Peanut butter contains saturated fat and sodium, so how can it be considered a healthy food? That's what a reader recently asked the Harvard Heart Letter.
It's a good question that gets to the heart of choosing foods that are good for health. Walter C. Willett, a nationally known nutrition expert and a member of the Heart Letter's editorial board, tackled that question as part of the newsletter's popular 'Ask the Doctor' feature.
The presence of saturated fat doesn't automatically kick a food, such as peanut butter, into the 'unhealthy' camp, Willett says. Olive oil, wheat germ, and even tofu -- all considered to be 'healthy' foods -- have some saturated fat. It's the whole package of nutrients, not just one or two, that determines how good a particular food is for health, Willett says in the July 2009 issue of the publication. A typical two-tablespoon serving of peanut butter has 3.3 grams of saturated fat and 12.3 grams of unsaturated fat. That puts it up there with olive oil in terms of the ratio of unsaturated to saturated fat.
Willett also notes that saturated fat isn't the deadly toxin it is sometimes made out to be. The body's response to saturated fat in food is to increase the amounts of both harmful LDL and protective HDL cholesterol in circulation. In moderation, some saturated fat is OK. Eating a lot of it, though, promotes artery-clogging atherosclerosis, the process that underlies most cardiovascular disease.
Peanut butter also gives you some fiber, some vitamins and minerals (including potassium), and other nutrients. Unsalted peanut butter has a terrific potassium-to-sodium ratio, which counters the harmful cardiovascular effects of sodium surplus. And even salted peanut butter still has about twice as much potassium as sodium.
Numerous studies have shown that people who regularly include nuts or peanut butter in their diets are less likely to develop heart disease or type 2 diabetes than those who rarely eat nuts. Although it is possible that nut eaters are somehow different from, and healthier than, non-nut eaters, it is more likely that nuts themselves have a lot to do with these benefits.
