European researchers had reported in their study published recently that being overweight or obese may increase a person's risk of developing up to a dozen different types of cancer. The link has long been suspected by doctors between weight gain and certain cancers, including colon and breast cancers. But the new study, published in the Lancet, suggest that it could also increase chances for cancer of the esophagus, thyroid, kidney, uterus, gall bladder and among others.
While the study suggests a link, there is no definitive proof that being fat in itself causes cancer. The study was done by compiling and analyzing data from one hundred forty one earlier reports to consider more types of cancers and more diverse populations than had been done previously. The research covered more than two hundred eighty thousand cancer cases from North America, Europe, Australia and Asia.
The subjects, both overweight and normal weight, were followed for about nine to fifteen years, with researchers tracking their Body Mass Index (BMI), a calculation of body but based on people's weight divided by the square of their height and correlating it with accidents of cancer. In men, an average 15 kg (33 pounds) of gain gain, increased the risk of esophageal cancer by fifty two percent, thyroid cancer by thirty three percent and colon and kidney cancers each by twenty four percent, the research found.
In women, an approx 13 kg (29 pounds) weight gain increased the risk of cancer in the uterus and gall bladder by nearly sixty percent, in the esophagus by fifty one percent and in the kidney by thirty four percent, the study said. The link was weaker in terms of bone and blood cancers for both men and women.
In Asian population, there appeared to be a strong link between increased BMI and breast cancer, the study said. Scientists are still unsure about how being overweight could make people more susceptible to cancer. One of the hypotheses is that the presence of excess fat cells could effect the levels of hormones in your body and at cellular level, that may favor the development of tumors in humans.
Since many studies have found that fatter people are more likely to get cancer, experts often recommend losing weight to reduce cancer risk. The simple message is manage to keep a healthy body weight to lower the risk of developing cancer.