How to Protect Your Brain Health: A Comprehensive Guide

The Power of Positive Relationships for Brain Health

When it comes to protecting brain health, most people think about eating a balanced diet, exercising regularly, and getting enough sleep. While these are essential, there’s more you can do to boost your brain’s functioning and protect it from decline. According to experts, building good habits early in life—even in your teenage years and 20s—can set the foundation for lifelong physical and cognitive health. However, it’s never too late to start making positive changes, no matter your age.

One of the most powerful tools for brain health is nurturing positive, satisfying relationships. Decades of research, including the Harvard Study of Adult Development, which has followed families for 86 years, reveals that warm, meaningful relationships are the key to a longer, happier life with a sharper mind. As Dr. Robert Waldinger, the study’s director and a Harvard Medical School professor, explains, “Warm relationships keep people physically stronger and their brains sharper as they age. Good relationships act as stress regulators.”

The consequences of social isolation and loneliness are stark. Studies link them to an increased risk of early death, anxiety, depression, heart disease, stroke, type 2 diabetes, and dementia. Dr. Rudy Tanzi, a professor of neurology at Harvard Medical School, notes that loneliness—defined as feeling alone and not liking it—doubles the risk of Alzheimer’s disease.

Fortunately, you don’t need intimate relationships to reap the benefits. Connections with friends, family, or even supportive colleagues can improve mental health if they are nurturing. Waldinger emphasizes the importance of having at least one person in your life who you feel has your back—someone you can turn to in times of trouble. This kind of support is essential for maintaining happiness and overall health.

Tanzi also advises evaluating toxic relationships, as they can negatively impact brain health. “The brain doesn’t do as well when it’s not stimulated by positive social interactions,” he says. “Maximize relationships that make you feel good.”

Belly Fat and Brain Health: The Hidden Connection

Did you know that belly fat, also known as visceral fat, can shrink the brain’s memory center and increase the risk of Alzheimer’s disease? Research shows that as belly fat grows, the hippocampus—the brain’s memory hub—begins to shrink, and hallmark signs of Alzheimer’s, such as beta-amyloid plaques and tau tangles, can appear. This process can start as early as your 40s and 50s, long before any cognitive decline is noticeable.

Visceral fat wraps around vital organs deep in the abdomen, often expanding the waistline. While some people with larger waistlines may have high visceral fat, even thin individuals can have dangerous levels, detectable through body scans. Dr. Kellyann Niotis, a preventive neurologist researching Alzheimer’s and Parkinson’s, warns, “Visceral fat is metabolically unhealthy and secretes inflammatory chemicals that can cause brain atrophy and impact cognition.”

To protect your brain, focus on body composition rather than just your weight. Dr. Richard Isaacson, director of research at the Institute for Neurodegenerative Diseases, advises tracking body fat versus muscle mass. “Lean muscle mass burns fat more efficiently,” he says. “We want people to gain muscle and lose body fat for optimal brain health.”

Measuring your waistline is a simple way to assess your risk. For non-pregnant women, a waist size greater than 35 inches (88.9 cm) and for men, more than 40 inches (101.6 cm), signals a higher risk of visceral fat. While tools like DEXA scans and biometric scales can measure body composition, they may not be accessible or affordable for everyone. Isaacson notes that biometric scales, though imperfect, can still provide a general sense of body fat and muscle mass to guide exercise and nutrition plans.

If you need to build muscle, focus on strength training and consume adequate protein and healthy carbs within a few hours of exercise. Isaacson also recommends monitoring muscle mass over time and consulting a doctor if progress stalls, as issues like low testosterone could be a factor.

Insulin Resistance and Blood Sugar: Protecting Your Brain

Visceral fat doesn’t just harm the brain directly; it also contributes to insulin resistance, a condition where muscle, fat, and liver cells stop responding properly to insulin. Insulin is vital for moving glucose from the blood into cells, including brain neurons, to provide energy. When cells become insulin resistant, blood sugar levels spike, triggering the pancreas to produce more insulin. High levels of both insulin and glucose can lead to heart and kidney disease, type 2 diabetes, and damage to the brain’s memory center.

Niotis warns that high blood glucose levels are “directly neurotoxic” and can shrink the thinking part of the brain over time. While many doctors focus on average blood sugar levels over three months, daily monitoring is crucial for brain health. Isaacson explains, “Keeping blood sugar levels relatively constant throughout the day is key for good brain health. Blood sugar spikes cause inflammation, disrupt brain metabolism, and shrink the brain’s thinking centers.”

One effective way to monitor blood sugar is by wearing a continuous glucose monitor (CGM) for two weeks. These devices, now available without a prescription, track blood sugar levels in real time. Isaacson recommends aiming for an average blood sugar level of less than 105 mg/dL, with optimal control being between 98 and 100 mg/dL.

By journaling the foods you eat while wearing a CGM, you can identify which foods cause blood sugar spikes and how to manage them. For example, eating fiber and healthy fats before simple carbs, such as having a salad with olive oil before pasta, can slow digestion and reduce blood sugar surges.

CGMs also track two critical measures for brain health: the variability between blood sugar highs and lows (called standard deviation) and the highest spike after meals. Isaacson advises striving for less than a 15% deviation in daily blood sugar levels, with 10% being optimal. He also recommends keeping post-meal spikes below 150 mg/dL, as higher levels can damage the brain.

The Role of Physical Activity in Brain Health

Physical activity is a cornerstone of a long, healthy life, and it’s especially beneficial for the brain. “Getting your blood flowing faster is good for your brain,” says Tanzi. “Exercise induces the birth of new nerve cells and helps remove amyloid plaques linked to Alzheimer’s disease.”

Aim to raise your heart rate by at least 50% for 30 minutes daily—whether through brisk walking, cycling, or another activity. While cardio is excellent for getting the heart pumping, strength training, or resistance exercise, is equally important for brain health. When muscles contract during exercise, they release a hormone called irisin, which triggers an enzyme that breaks down Alzheimer’s-related amyloid plaques.

Research shows that resistance training, especially when progressively challenging, boosts irisin levels, particularly in older adults. Irisin also increases energy expenditure by converting white fat into brown fat. Brown fat burns glucose and fat to produce heat, while white fat is stored and contributes to weight gain.

The American Council on Exercise recommends exercises that engage multiple joints, such as dead lifts, lunges, planks, presses, pull-ups, and push-ups. These movements elevate oxygen use and hormone release, improving blood flow and heart rate. As you build lean muscle, aim to gradually increase weight, sets, and repetitions while reducing rest between exercises. If you’re unsure how to proceed safely, consider consulting a physical trainer.

Putting It All Together: A Holistic Approach to Brain Health

Protecting your brain health is a multifaceted endeavor that requires attention to relationships, body composition, blood sugar levels, and physical activity. By nurturing positive relationships, reducing belly fat, managing insulin resistance, monitoring blood sugar, and engaging in regular exercise, you can safeguard your brain and maintain cognitive function well into old age.

The good news is that these changes are within reach, no matter your age or current health. Small, consistent steps—like building lean muscle, avoiding blood sugar spikes, and fostering meaningful connections—can have a profound impact over time. As Isaacson says, “The brain needs daily care, just like the rest of the body.” By prioritizing your brain health today, you’re investing in a sharper, healthier mind for the future.