The brain is the most complex organ and one that still remains a mystery in many aspects. The human brain weighs just over three pounds and is packed with as many as 100 billion neurons, or nerve cells. It’s neurons that carry information and allow you to think, feel, and interact with the world around you.
Unfortunately, the human brain and its neurons age just as the rest of your body does. The ability to process information quickly, also known as fluid intelligence, peaks at around age 20. However, other cognitive skills peak later in life. For example, short-term memory doesn’t reach a zenith until age 25, whereas the ability to read other people’s emotional states peaks much later, as late as age 50. So, there are different types of intelligence and they reach their greatest functional capacity at different stages of life.
Yet we also know that brains age at different rates based on lifestyle. In fact, brain aging is closely correlated with aging of the heart. In fact, the same factors that promote heart disease also speed up brain decline. So, living a heart-healthy lifestyle is good for your brain. One of the most feared complications of brain aging is Alzheimer’s disease. Although much about Alzheimer’s disease remains a mystery, it’s characterized by loss of cognitive function
There’s no guarantee that living a healthy lifestyle will stave off the ravages of Alzheimer’s disease, since there’s a genetic component, yet even people who are strongly genetically predisposed don’t always develop the disease. Environment and lifestyle definitely play a role. In fact, researchers have developed an index called LIBRA (Lifestyle for Brain Health Index). This index lists twelve modifiable risk factors that can explain over half of all cases of Alzheimer’s disease.
Here are the twelve factors that make up the LIBRA index:
· High Cholesterol
· Mental Activity
· Physical Inactivity
· Coronary Heart Disease
· Kidney Disease
As you can see the risk of developing the diseases associated with a higher risk of dementia are at least partially preventable through lifestyle or treatable, such as high cholesterol, hypertension, type 2 diabetes, coronary heart disease, and obesity. The evidence that you can prevent depression and kidney disease is a bit weaker. Let’s look at a few of the factors in the index in more detail.
Two lifestyle habits linked with Alzheimer’s disease are smoking and overuse of alcohol. In fact, people who smoke heavily during mid-life have a two-fold greater risk of developing Alzheimer’s disease twenty years later. Fortunately, former smokers who smoked less than a half-pack daily and kicked the habit do not appear to be at higher risk. Smoking also increases the risk of dementia by damaging the heart and vascular system and increasing the risk of atherosclerotic disease and stroke.
Alcohol is a bit trickier Drinking moderate amounts of alcohol may actually lower the risk of developing dementia, including Alzheimer’s dementia while heavy drinking and binge drinking seem to heighten the risk. What is the definition of modest alcohol consumption? For men, it’s drinking two alcoholic drinks daily and for women, only one.
How might moderate drinking lower the risk of dementia? Low levels of alcohol may stymy inflammation within the brain and nervous system. However, drinking alcohol, even modest amounts, may raise the risk of other health problems, for example, breast cancer in women. So, don’t drink alcohol without considering the other possible health ramifications.
How about diet? That’s something we have control over. The evidence is strongest for the Mediterranean diet with regard to protecting against dementia. A study published in the Annals of Neurology linked a Mediterranean diet with a lower risk of Alzheimer’s disease as well as a slower rate of cognitive decline. The Mediterranean diet emphasizes fruits, vegetables, whole grains, nuts, fish, and monounsaturated fat from sources like nuts and extra-virgin olive oil. It’s a nutrient-rich diet that’s also linked with heart health and a lower rate of all-cause mortality.
Exercise, of course, is a must-do for heart health and to lower the risk of chronic health problems that raise the risk of Alzheimer’s disease. Yet, aerobic exercise also has more direct effects on brain health. Specifically, studies show regular physical activity increases volume in the hippocampus, a portion of the brain involved in cognition. Aerobic exercise also boosts neurogenesis, the capacity of nerve cells to form new connections that benefit learning and brain health. Based on a meta-analysis, regular exercise is also correlated with better scores on memory, brain processing speeds, and executive function in adults.
What about cognitive exercise? Although most studies don’t support the idea that brain games protect against Alzheimer’s disease, certain types of mental activities do. Research suggests that building up “cognitive reserve” by learning new things throughout life may lower the risk of Alzheimer’s disease. Having more years of education is associated with a lower risk of dementia, possibly due to more education leading to greater cognitive reserve. Learning a second language is also linked with better brain health. To really build cognitive reserve, you need to learn novel skills that your brain hasn’t been exposed to. For example, reading books in a field you’re already well-versed in won’t increase cognitive reserve as much as taking a class in an entirely new field that you have no training in.
Avoid Other Chronic Health Problems
Doing what you can to prevent heart disease, hypertension, high cholesterol, type 2 diabetes, and obesity will also help reduce premature brain aging and lower the risk of dementia. Fortunately, exercising, eating a Mediterranean diet, not smoking, and not overconsuming alcohol will lower your risk of most of these health problems as well. That’s the benefit of living healthy!
The Bottom Line
Lifestyle is very much tied to Alzheimer’s risk. Now you know of some simple lifestyle habits that may reduce YOUR risk. You have more control over health than you think and it’s directly related to the decisions you make.
MIT News. “The rise and fall of cognitive skills”
Family Practice News. “Poverty’s Increased Dementia Risk is Not Set in Stone”
WebMD. “Smoking Linked to Alzheimer’s and Dementia”
WebMD. “Alcohol Use and the Risk of Developing Alzheimer’s Disease”
Ann Neurol. 2006 Jun; 59(6): 912–921. doi: 10.1002/ana.20854.
Mayo Clin Proc. 2011 Sep; 86(9): 876–884 doi: 10.4065/mcp.2011.0252.
Lancet Neurol. 2012 Nov; 11(11): 1006–1012.doi: 10.1016/S1474-4422(12)70191-6.
Scientific American. “Antibiotics Linked to Weight Gain”