We have become more aware of the fact that obesity causes heart issues, hypertension, stroke and diabetes. Now, obesity has been linked to cancer. Obese people are six times more vulnerable to gullet (esophageal) cancer than people of average weight, as found by a recent British research.

Levels of esophageal cancer have been rapidly increasing and in some countries even faster than those of any other major type of cancer. The research team compared about 800 people with esophageal cancer and 1600 randomly selected healthy subjects. Men and people under the age of 50 were the most vulnerable categories to this disease.

The acid reflux and gullet cancer connection was well known, and unsurprisingly, repeated episodes of severe heartburn or gastrointestinal reflux disease (GORD) were linked to a much higher risk of the cancer. The more frequent the symptoms, the higher the probability of developing esophageal cancer.

GORD increased the probability of esophageal cancer by 5 times, but a combination of obesity and GORD boosted the chances of developing it by 16 times.

Subjects who were clinically obese presented a much higher risk of esophageal cancer than those with a "healthy" weight, no matter if they had GORD or not. People with a body mass index (BMI) of at least 40 were six times more prone to develop the cancer as those with a BMI of 18.5 to 25. The results remained valid even after considering other factors connected to this disease, like smoking and high alcohol intake.

"This suggests that obesity is an independent risk factor for the disease," wrote the authors.

Higher amounts of fat tissue in the body increase insulin synthesis, which in turn boosts the levels of circulating insulin-like growth factor.

"Both these hormones stimulate cell growth and curb cell death, conditions which favor the development of cancers. Fat cells also produce other hormones, collectively known as adipocytokines, which speed up cell growth and are involved in inflammatory processes in the body," wrote the authors.