Lack of 'Good' HDL Cholesterol Linked to Memory Loss
News today that low levels of the "good" HDL cholesterol raises a person's risk of memory loss and dementia may send many folks rushing to their doctor for a cholesterol check. Indeed, the findings are pretty scary. Study participants with the lowest HDL levels—defined as less than 40 mg/dL—were 53 percent more likely to perform poorly on short-term memory tests compared to those with high HDL, defined as 60 mg/dL or greater. (These healthy participants were age 61, on average, experiencing the earliest signs of dementia that typically start in middle age.) Those whose HDL levels plunged over the six-year study also experienced a decrease in the number of words they were able to recall on the memory test, says study leader Archana Singh-Manoux, senior research fellow in epidemiology at the University College London.
The study, published in Arteriosclerosis, Thrombosis and Vascular Biology: Journal of the American Heart Association, underscores the dangers of allowing HDL levels to fall as you age, which often occurs with a sedentary lifestyle and expanding waistline; in fact, low HDL levels along with abdominal obesity were partially blamed for journalist Tim Russert's sudden death by heart attack, according to Michael Newman, the internist who was Russert's regular physician. The main function of HDL is to remove cholesterol from the artery wall, which reduces plaque buildup, explains cardiologist Karol Watson, codirector of the UCLA Center for Cholesterol and Lipid Management. "It also protects against oxidation and inflammation," she adds, "which can damage the vascular system that provides blood flow to the brain." Without adequate HDL, Watson speculates, blood flow may be blocked to the brain, triggering "mini" strokes that cause lingering effects like memory decline and senility similar to Alzheimer's disease.
There's currently no quick fix for low HDL levels. Statin drugs, which are great at lowering the "bad" LDL cholesterol, only modestly boost HDL. Plus, today's study found that statins had no protective effect against memory loss. The experimental HDL-boosting drug torcetrapib, which sent HDL levels soaring to above 70 mg/dL, fell by the wayside last year when it was found to cause an 80 percent spike in deaths from heart disease, cancer, and infections. Prescription niacin may be helpful at increasing HDL levels, says Watson, but many people can't tolerate the drug's side effects, which include flushing, itching, and upset stomach.
And while low HDL levels clearly are bad, having a high HDL level may not always be protective. Researchers are just learning about the complexities of HDL—how in some people, for example, it may actually fuel inflammation in the arteries and spur cardiovascular disease. Watson points to a review study she conducted showing that those with metabolic syndrome (typical in those with a large waist circumference and high glucose levels) who had naturally high HDL levels didn't lower have any lower risk of heart attacks compared with those with lower levels. "People certainly shouldn't be reassured if they're overweight and have a high HDL," Watson emphasizes.
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Reader Comments
Memory Loss
I have experienced measurable memory loss at age 63 after several years on a statin for moderately high cholesterol. I stopped taking the statin about a year ago, and after briefly trying another cholesterol medication, I now take none. I cannot prove the statin is to blame, but I believe that it is. I am not a doctor, but I have a mensa level IQ and I am not prone to make rash judgments about anything.
My ability to make rapid intelligent decisions has also been affected - I find myself laboring over decisions that a few years ago would have been clear in a split second. I believe these are tied together.
My mother had extremely high cholesterol readings and lived to 86, dying of non-related cancers. I agree that build up in the arteries cannot be good, but see no simplistic cure, and strongly suspect that the widely promoted cures may be worse than the disease.
Despite the fact that I remain slightly overweight, and prone to a marginal diet, I believe the memory loss has slowed and perhaps even slightly corrected since leaving the medications. It is anecdotal - I cannot prove it. But I believe it to be true for me.
So as for me, I strongly believe that resorting to statin drugs for cholesterol is more risky than many believe, and that a moderate amount of diet and weight control can lower the cholesterol to tolerable levels for most people without introducing the potential for loss of cognitive function and memory loss. Just an uneducated opinion.
HDL & comments
The point raised by Michael of FL regarding the power of big pharma companies need to be carefully taken up/investigated by the FDA USA and try to find out the Truth. If there are laws to prevent Restrictive Trade Practices and several companies have been penalised by the courts, then how come there is no awareness on part of general public and consumer protection organisations to come to the rescue of poor patients. They are penalised both with non-or lower improvement in health condition and loss of money. It appears from the comments that they are not getting Value for Money.
Sharad Kapadia
Surat, India
Other causes of memory loss
I have almost no protective HDL, and I have memory and concentration problems at age 65 that started almost 20 years ago. Very interested in this subject -have taken statins the whole time. BUT, other factors can be low testosterone for men (I have that too). I advise anyone at risk to have their endrocrine system checked.
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