of DHA fat (from the conversion of short-chain omega-3 fats) found in such foods as flax and walnuts, if they don't eat fish. I advocate that vegans and people who do not eat fish should supplement with DHA or get a blood test to assure adequacy.
Obviously, these three areas of potential deficiency on a vegan diet are easily remedied by taking a few supplements. There are loads of advantages of a vegetarian diet however that also should be considered, but that is not the topic of this article. And clearly a poorly designed vegetarian diet or one that is not supplemented properly with B12, Vitamin D (the sunshine vitamin), can be dangerous for one's health, but that still cannot be used as an argument to justify dietary recommendations with lots of high saturated fat animal products.
Meat in a Vegetable-Based Diet
Ignoring the ethical and environmental benefits to a vegan diet, which undoubtedly are substantial; claiming that a vegan diet-style is healthier and will make one live longer than a diet-style that contains even a small amount of animal products is not an argument that can be made with good scientific integrity.
We have substantial evidence from not only the China Study, but thousands of other studies to conclude that animal products when consumed in even moderate amounts such as 20 ounces a week can contribute to the development of chronic disease and are not health promoting. Many of these studies are referenced in my book Eat To Live and some can be reviewed elsewhere on this blog. However, these studies and the China Study cannot be used to validate the necessity of a strict vegan diet for optimal health as vegan populations were not studied in this enormous project. The lowest ranges of animal products consumed in the China Study were in the range of 1.7 servings per week or about 10 ounces per week.
Below that level of animal product consumption supplementation with B12 become critical for populations. If there were studies with large populations on vegan diets, a J-shaped* curve would likely be experienced, showing that as diets get lower than one serving of animal products per week, later life morbidity and mortality would start to be increased. The reason for this is that strict vegans who don't take supplements will likely develop B12 deficiencies (rural villagers do not take supplements) leading to life shortening events, lessening the reduction in heart attack or cancer deaths achieved by the reduction of animal foods.
Besides B12, there are also nutritional advantages to a small amount of animal products for some individuals, as there are individual differences in the production of non-essential amino acids, and reduction in the absorption and metabolism of essential amino acids that makes the ingestion of additional amino acids beneficial for some individuals, such as those with digestive impairments. For others, the addition of pre-formed DHA from fish or fish oil may be beneficial because the enzymes converting short-chain omega 3 fatty acids (obtained from plant) to these longer chain fats (what is already present in fish) may not be as efficient in some individuals. It also may be possible that some people have heightened needs for DHA, taurine or other protein components as they age and digestion and conversion is decreased. I have counseled thousands of individuals on vegan and near vegan diets over the last 15 years and have found these recurring issues when investigating patients with health problems and health concerns after doing extensive evaluations to discern a cause of their complaints.
A Research-Based Approach
It is too frequent that writers on both sides, the vegan proponents and those advocating inclusion of substantial amounts of animal products as health supporting, have pre-formed biases and try to defend their views, rather than evaluating all the evidence with logic and clarity. Nevertheless, the reality is that for the majority of individuals, allowing under 10 - 12 ounces of animal products per week does not appear to have disease risks as long as the animal products are low in saturated fat and not contaminated with parasites or toxic pollutants. Certainly, I have no desire to promote the consumption of animal products, and I am always willing to modify my recommendations if more science suggests that this guideline is not accurate in any way. However, we have to go with whatever data we have available today, and I suggest that for those who want to include animal products in their diet, we cannot with good science insist that this small amount is cancer or heart disease promoting.
I argue that either way of eating (vegan or non-vegan) can be made health-supporting (and should be supplemented appropriately to assure nutritional adequacy) and that debating which is better is not a valuable exercise. Therefore, I advocate a plant-based (vegetable-based) diet that is either vegan or one that is near vegan with a small amount of animal products, and my food pyramid designed for public guidance contains two to three servings of animal products permitted per week, assuming that the total ounces per week is under the 10 - 12 ounces range. Beef and cheese are too high in saturated fat and should not be considered health-supporting foods to be utilized on a regular basis in one's diet. Plus those animal foods rich in fat are much higher in environmental pollutants.
FISH: Not the Easy Answer
Even though some fish in the diet has been shown to be beneficial at reducing heart disease risk, presumably because of those beneficial fish oils, and there are studies that indicate some fish in the diet is longevity promoting.1 I still do not recommend people eat much fish. We do not need to eat fish to get those benefits from fish oil, we can take a supplement for that and there is too much good evidence linking fish consumption with higher rates of breast cancer, plus the pollutants in fish are of a major concern. Whether it is the pollution in fish or the cancer promoting effect from the high level of animal protein, eating fish is linked to a higher rate of breast cancer. When 23,963 women were followed as part of the Diet, Cancer and Health study, what stood out most was the link between fish consumption and breast cancer. The conclusion of the researchers was, "this study showed that higher intake of fish was significantly associated with higher incidence rates of breast cancer."2 Surprisingly, women consuming little or no fish were found to have approximately half the incidence of breast cancer compared to high consumers of fish. This study should not be ignored. It received scant media attention. Frequent fish consumption has also been linked to increased occurrence of thyroid cancer.3
If fish are consumed on a regular basis it should be a maximum of once per week and it should be of the cleanest variety, not those in the highest range of mercury or other pollutant contamination. That limits the choice in most cities in the continental US to ocean perch, shrimp, haddock, scallops, talapia, hake and trout, eliminating swordfish, pike, mackerel, shark, lobster, tilefish, grouper, sea bass, marlin, snapper and halibut as simply too high in mercury and bluefish, herring, clams, crab and oysters as simply too polluted. Most other fish are in-between these two categories.
EGGS, WHITE MEAT FOWL, FAT FREE DAIRY: Guidelines
Therefore, I do not recommend the eating of fish more than a few times a month, and I would much rather people who eat some animal products utilize eggs, (especially those high omega-3 eggs) and white meat fowl, such as turkey, chicken or fat-free dairy.
To conclude, if you want to eat animal products on a regular basis, limit the consumption to one or two servings of two eggs or egg whites, or one serving of eggs and one serving of white meat turkey a week, or one serving of eggs and one serving of low-fat dairy and one serving of white meat or an occasional fish. Do not eat fish for the supposed health benefits of fish. It is not advisable to consume enough fish to get enough omega-3 fats for your heart health. (It is much more reasonable to just take a daily amount of DHA to assure nutritional excellence and adequacy, such as my DHA Purity, which is algae-derived DHA and refrigerated to maintain freshness.)
1. Pauletto P, Puato M, Caroli MG, et al. Blood pressure and atherogenic lipoprotein profiles of fish-diet and vegetarian villagers in Tanzania: the Lugaiawa study. Lancet 1996;348:784-788.
Key TJ, Fraser GE, Thorogood M, et al. Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies. Am J Clin Nutr 1999;70(3):516S-524S.
2. Stripp C, Overvad K, Christensen J, et al. Fish intake is positively associated with breast cancer incidence rate. J Nutr 2003;133(11):3664-3669. J Urol 2004 Apr;171(4):1402-7.
3. Glattre E, Haldorsen T, Berg JP, et al. Norwegian case-control study testing the hypothesis that seafood increase the risk of thyroid cancer. Cancer Causes and Control 1993;4:11-16.