Environmental, rather than biological, factors explain why men are much more likely to die from coronary heart disease, say British researchers. This means that lifestyle changes should slash male heart disease deaths.
For years it has been assumed that higher oestrogen levels protect women against heart disease. Previous studies have indicated that oestrogen can improve a person鈥檚 cholesterol profile and also help dilate coronary arteries, which might lessen susceptibility to heart disease.
The new study carried out at Bristol University in the UK looked at death rates from heart disease dating back 70 years from 50 different countries. The analysis indicates that the dramatic rise coronary heart disease in men during the 20th century cannot be explained by hormonal differences.
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鈥淭he difference is not primarily to do with hormones,鈥� says researcher Debbie Lawlor. 鈥淓ven if oestrogen has some effect, it is mostly caused by environmental factors.鈥�
The study has, however, been criticised by some for its scope. Belinda Liden of the British Heart Foundation says that the researchers may be trying to draw too many conclusions from too broad an amount of data. 鈥淚t鈥檚 a fascinating study, but it may ask more questions that it answers,鈥� she told 快猫短视频. Liden says that a broad range of cultural and historical factors could have had an effect on the results of the study. 鈥淲e need to keep searching for answers,鈥� she says.
Men in England and Wales are roughly two and half times more likely to die from coronary heart disease than women.
Dramatic difference
Lawlor鈥檚 team studied health records dating back to 1921 for England and Wales and 1947 for Japan, Sweden, Australia, France and the US. More recent data came from more over 40 other countries.
They found that levels of coronary heart disease increased dramatically in men between 1940 and 1980. This increase then slowed.
Lawlor says that a protective effect of oestrogen cannot account for this change. Lawlor speculates that a combination of changing 鈥渆nvironmental鈥� factors 鈥� such as smoking and exercise 鈥� and changing dietary habits might instead be the cause.
Lawlor says women produce more high density lipoprotein cholesterol (also known as 鈥済ood cholesterol鈥�) in response to eating fatty foods. This could explain a different reaction to a high fat diet.