According to the Mayo Clinic website, lower levels of cholesterol are better. For total cholesterol, says the Mayo Clinic, below 5.2 mmol/L (= 200 mg/dL) is “desirable”. A level from 5.2 to 6.2 mmol/L is “borderline high”, and above 6.2 mmol/L (= 240 mg/dL) is “high”.
A 2011 study from Norway, based on 500,000 person-years of observation, found drastically different results. For both men and women, the lowest levels of total cholesterol (below 5.0 mmol/L) were associated with the most death. For men, the best level was intermediate — what the Mayo Clinic calls “borderline high”. For women, the safest levels were the highest.
If high cholesterol causes heart disease, as we are so often told, the pattern for women makes no sense. For a long time, experts have told us to limit egg consumption because eggs are high in cholesterol. However, a new study shows that egg consumption has no association with heart disease risk.