Dear Dr. Roach: A 74-year-old woman has a total cholesterol of 123 and was told that low cholesterol like this greatly increases the risk of diabetes, stroke and cancer. It seems she has had low cholesterol for many years. What do you think is the optimum healthy level? What would you recommend to increase her total cholesterol? R.I.
Answer: When cholesterol questions come in, most people are concerned about a too-high level. Coronary artery disease remains the biggest killer in industrialized societies, and high LDL and total cholesterol are risk factors for developing the blockages in the arteries of the heart that are the hallmark of this disease. High cholesterol is not the only risk factor: People certainly can develop CAD with normal cholesterol levels, and some people with high cholesterol levels never develop that type of heart disease. However, lowering cholesterol with diet and exercise, statins and, to a lesser extent, some other drugs reduces coronary disease risk for people at above-average risk. It appears that the more the cholesterol is reduced, the greater the risk reduction.
Most types of stroke have the same risk factors as CAD, so these treatments reduce stroke risk as well. However, there is one less-common type of stroke, hemorrhagic stroke, that is somewhat increased in a person with low cholesterol levels. Still, overall stroke risk is reduced by decreasing cholesterol.
With the possible exception of liver cancer, there is no good evidence that either high or low blood cholesterol is a major risk for cancer. There are conflicting studies and no consensus. What is clear is that people with cancer may develop low cholesterol levels as a result of either the cancer itself or nutritional challenges associated cancer treatment. This can lead people to mistakenly attribute the low cholesterol that is due to the cancer as a cause of the cancer.
It is also clear that raising cholesterol shouldnt be a goal. For someone who has had low cholesterol for a long time, there is probably nothing that need be done beyond age-appropriate cancer screening, such as a mammogram, possibly a colonoscopy, and consideration of lung cancer screening if she had been a heavy smoker.
Separating cause and effect is very difficult in this instance. I would still recommend a diet of mostly plants, whole grains, nuts, and fatty fish if she likes it. If she is underweight, then high-quality nutrition becomes even more important, she should consult with a registered dietitian nutritionist.
