Calorie restriction slows brain ageing in monkeys, study reveals

A decades-long study has shown that cutting calories by nearly a third can slow brain ageing in rhesus monkeys. Researchers at Boston University and the National Institute on Aging tracked the animals for 20 years, originally aiming to see if dieting extended their lives. The findings, now published in Aging Cell, reveal broader benefits for brain health.

The experiment started in the 1980s with 24 monkeys, split into two groups aged between 22 and 37. One group ate a standard balanced diet, while the other received 30% fewer calories from the same foods. Over time, the calorie-restricted monkeys showed fewer signs of metabolic dysfunction and less oxidative damage in their brains after death.

Post-mortem examinations also found better-preserved glial cells and stronger neuronal connections in the brains of the dieting monkeys. Ana Vitantonio, the study's lead author, highlighted that these neuroprotective effects could apply to other long-lived species, including humans. While not part of the research, dietitian Michelle Routhenstein pointed to human studies where modest calorie cuts—around 10–20%—improved insulin sensitivity, reduced inflammation, and lowered blood pressure.

Routhenstein warned against extreme dieting, stressing that sustainable, smaller reductions may offer similar benefits without severe restriction.

The study confirms that long-term calorie restriction can slow brain ageing in primates. The results suggest even moderate dietary changes might support healthier ageing in humans. Researchers now call for further studies to explore practical applications for people.