EXERCISE, alcohol intake and diet during adolescence and early adulthood are emerging as key factors in reducing a woman’s breast cancer risk in later life, a visiting expert says.
Population health specialist Graham Colditz said growing evidence was pointing to the years between menstruation and first pregnancy as being a critical time for women in terms of breast cancer prevention.
Professor Colditz, a world cancer prevention authority based at the Washington University School of Medicine, is in Brisbane for a month as a visiting Bancroft Fellow at the QIMR Berghofer Medical Research Institute.
He said studies suggested exercise during teenage and early adult years significantly reduced a woman’s risk of developing breast cancer, and diets high in fibre and soy may also be protective.
“We’re working to disentangle fibre sources – fruits, vegetables, legumes – and how the different composition of diet potentially modifies risk,” Prof Colditz said.
A paper, published today in the Journal of the National Cancer Institute, shows alcohol intake between a woman’s first period and her first pregnancy – when breast tissue rapidly grows – is associated with her likelihood of developing breast cancer.
The researchers, including Prof Colditz, used data from more than 91,000 nurses, who were asked about alcohol intake in 1989 and followed for the next 20 years.
“The bottom line is the more a woman drinks, the more her risk increases; and the longer the interval between onset of her menstrual periods to first pregnancy, the bigger the adverse effect of the alcohol,” he said. “You can’t say: ‘I’ll wait until I’m 50 to worry about alcohol intake, or I’ll wait until I’m out of uni, then I’ll stop’.”
Teenage twins Gretel and Jemima Whiteman lead a lifestyle that, if the latest research holds true, should be protective against developing breast cancer later in life.
The 18-year-olds, whose mother Cathy is a GP and father David a population health expert, regularly cycle to university, cook healthy recipes and prefer the odd cocktail to getting drunk on “cheap drinks”.
Prof David Whiteman, who aims to “lead by example” on living an active and healthy lifestyle, said research was pointing to specific periods of life when “cells are more susceptible to the commencement of cancer”.
“The message to younger people that we’ve had so far has centred around risky drinking in terms of injuries, accidents and unsafe sex,” he said. “The risk relating to breast cancer is yet another reason to drink modestly.”
Prof Colditz agrees, saying that telling young adults not to drink was “unrealistic”.
“Limiting drinking, encouraging exercise and finding how a healthier diet can counteract the adverse effects of alcohol is going to be a much more acceptable prevention message,” he said.