The message from research is that Eating fruit and vegetables reduces risk of breast cancer and the more consumed, the greater the protection. Eating just one serving of vegetables a day reduces the risk of breast cancer by 21% and just one serving of fruit of day reduces the risk by 17%. The meta-analysis research review also covered beta carotene and Vitamin C information as well

As the consumption of fruit and vegetables increased, risk of breast cancer decreased and similarly, as vitamin C and beta-carotene intake increased, risk decreased. A summary of the results of the research review found that six servings of vegetables a week was associated with a 21% reduced risk of getting breast cancer and six servings of fruit a week was associated with a 17% reduced risk, compared with one serving a week (relative risks and 95% confidence intervals 0.79, 0.77 to 0.80 and 0.83, 0.79 to 0.87 respectively).

Compared with 50 mg of vitamin C a day, 400 mg was associated with a 23% reduced risk. Compared with 1000 micrograms of beta-carotene a day, 5000 micrograms was associated with a 9% reduced risk. (Relative risks and 95% confidence intervals 0.77, 0.72 to 0.83 and 0.91, 0.90 to 0.93 respectively).

This does seem to suggest that 50mg of vitamin C is a good bet for helping to reduce risk – and that eating six servings of vegetables is possibly more effective than six servings of  fruit. This also suggests that even a relatively modest  proportion of vegetables and fruit is likely to be preventative. And reduce risk of breast cancer.