The more scientists delve into the interrelationship between the brain and the cardiovascular system, the more evidence they find that blood vessel problems are important factors in cognitive decline and the neurodegeneration associated with Alzheimer’s disease (AD). The findings offer hope for those of us who are worried about losing our memories in older age, because they imply that taking steps to keep the circulatory system clear and blood vessels healthy may very likely help prevent or slow the loss of mental acuity and the development of dementia.
“We are learning that maintaining healthy blood vessels may be just as essential for protecting mental acuity as it is for avoiding a heart attack,” says Maurizio Fava, MD, Executive Vice Chair of the Department of Psychiatry and Director of Clinical Research at Massachusetts General Hospital (MGH).
WHAT YOU CAN DO
The following important strategies can prevent damage to blood vessels that could ultimately harm the brain:
- Exercise regularly. With your doctor’s okay, try to engage in regular aerobic workouts (30 minutes or more at least five days a week). Research suggests that aerobic exercise is linked to lower blood pressure while at rest and while exercising, improved brain blood flow, and higher scores on tests of cognitive performance .
- Avoid tobacco smoke. Cigarette smoking is a major risk factor for cardiovascular disease, and is so damaging to the cardiovascular system that even secondhand smoke has negative effects on cognition. In one study, a correlation of secondhand tobacco exposure levels with cognitive performance revealed that participants with the highest levels of exposure to secondhand smoke had a 44 percent greater risk of scoring in the bottom 10 percent on cognitive tests than those with the lowest levels of exposure to secondhand smoke.
- Manage medical conditions that can negatively affect the cardiovascular system. Have regular checkups, and consult with your doctor to learn about lifestyle changes and medical treatments that can help you control conditions such as diabetes, high blood pressure, heart disease, or high levels of “bad” LDL cholesterol (a level higher than 100 mg/dL).
- Prevent metabolic syndrome. This condition is present when a person has at least three of the following risk factors: a large waistline (abdominal obesity); high blood pressure; lower-than-normal levels of “good” HDL cholesterol; higher-than-normal triglyceride levels in the blood; and higher-than-normal fasting blood sugar. Research suggests that metabolic syndrome can boost the risk of developing cognitive impairment by 20 percent.
- Maintain adequate levels of B vitamins. Research suggests a deficiency of vitamins B12, B6 and folate (B9) may damage small blood vessels in the brain, and lead to problems with spatial learning and memory, and a reduction in the length and density of brain capillaries.
A new study that focuses on the association between cardiovascular health and brain health suggests that there may be a direct link between the development of atherosclerosis and a buildup in the brain of beta-amyloid plaque, a hallmark of AD. Atherosclerosis is a progressive hardening, or stiffening, of the arteries caused by an accumulation on the inside of the blood vessels of a fatty deposit composed of cholesterol, cells, anddebris. Over time, this accumulation narrows the arteries, interferes with blood flow and causes the blood vessels to lose their flexibility. Arterial hardening, which begins with the larger arteries near the heart and gradually spreads to the peripheral arteries and beyond, worsens with age.
According to a report in the March 31, 2014 issue of JAMA Neurology, the researchers conducted PET scans to measure the beta-amyloid plaque in the brain tissue of 81 healthy older adults, and used a special process called pulse wave velocity to gauge the stiffness of their arteries. They found that participants with the most beta-amyloid plaque in their brain tissue also had the greatest degree of arterial stiffening. After another two years, those whose atherosclerosis was most advanced had deposited the most amyloid
“This is very important research that adds to evidence that hardening of the arteries has significant implications for brain health, and specifically for the development of AD,” says Dr. Fava. “The arteries stiffen, lose their elasticity, and are no longer able to expand to compensate for variations in blood pressure. Blood pressure variations are transmitted up the line to smaller arteries and blood vessels and may eventually lead to brain bleeds or strokes that kill brain cells, a process that is generally thought to play a role in declining mental function and dementia in older adults. This research suggests that there is yet another process—the formation of beta-amyloid plaque—that increases risk for AD.”
Recent studies have identified other blood vessel problems that wreak havoc on brain health, and strongly reinforce the theory that interference with proper blood flow to brain tissue is a major factor in mental decline.
- A study presented at an American Academy of Neurology meeting in April 2014 suggests that narrowing of the carotid arteries, the major blood vessels that deliver blood through the neck to the brain, is associated with significant problems in memory and thinking.
- A study published in the January 2014 issue of the Journal of Alzheimer’s Disease suggests that accumulation of deposits of beta-amyloid within the cerebral blood vessels themselves—a condition called cerebral amyloid angiopathy—occurs in the earliest stages of AD, and appears to trigger early cognitive decline.
- Yet another study presented last year at the European Society of Cardiology meeting found that among 57,669 healthy adults over 65, those who took the highest doses of statin medications, designed to lower cholesterol levels, had a 59 percent reduced risk of new-onset dementia over a 4.5-year period compared to those who did not take statins. Participants who took low-dose statins reduced their dementia risk by 31 percent.
- Research published in July 2013 in the journal Brain involving analysis of medical data on more than 5,700 AD patients found that almost 80 percent had blood vessel problems including hardening of the arteries, blocked or narrowed blood vessels, and bleeding in the brain. Restricted blood flow related to blood vessel problems was also found to play a role in Parkinson’s disease and Lou Gehrig’s disease.
Keeping vessels clean
“While we have not yet succeeded in finding treatments to reverse the devastation caused by AD and many other brain disorders, these studies suggest that by working to protect the health of our blood vessels we may be able to prevent brain injury in the first place,” Dr. Fava says. “That’s good news for those of us who are concerned about staying sharp through the years.”
Adopting a healthy lifestyle is one important way to maximize blood vessel health. Be sure to control your weight;manage your blood pressure (an ideal blood pressure reading is 120/80 mmHg or lower); stay physically and mentally active; and eat a balanced, low-fat diet with abundant fresh fruits and vegetables, low-fat dairy products, lean meats, fish, whole grains, nuts and seeds; and healthful monounsaturated, polyunsaturated, and omega-3 fats. Avoid processed foods, saturated fats and trans fats, and excessive amounts of sugar and alcohol (no more than one drink a day is advised).
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