Significant weight loss equates to a brain makeover, according to a Quebec study published in the latest issue of the journal Neurolmage. The research, carried out on 32 patients who underwent bariatric surgery, showed that their brains had rejuvenated by more than five years 24 months after the intervention.
The white and gray matter tend to atrophy with age, “a completely normal phenomenon”, emphasizes Andréanne Michaud, director of the study and professor at the School of Nutrition at Laval University, but which tends to accelerate in overweight people. “The reductions in gray matter due to obesity also correspond to the profile of cerebral atrophy associated with age”, specifies the study.
“Obesity therefore leads to premature aging of the brain,” explains Professor Michaud. There are also more and more studies linking brain abnormalities to ailments related to excess weight, such as inflammation, insulin resistance, diabetes or hypertension.
The study conducted under the direction of the researcher proves for the first time that the brain has the ability to recover from the deterioration caused by obesity.
Twelve months after undergoing bariatric surgery, the patients observed had a three-year-rejuvenated brain. Still twelve months later, two years after the intervention, the rejuvenation had almost doubled, cutting off 5.6 years of old age on average.
To reach these conclusions, Andréanne Michaud and her team first developed, in collaboration with Professor Yashar Zeighami, of McGill University, a model that is used to determine the evolution of the density of gray matter in the brain as a function of of age. “We used brain images from nearly 600 healthy adults aged 18 to 75,” says the research director.
The team was then able to document, with supporting images, the evolution of the brain of the 32 patients observed. The research led to the following conclusion, explains Professor Michaud: “the greater the reduction in weight, the greater the decrease in brain age”. The drop in blood pressure and the improvement in insulin sensitivity induced by weight loss would explain this cerebral rejuvenation, according to the professor.
However, the study mentions that certain factors could not be taken into account in reaching these conclusions. Smoking, alcohol consumption, education and level of physical activity of patients are all factors likely to influence their brain health. However, the team was unable to neutralize the group-wide effect. Ditto for the characteristics of cerebral aging specific to women or men. “Due to the limited sample, we were unable to explore the changes separately,” the scientific paper states.
A first step
Although the study did not make it possible to identify “the mechanisms by which premature aging takes place”, it points out some lines of thought. “The literature shows that obesity leads to a low-level inflammatory state that could impact brain tissue. We are in the hypothesis, but it could cause atrophy of the gray matter or changes in the vascularization of the brain, ”continues Andréanne Michaud.
The findings of this first study lay the groundwork for future research. The researcher’s team would like to follow the patients over the longer term to determine if the brain rejuvenation is permanent or ephemeral.
“A year after the procedure, people are in the ‘honeymoon’ phase and they are losing a lot of weight. Beyond that, some regain weight, others continue to lose it, others maintain it, ”recalls the professor. Research conducted over a longer period would indicate in particular how the brain reacts to increased weight. “We also want to evaluate the cognitive performance of our patients, concludes Professor Michaud, to see if there are behavioral changes. »