A study of more than 80,000 women form the Nurses' Health Study
was performed in 1980 with a 16 year follow-up, to asses the association
between folate intake and the risk of breast cancer and whether
a higher folate intake may reduce excess risk among women who
consume alcohol.
Results.
A total of 3,483 cases of breast cancer were documented. Total
folate intake was not associated with overall risk of breast cancer.
Women, who consumed at least 15g/d of alcohol, the risk of breast
cancer was highest among those with low folate intake. For total
folate intake of at least 600ug/d compared with 150 to 299 ug/d,
the multivariate relative risk (RR) was 0.55 (95% confidence interval
(CI), 039-0.76; P for trend= 001). After additional adjustment
for intake of beta-carotene, lutein/zeaxanthin performed vitamin
A and total vitamins C and E the association was only slightly
attenuated.
The strongest risk of breast cancer associated with alcohol intake
was among women with total folate intake of less than 300ug/d
(for alcohol intake >15g/d vs <15g/d, multivariate RR, 1.32; 95%
CI, 1.15-1.50). Women who consumed at least 300ug/d of folate,
the multivariate RR for intake of at least 15g/d of alcohol vs
less than 15g/d was 1.05 (95% CI, 0.92-1.20). Use of multivitamins
supplements, the major source of folate, was associated with a
lower breast cancer risk among women who consumed at least 15g/d
of alcohol.
The findings suggest that with adequate folate intake the excess
risk of breast cancer associated with alcohol consumption may
be reduced.
Source:Wannamethee SG; Sharper AG, "Type of alcoholic drink and risk
of major coronary heart disease events and all-cause mortality",
American Journal of Public Health, Vol 89, No5, 1999, pp685-690
