Introduction to Brain Age
As you age, you gradually lose muscle mass and gain visceral body fat, a type of fat deep inside your body that surrounds your heart, kidneys and other organs. Now, scientists say the ratio of visceral fat to muscle can uncover clues about your brain health.
People with higher muscle mass and a lower visceral fat-to-muscle ratio tend to have younger brains, according to research being presented next week at the annual meeting of the Radiological Society of North America.
Understanding Brain Age and Its Factors
“We know that the age of a person, in terms of their appearance, might not match with their chronological age,” said senior study author Dr. Cyrus Raji. “Turns out, the age of their organs might not match their chronological age either.” One reason the findings are so important is because chronological age — and therefore an aging brain — is “by far” the top risk factor for developing Alzheimer’s disease and other forms of dementia, said Raji, an associate professor of radiology and neurology at the Mallinckrodt Institute of Radiology at the Washington University School of Medicine in St. Louis.
The Relationship Between Visceral Fat and Brain Health
Previous research, including Raji’s own, has studied the relationship between visceral fat and health outcomes such as brain volume loss, cognitive impairment and structural changes in the brain. The study involved 1,164 healthy people whose average chronological age was 55.17. About 52% were women and 39% were nonwhite. All underwent a whole-body MRI that looked at brain, fat and muscle tissue.
Determining Brain Age
To determine participants’ brain age, Raji and his colleagues used an algorithm that had been trained on the MRI scans of 5,500 healthy adults ages 18 to 89. The average brain age of study participants was 56.04 — older than their average chronological age. Researchers called this difference the “brain age gap.” The average brain age gap was 0.69 years, meaning participants’ brains looked slightly older than they should. However, this metric was not statistically significant.
The Impact of Visceral Fat on Brain Age
Just as higher muscle mass and a lower visceral fat-to-muscle ratio corresponded to a younger brain age, lower muscle mass and a higher visceral fat-to-muscle ratio corresponded to an older brain age. This link between body fat and brain age only held true for visceral fat, which is also known as hidden fat, active fat or deep belly fat. Subcutaneous fat, the layer of fat just below the skin’s surface, wasn’t associated with brain age, the study found.
BMI and Its Limitations
Understanding BMI
From a clinical perspective, the study results are on par with what Dr. Zhenqi Liu, the James M. Moss professor of diabetes at the University of Virginia School of Medicine, would expect. “When people are very young and healthy, they tend to have more muscle mass and they will have [a] younger brain age,” said Liu, who wasn’t involved in the research.
Limitations of BMI
The limitations of body mass index, or BMI, as a measure of health are also on display in this research, Liu said. BMI is a standardized, nearly 200-year-old body fat metric calculated using your height and weight. But it’s fallen out of favor in recent years, namely because it doesn’t take into account how your fat — neither visceral nor subcutaneous — is distributed throughout your body.
Building Muscle and Burning Visceral Fat
If it’s been ages since you’ve touched a dumbbell or gone for a long walk, fear not, said Siddhartha Angadi, a colleague of Liu’s and an associate professor of kinesiology at UVA’s School of Education and Human Development. “Anyone can exercise — regardless of their age,” said Angadi, who wasn’t involved in the research. “There’s excellent data across the lifespan, across the health span, across multiple diseases showing that exercise is incredibly safe.”
Exercise Guidelines
Angadi recommends following the American College of Sports Medicine’s physical activity guidelines. At least twice a week, healthy adults 65 and younger are encouraged to do muscle-strengthening activities that work all major muscle groups. “Do 10 to 15 different exercises,” Angadi said. “You want to do one to three sets; in each set, you want to have eight to 12 reps. Use machines if you’re not familiar with resistance training, which is a fancy way of saying weightlifting.”
Importance of Strength Training
Glenn Gaesser, a professor of exercise physiology at the Arizona State University College of Health Solutions, said baby steps can help build muscle and burn visceral fat. “A lot of people think that it takes a lot to produce some sort of health benefit from exercise, and that is not necessarily true,” said Gaesser, who wasn’t part of the study. “The biggest return on investment is with the initial few minutes of exercise.”
Conclusion
In conclusion, the study highlights the importance of maintaining a healthy balance between muscle mass and visceral fat to support brain health. By engaging in regular exercise, such as strength training and aerobic activities, individuals can help build muscle and burn visceral fat, potentially reducing their risk of cognitive decline and dementia.
FAQs
Q: What is the relationship between visceral fat and brain age?
A: The study found that individuals with higher muscle mass and a lower visceral fat-to-muscle ratio tend to have younger brains.
Q: How can I determine my brain age?
A: Brain age can be determined using an algorithm that has been trained on MRI scans of healthy adults.
Q: What are the limitations of BMI as a measure of health?
A: BMI does not take into account the distribution of fat throughout the body and can be misleading as a measure of health.
Q: What exercises can help build muscle and burn visceral fat?
A: Strength training and aerobic activities, such as weightlifting and walking, can help build muscle and burn visceral fat.
Q: Is it ever too late to start exercising and improving my brain health?
A: No, it’s never too late to start exercising and improving your brain health. Even small amounts of exercise can have significant benefits.
