Studies Much body fat increases breast cancer risk even with normal BMI

How does the body fat percentage affect the cancer risk?

Women who have a normal body mass index (BMI) after their menopause but have higher levels of body fat increase the risk of developing breast cancer. Researchers found that despite normal BMI, breast cancer risk increases by 35 percent per five kilograms of body fat.

Researchers at the Memorial Sloan Kettering Cancer Center in New York found in their current research that high body fat levels increase the likelihood of cancer, even if the women in question actually have a normal BMI. The experts published the results of their study at this year's "Conference of the American Association for Cancer Research" in Texas.

Especially women should make sure that their body fat content is not too high. Otherwise there is a risk of developing breast cancer. (Image: BillionPhotos.com - fotolia)

What is the BMI?

BMI refers to the ratio of weight to height, but is not an accurate method of determining body fat percentage because muscle mass and bone density can not be distinguished from fat mass. The Dual Energy X-ray Absorptiometry (DXA) used in the current study, on the other hand, is a technology that can specifically measure fat content, leading to a more accurate estimate of total body fat percentage, experts explain.

Increased risk in postmenopausal women with high body fat

It has not been known to date whether individuals with a normal BMI but an elevated body fat percentage are at increased risk for cancer. Results show that the risk of invasive breast cancer is increased in postmenopausal women with normal BMI and higher body fat, Neil Iyengar of Memorial Sloan Kettering Cancer Center, New York, said in a news release on the subject portal "EurekAlert!". This means that a large proportion of the population is at risk of undetected cancer, the expert adds.

A high level of activity is important for health

The study also found that physical activity levels are lower in women with a higher body fat percentage. This suggests that physical activity is very important not only in overweight people but also in normal weight people.

Physicians evaluate the data of women between the ages of 50 and 79 years

For the research, the researchers analyzed the data of the so-called Women's Health Initiative (WHI). This observational study examined the health of postmenopausal women aged 50 to 79 years. The study included participants with a normal BMI (between 18.5 and under 25.0) and no history of breast cancer. During the 16-year follow-up, women were screened at their risk of developing invasive breast cancer.

182 cases of invasive breast cancer

Of the 3,460 participants in the study, 182 developed invasive breast cancer during the follow-up, and 146 of those cases were ER-positive, the researchers explain. Experts believe that about 80 percent of all breast cancers are ER-positive. In analyzing the data, researchers also found a link between breast cancer risk and a higher total body fat percentage in women with a normal BMI. Despite a normal BMI, the risk of ER-positive breast cancer is 35 percent higher for any increase in body fat by 5 kilograms, say the doctors.

Women should pay particular attention to their body fat percentage

These findings are likely to be equally surprising for many physicians and patients, as BMI is the current standard method for assessing the risks of body weight related diseases, the experts explain. Researchers hope the findings will alert women to the potential for increased breast cancer risk associated with body fat, even if they have a healthy weight. (As)