Your Brain in Your 30s

Many experts believe your brain reaches a performance peak in your 30s. Brain cells and connections are fully developed. Executive function — the brain’s ability to handle tasks such as planning, organizing and managing time — is at top form. The myelin sheath, which enables electrical impulses to zip along nerve cells, is at its height as well.

When it comes to short-term memory, that starts to decline in our 30s, but this is still a great time for your brain. Importantly, the habits you form now can help your mind later in life. This includes getting regular exercise (you have plenty of options), eating a healthy diet, sleeping well and managing stress, says Anna Hohler, M.D., chair of neurology at Boston Medical Center - Brighton.

If you're in your 30s, consider these strategies.

Lower your cholesterol

Having high cholesterol as early as your late teens and 20s can increase your risk of midlife cardiovascular events, such as heart attacks and strokes, a 2020 study led by the University of Maryland School of Medicine found. The research followed nearly 5,000 young adults, ages 18 to 30 when the study began, for more than 30 years. And heart issues can raise your risk of dementia later in life. In 2024, the Lancet Commission on dementia added high LDL cholesterol to its list of modifiable risk factors for dementia. Treating this and other cardiovascular problems — including high blood pressure and obesity — will likely reduce dementia risk, the report found. In a 2022 report based on the Framingham Heart Study, researchers found that low levels of HDL cholesterol, the "good" cholesterol, starting at age 35, were associated with a higher risk of Alzheimer's disease decades later.

Reduce your stress

Gen Z and Millennials report higher stress levels than the older generations, a February 2025 survey of 2,000 adults found. And, according to the American Psychological Association, Gen Z adults and younger Millennials are “completely overwhelmed” by stress, which is bad for the brain.​ When we’re stressed, our adrenal glands produce high levels of cortisol, often called the stress hormone. Elevated cortisol has been linked to problems ranging from reduced brain processing speed to an increased risk of Alzheimer’s disease. Good stress management techniques include meditation, exercise, taking 20-minute breaks and, yes, laughing, the APA says.