As dementia rates continue to rise globally, the search continues for simple and effective prevention strategies that work for everyone.
In this context, a recent study revealed that maintaining mental abilities may depend not only on the type of food, but also on the timing of eating it .
The study showed that limiting food intake to a nine-hour window per day, and refraining from eating at least four hours before bedtime, may help maintain cognitive abilities and reduce cognitive decline with age.
The researchers conducted the experiment on 47 women aged between 50 and 79, all of whom were overweight or obese, and they followed a low-calorie diet, reducing their daily intake by about 500 calories for six months.
During the study period, 26 participants committed to eating within a nine-hour time window, usually between 10 a.m. and 6 p.m., while the remaining participants spread their meals over approximately 12 hours a day.
At the end of the experiment, all participants lost a similar weight, averaging about seven kilograms. However, cognitive tests showed remarkable differences; the women who adhered to the shorter time window achieved better results in spatial planning and problem-solving tests, and made fewer mistakes in memory and learning tests, while no differences were recorded between the two groups in multitasking or response speed tests.
Professor Sue Shapsis, a professor of nutritional sciences at Rutgers University in the United States and supervisor of the study, said that these effects are "modest," but they may mean that restricting mealtimes contributes to improving the ability to remember information related to daily tasks, and reduces errors in memory, attention, and problem-solving.
The researchers intend to study the mechanisms behind these benefits, which may be related to a complex interaction between the body's biological clock, metabolism, and inflammation levels.
These findings come amid a continued rise in dementia rates worldwide. While some risk factors, such as age and genetic predisposition, are beyond our control, experts suggest that around half of all dementia cases could be prevented or their onset delayed through lifestyle improvements, especially since obesity in middle age is linked to a nearly 30% increased risk of developing dementia later in life.
Recent studies also point to health benefits from increasing the duration of nighttime fasting, as a scientific review published in January showed that finishing eating before 7 pm is associated with improvements in body weight, waist circumference, blood pressure, and metabolic indicators.
This study reinforces the growing body of evidence that the timing of meals is just as important as the type of food consumed for maintaining brain and body health. While the findings are still preliminary, they offer a practical recommendation: limiting meals to a nine-hour window and avoiding eating four hours before bedtime, along with a balanced diet and maintaining a healthy weight, may help preserve cognitive function as we age.
