Young women with high body fat levels are less likely to develop breast cancer before menopause, suggests a study conducted by an international team of researchers led by the National Institutes of Health (NIH). Gaining weight – especially after menopause – is a known risk factor for breast cancer, so this finding may indicate that biological factors other than weight contribute to breast cancer in younger women, according to the researchers.
This research involved data on 758,592 women from 19 studies worldwide, 13,082 of whom developed breast cancer. Participants in each study completed several questionnaires including information about height, weight, and other health factors. The researchers used this information to evaluate breast cancer risk related to body mass index (BMI) in four age ranges: 18 to 24, 25 to 34, 35 to 44, and 45 to 54.
According to the researchers, the relative risk of premenopausal breast cancer was 12 to 23 percent lower for each five-unit increase in BMI, depending on age. The strongest effect was seen in very obese women 18-24 who were 4.2 times less likely to develop premenopausal breast cancer than their peers with low BMI.
Sourced from: JAMA Oncology