Research has shown for awhile that obesity lowers life expectancy by contributing to diabetes, high blood pressure, heart disease and stroke. More recently, ties between obesity and cancer have become evident.
“There is a well established link between obesity and an increased risk of cancer, especially certain cancer types including esophageal, breast, pancreas, colorectal, endometrial, kidney, thyroid and gallbladder,” said David Basel, MD, Avera Medical Group Vice President of Clinical Quality.
Obesity can increase risk as much as 30 to 40 percent for some cancers, Basel said. “The strongest is esophageal and endometrial,” Basel said.
With more than one-third of Americans being overweight, the obesity epidemic across the U.S. is only getting worse.
One of the leading theories on why obesity leads to increased cancer is because individuals who are overweight have higher levels of hormones in their bloodstream, because fat cells produce estrogen.
“Another reason we think that obesity leads to cancer is that there are higher insulin levels in obese individuals,” Basel said. Higher insulin levels can cause inflammation and also prevent cancer cells from dying.
The connection between obesity and breast cancer is particularly striking, says Amy Krie, MD, oncologist with Avera Medical Group Oncology & Hematology. Research shows:
- Obese women are 30 to 50 percent more likely to develop breast cancer than women of a healthy weight.
- Women who walk 30 minutes per day lower their rate of breast cancer by 20 percent.
- Women who gain 20 to 30 pounds after age 18 are 40 percent more likely to develop breast cancer than those women who stay within five pounds. Women who gain 70 pounds double their risk of breast cancer.
Research shows that breast cancer survivors who do not gain weight after their diagnosis and maintain a healthy weight are less likely to have a recurrence of breast cancer.
“Certainly, the connection between obesity and cancer is one we’re still unraveling,” Krie said. “In order for a cancer cell to grow, it needs to have the right microenvironment. If your microenvironment is healthy, it is harder for cancer cells to set up shop.”
For weight loss to last, it needs to be a lifestyle change. “Commit to a lifestyle change of healthier eating habits, increasing fruits and vegetables and decreasing carbohydrates. Exercise is the No. 1 key. That in itself can have an effect on decreasing your cancer risk separate from obesity,” Basel said.
Aim for 30 minutes of moderate exercise five times a week, which are the recommended guidelines from the Centers for Disease Control and Prevention. If you can fit in more, that’s even better.
“Exercise lowers estrogen and insulin levels, decreases inflammation, relieves stress and improves your immune system,” Krie said. “Exercise is the single most important thing a woman can do to modify her risk.”
Adults need at least:
30 minutes of moderate intensity aerobic activity (such as walking quickly or riding a bike) five times a week for a total of 150 minutes per week, or 75 minutes per week of vigorous-intensity aerobic activity (such as running) or an equivalent mix of moderate- and vigorous-intensity aerobic activity
Muscle-strengthening activities on two or more days a week that work all major muscle groups
Source: Centers for Disease Control and Prevention