A diet rich in fruits, vegetables, and whole grains is generally recommended to improve health and reduce the risk of cancer and other diseases.
But new research from the Norris Comprehensive Cancer Center, part of the Keck School of Medicine at the University of Southern California, presented at the annual meeting of the American Association for Cancer Research, suggests that this type of diet may increase the risk of developing lung cancer in nonsmoking Americans under age 50.
Our study shows that young non-smokers who consume more healthy foods than the general population are more likely to develop lung cancer. These counterintuitive findings raise important questions about unknown environmental risk factors for lung cancer associated with beneficial foods that need to be addressed. ”
Jorge Nieva, MD, USC Norris medical oncologist and lung cancer specialist and principal investigator of this study
Nieva and his colleagues speculate that the risk factor may be pesticides used to protect crops from pests. Nieva says commercially produced (non-organic) fruits, vegetables and whole grains are likely to have more pesticide residue than dairy products, meat and many processed foods. He also noted that agricultural workers exposed to pesticides generally have higher rates of lung cancer, lending credence to the theory.
The study also showed that young women who don’t smoke have higher rates of lung cancer than men, and that women tend to eat diets higher in produce and whole grains than men.
A new epidemic of lung cancer
Lung cancer usually affects older people (the average age of onset of lung cancer is 71 years), men more than women, and smokers.
Although smoking rates have declined since the mid-1980s, resulting in decreased lung cancer rates across the United States, nonsmokers under age 50, especially women, are more likely to develop lung cancer than men, with the exception of one special group.
To investigate this trend, researchers launched the Juvenile Lung Cancer Epidemiology Project, which looked at 187 patients diagnosed with lung cancer before age 50. Patients provided details about demographics, diet, smoking history, and lung cancer diagnosis.
Most patients had never smoked and had a form of lung cancer that is biologically different from the lung cancer caused by smoking. A 2021 study by the Juvenile Lung Cancer Epidemiology Project, the Juvenile Lung Cancer Genomics Project, found that subtypes of lung cancer in people under 40 are different from lung cancer in older people.
Researchers compared the patients’ diets to the broader U.S. population using the Healthy Eating Index (HEI), which ranks the overall quality of Americans’ diets on a scale of 1 to 100. The average HEI score for young non-smoking lung cancer patients was 65 out of 100, compared to a national average of 57. Among study participants, women had higher HEI scores than men.
On average, young lung cancer patients ate more fruits, vegetables, and whole grains each day than the general population. For example, participants ate an average of 4.3 servings of dark green vegetables and legumes and 3.9 servings of whole grains per day, while the average U.S. adult consumed 3.6 servings of dark green vegetables and legumes and 2.6 servings of whole grains per day.
Further research required
Nieva said more research is needed into the link between pesticides and lung cancer in young people, especially women.
In this study, the researchers did not test specific foods for pesticides. Instead, they used published data on average pesticide levels in food categories such as fruits, vegetables, and grains to estimate exposure. Nieva said the next step is to confirm the link by directly measuring pesticide levels in patients’ blood or urine samples. This could also help reveal whether some pesticides increase the risk of lung cancer more than others.
“This study represents an important step toward identifying modifiable environmental factors that may contribute to lung cancer in young adults,” Nieva said. “Our hope is that these insights will inform both public health recommendations and future research on lung cancer prevention.”
This research is supported by the Addario Lung Cancer Medical Institute, a nonprofit organization focused on advances in lung cancer research and treatment, as well as AstraZeneca, the Beth Longwell Foundation, Genentech, and GO2 for Lung Cancer and Advanced Lung Cancer.
The researchers also received funding from the National Institutes of Health (grant number R25CA225513) and the National Cancer Institute (grant number P30CA014089).
sauce:
University of Southern California – Health Sciences
