Adopting a healthier lifestyle is a recommended approach for preventing a range of chronic illnesses and mitigating complications from conditions like obesity, hypertension, and diabetes. A new study suggests that such lifestyle changes could also avert approximately 40% of new cancer cases in adults aged 30 and above, and nearly half of all cancer-related deaths.

The study by the American Cancer Society examined data from 2019 to understand the proportion and number of cancer cases and deaths linked to potentially modifiable risk factors, such as smoking and excess body weight. After analyzing 30 types of cancer and 18 risk factors, researchers observed that lifestyle factors were responsible for over half of the new cases of 19 types of cancer.

Nearly 1.8 million new cases of cancer were reported in the U.S. in 2021. The study noted that lifestyle factors accounted for more than 700,000 new cancer cases and over 262,000 cancer deaths.

Cigarette smoking emerged as a significant risk factor for cancer, responsible for nearly 20% of all cases and 30% of all cancer deaths. Smoking increases the risk of cancers in the lungs, mouth, cervix, bladder, pancreas, stomach, liver, and kidneys. According to the Centers for Disease Control and Prevention (CDC), within 5-10 years of quitting, the chance of getting cancer of the mouth, throat, or voice box drops by half.

"As such, expanding comprehensive tobacco control programs can have the greatest impact on reducing cancer cases and deaths. Among tobacco control policies, increasing the price of cigarettes through excise taxes has shown the strongest effect in the United States," the researchers wrote.

Following smoking, excess body weight was found to be the second-largest contributor, associated with around 5% of new cases in men and almost 11% in women. It was linked to over a third of deaths from cancers of the endometrium, gallbladder, esophagus, liver, and kidney.

Other significant factors include alcohol consumption, poor diet, lack of physical activity, exposure to UV radiation, and infections.

"We estimated that of all cancer cases and deaths in the United States, nearly 7%–8% were attributable to excess body weight, 4%–5% were attributable to alcohol consumption, 4% were attributable to dietary factors (all evaluated dietary factors combined), and 3% were attributable to physical inactivity," the researchers wrote.

"These are things that people can practically change how they live every single day to reduce their risk of cancer," Dr. Arif Kamal, chief patient officer with the American Cancer Society, told ABC News.

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