With two thirds of UK adults now overweight and a fifth classified as obese, we are seeing a huge increase in associated diseases – such as type-2 diabetes and, as recent studies have shown, a number of certain cancers.
A recent study, published in the Lancet medical journal, looked at more than five million people to establish the links between obesity and cancer – and the results were stark.
It seems that more than 12,000 new cancers each year in the UK are associated with being overweight and that your risk goes up in line with your weight.
In fact, for every five point increase in your BMI, you could be 62% more likely to get cancer of the uterus and 25% more likely to get kidney cancer.
Scary statistics – and ones many of us don’t want to face. However, unlike hereditary cancer risks, this is one factor that we can tackle to reduce our cancer risks.
Did you know that oesophageal adenocarcinoma (gullet cancer) is on the rise, probably due to the increase in acid reflux that we see in association with obesity? Losing weight can help your symptoms of indigestion and should therefore reduce your risk of developing cancer later.
Fat is not just sitting there doing nothing. It produces hormones, one of which is oestrogen. After the menopause, when the ovaries have stopped producing hormones, fat is the main source of oestrogen.
This means that post-menopausal women who are overweight are at greater risk of tumours that are stimulated by oestrogen. This includes some breast cancers, endometrial cancer (cancer of the lining of the womb) and perhaps ovarian cancer. As many as 41% of womb cancers may be attributable to obesity.
Excess fat not only increases risks of developing some breast cancers but it can also make treatment less effective.
In addition, a recent study, on mice admittedly, showed that reducing food intake may reduce the risk of breast cancer spread, prompting an ongoing trial of nutritional advice and weight loss in women undergoing breast cancer treatment.
Colon cancer is definitely more common in people, particularly men, who are obese. It is more likely in people with a higher waist:hip ratio, the classic male beer belly, and may be associated with increased insulin levels – something seen in type 2 diabetes. Around 10% of colon cancers are linked to obesity.
Fatty liver disease is on the increase thanks to the rise in obesity. It is also seen in type 2 diabetes, which often goes hand in hand with obesity, and is more common in people who carry most of their fat around their middle rather than their bottom and thighs – so-called apples rather than pears. Fatty liver can, in some cases, proceed to cirrhosis, which is a risk factor for liver cancer.
Obesity is also a risk factor for pancreas cancer, gallbladder cancer, thyroid cancer and kidney cancer, too.
While it is very difficult to prove that losing weight will reduce an individual’s risk of cancer, studies on groups who have lost a lot of weight with weight-loss surgery show convincingly that there is a reduction in the number of cancers seen.
If you are overweight or obese, or even if you are not, be vigilant for signs that may suggest cancer in any of these areas.