Holy Cow! What's Good For You Is Good For Our Planet
Comment on "Red Meat Consumption and Mortality"
Arch Intern Med. Published online March 12, 2012. doi:10.1001/archinternmed.2012.174
Is red meat bad for you? In a word, yes. In this issue, Pan et al1 describe the outcomes from more than 37 000 men from the Harvard Health Professionals Follow-Up Study and more than 83 000 women from the Harvard Nurses Health Study who were followed up for almost 3 million person-years.
This is the first large-scale prospective longitudinal study showing that consumption of both processed and unprocessed red meat is associated with an increased risk of premature mortality from all causes as well as from cardiovascular disease and cancer. In a related study by Pan et al,2 red meat consumption was also associated with an increased risk of type 2 diabetes mellitus.
Substitution of red meat with fish, poultry, nuts, legumes, low-fat dairy products, and whole grains was associated with a significantly lower risk of mortality. We have a spectrum of choices; it's not all or nothing.3
Plant-based foods are rich in phytochemicals, bioflavonoids, and other substances that are protective. In other words, what we include in our diet is as important as what we exclude, so substituting healthier foods for red meat provides a double benefit to our health.
Pan et al1 reported that adjustment for saturated fat, dietary cholesterol, and heme iron accounted for some but not all of the risk of eating red meat. Thus, other mechanisms such as nontraditional risk factors may be involved.
For example, a recent study by Smith4 found that high-fat, high-protein, low-carbohydrate (HPLC) diets (which are usually high in red meat, such as the Atkins and Paleolithic diets) may accelerate atherosclerosis through mechanisms that are unrelated to the classic cardiovascular risk factors. Mice that were fed an HPLC diet had almost twice the level of arterial plaque as mice that were fed a Western diet even though the classic risk factors were not significantly different between groups. The mice that were fed the HPLC diet had markedly fewer circulating endothelial progenitor cells and higher levels of nonesterified fatty acids (promoting inflammation) than mice that were fed the Western diet.5
Therefore, studies of HPLC diets that only examine their effects on changes in weight, blood pressure, and lipid levels may not adequately reflect the negative influence of HPLC diets on health outcomes, such as morbidity and mortality.
There is an emerging consensus among most nutrition experts about what constitutes a healthy way of eating:
- little or no red meat;
- high in "good carbs" (including vegetables, fruits, whole grains, legumes, and soy products in their natural forms);
- low in "bad carbs" (simple and refined carbohydrates, such as sugar, high-fructose corn syrup, and white flour);
- high in "good fats" (-3 fatty acids found in fish oil, flax oil, and plankton-based oils);
- low in "bad fats" (trans fats, saturated fats, and hydrogenated fats);
- more quality, less quantity (smaller portions of good foods are more satisfying than larger portions of junk foods, especially if you pay attention to what you are eating).
More than 75% of the $2.6 trillion in annual US health care costs are from chronic diseases. Eating less red meat is likely to reduce morbidity from these illnesses, thereby reducing health care costs.