Could obesity be quietly aging our brains and increasing our risk of dementia? Obesity refers to excess body fat that can negatively affect health, including brain health. Cali McEntee, Eva Feldman and colleagues describe in a new review in Nature Reviews Neurology how obesity may affect memory, thinking and the biological pathways involved in dementia. Key points: - Midlife obesity is associated w/ cognitive decline and an increased risk of dementia, even when weight decreases later in life. - Obesity may affect the hippocampus and prefrontal cortex, brain regions essential for memory, attention and decision-making, through inflammation, insulin resistance and vascular dysfunction. - Exercise, healthier nutrition, weight-loss surgery and newer weight-management medications offer potential opportunities to improve metabolic health and possibly protect cognition, although more definitive trials are needed. My take: What resonates w/ me is that obesity is not simply a number on a scale. It is a biological condition that can influence how our brains function and age. The brain and body are not separate universes. Inflammation, blood vessel health, insulin signaling and metabolism all matter. Perhaps most importantly, the timing of obesity matters. Carrying excess weight in midlife may have consequences that are not completely reversed by losing weight decades later. Here are 5 points that resonated w/ me: 1- Midlife may represent an important window of opportunity for protecting long-term brain health. 2- Where fat accumulates may matter as much as how much we weigh, particularly when it collects around the abdomen. 3- Obesity can create a vicious cycle in which inflammation disrupts the brain circuits controlling appetite, potentially promoting further weight gain. 4- Exercise, nutrition and appropriate medical treatment should be viewed as investments in brain health, not simply strategies for changing appearance or body weight. 5- We still need randomized trials to establish whether treating obesity actually prevents dementia, but the opportunity to improve metabolic and vascular health is already in front of us. nature.com/articles/s41582-0…