A new study published in American Journal of Epidemiology suggests that eating folate rich vegetables may help prevent breast cancer risk.
Martha Shrubsole from Vanderbilt Epidemiology Center, Division of Epidemiology and colleagues conducted the study and found premenopausal women in the highest quintile of folate or folic acid intake were 48 percent less likely to develop breast cancer, compared to those in the lowest quintile.
For the study, researchers analysed data on incidence of breast cancer and intake of nutrients including methionine, folate, vitamin B6, vitamin B12, niacin and ribiflavin from participants including 718 Chinese breast cancer patients who were enrolled between 1997 and 2008 in a prospective cohort Shanghai Women's Health Study.
No association was found between dietary intakes of methionine and B vitamins and risk of breast cancer in postmenupausal women. Among premenopausal women, higher intake of folate was linked to decreased breast cancer risk.
The highest intake of niacin, however, was associated with 62 percent increased risk of ER+/PR+ breast cancer, compared to those who had the lowest intake of niacin.
The study suggests that eating folate rich vegetables may reduce risk of breast cancer. In China, folate is not added to wheat flour and the major source of this vitamin is vegetables. This means that eating folate rich vegetables may cut the risk of breast cancer.
But high intake of fortified folate may do more harm than good although folate from vegetables won't cause any side effects no matter how big its intake is.
A study published in Revista Medica de Chile suggests an increased folate intake may be beneficial in deficient populations, but may increase risk of breast cancer in those who would otherwise have sufficient folate without food fortification.
C. Castillo-L at Universitat de les Illes Balears in Illes Balears, España and colleagues reviewed 14 case-control studies, 14 cohort studies, 7 case-control nested studies, 2 randomized trials and 2 meta-analyses found in MEDLINES and concluded that high intake of folate does not necessarily lead to a better outcome.
The authors did not see any evidence to support the notion that higher intake of dietary folate reduces the risk for breast cancer. Instead, high folate intake particularly through exposure to fortified folic acid may boost the risk of breast cancer.
The review suggests that caution should be exercised to limit the exposure of women to high intake of folic acid, particularly in countries where folic acid fortification is mandated.
Breast cancer is expected in more than 230,000 women in 2012 in the United States and the disease and its complications are expected to kill about 40,000 women in the country in 2012, according to the National Cancer Institute.
Breast cancer in many cases is preventable. An authoritative organization says that two major risk factors for breast caner are medical radiation and hormone therapy.
