Scientists Say This Nut Butter Boosts Strength in Older Adults—Here’s How

The researchers had half of the participants eat 43 grams (or about 3 tablespoons) of natural peanut butter a day, while the others kept up with their usual diet and exercise routines.

After six months following this protocol, people in each group were asked to do five sit-to-stand tests (where you’re seated and then need to stand up with your arms crossed). People in the peanut butter group were able to do the tests 1.23 seconds faster than those who didn’t eat the peanut butter. This suggested better lower-body function, which may help with everyday activities like climbing stairs.

The researchers also found that people in the peanut butter group had an increase in their overall diet quality. While their peanut butter intake added about 250 calories, 20 grams of fat, and 10 grams of protein to their day, they didn’t gain weight. The study didn’t find that people in the peanut butter group had better overall strength, though.

This news sounds like a win if you’re a fan of the popular spread. But why might peanut butter help with this, and what does it suggest going forward? Experts explain.

Why might peanut butter help with strength in older adults?

The researchers didn’t find why peanut butter may help with strength in older adults—it just discovered that they were able to do the sit-to-stand test faster than the others. Still, there are some theories.

“Peanut butter is a good source of protein, fat, and fiber,” says Jessica Cording, M.S., R.D., author of The Little Book of Game-Changers. “It doesn’t offer a ton of fiber, but it can be a convenient way to boost protein intake, which is really important for older adults.”

But the fat and calories that peanut butter provides are important, too, says Michael Ormsbee, Ph.D., director of the Florida State University Institute of Sports Sciences and Medicine. “The added energy can support some functions, especially in older adults who may under-eat,” he says.

Peanut butter is nutrient-dense overall, with healthy unsaturated fats, magnesium, potassium, and vitamin E, points out Sandra Zhang, R.D.N., L.D.N., registered dietitian nutritionist at the Frances Stern Nutrition Center at Tufts Medical Center. Its small serving size makes it easier for older adults to eat, and may be especially helpful for those who have trouble taking in enough calories, says Carissa Mondelli, R.D., registered dietitian at Northwell’s Phelps Hospital.

“There are many properties of peanut butter—and all plant foods—that confer benefits on health, including strength,” says Christen Cooper, R.D.N., an associate professor in the College of Health Professionals at Pace University. “These findings are a testament to the power of eating ample plant foods.”

But Ormsbee stresses that people shouldn’t “over-interpret” the study’s results. “The peanut butter did not build muscle, but it did help them eat more, maybe a little better, and [they] did stand up faster,” he says. “That alone is great, as a drop in power is linked to higher mortality.”

Do other nut butters have the same impact?

This study only looked at peanut butter, but experts say it’s likely that other nut butters and seed spreads would have a similar impact. “Most nut butters would provide similar calories, healthy fats, and adequate energy to support physical activity,” Mondelli says. She lists off almond butter, cashew butter, walnut butter, and sunflower seed butter (for people with nut allergies) as good options.

The bottom line

This study was observational in nature and established a link, not a clear cause and effect. There’s a lot of variation when it comes to choosing a peanut butter, Cording points out. This particular study looked at natural peanut butter (meaning, it just featured ground-up nuts), and Cording recommends sticking with that. “If your sodium levels are in a good place, a little salt is fine, too,” she says.

Natural peanut butter tends to be pricier than other options, which is why Cooper recommends just picking up what you can. “Select a peanut better that has as few ingredients and added sugar as possible,” she says.

While you can simply eat your peanut butter as-is, Zhang suggests pairing it with things like apples, bananas, yogurt, oatmeal, crackers, or toast to get in more nutrients. It’s also a good addition to smoothies, she adds.

Adding peanut butter to your day isn’t a magical boost for strength as you age, but it can serve as a tasty strength-supporting helper over time.