Cholesterol and Brain Health – How to prevent a Stroke
Cholesterol: Good and Bad
There’s plenty of evidence that blood cholesterol is heavily involved in atherosclerosis that clogs and stiffens the blood conduits of the body, the cerebral blood vessels as well as coronary arteries. The worst appears to be LDL (low density lipoprotein) cholesterol that when “oxidized” (turned rancid by free-radical chemicals) is able to infiltrate blood vessel walls and accelerate plaque buildup, eventually reducing blood flow and encouraging release of blood clots.
It’s known, for example, that high levels of bad-type LDL blood cholesterol are tied to greater susceptibility to strokes as well as heart attacks. A recent study by Canadian neurologists at London Health Sciences Centre-University Campus in Ontario, documented that stroke risk goes up along with rises in total cholesterol and bad-type LDL cholesterol in particular. High triglycerides also pushed up stroke chances. On the other hand, investigators found that having high levels of good-type HDL cholesterol reduced the odds of stroke, just as it does heart attacks.
Several studies confirm that high good-type HDL cholesterol may help you evade a stroke, notably the most common “ischemic” or blood-clot caused strokes. Urhan Goldbourt, at the Sheba Medical Center in Tel-Hashomer, Israel, studied 8586 men for twenty-one years. Decidedly, men with the lowest HDL cholesterol—below 35.5 milligrams per deciliter (mg/dl) were 32 percent more likely to have a stroke then men with the highest HDLs—above 42.5 mg/dl. “Blood HDL cholesterol should be considered
a risk factor for stroke,” he declared. However, he added that high blood pressure poses a greater stroke threat than low HDLs.
CHOLESTEROL AND ALZHEIMER’S
Bad-type LDL cholesterol is even incriminated in Alzheimer’s disease, recent evidence reveals. LDL cholesterol encourages the deposition of a protein called beta amyloid, a major component of senile plaques that characterize Alzheimer’s. This beta amyloid is thought to be a major instigator of brain cell deterioration in the disease. This connection between bad cholesterol and beta amyloid might help explain why Alzheimer’s brains worsen in the presence of diseased blood vessels.
High cholesterol may be linked to low-level chronic inflammation, now recognized as extremely detrimental to blood vessels and brain tissue. Indeed, Harvard investigators in 1997 found that people with high levels of a blood protein reflecting increased inflammation were twice as apt to have a stroke. The protein is called C-reactive protein (CRP); it’s a measurable chemical marker in the blood that goes up as inflammation worsens.
Remarkably, follow-up 1999 research by Harvard cardiologist Paul Ridker, finds that a major way cholesterol-lowering drugs work to fight heart disease is by combating inflammation. During a five year double-blind study patients taking one of the “statin” anticholesterol drugs, pravastatin (Pravachol), had 38 percent lower levels of the CRP inflammatory protein than those who took a placebo pill. The anti-inflammatory benefits were totally independent of the blood cholesterol levels. What causes the inflammation is a mystery, although, says Ridker, “atherosclerosis may ultimately prove to be an inflammatory disease in the same way that we currently consider rheumatoid arthritis to be an inflammatory condition.”
BOTTOM LINE: Keeping your blood vessels healthy is a powerful way to keep your brain healthy.
WALK AWAY FROM A STROKE
Exciting new evidence shows that moderately intense physical exercise can cut your chances of having a stroke by an astounding 50 percent. That means an hour-long brisk walk five days a week or a comparable expenditure of energy, according to Harvard and Stanford researchers who studied 11,130 Harvard alumni for a dozen years. Compared with men who did little or no exercise, those who expended 2,000 kilocalories a week—equivalent to walking briskly for an hour five days a week—had a 46 percent lower risk of stroke. Walking briskly for half an hour five days a week—or the equivalent—cut the odds of stroke by 24 percent.
Why? Researchers speculate such physical activity reduces blood clotting, lowers cholesterol, reduces blood pressure and weight, all factors related to promoting strokes. Although the study was done on men, researchers say it’s logical to think it holds true for women, too.
“Walking, stair-climbing, and participating in moderately intense activities such as dancing, bicycling and gardening were shown to reduce the risk of stroke. “—I-Min Lee, M.D., Harvard School of Public Health
SIX NON-DRUG WAYS TO REDUCE BLOOD PRESSURE
- Take 1000 milligrams vitamin C daily. U.S. Department of Agriculture research showed that six weeks of vitamin C supplementation shaved an average 8 to 10 points off systolic readings and an average 7 points off diastolic readings in those with borderline high blood pressure. It even decreased normal blood pressure.
- Cut sodium intake to no more than 2400 milligrams a day. Best way, cut down on highly salted processed foods with hidden sodium. Check the label.
- If overweight, take off pounds. A slight loss of only ten pounds can have an impact. Excessive weight is the most prevalent cause of high blood pressure. A recent analysis of many studies found that weight loss was almost twice as effective as other dietary measures in reducing blood pressure. Losing weight depressed systolic blood pressure by 5.2 points compared with 2.9 points for salt restriction.
- Avoid alcohol entirely is the most effective advice. Otherwise, at least limit yourself to two drinks a day if you’re a man or one drink per day if a woman.
- Get regular physical exercise—such as half an hour to an hour of brisk walking every day.
Eat fruits and vegetables. It’s clear, say Harvard nutritionists, that chemicals and fiber in fruits and vegetables lower blood pressure. One Israeli study of two hundred people showed that only 2 percent of vegetarians had high blood pressure compared with 26 percent of meat eaters.