A few tablespoons of unsweetened peanut butter each day can ease some aspects of age-related muscle deterioration, according to Healthline. A new study conducted on 120 older community residents By researchers at the School of Exercise and Nutritional Sciences at Deakin University in Geelong, Victoria, Australia.
In general, nuts are a good food source of protein, healthy fats, and fiber. Pistachios and peanuts are particularly rich in anti-inflammatory and antioxidant phytochemicals that can relieve chronic inflammation and oxidative stress, two major drivers of muscle loss.
there
Some evidence from population studies Increased nut consumption is associated with a lower risk of musculoskeletal and cognitive decline among older adults. But to date, the direct effect of daily walnut consumption on muscle strength and function has not been evaluated in a randomized intervention trial.
Eleli Veisa and a research team from Deakin University aim to correct this. They recruited 120 generally healthy, non-exercise, community-dwelling people over the age of 65 to participate in a 6-month study on the effects of daily peanut butter consumption on a range of biometric and functional assessments.
Simple, practical and inexpensive
They randomly assigned participants into two groups: control subjects were instructed to maintain their usual eating and lifestyle habits over a 6-month period; The intervention group also maintained their usual routine but with the addition of 43 grams per day of peanut butter, which the researchers provided for free. This daily “dose” of peanut butter is equivalent to about 2.7 tablespoons.
Veisa and her colleagues chose peanut butter as a nut delivery vehicle because “the form of butter is simple, practical, age-appropriate, and inexpensive.” Barring allergies or sensitivities, most people love peanut butter, and its smooth texture makes it ideal for people with dental problems — a common problem among older adults.
After 6 months, participants in the peanut butter group showed better times on the 5STS test, as well as improvements in muscle strength compared to those in the control group.
A 43-gram serving, equivalent to about 1.5 ounces of whole peanuts, provides about 250 calories, 20 grams of fat (more than 90% trans), and 10 grams of protein.
Basically, the researchers ran subjects through a wide range of questionnaires and muscle function tests. These included:
- Fall risk screening using a standardized protocol consisting of 6 parameters: age; History of slips or trips (not falls) in the past year; Feeling unsteady while standing, walking, or doing daily activities. Subjective feeling of risk of falling; Difficulty getting out of a chair or toilet without using your arms; Using 4 or more prescribed medications.
- Walking speed was measured by timing participants as they walked 4 meters at their usual speed.
- Five Sit-Stand Test (5STS): In this test, the participant is asked to stand up from a chair, with arms crossed over the chest, five times, as quickly as possible. The time required to complete the task is an indicator of the strength and power of the leg muscles.
- 30-Second STS: A closely related test that measures the total number of times someone can get up from a chair with their arms crossed during a 30-second period.
- Four Square Step Test (FSST): In this test, participants step forward, sideways, and backward as fast as possible on two bars arranged in a criss-cross formation. Investigators record the time needed to complete the task.
They also assessed the condition of the upper and lower body muscles through measurements of hand grip strength and knee extensor strength.
A total of 108 people (76 women, 32 men, average age 76 years) completed the full 6-month trial. At baseline there were no significant differences between the control and intervention groups in terms of body mass index, or general dietary habits and lifestyle. Complete compliance with the peanut butter intervention was 86%.
Better muscle strength
Peanut butter was by no means a magic elixir for muscle strength, but it had statistically and clinically significant effects on some of the ratings mentioned above.
After 6 months, participants in the peanut butter group showed better times on the 5STS test, as well as improvements in muscle strength compared to those in the control group. Muscle power, which reflects muscle strength and action speed, was calculated using a validated formula that divides body weight, height, and chair height by the total STS time.
On average, the peanut butter group showed an improvement of 1.23 seconds on the 5STS, a result the authors considered “small but clinically meaningful.” Age-related decline in 5STS performance It is strongly associated with increasing disability Weakness in daily activities. Improvements in 5STS, even if gradual, can help avoid disability.
Participants in the peanut butter group also showed a 0.25 W/kg increase in muscle strength compared to people in the control group. This may not seem like a lot, but again, incremental improvements are important. Viesa and colleagues note that decreased relative muscle strength is associated with increased mobility impairment, especially difficulty walking.
They explain that muscular strength, defined as muscle strength multiplied by speed, may be a more important predictor of overall functional performance and personal independence than muscle strength alone (Carbone S, et al. Mayo Clinic procedures, 2025). Moreover, as people age, Muscle strength tends to decrease earlier And faster muscle mass and muscle strength.
“The improvement in muscle strength documented in our study is of clinical significance.”
Important questions
However, peanut butter consumption had no statistically significant effect on muscle tone, strength, muscle mass, or walking speed. This raises an interesting question: Why did muscle strength increase, while other measures of muscle function showed no changes?
Elely and her collaborators addressed this apparent paradox, showing that participants in the peanut butter group were able to complete the 5STS task in a shorter time, suggesting higher speed. Since speed is a key factor in the muscle strength equation, this resulted in increased strength calculations despite no change in muscle strength as demonstrated by knee extensor strength measurements.
But why no increase in strength?
The recommendation that older adults increase their protein intake to maintain muscle mass and strength “is based on the hypothesis that aging muscle requires a greater intake of amino acids to optimally stimulate muscle protein synthesis, particularly in the context of anabolic resistance, which is characterized by a decreased response of muscle protein synthesis to anabolic stimuli,” the authors explain.
The 43-gram daily peanut butter serving tested in this trial provides approximately 13 grams of protein which may not be enough to offset age-related anabolic resistance. Add to this the fact that most participants in this trial were eating, on average, 1.12 g/kg of protein per day, which is well above the recommended daily allowance of 0.8 g/kg of protein in this age group. This likely weakens the potential effect of additional protein intake.
Furthermore, the study participants did not exercise regularly. Illili and colleagues point out A systematic review and network meta-analyses of 38 randomized controlled trials Protein supplementation combined with sustained exercise is shown to be most effective for improving muscle mass, strength, and physical function in older adults. Increasing your protein intake in the absence of regular exercise may not do much.
The peanut butter supplements added calories — an average of 256 calories — to the participants’ daily intake. She also added fat — about 21 grams — along with protein. But this did not lead to any net weight gain or increase in body fat in the intervention group compared to the control group.
Why not? The authors hypothesize that the high levels of mono- and polyunsaturated fatty acids in peanuts are more easily oxidized by the body and have greater thermogenic effects. They add that their findings are consistent with other studies on nut consumption that show that increasing nut intake does not automatically lead to weight gain.
The recommendation that older adults increase their protein intake is based on the premise that aging muscle requires a greater intake of amino acids to optimally stimulate muscle protein synthesis, especially in the context of anabolic resistance.
The peanut butter intervention was well tolerated. In fact, many participants said they loved it and planned to continue eating peanut butter daily after the experiment ended.
There were no incidents of allergic reactions or serious adverse effects, although one participant reported diarrhea and bloating, while another experienced unpleasant belching. One individual withdrew from the intervention due to concerns about possible high cholesterol.
“Peanut butter supplementation is a feasible nutritional strategy” to enhance dietary protein in older adults, the authors say. “Peanuts are a nutrient-dense food, and peanut butter supplements are a simple, practical, age-appropriate, inexpensive nutritional strategy that can be easily adopted by older adults.”
It may not be a cure-all for age-related muscular degeneration. But it’s an inexpensive and delicious way to maintain muscle strength and function, while mitigating the potential risk of disability.
end
