Over 100,000 types of cancers are caused by excess body fat, according to the American Institute for Cancer Research, which Thursday released comprehensive data on cancer cases in the United States and reaffirmed its message that people should maintain a normal body weight and remain physically active throughout life.
Being overweight makes a person susceptible to cancer because it increases the amount of hormones like estrogen circulating in the body and disrupts how the body processes insulin, which is linked to higher risk of cancer. Being overweight also creates low-grade inflammation in the body, which is increasingly being found to play a role in cancer, according to AICR health experts.
Weight gain after a cancer diagnosis is also likely to affect the outcome, they say.
"An increasing number of studies suggest that regular physical activity improves cancer survival, even among survivors who are overweight or obese," said AICR researchers in a press conference.
Furthermore, nearly half of all Americans are not aware of the risks of being obese and its connection to cancer.
"Public awareness of the link between obesity and cancer risk is alarmingly low," said Alice Bender, MS, RD, Nutrition Communications Manager at AICR. "We are working towards a day when obesity is right up there with tobacco in the public eye."
The American Cancer Society has said that 1.47 million people in the United States will be diagnosed with cancer this year and 562,000 will die of it.
The AICR estimates show that excess body fat is linked to:
-49% of endometrial cancers (20,700 cases per year),
-35% of esophageal cancers (5,800 cases per year),
-28% of pancreatic cancers (11,900 cases per year),
-24% of kidney cancers (13,900 cases per year),
-21% of gallbladder cancers (2,000 cases per year),
-17% of breast cancers (33,000 cases per year),
- 9% of colorectal cancers (13,200 cases per year).