A new research, published in Neurobiology of Aging, suggests that not only is obesity bad for overall body health, it can also be harmful for the brain. The white matter volume in a 50 year old obese individual was found to be comparable to that of a 60 year old lean person.
Through an imaging study it was shown that obese middle-aged individuals had smaller volumes of white matter. The comparison was done between obese and lean middle-aged individuals. The authors of the research did note that the reduction in white matter in obese middle-aged individuals was not linked to a decrease in their cognitive functions. However, it may increase the risks of Alzheimer’s and other cognitive diseases.
The lead author of the study, Lisa Ronan, MD, Department of Psychiatry, University of Cambridge, UK, told Medscape Medical News said that, “At this point, the implications of these findings are unclear; however, it is important to emphasize that despite significant differences in brain structure between people who are overweight or obese and their lean, age-matched counterparts, we found no significant differences in cognitive abilities between the two groups.”
Dr. Lisa Ronan explained that previous studies that suggested a link between obesity and brain aging served as the starting point for the current research. A total of 473 adults aged 20 to 87 years participated in the study. The researchers examined the association between brain structure and body mass index (BMI) by analyzing the MRI scans of all the participants. Then the white matter volume between the lean individuals (BMI, 18.5-25) and obese/overweight individuals (BMI more than 25) was compared.
The final data collected showed that all of the participants were healthy with regards to cognitive functions. Fifty-four was found to be the mean age, 26 kg/m2 was the mean BMI (18.5-45.5), a total of 246 participants were found to be lean, 150 were overweight, while 77 were obese.
The results of the study indicated that the white matter volume in obese and overweight participants was linked to a greater degree of brain atrophy. The maximum effects of which were seen in middle aged men and was associated with a 10-year acceleration of brain aging.
Income, education, exercise didn’t not affect the BMI related effects on the structure of the brain. A past diagnosis regarding an increase in the cholesterol level was also linked with decreased white matter volume and above the effects of BMI and age. The diagnosis suggested that the common metabolic co-occurring diseases associated with obesity may play a part in increasing the risk of neurodegeneration.
Dr. Lisa Ronan further stated that the current findings required more analysis. “Although our results raise the possibility that being overweight or obese may increase the risk for developing age-related disorders linked to neurodegeneration, it is important to acknowledge that we found no such links in our current study, which included only adults who were cognitively healthy at the time of recruitment.”
However, she did went on to say that the brain aging of the global population made it crucial to understand the complete effects of an increased body mass on the overall health of a person. “As such, this study is part of a larger effort to understand the role obesity has on our health. It will be important for future studies to establish whether an increased BMI impacts on brain health, or whether brain changes somehow influence BMI.”
She further went on to note that the current findings are not enough to start providing patients with specific advice.
Though more research is required, nevertheless, the current study has been considered to be noteworthy by other experts in the field. Dilip V. Jeste, MD, Professor of Psychiatry and Neurosciences and director, Sam and Rose Stein Institute of Research on Aging, University of California, San Diego, said that the study shows “that at population level, obesity is associated with degenerative changes in the brain white matter. Strikingly, the greatest effects of obesity in this report were seen in middle age and corresponded to an estimated acceleration of brain aging by 10 years. Notwithstanding the acknowledged study limitations, such as the use of BMI as a measure of adiposity, omission of extremely obese subjects due to scanner limitations, and the cross-sectional nature of the analysis, the take-home message is that planning for successful aging shouldn’t start on the 65th birthday. To reduce the risk of accelerated brain aging, we need to maintain healthy body weight through diet and activity, beginning in young adulthood.”
The Director of the Center for Neuromodulation in Depression and Stress at the University of Pennsylvania’s Perelman School of Medicine, Dr. Yvette Sheline, said that the study was “interesting from several perspectives.”