For sailors, the phrase “roaring forties” refers to the area below 40 degrees south latitude, where the ocean begins to become unrelentingly dangerous to small vessels because of huge waves and high winds. But for every man and woman, the term can also mean a time after age 40, when the brain faces increasing danger of decline. New research has shown that in the brains of people in their 40s, the parts of the brain involved in memory and cognitive function start losing their ability to function, at least in some people. Though studies are by no means conclusive, it suggests that in our fifth decade of life, many of us may start experiencing physical brain breakdown without realizing it.
We do not see this as any surprise. After all, many of us have experienced difficulty remembering things in middle age — where we left the car keys, what we went into the kitchen to get, and so on. That the brain, like the rest of the body, undergoes some age-related change is not news. We lose between 5 and 10 percent of our brain mass between the ages of 20 and 80, and with that natural change comes some impairment, such as slower reaction time behind the wheel of a car, or failure to recall the name of a recent acquaintance. But although the aging brain naturally suffers some damage, dementia is not an unavoidable outcome of age. There is much you can do to prevent it.
Another commonly held myth about the aging brain is that our genetic inheritance puts our ultimate brain health beyond our control. We assume that because Aunt Sally forgot who she was by the time she was 85, the same experience is likely in store for us. But was Aunt Sally obese? Did she exercise? What was her diet like? Did she learn new things as she got older, or did she stop learning? A raft of long-term research, particularly work carried out by the MacArthur Foundation, confirms that health that continues into old age is only 15 to 30 percent determined by our genetic heritage. The remainder is mainly determined by our lifestyle choices and behaviors, psychology, environment, and life events.
Think for a moment about the implications. You are not powerless against your DNA. We all have the power to control at least 70 percent of our aging process through the lifelong choices we make in diet, exercise, mental health, learning, and relationships. We do not have to stand passively watching and hoping as our bodies and brains age, accepting the outcome as “just the way it is.” We can make proactive, conscious choices to help our bodies and brains remain healthy and vital into our 70s, 80s, and 90s. That is a serious responsibility, but it also represents a wonderful hope for the future.
The reality is that old age by itself does not guarantee a loss of brain function. True, recent research shows that people with a certain gene are more likely to develop Alzheimer’s disease or lose memory function. However, the same study shows that diabetes and heart disease carry the identical risk, and as we have said, these are diseases of lifestyle. It has become clear after decades of research that physical wellness, lifestyle, weight, diet, and exercise are far more important factors in brain health than genetics or age. Age is not a choice; healthy living is. The lifestyle choices we make today play a large role in determining how sharp our minds and memories will be tomorrow.
Here are some other widespread myths related to the brain and age.
Myth: Serious Brain Decline Is Inevitable
Yes, changes in brain structure and chemistry do occur with age. But they do not have to lead to a steep decline in mental ability. Writing in Newsweek, Gene Cohen, M.D., Ph.D., founding director of the Center on Aging, Health and Humanities at George Washington University Medical Center, says that in his work designing games to improve the mental function of aging men and women, he has found that the brain’s left and right hemispheres (the left is responsible for linear, logical thinking; the right, for creativity and intuition) actually become better integrated as we age, leading to greater creative potential. Cohen writes that it is becoming clear that with the proper lifestyle and challenges, the brain can in many respects become stronger with age.
Myth: I Am Getting Dumber Because My Brain Cells Are Dying
It is true that brain cells die as we age. Brain cells die and new cells are born throughout our lives. But for many years people have assumed that, barring excessive drinking during college, brain cells cash in their chips at a higher rate as we get into the retirement years. But as it turns out, that is not true either. It appears that we lose brain cells at a consistent rate throughout life, owing to causes that range from stress and nutritional deficiencies to environmental toxins. Also, some neuroscientists now believe that brain-cell death may be a part of the brain’s learning process. The loss of some cells paves the way for new connections to develop as we learn, part of the sculpting of the brain that occurs when the brain remains active and constantly learning.
Myth: The Adult Brain Cannot Form New Connections
For many years, brain scientists were certain that the brain could not make new nerve cells to replace lost ones. But in the mid-1990s, researchers began to see evidence that indeed the brain can produce new nerve cells in some areas of the brain related to memory — a process called neurogenesis. This phenomenon is particularly responsive to regular physical exercise, meaning that working out is not just good for your heart, bones, and muscles, but good for your mind as well. Studies based on the work of Columbia University neurologist Scott Small and Salk Institute neurobiologist Fred Gage suggest that regular exercise delivers more oxygen-rich blood to the brain, as well as a chemical called brain-derived neurotrophic factor, or BDNF. These factors and others appear to improve memory, learning, and other brain functions.
Perhaps the most exciting discovery is that, like the rest of the body, brain vitality is a “use it or lose it” proposition. A study at the University of Pittsburgh School of Medicine shows that the more stimulating and intellectually challenging we make our lives, the better are our odds of keeping our aging brains vital, sharp, and agile. Just as with muscles, it appears that with lack of use our brains atrophy, failing to create new neural connections and replace dying brain cells. Older people who follow the traditional path of retirement, sitting on the porch in a rocker and doing little or nothing, are inviting dementia and decline in brain function. By comparison, an enriched environment, as author and brain scientist Marion C. Diamond calls it — one filled with play, discovery, learning, and challenge — keeps the brain active and constantly producing new connective pathways. This quality, known as neuroplasticity, suggests that in the right environment our brains can evolve and change in wondrous ways throughout our lives.
So much for the idea that old dogs can’t learn new tricks. Not only can they, but they should. Designing your life so that every day you are learning something new or looking at the world in a new way not only enhances brain health and mental activity but brings greater delight and satisfaction to living. What’s good for your brain is also good for your soul.
This article is excerpted from “In Full Bloom: A Brain Education Guide for Successful Aging” by Ilchi Lee and Jessie Jones, Ph.D.
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