A study has found that aging in patients’ brains can be slowed by up to 9 months through weight loss.
A diet rich in fresh vegetables and low in processed foods has been shown by new research to have the potential to work wonders for the biological age of our brains. According to the study conducted by an international team of researchers, a Mediterranean diet abundant in vegetables, seafood, and whole grains, or simply adhering to dietary guidelines, seems to be associated with the slowing of signs of accelerated brain aging typically observed in obesity when there is as little as a 1 percent reduction in body weight.
After 18 months, brain scans revealed that the participants’ brain age appeared almost nine months younger than anticipated, as compared to estimates of their brain’s chronological age.
Similar to the participants in the clinical trial, one might not perceive oneself as old as the years one has lived, or perhaps one’s body feels like it’s aging faster than one is. This highlights the disparity between biological and chronological age. In any case, research indicates that the body’s biological age is more than just a subjective feeling: Indicators of biological aging can be located along one’s DNA, etched onto the ends of one’s chromosomes, or, as indicated by this study, in the loosening connections of the brain.
While an expanding body of research suggests that stressful events may lead to reversible biological aging, it is demonstrated by this new study that enhancing one’s diet could be one of the simplest means of improving body condition, regardless of one’s age.
In the study, the brains of 102 participants involved in a larger workplace clinical trial conducted in Israel were imaged by the researchers. Brain scans were conducted both before the commencement of the trial and after 18 months, in conjunction with a battery of tests measuring liver function, cholesterol levels, and body weight.
Three diets were consumed by the groups: a Mediterranean diet featuring abundant nuts, fish, and poultry instead of red meat; a Mediterranean diet with supplementary elements like green tea for its polyphenols; or a diet adhering to healthy dietary guidelines.
Brain age estimates were generated using an algorithm that had been trained on brain scans from a separate cohort of nearly 300 individuals, with the model accurately deducing age based on measures of brain connectivity.
On average, a weight loss of approximately 2.3 kilograms was observed among the trial participants. For every 1 percent of body weight lost through adherence to a prescribed diet or health guidelines, it was determined by the researchers that the participants’ brains appeared nearly nine months younger than their chronological age.
The question of whether alterations in brain connectivity indeed result in enhancements in brain function remains largely unknown. The brain is a complex network of flexible connections that we are only just beginning to chart, although a recent review suggests that the Mediterranean diet may positively influence memory in older individuals.
Signs of decelerated brain aging were also linked to reduced levels of liver fat and an improved lipid profile, yet once again, these changes may be surface-level or temporary in nature.
“The importance of maintaining brain health through a healthy lifestyle, including reduced consumption of processed food, sweets, and beverages, is highlighted in our study,”
notes Gidon Levakov, a neuroscientist from Ben-Gurion University of the Negev in Israel, who is the lead author.
Such advice may sound prudent, and even though the findings stem from a clinical trial in which participants were randomly assigned dietary regimens, there are several other noteworthy limitations to consider.
Most of the participants were men, and their dietary and lifestyle habits were assessed through online surveys, potentially introducing recall bias or selective reporting into the data.
Additionally, factors related to participants’ work-related activity levels were factored in, and they were provided with a complimentary gym membership as part of the trial, making exercise an influencing factor as well.
Furthermore, previous research has illuminated the cellular mechanisms through which the beneficial fats of a Mediterranean diet operate. However, it has also unveiled notable disparities in who reaps the health advantages of a diet rich in Mediterranean staples.
Individuals with higher incomes and more extensive education, who had the means to purchase ample quantities of fish and whole grains, experienced greater improvements in cardiovascular health compared to those with lower incomes, even if their adherence to the diet was equivalent.
Obesity negatively impacts multiple bodily systems, including the central nervous system. Retrospective studies that estimated chronological age from neuroimaging have found accelerated brain aging in obesity, but it is unclear how this estimation would be affected by weight loss following a lifestyle intervention.
In a sub-study of 102 participants of the Dietary Intervention Randomized Controlled Trial Polyphenols Unprocessed Study (DIRECT-PLUS) trial, we tested the effect of weight loss following 18 months of lifestyle intervention on predicted brain age based on magnetic resonance imaging (MRI)-assessed resting-state functional connectivity (RSFC). We further examined how dynamics in multiple health factors, including anthropometric measurements, blood biomarkers, and fat deposition, can account for changes in brain age.
To establish our method, we first demonstrated that our model could successfully predict chronological age from RSFC in three cohorts (n=291;358;102). We then found that among the DIRECT-PLUS participants, 1% of body weight loss resulted in an 8.9 months’ attenuation of brain age. Attenuation of brain age was significantly associated with improved liver biomarkers, decreased liver fat, and visceral and deep subcutaneous adipose tissues after 18 months of intervention. Finally, we showed that lower consumption of processed food, sweets and beverages were associated with attenuated brain age.
Successful weight loss following lifestyle intervention might have a beneficial effect on the trajectory of brain aging.