Excess body fat responsible for specific cancers

Obesity is a medical condition in which excess weight accumulates in the body, thereby adversely affecting the health. A body mass index (BMI) of 30 or more is considered to be obese.

It is also the known cause of cardiovascular events, diabetes, and high blood pressure.

Obesity was found to be a probable cause of cancer
Researchers from the AICR reviewed hundreds of studies and found a ‘convincing evidence’ that obesity is the most probable cause of many types of cancers.

The researchers specifically looked at seven cancers believed to have been triggered by obesity.

They found that 49 percent of endometrial cancers--malignancy which arise from lining of the uterus-- 35 percent of esophageal cancer cases--cancer of the food pipe, 28 percent of pancreatic cancer cases, 24 percent of kidney cancer cases, 21 percent of gallbladder cancer cases, 17 percent of breast cancer cases and 9 percent of colorectal cancer cases had a probable link with obesity.

"This is the first time that we've put real, quantifiable case numbers on obesity-related cancers," said Glen Weldon, the American Institute for Cancer Research educational director. In addition, he said, it's not just causing cancer that's an issue.

"Obesity not only raises the risk for getting cancer," Weldon said. "It also has a negative effect on survival and can make treatment more difficult."

The researchers also noted that excess body fat makes the cancer treatment more difficult and even shortens survival.

How is excess weight linked to cancer?
The researchers speculated that excess estrogen--female sex hormones-- released by the fat cells could be the most common factor which triggers cancer tumors especially breast and endometrial cancers in women.

Previous studies have also shown that fatty tissues could also affect the processing of insulin which can cause cancer. Excess fat is also believed to be the culprit in increasing the inflammatory compounds in the blood.

Donna Ryan, an oncologist and president of the Obesity Society, US, said, "Insulin resistance and elevated insulin levels frequently occur in obese people. Insulin is a very powerful cellular growth factor, and it affects cancer cells."

Health experts suggest that maintaining a normal weight, increasing physical activity, eating a healthy diet, could help in the prevention of atleast half of these cancers.

"An increasing number of studies suggest that regular physical activity improves cancer survival, even among survivors who are overweight or obese," AICR researchers recommended.

According to Centers for Disease Control and prevention, U.S., (CDC), nearly 34 percent of American adults aged 20 and over are obese, 30 or more pounds over a healthy weight.