Results from a recent neuroimaging study
By Austin Perlmutter, MD
KEY POINTS
Aging is linked to worse brain function
Aging increases risk for brain diseases including Alzheimer's dementia
Losing a small amount of weight was linked to slowing of brain aging using brain imaging
This new data provides more reason to prioritize a healthy diet and daily physical activity to protect long-term brain function
As our bodies age, our brains can age too. Aging of the brain is linked to trouble with memory and cognition, and it is a major risk factor for developing conditions like dementia. With modern day humans living longer than ever before, finding strategies to prevent or even reverse brain aging have become increasingly relevant. Now one new study suggests that dietary modification linked to healthy weight loss may provide some important answers.
It is thought that certain health states may contribute to faster brain aging markers. Inflammation and chronic stress for example may both promote brain shrinkage by suppressing healthy brain function and the creation of new brain cells. One health state linked to activation of pathways associated with brain aging is obesity. It’s known that people can be metabolically healthy and overweight (as well as metabolically unhealthy and of normal weight). However, accumulation of fat, especially around the midsection and around our organs is thought to amp up inflammation and metabolic dysfunction, both of which may damage the brain.
In a paper published in March of 2023 in the journal eLife, researchers from Israel and Harvard looked at how weight loss due to diet and exercise correlated with brain scans over an 18-month window. The participants in the study were aged 30 or older (average age around 52) with either obesity as measured by waist size or disordered blood lipids (high triglycerides and low HDL) and were instructed to consume a healthier diet as well as exercise. All participants were also given a free gym membership.
At the start and end of the 18-month period, the participants had a functional MRI scan performed to look at their brains. Based on previous research, the scientists were able to use this scan to predict a person’s brain age. The results showed that at the end of the 18 months, participants had lost on average about 2.3 kg of weight (around 5 lbs), with a decrease in body mass index (BMI) of around 0.8. Most striking, the people who decrease their BMI by 1% showed an average slowing of brain aging by around 8.9 months.
The data presented by this paper demonstrates more evidence for the idea that lifestyle changes can significantly impact our brain state and rate of aging. It was notable that on review of participants’ questionnaires, those who lowered their consumption of processed foods and sugary foods and beverages had the most evidence for slowing of brain aging.
This paper helps to clarify the value of lifestyle factors in the state of our brains. In particular, it provides empowering evidence that over a relatively short period our lifestyle changes may be sufficient to visibly change the health of our brains, and potentially, to help slow the rate of brain aging.