Washington D.C. [USA], April 11 : While high dietary fibre foods such as fruits, vegetables and nuts are helpful in maintain bowel health, a recent study suggests that there is a significantly lower breast cancer risk among women who eat fibre-rich foods, during their adolescence as compared to peers who eat less dietary fibre when young.
The new large-scale study led by researchers at Harvard Chan School of Public Health was published online in the journal of 'Pediatrics.'
Maryam Farvid, a visiting scientist at Harvard Chan School and lead author of the study, said: "Previous studies of fibre intake and breast cancer have almost all been non-significant, and none of them examined diet during adolescence or early adulthood, a period when breast cancer risk factors appear to be particularly important."
"This work on the role of nutrition in early life and breast cancer incidence suggests one of the very few potentially modifiable risk factors for premenopausal breast cancer," he added.
The researchers looked at a group of 90,534 women who participated in the Nurses' Health Study II, a large long-running investigation of factors that influence women's health.
In 1991, the women -- aged between 27-44 at the time -- filled out questionnaires about their food intake and did so every four years after that. They also completed a questionnaire in 1998 about their diet during high school.
The researchers analysed the women's fibre intake while adjusting for a number of other factors, such as race, family history of breast cancer, body mass index, weight change over time, menstruation history, alcohol use, and other dietary factors.
Breast cancer risk was 12 per cent to 19 per cent lower among women who ate more dietary fibre in early adulthood, depending on how much more they ate. High intake of fibre during adolescence was also associated with 16 per cent lower risks of overall breast cancer and 24 per cent lower risk of breast cancer before menopause.
Among all the women, there was a strong inverse association between fibre intake and breast cancer incidence. For each additional 10 grams of fibre intake daily -- for example, about one apple and two slices of whole wheat bread, or about half a cup each of cooked kidney beans and cooked cauliflower or squash -- during early adulthood, breast cancer risk dropped by 13 per cent. The greatest apparent benefit came from fruit and vegetable fibre.
The authors speculated that eating more fibre-rich foods may lessen breast cancer risk partly by helping to reduce high estrogen levels in the blood, which are strongly linked with breast cancer development.