An international team of experts has found that older people with high levels of "bad" cholesterol live as long — or longer — than their peers with low levels.
The findings, which came after analyzing more than 68,000 patients over the age of 60, call into question whether seniors with high cholesterol, especially high levels of low-density lipoprotein or LDL (LDL-C), are more at risk of dying from heart attack and stroke and need statin drugs to lower their cholesterol levels.
"We have known for decades that high total cholesterol becomes a much weaker risk for cardiovascular disease with advancing age," said researcher David Diamond of the University of South Florida. "In this analysis, we focused on the so-called 'bad cholesterol' which has been blamed for contributing to heart disease.
"We found that several studies reported not only a lack of association between low LDL-C, but most people in these studies exhibited an inverse relationship, which means that higher LDL-C among the elderly is often associated with longer life," said Diamond.
Diamond also noted that the findings suggest that high cholesterol may be protective against diseases which are common in the elderly. For example, high levels of cholesterol are associated with a lower rate of neurological disorders, such as Parkinson's disease and Alzheimer's disease. Other studies have suggested that high LDL cholesterol may protect against some often fatal diseases, such as cancer and infectious diseases, and that having low LDL-C may increase one's susceptibility to these diseases.
"Our results pose several relevant questions for future," said study leader and co-author health researcher Uffe Ravnskov. "For example, why is total cholesterol a factor for cardiovascular disease for young and middle-age people, but not for the elderly? Why do a substantial number of elderly people with high LDL-C live longer than elderly people with low LDL-C?"
The researchers have published other studies indicating that the benefits of taking statin drugs have been exaggerated.
"Our findings provide a contradiction to the cholesterol hypothesis," concluded Diamond. "That hypothesis predicts that cardiovascular disease starts in middle age as a result of high LDL-C cholesterol, worsens with aging, and eventually leads to death from cardiovascular disease. We did not find that trend.
"If LDL-C is accumulating in arteries over a lifetime to cause heart disease, then why is it that elderly people with the highest LDL-C live the longest?" he asked. "Since people over the age of 60 with high LDL-C live the longest, why should we lower it?"
The study is published in the open access version of the
British Medical Journal.