It has long been known that severe obesity increases the risk of several different forms of cancer, for example colon and rectal cancer, kidney cancer and breast cancer after menopause.
But the new study links 18 more cancers to overweight and obesity than previously known. Thus, a total of 31 forms of cancer can be linked to obesity.
– There are, for example, several blood cancers, head and neck cancer, cancer of the penis and vulva that we can now also link to overweight and obesity, says Tanja Stocks, associate professor of epidemiology at Lund University who is one of the researchers behind the study.
Being overweight also increases the risk of cancer
The study was made using data from several Swedish registers, for example the Conscription Register and the Medical Birth Register, and includes 4.1 million individuals who were followed for an average of 24 years.
Using the information in the various register documents, BMI was calculated. The study shows that the risk of getting cancer increases even with a few kilos of excess weight, that is – the higher the BMI, the greater the risk of cancer.
– The relationship is linearly increasing across the whole BMI range, says Tanja Stocks.
But exactly what the connection between cancer and obesity looks like is not clear.
– We have only looked at BMI, but we and others will look at other factors as well. For example, we want to know what people eat, how physically active they are and, for example, their stress level, says Tanja Stocks.