Global scientific research on diet, nutrition, physical activity and breast cancer was gathered and analysed by a research team at Imperial College London, UK, and then independently assessed by a panel of leading international scientists.

The report from World Cancer Research Fund reviewed evidence from 119 studies from around the world.

The studies examined more than 12 million women and over 260,000 cases of breast cancer.

Key findings for premenopausal breast cancer

There is strong evidence that:

• consuming alcoholic drinks increases risk
• undertaking vigorous physical activity decreases risk
• being overweight or obese between the ages of about 18 and 30 years decreases risk
• being overweight or obese in adulthood before the menopause decreases risk
• developmental factors leading to greater linear growth (marked by adult attained height) increase risk
• factors that lead to greater birthweight, or its consequences, increase risk
• breastfeeding decreases risk (breast cancer type unspecified) in the mother

Key findings for postmenopausal breast cancer

There is strong evidence that:

• consuming alcoholic drinks increases risk
• being physically active (including vigorous physical activity) decreases risk
• being overweight or obese between the ages of about 18 and 30 years decreases risk
• being overweight or obese throughout adulthood increases risk
• greater weight gain in adulthood increases risk
• developmental factors leading to greater linear growth (marked by adult attained height) increase risk
• breastfeeding decreases risk (breast cancer type unspecified) in the mother

Much of the new evidence reviewed in this report relates to body fatness (including body fatness in young adulthood), adult weight gain, alcohol and vigorous physical activity. 

Source: World Cancer Research Fund