Peanut butter is a staple of the American diet, with lots of brands and some important differences between them. Simply put, some peanut butter varieties are a lot more “real” than others. And there are a couple of surprises to its story. Let’s dive in.
The first surprise is that peanuts really aren’t nuts at all—they’re a type of legume, in the same family as peas and lentils. Like other legumes they’re basically healthy foods, with relatively high protein levels (all 20 amino acids!) and a fair amount of fiber. Peanuts are also an excellent source of compounds like resveratrol, flavonoids, and Co-enzyme Q10 (1). These nutritional properties of peanuts have been shown to reduce heart disease and certain types of cancer, improve weight management, and contribute to overall health and wellness (2).
To make peanut butter, peanuts are harvested from the roots of a flowering plant and then shelled to remove the outer covering. They then are dry roasted and rapidly cooled to prevent over cooking, and during that process much of the skin of the peanut falls off. Usually, but not always, the next step is blanching (peanuts are quickly boiled and then any remaining skin is rubbed off). And sometimes the nuts are split, and the “hearts” removed, because they tend to have a bitter taste.
Turning peanuts into the creamy product we know and love is just a matter of grinding them up. During grinding, the peanuts are generally kept under pressure to prevent air bubbles from forming. This prevents bacteria from infiltrating and reduces oxidation caused from air exposure, which would reduce the shelf life.
Next come the additives.
The natural oil of peanut butter separates after it’s packaged, so the peanut butter needs to be stirred after purchase. To avoid this inconvenience, some peanut butter manufacturers introduce hydrogenated vegetable oil during grinding. If that’s the kind of peanut butter you buy, you might want to check the ingredients for the type of oil used, then investigate the omega 6 to 3 fatty acid ratio of that oil (see “The Fatty Acid Motel”). Often such added oils are the result of industrial processing. In any case, if you want to keep your peanut butter real, it’ll require a little of your own mechanical action.
And as with many, many foods you’ll find in your grocery aisle, some manufacturers add sugar to peanut butter, in the form of the simple sugar dextrose and corn syrup. No surprise here: the higher the sugar content, the more destructive the food to your short- and long-term health.
In addition to avoiding additives, you can reap more nutritional benefits from peanut butter by looking for varieties made with unblanched peanuts. This leaves more skin on the peanut, which has been found to significantly increase the fiber and antioxidants of peanut butter (1). One way to find these varieties is to look for darker-colored peanut butters (due to the skin’s darker appearance) and check the ingredient list for ‘unblanched peanuts.’
Note that (and here’s the second surprise) not all peanut processing reduces nutritional value. The processing steps of roasting and boiling peanuts have been shown to actually increase the concentration of several beneficial compounds (1).
No surprise here: peanut butter is a highly useful food: inexpensive, accessible, and nutrient-dense. If you’re looking for healthy peanut butter, just stick with what’s nutritious about it…the peanuts. Your best bet for nutrition and health is to choose a more real variety made with no more ingredients than peanuts and salt.
References
1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4711439/
