If you're deciding what to have for breakfast, it might be worth considering a new study that suggests a pantry staple could help support muscle health.
The research, published last month in the Journal of Cachexia, Sarcopenia and Muscle, followed 120 older adults to examine the effects of peanut butter consumption in people aged 65 and over.
Over a six-month period, participants consumed around three tablespoons of peanut butter daily. Their performance was then assessed using a key lower-body function test known as the ‘five-times sit-to-stand test’, with results compared against a control group.
The test measures functional lower-limb strength by requiring participants to stand up and sit down five times as quickly as possible from a standard chair, without using their arms.
‘In this trial, we measured different aspects or dimensions of physical function, such as mobility, balance, muscle power and muscle endurance,’ said lead researcher Dr Sze-Yen Tan, associate professor of nutrition at Deakin University’s Institute for Physical Activity and Nutrition.
Of the 120 participants, those who consumed natural peanut butter completed the sit-to-stand test about 1.2 seconds faster than those in the control group. ‘Eating 43 grams per day over six months was found to be effective in increasing protein intake and better muscle power,’ Tan said.
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‘Peanut butter intervention had a positive effect on muscle power, which is important for activities such as getting out of a chair and climbing the stairs – but it did not help older people walk faster.’
While an improvement of 1.23 seconds may sound small, Tan noted that ‘previous studies suggest that a difference of one second is clinically meaningful and can potentially be associated with lower physical disability in the future.’
The findings from Deakin University in Australia also align with another 2025 study examining the impact of peanuts on cellular ageing.
In that research, scientists randomly assigned 58 young, healthy volunteers to one of three groups: those who ate 25g of skin-roasted peanuts daily for six months, those who consumed 32g of peanut butter daily, and a control group.
By measuring participants’ telomeres – protective structures at the end of chromosomes that shorten as we age – researchers observed a significant difference in telomere length changes between the peanut and control groups. Over six months, those eating skin-roasted peanuts retained, on average, about half a unit more telomere length than the control group.
Taken together, the research suggests that whether it’s spread on toast, stirred into porridge or drizzled over fruit, adding peanut butter to your diet could offer more than just flavour.
Ed Cooper is the former Deputy Digital Editor at Men’s Health UK, writing and editing about anything you want to know about — from tech to fitness, mental health to style, food and so much more. Ed has run the MH gauntlet, including transformations, marathons and er website re-designs. He’s awful at pub sports, though. Follow him: @EA_Cooper
