Excess body weight, alcohol and tobacco: How lifestyle can affect your cancer risk

Estimated reading time: 6 minutes

By Nicole Brudos Ferrara

In 2023, the American Association for Cancer Research (AACR) reported that 40% of all cancers in the U.S. are associated with modifiable risk factors, including excess body weight, alcohol consumption and tobacco smoking. Globally, nearly half of all cancer deaths in 2019 were related to those same risk factors.

Jon Ebbert, M.D., is a Mayo Clinic internist who specializes in smoking cessation and researches disease prevention and early cancer detection. Here, he discusses the link between these risk factors and cancer and the steps you can take to reduce your risk. He says there is always time to make lifestyle changes to improve your health.

Excess body weight and cancer risk

The prevalence of obesity among U.S. adults has increased from 12.5% in 1960-62 to 41.9% in 2020. Being overweight or obese as an adult increases your risk for 15 types of cancer:

Excess body weight leads to long-lasting inflammation, abnormal levels of insulin, and higher-than-normal levels of sex hormones. "It increases estrogen and insulin, which can increase the rate of cellular division, which can increase the risk for cancer. Also, excess body weight is associated with inflammation, a known risk factor for the development of cancer," says Dr. Ebbert.

If you have excess body weight, try to lose weight by increasing your physical activity and reducing the calories you consume. "Small, sustainable steps toward weight loss through diet and exercise are most effective," says Dr. Ebbert. "Those are the classic approaches."

If you're a cancer survivor, excess body weight may increase your risk of recurrence. "If your cancer was related to excess body weight, you can have a cancer recurrence. The only way to reduce your risk for those cancers long term is to lose the excess weight," says Dr. Ebbert.

Talk to your healthcare professional about weight-loss options if you struggle to lose weight. In addition to support from dieticians and weight-loss programs, you may be a candidate for bariatric surgery, which can reduce cancer risk. "Weight-loss surgery can reduce your risk for hormone-related cancers such as breast and endometrial, as well as prostate. They've also been shown to decrease the risk for pancreatic and colorectal cancer," says Dr. Ebbert.

There are also new weight-loss medications that may be an option for you. "Those tend to be a less drastic approach than surgery," says Dr. Ebbert.

Alcohol and cancer risk

Drinking alcohol increases the risk of six different types of cancer, including head and neck, esophageal, breast, colorectal, liver and stomach cancer.

"When you consume alcohol, it's converted to acid aldehyde, a toxin that increases risk for harm to cells. It also increases estrogen and insulin, which causes increased division in cells, which can increase the likelihood of cancer developing. And in the areas that are exposed to alcohol during consumption, such as the head and neck, there's an increased absorption of toxins in those areas," says Dr. Ebbert.

The more alcohol you drink, the higher your risk of developing alcohol-associated cancer. But any amount of alcohol consumption comes with a cancer risk. "If you drink, you have a risk for cancer. There is cancer risk at every level of alcohol consumption, but heavier drinkers have higher cancer risk than lighter drinkers," says Dr. Ebbert.

If you are a cancer survivor and are undergoing cancer treatment, avoid alcohol. "If your cancer is related to alcohol consumption, you're going to have an ongoing risk for cancer recurrence and an ongoing increased risk for any other alcohol-related cancers," says Dr. Ebbert. "Also, drinking alcohol during cancer treatment increases the likelihood of side effects, and it can decrease the effectiveness of treatments."

Research shows that people who use both alcohol and tobacco have a much greater risk of cancers of the mouth, throat and esophagus.

If you struggle with alcohol use, talk to your healthcare professional. Alcohol use disorder can escalate and lead to serious problems, so early treatment is important.

Tobacco and cancer risk

While Americans are smoking less — cigarette smoking rates for U.S. adults have dropped from 42% in 1965 to 11.2% in 2021 — smoking remains a major risk factor for cancer.

"In the US, we do see decreasing prevalence, but we see higher smoking rates among people in lower socioeconomic groups and people who struggle with addiction. Cigarette smoking seems to be concentrated and more common in certain demographic groups," says Dr. Ebbert.

This concentration contributes to differences between population groups in cancer diagnosis rates and cancer treatment outcomes, widening the healthcare disparities gap.

"Tobacco — smoked tobacco — produces about 7,000 chemicals. When you inhale those chemicals into your body, they cause alterations in cells, and it's those cell alterations that can lead to cancer," says Dr. Ebbert. "Tobacco smoking also impairs your immune function, which reduces your body's ability to fight cancer cells."

Exposure to secondhand smoke carries these risks as well.

In addition to lung cancer, tobacco use is associated with the development of 17 other types of cancer:

Tobacco products cause nearly 20% of all cancer cases and 30% of all cancer-related deaths. These products include cigars, smokeless tobacco (chewing tobacco and snuff) and water pipes (hookahs).

If you are a cancer survivor or undergoing cancer treatment, using tobacco can increase the risk of cancer recurrence and decrease treatment effectiveness. "If you have a tobacco-related cancer, continuing to use tobacco can increase the likelihood of cancer recurrence. But most importantly, if you smoke, it increases the risk for any tobacco-related cancer," says Dr. Ebbert. "Smoking also increases the likelihood of side effects from almost all types of cancer treatment."

Quitting tobacco will reduce your cancer risk, no matter how long you've used tobacco products."It's never too late to stop," says Dr. Ebbert. "For example, after quitting cigarette smoking, the risk for cancer goes down. But it takes some time. About 15 years after quitting, your risk of cancer is half of what it would have been if you had continued to smoke."

If you've repeatedly tried to stop using tobacco, Dr. Ebbert says, keep trying. "Every time you try to quit, it increases the likelihood you'll be successful long-term. Consider using medication treatments and behavioral therapies. Those are the cornerstones of treatment. Using them together increases the likelihood of long-term success." Talk to your healthcare professional about strategies to help you quit.

Learn more

Learn more about cancer and how to reduce your risk of developing the disease.

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