Fasting every day, research suggests, can protect against breast cancer. A study found that obese mice could only eat ‘ dramatically ‘ within a strict eight – hour window reduced their disease risk.
Even among rodents injected with breast cancer cells or those genetically at risk of the disease, this was true. It was also found that eating time was more important than consumed, despite a high – fat diet and obesity both associated with a higher risk of breast cancer.
Restricting when eating can reduce our levels of insulin, with excessive amounts of the hormone previously associated with the disease. The research was conducted by the University of California, San Diego, and led by Dr. Manasi Das, a medicine postdoctoral scholar at the health sciences school.
Around one in eight women in the US and UK will develop breast cancer at some point in their lives, statistics reveal. The scientists set out to determine how a woman’s metabolic health may influence her risk.
According to the NHS, metabolic syndrome is the medical term used to combine diabetes, high blood pressure and obesity. The researchers conducted three mice experiments to better understand how metabolic health relates to our cancer odds.
No ovaries were available to all rodents to imitate a post – menopausal state. However, according to the MD Anderson Cancer Center, menopause itself does not cause cancer, our risk of developing the disease increases with age. Therefore, postmenopausal women are more at risk as they are older.
Mice were made obese in the first experiment by eating a 60% fat diet for ten weeks. They were then divided into two groups – one with access to food for 24 hours and one with access for eight hours at night. Because mice are nocturnal, they are the most active at night.
Both these groups of obese rodents were then compared against lean mice with access to a low-fat diet for 24 hours a day. All the animals were injected with breast-cancer cells three weeks into their eating plans.
In the second study, genetically modified mice were divided into two groups, one with constant access to a high – fat diet and the other with restricted access. Mice on a low – fat diet were equipped with either an insulin pump or a saline control for the third and final study.
These were compared to rodents on a fatty eating plan that reduced their insulin levels by adding to their feed the drug diazoxide – which blocks the release of the hormone. Mice were subjected to ultrasound scans in all three studies to determine any tumors.
Time – restricted eating revealed overall results had a ‘ dramatic ‘ effect on the rodents ‘ breast cancer risk. Tumor development was delayed only by eating within a strict window. It also reduced cancer cell growth on a high – fat diet in the obese mice to be the same as that of lean rodents.
According to Breast Cancer Now, if a woman is overweight or obese after menopause, the risk of developing breast cancer increases. The mice implanted with an insulin pump also had faster growth of the tumor, while those fed with diazoxide were less at risk.
Full results will be presented in New Orleans on Saturday at ENDO 2019, the annual meeting of the Endocrine Society. ‘ The results suggest that the time – restricted eating anti – tumor effect is at least partially due to lower insulin levels, suggesting that this intervention may be effective in the prevention and therapy of breast cancer, ‘ Dr Das said.
‘Exploring the ability of time-restricted eating to prevent breast cancer could provide an inexpensive but effective strategy to prevent cancer impacting a wide range of patients and represents a groundbreaking advance in breast cancer research.’
Insulin triggers cells – including cancerous ones – to grow, previous research has suggested.And other hormones related to insulin may also be higher among the obese, which could trigger breast cancer, scientists have previously said.