Friday, August 2, 2019

Does Paleo Diet Increase Risk for Heart Disease?

A recent flurry of articles in the popular press claim that following the Paleo diet causes an increase in your risk of  heart disease, primarily because of a molecule called TMAO (trimethylamine N-oxide).

Most people agree that the bacteria in your colon convert carnitine, found in red meat, to TMAO. How dangerous this is, however, is not as clear, and several  bloggers have detailed why they don't think we should lose sleep about TMAO, so I won't repeat their analyses.

Two things I think should be emphasized: (1) resistant starch increases TMAO and (2) some fish increase TMAO.

The author of the recent study emphasized the lack of whole grains in Paleo diets, saying, "We know that whole grains are a fantastic source of resistant starch." But wait! Resistant starch increases TMAO levels.

Another study even suggests that vegetables can increase TMAO levels and increased TMAO levels are helpful in heart failure.

I think we don't know enough about the relation between TMAO and heart disease to make any dietary changes according to what increases or decreases its levels. Fish and resistant starch are supposed to be healthy but they both can increase TMAO. Some people think red meat is unhealthy, but it can increase TMAO.

I think the publicity about the Paleo diet and TMAO is an example of some people thinking that any diet that doesn't follow the recommendations of the Dietary Guidelines for Americans is a fad diet and then looking for reasons to avoid it.

I remember one nutritionist criticizing low-carb diets because "They don't provide the 60% carbohydrate content recommended by the DGA." Um, isn't that what "low-carb" means? Sometimes I wonder where such people learned to think. . . if they ever did.

So I'd say one shouldn't lose sleep over TMAO. Eat what works for you to keep your blood glucose levels as close to normal as you can, keep an eye on your blood pressure and blood lipid levels, and don't panic over every flashy headline that appears in the popular press.