Aerobic Exercise May Help Keep Your Brain Younger

It turns out that maintaining a regular aerobic exercise routine may do more than just improve your mood and stamina. Recent research indicates that it can actually influence your brain’s biology, making it appear younger according to brain scans.

Over the course of a year, adults who consistently engaged in cardiovascular workouts ended up with brains that appeared nearly a year younger compared to those who maintained their usual activity levels.

This study, conducted by the AdventHealth Research Institute, examined something called “brain age,” which is an MRI-based estimate of how old one’s brain looks compared to their actual age. A higher brain-predicted age difference (brain-PAD) suggests a brain that seems older than expected.

Previous research has found a correlation between a higher brain-PAD and poorer physical and cognitive health outcomes, as well as an increased risk of mortality.

Assessing Brain Age

Many studies on brain health often rely on memory or attention tests, or wait for obvious clinical symptoms to emerge. However, this research took a different approach: it aimed to see if lifestyle changes, in this case exercise, could influence a biological marker before any issues arose.

The team used MRI scans to estimate participants’ brain ages at the beginning and again at the end of the year. They specifically tracked brain-PAD, focusing on the difference between predicted brain age and actual age.

“We discovered that a straightforward exercise program based on existing guidelines can make the brain look measurably younger in just 12 months,” remarked lead researcher Lu Wan. “Many worry about how to sustain brain health as they grow older. Studies like this provide encouraging insight backed by everyday habits. These changes are modest, but even a year’s improvement in brain age could have significant implications over time.”

Study Details

The clinical trial included 130 healthy adults ranging from 26 to 58 years old. Participants were divided randomly into either an exercise group or a usual-care group that did not alter its routine.

The aerobic group followed a plan aligned with widely accepted fitness guidelines, completing two supervised hour-long sessions each week and incorporating home exercises to achieve about 150 minutes of aerobic activity weekly. This works in line with recommendations from the American College of Sports Medicine.

Beyond MRI evaluations, the researchers measured cardiorespiratory fitness through peak oxygen uptake (VO2peak) at the study’s start and conclusion.

Impact of Exercise on Brain Aging

By the end of the year, the exercise group’s average brain-PAD decreased by approximately 0.6 years. In simple terms, their brains appeared a bit younger at the follow-up than at the start. In contrast, the control group experienced a slight increase in brain-PAD of around 0.35 years, though this change wasn’t statistically significant.

What really highlighted the findings was the disparity between the two groups. When comparing both trajectories, the difference in brain age approached a full year, favoring those who exercised.

“Even if it’s less than a year, past studies indicate that each extra ‘year’ in brain age can impact health later in life,” noted senior author Kirk I. Erickson. “From a lifespan perspective, making the brain appear younger during midlife could be crucial.”

Exploring Biological Pathways

Exercise is known to enhance various factors that theoretically support brain health—like cardiovascular performance, blood pressure, and body composition—as well as specific molecules involved in neuroplasticity. The researchers explored whether these changes could clarify the impact on brain-PAD.

They looked into several factors, including improvements in fitness, shifts in body composition, and blood pressure. Additionally, they assessed levels of brain-derived neurotrophic factor (BDNF), a protein associated with learning and memory.

Unanswered Questions About Brain Aging

While fitness undeniably improved among the exercise participants, none of the measured factors statistically explained the observed brain age change in this study.

“It was unexpected,” Wan commented. “We anticipated that enhancements in fitness or blood pressure would clarify the effect, but they didn’t.”

“Exercise may influence brain health through mechanisms we haven’t identified yet, such as subtle structural changes in the brain, inflammation, vascular health, or other molecular factors.”

In essence, while the brain age shift appears valid, the underlying reasons remain uncertain. It could involve various small changes happening simultaneously or factors that were simply not measured sufficiently.

The Importance of Early Intervention

Much of the research linking exercise and brain health focuses on older adults, where cognitive decline is more apparent. This trial sought to intervene earlier, targeting individuals in early to mid-adulthood, when changes might be subtle yet significant for prevention.

The intention isn’t to imply that those in their 30s, 40s, or 50s are doomed to cognitive decline, but rather that brain aging is a gradual process. Intervening sooner might positively influence future trajectories.

“Intervening during these decades gives us a head start,” said Erickson. “If we can slow down brain aging before major problems arise, it might help delay or reduce the risk of cognitive issues and dementia.”

Future Research Directions

The researchers point out that the participants were healthy and better educated than the general population, which may limit how broadly the results can be applied. Although the changes in brain age were modest, they are still of meaningful significance.

Brain-PAD shows promise as a biomarker, but it serves as a proxy. Larger studies and longer follow-ups are necessary to determine if a younger brain age seen in scans translates to fewer strokes or reduced dementia risk.

Ultimately, for those looking for actionable advice right now, the conclusion is remarkably straightforward.

“People frequently ask if there’s anything they can do now to safeguard their brain for the future,” noted Erickson. “Our findings support that adhering to current exercise guidelines—150 minutes a week of moderate-to-vigorous aerobic activity—can help maintain a biologically younger brain, even in midlife.”

The study has been published in the Journal of Sport and Health Science.