For decades people have been told to reduce their intake of cholesterol. Yet, this fatty substance has many important functions in the human body. In fact, scientists say that it is vital for good health.
Yet your doctor may say that having high total cholesterol is not healthy. And, it may be a main cause of narrowing of the arteries and cardiovascular disease. The theory known as the cholesterol hypothesis.
Cardiovascular disease includes heart disease, stroke, heart failure and heart attack. If a doctor tests for and finds high cholesterol levels in your blood, they may recommend drugs that lower these levels, such as statins.
However, there may be reasons to question this approach for everyone. Research from 2016, in the British Medical Journal, suggests that having high levels may not be harmful to people over 60. In fact, the opposite might be true.
Evidence from Japanese studies suggests that high total cholesterol is not a risk factor for stroke. And, controversially people with lower levels have a higher risk of death.
So, the situation is confusing and not so straightforward.
Recent work suggests a link between total cholesterol and a higher risk of death from cardiovascular disease. But, further analysis shows that this association reduced with increasing age. So, high total cholesterol may not be a problem for older people. Contrary to the hypothesis, the link between total cholesterol and cardiovascular disease was minimal for the over 80s.
Could it be that total cholesterol is not the problem? After all, we know that there are different types. Total cholesterol includes the ‘good’ or high-density lipoprotein cholesterol (HDL). It also includes the ‘bad’ or low-density lipoprotein cholesterol (LDL). So, if total cholesterol is not harmful for older people, is LDL an issue?
Is LDL cholesterol a risk factor for older people?
To answer this question the BMJ study goes on to assess the data from several trials. This analysis involves a total of over 68,000 people. Studies with more people make it easier to see if there is a link between LDL levels and the risk of death in older people.
Amazingly, the researchers report that the pooled data suggest that having high LDL reduces the risk of death. They say deaths from cardiovascular disease were either lower in people with high LDL, or there was no link.
There may be several theories for this. But, one explanation involves the observation that levels go down during serious illness. However, the researchers took this into account and they still found no association between LDL and death from all causes. Indeed, in some cases, lower LDL was associated with a higher risk.
So, in summary, the research shows that for people over 60 there is either no link between LDL and risk of death from all causes or having higher LDL means a lower risk of dying. In other words, it appears that this research supports the direct opposite of the hypothesis for people over 60. For people who are interested in healthy ageing, this might be an important fact to know.