Running three times a week drastically cuts breast cancer risk: Study

Breast cancer is the most common cancer in the UK. As many as 55,900 new cases are diagnosed in the country every year.

There is now good news for women as a major study has revealed that exercising three times a week significantly reduces the risk of developing breast cancer.

The study published in the British Journal of Sports Medicine has said that high-intensity exercise such as running intervals appeared to be more protective than light exercise.

The research, based on data from 131,000 women, added that staying physically active reduced the chance of developing the disease, media reports said. These included 77,000 women with breast cancer and a comparison group of 54,452 women without breast cancer.

Researchers from Australia, the UK and US have used genetic analysis to establish a causal relationship between overall activity levels and cancer risk. Drinking too much alcohol, being overweight or obese and being older all increase the risk of breast cancer.

Prof Brigid Lynch of Cancer Council Victoria has said that women who tend to be more physically active might have healthier lifestyles.

“There has always been a little bit of uncertainty as to whether physical activity truly causes a lower rate of breast cancer or whether that relationship is confounded by other factors. The new study suggests that it is certainly a causal effect: physical activity does reduce your risk of developing breast cancer. We saw a risk reduction across all breast cancer types,” she said.

According to the study, women who go for a jog at least three days a week had a 38 per cent lower risk of getting breast cancer. There was a similar reduction for women who were generally fit and active throughout their lifetime, it added.

“Vigorous activity may be particularly important in preventing carcinogenesis. Short bouts of intense activity may be more protective than equivalent energy expenditure accumulated from light activity," the study added.

Women who sat down a lot might get triple negative breast cancer, the most aggressive form of the disease. The benefits of exercise include weight control, controlling sex hormones, reducing inflammation and strengthening the immune system.

The international team of scientists, including experts from the University of Bristol, pooled data collected from 76 studies in western Europe and Australia.

The study applied a technique called Mendelian randomisation, which measures variation in genes to determine causal effects, finding a clear cause-and-effect relationship between exercise and reducing breast cancer risk.

“We do already recommend that physical activity is one of things you can do to reduce your breast cancer risk,” Associate Prof Wendy Ingman of the University of Adelaide, who was not involved in the study, told The Guardian.

“The longer a woman breastfeeds for, the less breast cancer risk she has."

Dr Kotryna Temcinaite, senior research communications manager at Breast Cancer Now, told The Times: “By looking at people who may be genetically predisposed to having different physical activity levels, this innovative study further strengthens existing evidence of the importance of reducing the time we spend sitting and increasing the amount of time we spend moving to lower breast cancer risk.”

Up to 1 million cancer patients in Europe are estimated to have gone undiagnosed as about 100 million screening tests were not performed in the first phase of the pandemic, European Union data show.

Currently, the EU recommends regular monitoring only for breast, colorectal and cervical cancer, for which it set a non-binding target of screening at least 90 per cent of those at risk by 2025.

EU data show that lung tumour is the most common mortality cause among cancer patients, accounting for about a fifth of the 1.3 million deaths attributed to cancer in the EU in 2020, ahead of colorectal, female breast and pancreatic cancer.