Obesity now tied to 11 types of cancer
July 27, 2016
Texans are becoming more aware that obesity – a body mass index (BMI) of 30 or higher – is linked to a wide range of physical health conditions, including Type 2 diabetes and heart disease. Researchers have even suggested that obesity in kids leads to less education and lower-paying jobs later in life.
But not as many people are aware of the extent to which obesity affects cancer risk. A spring 2016 study associated obesity with stomach cancer, making it the 11th cancer proven to be associated with obesity.
Here’s a quick summary of obesity and cancer rates in Texas:
- As of 2014, more than 30 percent of Texas adults were obese.
- We’re currently the 11th fattest state in America.
- Our state has seen an increase in obesity rates nearly every year since 1996.
- In 2015, more than 1 million Americans were diagnosed with cancer.
- By 2030, nearly 811,000 cancer diagnoses will be obesity-related.
The World Cancer Research Fund estimates that 20 percent of cancers diagnosed in the United States are related to lifestyle choices, such as carrying excess body fat, physical inactivity, poor nutrition, and drinking too much alcohol. In other words, as many as one in five obesity-related cancer deaths could be prevented by making better lifestyle choices.
This is the full list of cancers for which obesity is a risk factor:
- Breast cancer (after menopause)
- Colon cancer
- Esophageal cancer
- Gallbladder cancer
- Kidney cancer
- Liver cancer
- Pancreatic cancer
- Prostate cancer
- Stomach cancer
- Thyroid cancer
- Uterine/endometrial cancer
How does obesity cause cancer?
Obesity is much more than an unhealthy accumulation of fat. Excess fat is associated with chronic inflammation, which research has proven to be linked to cancer by promoting cell mutation and tumor growth. The amount of fat we carry also influences our hormones, specifically our sex hormones and insulin levels, which researchers think has a major impact on our cancer risk.
Men’s sex hormones
Obesity is related to lower testosterone levels in men. Low testosterone may increase the risk for developing prostate cancer and/or lead to worse outcomes for existing cases of prostate cancer.
Individual studies don’t suggest a consistent link between obesity and prostate cancer, but data pooled from multiple studies suggest a slight increase in prostate cancer risk. Several studies suggest an increased risk of aggressive prostate cancer in obese men than in men of healthy weight.
Women’s sex hormones
Obese women tend to have higher levels of estrogen than women of healthy weight, putting them at higher risk for breast cancer. Researchers think this hormone imbalance may contribute to cancer cell growth.
Hormone-sensitive breast cancer cells contain hormone receptors that activate when hormones, such as estrogen, bind to them. This causes the genes to mutate, which can lead to tumor growth.
Some studies also have shown an association between BMI and increased risk of ovarian cancer, especially in premenopausal women. However, other studies have been inconclusive. Researchers are still working to determine whether there is an association between obesity, estrogen levels, and ovarian cancer.
As abdominal fat increases, the pancreas produces more insulin. Obese people often have elevated insulin levels, which can lead to insulin resistance. This is a vicious cycle for obese people. Insulin helps turn our food into energy. When the body makes too much insulin over a long period of time, energy can’t be properly stored by the body. Insulin resistance causes swings in blood sugar, which in turn can cause people to eat more to overcome feelings of hunger and low blood sugar.
Insulin resistance (hyperinsulinaemia) leads to Type 2 diabetes and other complications. Research has shown that hyperinsulinaemia increases the risk of certain cancers, including:
Reduce your risk of obesity-related cancer
If obesity trends continue, there will be about half a million additional cases of cancer in America by 2030. National Cancer Institute data suggest that if every American adult reduced his/her BMI by just 1 percent (about a 2.2 pound weight loss for the average adult), nearly 100,000 new cases of cancer could be avoided.
A study published in JAMA Oncology in May 2016 suggests that half of all cancer cases could be prevented if we incorporated just four lifestyle changes:
- Drink alcohol in moderation, or not at all. That means 1 drink per day for women and 2 for men – a drink is defined as 8 ounces of beer, 5 ounces of wine, or 1.5 ounces of spirits.
- Reduce your weight and bring your BMI to a level between 18.5 and 27.5.
- Exercise for at least 30 minutes, five days per week. Exercise may help decrease the risk for 13 types of cancer because of its impact on sex hormones, insulin, and inflammation within our bodies.
- Quit smoking, or don’t start if you are a non-smoker.
In a previous article, I provided tips for exercise, diet, and how to lose weight to get started with weight loss. I know losing weight is easier said than done, especially for folks who have tried every trick in the book to lose weight. I’ve been there – I’ve struggled with my weight since childhood.
Just because something is difficult, that doesn’t mean it’s impossible. If you could use some help losing weight to improve your overall health and reduce your cancer risk, request an appointment or give us a call at 214-645-8300.