New research suggests that a consistent 30 percent reduction in daily calorie intake could significantly contribute to living longer, particularly by slowing down brain aging and staving off cognitive decline. While calorie counting is known for weight management, scientists now highlight its potential neuroprotective benefits.

A landmark study, published in the journal Aging Cell by US researchers in collaboration with Boston University and the National Institute on Aging, provided long-term evidence for these claims. The study, initiated in the 1980s, observed two groups of rhesus monkeys over a period of 20 years. One group maintained a balanced diet, while the other consumed approximately 30 percent fewer calories. Researchers chose monkeys due to their similar brain aging processes to humans. Upon examining the brain tissue of monkeys who died between the ages of 22 and 37 (equivalent to human ages 67-108), it was concluded that the calorie-restricted group possessed brain cells that were metabolically healthier and more functional.

Speaking on the findings, Ana Vitantonio, an expert in pharmacology, physiology, and biophysics and study co-author, stated, "Calorie restriction is a well-established intervention that can slow biological aging; this study provides rare, long-term evidence that calorie restriction may also protect against brain aging in [humans]." Study co-author Dr. Tara L. Moore further added that dietary habits "may influence brain health and eating fewer calories may slow down some aspects of brain aging when implemented long term." For an adult following NHS daily guidance, a 30 percent calorie reduction would mean dropping from 2,000 to 1,400 calories for a woman and from 2,500 to 1,900 calories for a man. However, the research underscores that these reductions must be sustained over a long duration to yield meaningful results.

Cognitive decline, an inherent aspect of aging, manifests as delayed reactions, extended information processing times, and a diminished capacity for new social connections and adaptation. Health experts at The University of Cambridge suggest that the brain typically begins to show significant "directional changes in wiring" around age 30. Beyond brain health, restricting calorie intake can also preserve metabolic function across various parts of the brain, leading to improved blood sugar, blood pressure, brain, and kidney function.

Diet plays a crucial role in overall health and aging. Dieticians warn that ultra-processed foods, high in added sugar, unhealthy fats, and artificial additives, are known to accelerate aging. These foods can negatively impact blood sugar and cholesterol levels, increasing the risk of conditions such as type 2 diabetes, obesity, cardiovascular disease, and dementia. Alzheimer's disease, the most common form of dementia, affects 982,000 people in the UK and was responsible for 74,261 deaths in 2022, making it the country's biggest killer.

Amidst these health concerns, public awareness and policy initiatives are also taking shape. Studies show that over 37 percent of people in the UK are unaware of their daily calorie consumption, though mandatory calorie labeling in England has reportedly led to increased self-reported noticing. Furthermore, the government recently announced an expansion of the sugar tax to include milk-based drinks, building on the existing tax on fizzy and sugary bottled beverages. Health Secretary Wes Streeting commented on the broader implications, stating, "Obesity robs children of the best possible start in life, hits the poorest hardest, sets them up for a lifetime of health problems and costs the NHS billions." Emerging research consistently demonstrates that combining calorie reduction with healthier food choices can effectively slow cognitive decline and mitigate physical health issues.