Sometimes advice about prevention is simply wrong. Many of the things we believe are preventative may actually do more harm than good.
* Oestrogen: There is now no doubt that oestrogen in the Pill or as hormone replacement has no protective effect on the heart (JAMA, 1998; 280: 605-13), and may even increase coronary events by nearly 30 per cent (JAMA, 2002; 288: 321-33, 366-8), and increase heart-damaging triglycerides (Am J Clin Nutr, 2000; 72: 389-94; JAMA, 1995; 273: 199-208) and vascular inflammation (Circulation, 1999; 100: 713-6, 717-22).
* Lowering cholesterol: Ironically, most heart patients have normal cholesterol levels (Lancet, 1994; 344: 1182-6). Evidence shows that high cholesterol does not raise your risk of dying from anything, including heart disease (JAMA, 1994; 272: 1135-40). In fact, high blood-cholesterol levels are associated with longevity and good health in older people (Lancet, 1997; 350: 1119-23). In contrast, lowering cholesterol is associated with higher rates of depression and suicide (BMJ, 1992; 304; 431-3).
* Low-fat diets: Some researchers believe that saturated fats are not linked to heart disease at all (BMJ, 1996; 313: 84-90). Indeed, given all the advice we receive about lowering fat, it is surprising to find that the link between saturated fats and the heart is based on only one major trial (BMJ, 1996; 313: 1258).
* Giving up alcohol: While there are studies that have linked alcohol with high blood pressure (JAMA, 1985; 253: 1567-70), it may not be abstinence, but what you drink that is important. There is strong evidence of the heart-protective effects of red wine (BMJ, 1995; 310: 1165-9). Women, however, are in Catch-22 - moderate alcohol can help the heart but, in some, may raise the risk of breast cancer (N Engl J Med, 1995; 332: 1733-7).