Does obesity cause cancer ?

Numerous scientific studies have proven the link between cancer and obesity. Overweight and obesity are recognized as risk factors for developing certain types of cancer. According to the analysis of the Center for Disease Control and Prevention, more than half of cancers diagnosed in women are linked to obesity and overweight, compared to just a quarter in men. It is estimated that about 5% of cancers are related to being overweight.

Why obesity promotes cancer risk?

Many tracks are being studied to try to explain the action of overweight on the development of tumors. The main cause mentioned is the influence of hormones. Adipose tissue increases the production of hormones, which promotes the development of cancers in hormone-dependent organs (uterus, breast, prostate).

According to a report by the National Cancer Institute, fat tissue favors, for example, the conversion of androgens (masculinizing hormones) into estrogen (female hormones). An increase in estrogen levels that increases the multiplication of breast and uterine cells. On the other hand, these adipose tissues mass produce growth factors and cytokines, engines of tumor proliferation.

Second explanation: obesity causes chronic inflammation in the body, which weakens the tissues. For esophageal cancer for example, gastric reflux (common in obese people) irritates the lining of the digestive tract and greatly increases the risk of cancer.

In 2018, in the world, among adults aged 18 to 74, 54% of men and 44% of women with cancer were overweight or obese.

What are the cancers related to obesity

A team of British researchers from Imperial College London wanted to study the relationship between obesity and 36 different types of cancer. For this, they analyzed 204 most relevant scientific and compiled studies. According to this compilation, 11 types of cancers, mostly digestive or hormone-dependent, would be associated with solid evidence with cancer. Here is the list of cancers concerned:

Researchers at Imperial College have also linked [BMI] ( with 17 of the 22 most common tumors in the UK. Each five-point increase in BMI may have been associated with an increased risk of certain types of cancer, with the uterus leading the way (with an increased risk of 62%) in front of the gallbladder (31%) , the liver (25%), the cervix (10%), the thyroid (9%) and leukemia (9%).

Does the duration of obesity increase the risk of cancer?

The duration of obesity is a factor favoring cancers. This is the conclusion of a team of researchers, who publish their work in the journal PLoS Medicine. In this study of men and women aged 25 to 50, the authors show that the longer a person tends to be obese, the greater the risk of developing cancer.

The highest risk is for endometrial cancer (17%) and kidney cancer (16%). For breast cancer, the risk is 5%. For other cancers associated with obesity, the researchers found no significant increase in risk.

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