Gaining weight increases cancer risk, study suggest – casting doubt on idea people can be ‘fat but fit’

Weight gain can lead to an 11 percent higher risk of certain cancers, including colon, breast and pancreatic cancer.

Being overweight or obese is known to increase the risk of at least thirteen types of cancer.

But experts are less clear about whether people’s weight is the biggest problem, or their obesity-related diseases, including cardiovascular disease and type 2 diabetes.

Now a study of nearly 600,000 people has found that every five-point increase in body mass index (BMI) is associated with an 11 percent higher risk of obesity-related cancer, even in people without cardiovascular disease or type 2 diabetes.

This casts doubt on the theory that you can be ‘fat but fit’: carrying extra weight, without heart problems or diabetes, with little impact on your risk of disease.

A subgroup of 344,000 people from Britain included in the study were found to have a 23 percent higher risk of obesity-related cancers if they were overweight or obese, compared to normal weight, even if they were not. cardiovascular disease.

Carrying too much weight can cause inflammation in the body, or an excess of the hormone insulin, which can cause tumors to grow.

Dr. Heinz Freisling, senior author of the study from the International Agency for Research on Cancer, said: ‘We have often talked about people who are overweight but metabolically healthy, meaning they do not have type 2 diabetes or cardiovascular disease.

‘But this research shows that these people still have a higher risk of cancer and so may want to maintain a healthy weight.

‘But their risk increases if they also have cardiovascular disease.’

The study, published in the journal BMC Medicine, focused on 13 obesity-related cancers.

These include breast cancer only in postmenopausal women, ovarian and uterine cancer, which can be fueled by hormones produced by fat in the body when people are overweight.

The cancers also include colon, pancreatic, kidney and esophageal cancer.

The risk of developing these obesity-related cancers was 11 percent higher for every five-point increase in BMI, but 17 percent higher in people with cardiovascular disease.

This was calculated by looking at the BMI of 577,343 middle-aged people in Britain and Europe, whose BMI was measured before they were followed for an average of almost eleven years to see if they developed cancer.

The results suggest that anyone who is overweight may need to consider their cancer risk, but people with cardiovascular disease may need to be especially careful when it comes to their weight.

The study defined someone with cardiovascular disease as anyone who had had a heart attack, a stroke caused by loss of blood flow, who had heart failure or coronary artery disease, or an irregular heartbeat.

If these people were also overweight or obese, with a BMI over 25, they had a 3.4 times greater risk of developing obesity-related cancer.

This was compared with someone of a normal weight without cardiovascular disease.

But that result was only based on a group of people from the British Biobank health study that the researchers analyzed.

A second group of people, from the EPIC cancer study involving several European countries, including Britain, did not reach the same finding.

The researchers reassure people that being overweight or obese, even with cardiovascular disease, is linked to only 50 extra cases of cancer for every 100,000 people per year.

But while obesity-related cancers account for less than half of total cancer cases, they also include types such as colon and breast cancer, which are very common.

As a result, it was found that being overweight or obese, with cardiovascular disease, increases the risk of being diagnosed with any form of cancer by 68 percent, compared to being of normal weight without cardiovascular disease.

Dr. Helen Croker, deputy director of research and policy at the World Cancer Research Fund, which funded the study, said: ‘We already know that obesity is a major risk factor for cancer, but these striking findings show that the risk differs depending on demand. or people also have cardiovascular disease.

‘Maintaining a healthy weight can therefore provide even more benefits for certain groups.’