A study has found that the more overweight a person is, the higher the chance of developing almost all types of cancer.
The American Cancer Society study, which tracked 900,000 people over 16 years, found excess weight to be a likely factor in 20 per cent of all cancer deaths in women and 14 per cent in men.
With obesity on the rise in the United States and other industrialized nations, the study’s conclusions indicate that death from many types of cancer will soon increase, in some cases quite dramatically.
The study found links between obesity and cancers that had been largely overlooked by other researchers: Multiple myeloma, non-Hodgkin’s lymphoma and cancers of the esophagus, colon and rectum, liver, gallbladder, pancreas and kidney in men and women; cancers of the stomach and prostate in men and cancers of the breast, uterus, cervix and ovary in women.
Donna Ryan, head of clinical research at the Pennington Biomedical Research Centre in Baton Rouge, Louisiana, said: “The study is absolutely convincing. And therefore it’s frightening. Because of the magnitude and strength of the study, it’s irrefutable.”
The study, which began in 1982 when all the participants were cancer-free, found a variety of reasons for the link between weight and cancer.
Fat raises the amount of estrogen in the blood, increasing the risk of cancers in the female reproductive system.
Obesity increases the risk of acid reflux, which can cause cancer of the oesophagus.
Fat raises levels of insulin, prompting the body to create a hormone which causes cells to multiply, just like cancer.
Obesity also makes cancer harder to diagnose and treat. Lumps and bumps are harder to see or feel and some patients do not fit into CAT scanners, says Dr Robert Mayer of Harvard Medical School.
The results were published in the New England Journal of Medicine.
The study focused on 404,576 men and 495,477 women, of whom 57,145 died of cancer. The researchers found that the heaviest members of the group were those with the highest risk of dying of cancer, showing that weight played a greater role in cancer formation than previously known.
“Overweight and obesity has a very broad impact on cancer across most cancer sites,” Calle said. “That’s not something that’s really in the consciousness of the American people.”
Some 65 percent of the adult US population was overweight or obese in 2000, according to the Centers for Disease Control and Prevention.
The researchers recommended stronger efforts to promote exercise and a healthy diet among Americans.
Limit saturated fat. Choose lean meats and low-fat dairy products, and substitute vegetable oils for butter or lard. Every day, eat at least five servings of fruits and vegetables, especially ones with the most color.
Heart attacks, strokes, high blood pressure and cholesterol, diabetes, gallstones, gout, arthritis, sleep apnea, incontinence, low self-esteem and depression are other risks of OBESITY.