Heart-healthy lifestyles can also delay brain aging, researchers find

Most of us know that habits like poor diet and lack of exercise are bad for our hearts, but it turns out they’re bad for our brains, too. Conversely, heart-healthy lifestyles can also ward off brain aging and dementia, according to researchers with the University of Maryland School of Public Health and the School of Medicine at the University of Maryland, Baltimore (UMB).

They outline their findings in a study published online this month in eBioMedicine that utilized artificial intelligence (AI) and a massive dataset: MRI brain scans of nearly 20,000 participants aged 40-69 included in a United Kingdom database.

The researchers focused on white matter, which plays a key role in communications between brain regions; its natural decay over time can potentially lead to memory and cognitive problems. Using a machine learning method, the researchers estimated each person’s brain age based on the MRI scans of white matter and compared it to their actual age.

Next, they assessed each person for eight factors promoted by the American Heart Association (AHA). The Life’s Essential 8 (LE8) includes diet, exercise, smoking, sleep, body mass index, lipids, hemoglobin and blood pressure. The researchers found that higher LE8 scores were linked to less white matter loss, indicating delayed brain aging.

“People who want to live longer without the risk of early-onset dementia may want to exercise more or quit smoking, which might work better than medication,” said Tianzhou “Charles” Ma, UMD associate professor of epidemiology and biostatistics, who led the study. “You don’t want to wait until you have the disease, because once that happens it’s very hard to treat.”

Going a step further, Ma’s team looked at another variable: the APOE4 allele, the strongest known genetic risk factor for Alzheimer’s disease. Unsurprisingly, it found that APOE4 carriers were likely to have more white matter loss; notably, however, those hewing to AHA lifestyles always showed reduced white matter loss regardless of APOE4 status.

For this study, Ma partnered with Shuo Chen, a professor of epidemiology and public health at the School of Medicine. A biostatistician, Chen has spent his recent career applying machine learning to neurological imaging—finding, for example, that the brains of people with schizophrenia often appear 10 years older than they are. The LE8 study is significant because it measures several factors at once, he said.

Chen credited his collaboration with Ma for advancing the research more quickly.

“We borrow each other’s strengths and extend each other’s work,” he said. “It also helps us mentor students.”

In another recent paper authored by the UMD research team, published online by the American Journal of Epidemiology, they apply the same machine learning technique on the UK imaging sample, this time matching each person’s white matter with their chronic stress levels, based on functions like breathing rate.

Those findings showed that long-term experiences of stress can also accelerate brain aging, regardless of sex, socioeconomic status, smoking, diet and exercise. The results suggest that daily life experiences may contribute to low-level but chronic stress and anxiety.

Taken together, the studies spotlight the benefits of using AI to analyze large neuroimaging datasets; the method can capture nuanced biomarkers like white matter across thousands of scans in a way that the human eye cannot.

The findings also underscore the importance of long-term management to sustain brain health and lower dementia risk before it’s too late, said Ma.

In addition, they might encourage health care practitioners to create tailored prevention plans for patients based on genetic predispositions to dementia. Still, noted Edmond Shenassa, professor of epidemiology and senior author of the chronic stress study, “What’s exciting about these findings is that they show that these behaviors can help everyone.”