The True Meaning of 'Going Green'

Meat consumption has been associated with increased risk of colon cancer, although not all data are consistent. More recently, a study in the United Kingdom found that consuming a vegetarian diet and a high intake of dietary fiber (over 25 grams a day) were both associated with a lower risk of diverticular disease, a common bowel disorder. Since a majority of people in the Unites States fail to meet the recommended average intake of dietary fiber, this may have much to do with the growing rate of diverticular disease. At the same time, rising obesity rates will lead to substantial increases in heart disease, diabetes, and possibly cancer.

Vegetarian, plant-based diets are associated with longevity and a lower risk of chronic disease and are acceptable dietary practices in terms of health outcomes, but right now there is insufficient evidence that they confer greater benefit than, for example, a Mediterranean diet (which emphasizes whole grains, fish and seafood, olive oil, legumes, and fruits and veggies).

Bottom line: We need more research on the association between the spectrum of types of vegetarian diets and risk of chronic disease before we can make dietary recommendations to the general public. In addition to considering nutritional quality, researchers should also consider economics, and the environment. A compelling argument for the unique benefits of a vegetarian diet may be most appropriately made on ecological grounds. But until all the evidence becomes available, it seems most prudent to consume a mostly plant-based diet.

Paula Amato, MD, is a reproductive endocrinologist at Oregon Health & Science University in Portland and a member of the board of the Gay and Lesbian Medical Association.