Breast cancer: Eating meat, sleeping poorly and carrying excess weight around the waist are driving up breast cancer rates among Indian women, with cases projected to climb 5.6 per cent each year, adding roughly 50,000 new diagnoses annually, a government study has found.
The research, conducted by the Indian Council of Medical Research’s national disease data centre in Bengaluru, also pointed to reproductive patterns, hormone levels and genetics as major factors behind the country’s rising breast cancer burden.
Worldwide, 2.3 million women learned they had breast cancer in 2022, and 670,000 died from the disease. In India that year, doctors diagnosed 221,757 cases, representing nearly a quarter of all cancers in women.
Also Read | What types of breast cancer are more likely to return after treatment?
Researchers reviewed Indian studies on breast cancer risk published through December 2024. Of 1,871 articles examined, 31 met the criteria for analysis. Most were case-control studies rated moderate to high quality.
The findings showed women who reached menopause after age 50 faced more than twice the breast cancer risk of those who did so earlier. Risk also climbed with later age at marriage and rose sharply for women who had their first child after turning 30.
Women who’d had more than two abortions carried 1.68 times the risk of those who’d had none. How long women breastfed and whether they used birth control pills didn’t significantly affect their odds.
Body shape mattered more than overall weight. Women with a waist-to-hip ratio of 0.85 or higher showed stronger links to breast cancer than those judged by body mass index alone, suggesting fat around the midsection poses particular danger for Indian women.
Diet played a notable role. Women who ate meat faced a higher risk, possibly because of saturated fat and processed meat, which can boost estrogen production, the study said.
Poor sleep also increased the risk. Some individual studies found irregular sleep schedules and sleeping with lights on supported theories that suppressed melatonin contributes to cancer development. High stress levels appeared significant, too, though different measurement methods made firm conclusions difficult.
Surprisingly, drinking alcohol and using tobacco showed no clear connection to breast cancer in the Indian data. This might reflect low rates of use, underreporting or biological differences in the population, researchers said.
A major international analysis previously found that alcohol raises breast cancer risk by 7.1 per cent for every 10 grams consumed. But in developing nations where people drink little, about 0.4 grams daily, alcohol’s impact was minimal. Smoking showed almost no independent effect.
The ICMR study examined reproductive history in detail, looking at age at marriage and pregnancy, abortion history, timing of first and last birth, breastfeeding, contraceptive use and number of children.
