Fitting into your jeans is one good reason to try to lose weight but in a new study, scientists are handing you eight more reasons to fight obesity and excess weight.
Global researchers say excess weight is tied to at least eight types of cancer: stomach, liver, gall bladder, pancreas, ovary, thyroid, blood (multiple myeloma), and meningioma (a type of brain tumour).
The findings, out of the World Health Organization’s International Agency for Cancer on Research (IARC), suggest that limiting your weight gain over the course of decades is going to help you cut the risk of these cancers.
“The burden of cancer due to being overweight or obese is more extensive than what has been assumed. Many of the newly identified cancers linked to excess weight haven’t been on people’s radar,” Dr. Graham Colditz, a Washington University School of Medicine professor and chair of the IARC’s working group, said.
“Lifestyle factors such as eating a healthy diet, maintaining a healthy weight and exercising, in addition to not smoking, can have a significant impact on reducing cancer risk … but losing weight is hard for many people. Rather than getting discouraged and giving up, those struggling to take off weight could instead focus on avoiding more weight gain,” he suggested in a statement.
Colditz and his team of international scientists tied to the IARC reviewed more than 1,000 studies on excess weight and cancer risk to come to their conclusions.
And they warn that the findings have global reach: an estimated 640 million adults and 110 million children are categorized as obese. In Canada, one in four Canadian adults is clinically obese, according to the Canadian Obesity Network.
The medical community has already established excess weight as a risk factor for heart disease, diabetes, and cancer among other conditions.
Over the past few decades, the IARC has studied more than 1,000 things, such as chemicals, food and radiation to see if they could be tied to cancer risk.
In 2002, for example, it found “sufficient evidence” linking excess weight to higher risks of cancers in the colon, esophagus, kidney, breast and uterus.
WATCH ABOVE: Scientists from New Zealand are warning in a new study that suggests alcohol “directly causes” seven forms of cancer.
This time around, the scope widened as they discovered a “positive dose-response relationship” in the eight new cancers they zeroed in on. As body mass index – or BMI – crept up, cancer risk increased, too.
There’s no discrimination between men and women when it comes to excess weight and risk of these eight cancers. The researchers even found the risk was consistent across continents, from North America, to Europe, the Middle East and Asia.
They say there are many reasons why excess weight can tamper with cancer risk. For starters, it could lead to an overproduction of estrogen, testosterone and insulin. That, in turn, leads to inflammation, a catalyst for cancer growth.
“This is another wake-up call. It’s time to take our health and our diets seriously,” Colditz said.
Last month, a New Zealand scientist’s controversial commentary warned that alcohol – even in low and moderate levels – “directly causes” seven forms of cancer.
The medical community often talks about a “link” between cancer and drinking . This commentary goes well beyond that.
“There is strong evidence that alcohol causes cancer at seven sites in the body and probably others,” the researcher wrote in the study published in the journal Addiction.
Read Colditz and the IARC’s review published Thursday in the New England Journal of Medicine.