Weight gain with age is a common occurrence for many. This is often attributed to decreased activity and slowed metabolism, but recent research has revealed that appetite control cells within the brain deteriorate with age, making overeating more likely.
Dr. Zane Andrews of Monash University was the principal investigator of this study. He found that as one ages, cells in the brain that suppress appetite are attacked by free radicals, leading to cell deterioration. This in turn leads to many people incorrectly judging their food intake levels, overeating, and weight gain. This is termed by Dr. Andrews as a “chemical imbalance in the brain,” that leads to the overeating.
Dr. Andrews found that the number of free radicals attacking the appetite-suppressing cells was dependant on the types of foods being consumed, specifically immediately following meals. “The more carbs and sugars you eat, the more your appetite-control cells are damaged, and potentially you consume more,” concludes Dr. Andrews.
The mechanism by which the free radicals are triggered and attack the specified brain cells was explained by Dr Andrews as follows; “When the stomach is empty, it triggers the ghrelin hormone that notifies the brain that we are hungry. When we are full, a set of neurons known as POMC’s kick in. However, free radicals created naturally in the body attack the POMC neurons. This process causes the neurons to degenerate overtime, affecting our judgement as to when our hunger is satisfied.”
The research revealed that those between 25-50 years old were most at risk for having appetite-suppressing cells attacked and damaged. Perhaps not coincidentally, this is the prime age group that experiences adult onset obesity, which has been on a steady rise in the past decades. Along these lines, Dr. Andrews speculated on a parallel between common societal food trends, brain cell deterioration, and the rise in adult onset obesity incidence. He says that “a diet rich in carbohydrate and sugar that has become more and more prevalent in modern societies over the last 20-30 years has placed so much strain on our bodies that it’s leading to premature cell deterioration.”
This research provides an alternative, or at least complimentary, explanation to adult onset weight gain. It could substantiate diets low on sugars and carbs, and could also help lead to the development of treatments that attack the free radicals responsible for the deterioration of appetite-suppressing brain cells.
Source: Defeat Diabetes Foundation: Andrews, Zane. Blair, Samantha. Nature news release. August 2008.