Adding a daily serving of peanut butter improved lower-body muscle power in older adults in a new randomized clinical trial published in the Journal of Cachexia, Sarcopenia and Muscle.
The study was funded by The Peanut Institute Foundation. The authors report that the funder had no role in the study design, analysis or interpretation of the findings.
Researchers at Deakin University in Australia enrolled 120 independently living adults between the ages of 66 and 89 who were considered at risk for falls. Participants were randomly assigned to one of two groups. Half consumed 43 grams of natural peanut butter daily, roughly three tablespoons, while the control group continued their usual diet and activity patterns.
After six months, participants completed repeated sit-to-stand tests, a common measure of lower-body muscle power and functional performance. Those in the peanut butter group completed the tests faster than the control group.
“Being able to complete the test faster means greater muscle power,” said Dr. Sze-Yen Tan, the study’s lead investigator. “Muscle power enables older people to perform activities of daily living, such as stair climbing and rising from a chair. Increased muscle power also reduces the risk of falls, which is a common reason for loss of independence, compromised quality of life and even premature death.”
Participants consuming peanut butter increased their daily protein intake by about 10 grams and also increased their intake of unsaturated fats. Importantly, the additional calories did not lead to weight gain over the six-month period.
The study did not compare peanut butter to other protein-rich foods, so it is not clear whether similar improvements would occur with other dietary protein sources. The findings suggest that increasing protein intake through a familiar, energy-dense food may support muscle function in older adults, particularly those at risk for declining physical performance.
Strength and resistance training remain established strategies for preserving muscle and reducing fall risk with age.
“Our study shows that eating natural peanut butter, as a snack or part of a meal, can be used in combination with these therapies to further enhance muscle power and to improve nutrition at the same time,” Tan said.
The researchers note that maintaining adequate nutrition can be challenging for some older adults. While oral nutrition supplements are often used, adherence can vary due to cost, taste and familiarity. In this study, peanut butter provided an accessible food-based source of additional protein and calories.
As with many nutrition studies funded by commodity groups, the results should be interpreted in context. The trial demonstrates that adding peanut butter improved functional performance compared with maintaining usual intake. It does not establish that peanut butter is uniquely superior to other protein-containing foods or that it alone prevents falls.
Still, the findings contribute to a growing body of research emphasizing the importance of adequate protein intake and muscle power in maintaining independence later in life.