The scientists who research Alzheimer’s disease (AD) have yet to discover what causes the formation of abnormal protein structures (called plaques and tangles) that destroy brain cells.
However: It’s now clear that certain lifestyle practices can guard against the inexorable memory loss and personality changes associated with this dreaded disease.
Evidence: In a landmark study of 678 Mid¬ western nuns, autopsy reports found that the brains of one-third of the 251 nuns who died in the course of the study had the plaques and tangles of AD but did not show symptoms of the disease. On the other hand, some nuns who had fewer plaques and tangles had experienced AD symptoms
Assaults on the brain
AD gets the lion’s share of attention, but it’s just one of many enemies that menace the brain as we grow older. Among them…
This is a normal defense mechanism in which the immune system destroys foreign molecules, such as viruses, by releasing high-energy molecules, including free radicals. With aging, a mild degree of inflammation occurs in joints, skin and the brain, causing arthritis, skin wrinkles and memory problems.
Each mini stroke (blockage of tiny blood vessels within the brain) may kill too few cells to have any noticeable impact, but when mini strokes occur hundreds or even thousands of times, they take their toll.
It’s the cumulative impact that counts the plaques and tangles of AD, plus all the other sources of damage. Anything you do to promote the overall health of your brain may delay or even prevent memory loss and other AD symptoms.
Protect your brain
Many of the same practices that lower your risk for heart attack and stroke also reduce the chances that you will develop AD.
• Control blood pressure
High blood pressure can contribute to the narrowing of blood vessels and reduces blood flow to the brain, depriving it of oxygen and nutrients. This makes brain cells more vulnerable to AD damage and raises the risk for mini strokes.
Scientific evidence: Many studies have linked rising blood pressure with declining memory. A Scandinavian study of 1,449 middle-aged volunteers, reported in the British Medical Journal, found that those with mild hypertension 130 to 140 systolic (top number) had twice the chance of having AD 20 years later. Those who had more severe hypertension 141 to 160 systolic had nearly three times the risk.
Self-defense: Keep your blood pressure at 115/75 or less. If it exceeds 130/90 despite your efforts to bring it down losing weight, exercising and quitting smoking you may need medication, such as diuretics, beta-blockers or calcium channel blockers.
• Lower cholesterol
High cholesterol levels cause narrowing of blood vessels, which impairs circulation in the brain and may lead to mini-strokes. Some research suggests that high cholesterol promotes the development of AD plaques.
Scientific evidence: The same Scandinavian study found that people with total cholesterol above 250 mg/dl were more than twice as likely to develop AD in later life as those with normal levels.
Self-defense: Aim for total cholesterol under 150 mg/dl. A healthy diet, exercise and smoking cessation can help bring it down. If your cholesterol remains above 150, talk to your doctor about medication.
Statins, such as pravastatin (Pravachol) and atorvastatin (Lipitor), are the drugs of choice for elevated cholesterol. Several studies have found that individuals taking these drugs have 60% to 80% less risk of developing AD than those not taking them.
Diet for a healthy brain
Like the rest of your body, your brain must be well fed to function optimally and stay healthy.
•Eat at least five servings of fruits and vegetables daily.
They contain antioxidant vitamins and phytochemicals that protect brain cells from damage by free radicals.
Best antioxidant food sources: Blueberries, pomegranates, carrots and green, leafy vegetables.
One antioxidant that deserves particular attention is vitamin E.
Scientific evidence: A Dutch study of 5,395 people, age 55 or older, published in the Journal of the American Medical Association; found that those consuming the most vitamin E in foods and supplements had 43% less chance of developing AD than those consuming the least.
Boost your intake of vitamin E-rich foods, such as whole grains, avocados and olive oil.
• Have fish twice weekly
Cold-water fish, such as wild salmon and mackerel, contain omega-3 fatty acids that function as antioxidants as well as counter inflammation that can damage brain cells. Fish consumption also has been linked to improved circulation.
Scientific evidence: A study of 815 people, ages 65 to 94, found that those who consumed fish once or more weekly had 60% less risk of developing AD than those who did not.
• Drink in moderation
Temperate consumption of alcohol two glasses of wine, two beers or one drink containing hard liquor daily keeps brain cell membranes more flexible, which lets them function better.
Caution: Consuming greater amounts of alcohol, especially as you grow older, has been shown to impair memory and damage brain and other tissues.
Scientific evidence: A Dutch study published in The Lancet found that older adults who consumed mild to moderate amounts of alcohol daily had a 42% lower risk for dementia.
Activity for the brain
Brain function has been shown to improve in people who are active both mentally and physically.
• Stay mentally active
Mental workouts stimulate the release of growth factors chemicals that spur brain cells to forge a rich network of cells that can compensate if some cells are disabled by AD.
Scientific evidence: A study of 801 Catholic priests and nuns, age 65 or older, found that those who spent the most leisure time in activities that demanded thinking reading books, playing cards, solving crossword puzzles had half the AD risk of those who spent the least time involved in such pursuits.
Self-defense: Read books that make you think follow political developments around the world learn a foreign language, play games, such as chess, that require cognitive skills.
•Get regular exercise
Physical activity stimulates brain growth factors, improves circulation and reduces the risk for mini strokes.
Scientific evidence: A University of California at Los Angeles study that followed 6,000 women, age 65 or older, for six to eight years found that the more miles they walked daily, the lower their risk for dementia. Other studies that included men had similar results.
Self-defense: Just a little exercise makes a lot of difference. Do something active brisk walking, tennis or dancing for at least 30 minutes each day.