Eat more fruits in adolescence to lower breast cancer risk

Girls who eat more high-fibre foods during adolescence - especially lots of fruits and vegetables - may have significantly lower breast cancer risk than those who eat less dietary fibre when young, new research has found.

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 drops by 13 percent, the findings of this large scale study showed. 

"From many other studies we know that breast tissue is particularly influenced by carcinogens and anticarcinogens during childhood and adolescence," said senior author of the study Walter Willett, professor at Harvard T.H. Chan School of Public Health.

"We now have evidence that what we feed our children during this period of life is also an important factor in future cancer risk," Willett noted.

The researchers believe 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.

The study was be published online in the journal Pediatrics.

"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," lead author of the study Maryam Farvid from Harvard Chan School noted.

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. 

Breast cancer risk was 12-19 percent lower among women who ate more dietary fibre in early adulthood, depending on how much more they ate, the study said.

The greatest apparent benefit came from fruit and vegetable fibre.