New research has put a dent in the theories of hormone replacement therapy proponents that HRT protects against heart disease.
It has been widely claimed that HRT can reduce the risk of heart disease in postmenopausal women by as much as 50 per cent and that women with risk factors for cardiovascular disease should be prescribed HRT as a just-in-case measure.
But when Swedish researchers studied more than 1200 women over a period of 30 years, they found that those who went on to use HRT were already at lower risk of heart disease than those who did not.
This suggests that it is not HRT which protects the heart, but rather individual good health and a healthy lifestyle.
The women who went on to take HRT in this study were of a higher socioeconomic status than those who did not. They tended to be more physically active, have a more stable blood pressure and be leaner. This so-called 'healthy-user' effect has not been researched before, but it is tempting to theorise that it may play a significant role in explaining some of the other reported benefits of HRT (BMJ, 1999; 319: 890-3).