Weight loss can lead to memory gain in older people

Mild cognitive impairment causes slight but noticeable declines in memory and thinking skills, and increases the risk of Alzheimer’s or other forms of dementia developing later, according to the Alzheimer’s Association. 

Calorie restriction has many benefits for humans, including reduced abdominal fat mass, and may also improve the resilience of synapses in the brain, said lead author Dr. Nidia Celeste Horie of the University of Sao Paulo School of Medicine in Brazil. The researchers divided 80 obese people over age 60 with mild cognitive impairment into two groups, one of which received usual medical care while the other also met in group nutritional counselling meetings for a year. 

The average age was 68. All the participants were advised to meet physical activity guidelines, including doing at least 150 minutes of moderate-intensity aerobic exercise or walking throughout the week, or if limited due to health conditions, aiming to be as physically active as possible. 

The nutritional counselling group also met about 28 times for one-hour sessions, which included advice on eating a diet rich in fiber, fruits, vegetables and whole grains, and on how to achieve a daily 500-calorie deficit. At the start, all the participants had a body mass index (BMI) - a measure of weight in relation to height - of at least 30, the lower limit for obesity. By the one-year point, BMI had decreased by an average of 1.7 points. 

The proportion of those who were physically active did not change. The process of recruiting volunteers included information on the risks of obesity, which may have increased motivation to lose weight in both groups, Horie said. Performance on a battery of physical tests tended to improve during the study. As BMI decreased, thinking skills, verbal memory, language and executive function appeared to increase based on cognitive tests. The improvements were more pronounced for younger seniors, according to the results in the Journal of Clinical Endocrinology and Metabolism.