Jennifer Garrison, Assistant Professor and Co-Director of the Center for Healthy Aging in Women at the Buck Institute for Research on Aging
The human brain is arguably the most complex object in the known universe. It contains some 86 billion (86,000,000,000) neurons that form 100 trillion (1,000,000,000,000,000) connections to each other — numbers that, ironically, are far too large for the human brain itself to fathom. For comparison, if you have The Complete Works of William Shakespeare on your bookshelf, it contains 884,647 words. When you stop to consider that your brain contains more neurons than there are people on Earth, and more connections between them than stars in the Milky Way, it’s humbling.
As a neuroscientist studying the mind-body connection, my research focuses on understanding the fascinating ‘wifi’ style communication that occurs between the brain and the rest of the body, and how it changes as we age. This dynamic, ongoing conversation between the brain and peripheral organs orchestrates every aspect of our physiology. While we’ve decoded some of this chemical language, much remains to be discovered about how these conversations change as we grow older.
One thing that’s clear is that not everyone’s brain ages at the same rate. Some individuals in their 80s have brains functioning like those decades younger. This suggests that with the right approaches, we can influence how our brains age and potentially reduce our risk of cognitive decline. Some key lessons:
#1 Optimize Your Blood Pressure, Protect Your Brain
When we think about high blood pressure, most of us immediately think “heart health.” But compelling research shows that managing your blood pressure may be one of the most powerful ways to protect your brain as you age. The evidence is particularly striking for those of us in our 40s through early 60s – what scientists call “midlife.” During these crucial years, elevated blood pressure can set the stage for cognitive decline later in life.
One study found that people over 50 who maintained their systolic blood pressure below 120 mmHg significantly reduced their risk of mild cognitive impairment – often an early warning sign of dementia. Think of your brain’s blood vessels as a complex irrigation system; high blood pressure can damage these delicate channels, reducing vital blood flow to important areas. While you might not feel any symptoms, regular check-ups can catch elevation early. Simple lifestyle modifications and, if needed, medications can help maintain healthy levels, slowing cognitive decline as you age.
#2: Movement is Medicine for your Mind
Physical activity may be the most powerful prescription for long-term brain health available. While we don’t yet have a cure for Alzheimer’s disease or other types of dementia, prevention through active living offers remarkable protection for your cognitive function.
The science behind this is compelling: during exercise, your brain releases chemicals called neurotrophic factors, particularly BDNF, which act like fertilizer for your neural networks. These molecules nourish neurons, forge new connections, and can even increase brain volume. Moderate aerobic activity – whether it’s a brisk walk, swimming, or dancing – does more than just improve cardiovascular health; it activates beneficial signaling pathways in your brain, enhances immune response, and improves key factors like mood and sleep quality. The evidence is clear: incorporating regular physical activity into your daily routine is an investment in your cognitive future, and the benefits accumulate regardless of when you begin.
Lesson #3: Hydration Matters More Than You Think
Most of us know we should drink enough water, but few realize just how profoundly hydration affects our cognitive function. Even a modest 2% decrease in hydration can trigger short-term memory problems and difficulty with things like basic math calculations. For those over 50, maintaining proper hydration becomes especially crucial, as our natural thirst signals become less reliable with age.
When your brain cells don’t get enough water, they literally shrink in size, disrupting the intricate network of communication pathways that keep your mind sharp. This can manifest as “brain fog,” slower reaction times, and difficulty focusing on tasks. The effects are particularly noticeable in activities requiring sustained attention or complex problem-solving. Mood changes, including increased anxiety and irritability, can also signal dehydration’s impact on brain chemistry.
What’s important to know is how quickly proper hydration can reverse these effects. Unlike many aspects of brain health that require long-term lifestyle changes, improved cognitive performance can often be achieved within hours of restoring proper fluid balance. Drink up!
Lesson #4: Quality Sleep is Brain Care
Think of sleep as your brain’s nightly maintenance crew. During those crucial hours of rest, your brain activates its own cleanup system, removing accumulated waste products while simultaneously strengthening important memories and preparing for new learning. This process is so vital that chronic sleep disruption can accelerate cognitive aging.
We now know that sleep quality in early middle age correlates directly with brain health markers in late middle age. Beyond just feeling refreshed, getting a good night’s sleep enhances attention, problem-solving abilities, and creativity while supporting emotional well-being. If you experience daytime drowsiness or morning fatigue, talk to a doctor about potential sleep apnea, a common condition that is easily treatable but can significantly impact brain health if ignored.
Lesson #5: Stress Less, Think Better
The impact of chronic stress on brain health extends far beyond momentary mental tension. Persistent stress actually alters brain structure, particularly in regions crucial for memory and emotional regulation. Think of chronic stress as wearing down the gears in your brain’s machinery – over time, it can lead to measurable reductions in brain volume and function.
But here’s the empowering news: you can actively protect your brain through stress management. Approaches like Mindfulness-Based Stress Reduction, which combines meditation, body awareness, and mindful movement, can dramatically reduce anxiety and depression, improving both attention and concentration. Even more encouraging, these benefits seem to extend to overall cognitive performance and quality of life.
Along the same lines, cultivating a positive outlook can dramatically improve brain health with age. Those who maintain optimistic attitudes about aging tend to navigate age-related changes more successfully. By engaging in regular stress-reduction practices, whether through meditation, gentle movement, or other mindfulness techniques, you’re not just feeling better in the moment – you’re actively preserving your cognitive vitality for the future.
