Being Overweight Can Increase Your Cancer Risk

If you’re looking for a good reason to drop some pounds, here it is: being overweight can put you at higher risk for at least 13 types of cancer.

The obesity link is stronger for some cancers than others, and researchers are still learning more about the complex relationship. For example, gaining weight at certain points in life (childhood versus late adulthood) may impact risk differently.

Still, research has pointed to obesity as a risk factor for numerous cancers, which represent 40 percent of all cancers diagnosed each year in the United States. They include:

• Adenocarcinoma of the esophagus.
• Breast cancer (in women past menopause)
• Colorectal cancer
• Endometrial cancer (cancer of the lining of the uterus)
• Gallbladder cancer
• Stomach cancer
• Kidney cancer
• Liver cancer
• Ovarian cancer
• Pancreatic cancer
• Thyroid cancer
• Meningioma (a form of brain cancer)
• Multiple myeloma (a cancer of white blood cells)

Cancer-Obesity Link

In most cancers, it is difficult to say precisely how obesity increases cancer risk. And it is possible that some instances may be examples of correlation without causation. Or, more simply put, just because two things occur at the same time doesn’t mean one caused the other. In some cases, it could be that the same factors that cause obesity also affect cancer risk.

Researchers have pointed to a range of possible reasons to explain how obesity can change your body in ways that increase your risk. They include:

• Fat tissue produces the hormone estrogen. At elevated levels, it may increase your risk for breast, endometrial and ovarian cancers.
• Obesity can cause increased levels of insulin and insulin-like growth factor-1, which can lead to type 2 diabetes and stimulation of cell growth and cell division. This, in turn, increases your risk for abnormal changes in the genetic code of previously normal cells, turning into a higher risk for colon, kidney, prostate and endometrial cancers.
• Obesity can cause chronic inflammation, which can lead to gallstones or non-alcoholic fatty liver disease. These conditions can cause DNA damage and increase your risk of biliary tract and other cancers.
• Fat cells produce hormones that promote or inhibit cell growth, altering the normal lifespan of your body’s cells. For example, people with obesity are more likely to have high levels of the hormone leptin, which decreases the sensation of satiety with the subsequent increase of other hormones that promote the growth of abnormal cells. The hormones can also make cells live longer than they should, increasing the risk that they will turn cancerous.

Another area receiving increased attention is the gut microbiota – the community of bacteria, viruses and fungi that live in our digestive tracts. It’s important because 60 percent of your immune system is found in your intestines, and it is affected by the ultra-processed foods, extra calories, alcohol intake and abuse of antibiotics. An abnormal microbiota is the source of multiple medical problems ranging from obesity, high blood pressure, depression, diabetes and even cancer. 

Researchers have been studying how the food we eat impacts the microbiota and its ability to do its job – which includes protecting you from various cancers (colon, pancreatic and liver, for example.)

Reducing Your Risk

Losing weight requires a different way of living. It’s often said that one of the least effective ways to drop pounds is to go on a “diet.” Instead, think of it as a new lifestyle, with better eating habits and more physical activity.

In terms of what you eat, your goal is to shift to more of a plant-based diet. At least half of your plate should be filled with vegetables and salad but without dressings that only add preservatives to the food and eliminate the benefit of the nutrients. Grab foods with color, including carrots, peppers, berries, onions and tomatoes. Proteins are fine, but you should reduce red meat in favor of fish and poultry.

There are many diets out there that can work for the sake of losing weight, but science has proved how the Mediterranean diet can help you live longer. A Mediterranean diet includes:

• Vegetables, fruit, plant sources of fat like avocados, high protein content foods like lentil, chickpeas and beans, and sources of omega 3-6 like nuts
• Sources of antioxidants like berries, red fruits
• Whole grains
• Extra virgin olive oil
• Fish (particularly fish rich in omega-3 fatty acids like salmon, trout)
• Greek plain yogurt and white cheese
• Limited red meat
• Limited sweets or sugary drinks.
• Limited alcohol.

Increased physical activity can also have a significant impact on your weight. Cardio activities, including walking, running, cycling and swimming are excellent options.

But perhaps even more important, don’t neglect weight training. Loss of muscle mass is natural as you get older starting at age 30, particularly once you hit your 50s and beyond. Maintaining or building muscle will help you lose weight, while also boosting your overall health, which can prevent depression, falls, decline in function and cancer risk.