In the US, the levels of serum total cholesterol declined in every age group from 1960-62 to 1988-91.

In Japan, the levels of serum total cholesterol increased in very age group between 1980 and 1990. The levels remain similar between 1990 and 2000.

It is very interesting that the levels of serum cholesterol in young generations in the US and Japan are similar in 1990.

In middle and older age groups, there are still substantial differences in levels of total cholesterol between the US and Japan. In addition, the difference in the levels of cholesterol in these generations were much wider in the past, which is attributed to the huge difference in age-adjusted CHD mortality between the US and Japan to great extent.

Source: NHANES and National Cardiovascular Survey of Japan.