A recent study published in The Journal of Nutrition, Health and Aging has found that low-fat diets can significantly reduce lung cancer risk in older adults.
Researchers examined dietary patterns and their impact on lung cancer risk in a large cohort of American adults over the age of 55. The study focused on the long-term effects of consuming different types of fat—saturated and unsaturated (mono and polyunsaturated fats)—over approximately 8.8 years. To gain deeper insights, the study also differentiated between small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).
Key Findings
The study concluded that adhering to low-fat diets substantially lowered the risk of lung cancer across different subtypes. This protective effect was most pronounced among current smokers. Conversely, high consumption of saturated fats was linked to an increased risk of lung cancer.
The Link Between Diet and Lung Cancer
Lung cancer remains a leading cause of death globally, with the Global Cancer Observatory (GLOBOCAN) reporting 2.2 million new cases and 1.8 million deaths in 2020 alone. While smoking is the primary risk factor, other health behaviors, including diet and sleep patterns, are increasingly recognized for their role in lung cancer development and progression.
Recent research has highlighted the impact of specific dietary elements on lung cancer risk. Studies from European cohorts have identified certain foods like retinol, beer, cider, and offal as risk factors, whereas fiber, fruits, and vitamin C have been found to reduce risk. Dietary fat, particularly the balance between low-fat and high-fat consumption, has also been scrutinized for its potential role in lung cancer pathology.
Study Methodology
The researchers used data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO), a large, long-term randomized controlled trial conducted by the National Cancer Institute (NCI) in the United States. Participants were included if they had no history of cancer at baseline and had completed comprehensive demographic and medical questionnaires. Data collection involved baseline health assessments and annual follow-up questionnaires, including the Dietary History Questionnaire (DHQ) and a Supplemental Questionnaire (SQX).
Cancer diagnoses were confirmed annually through medical records, detailing diagnostic procedures, stage, grade, histopathology, and any ongoing treatments. The researchers computed Cox proportional hazard ratios (HRs) for various participant strata, adjusting for demographic and medical variables.
Detailed Results
Out of over 155,000 participants in the PLCO trial, 98,459 met the inclusion criteria for this study. The cohort was 47.96% male and 92.65% white. Higher adherence to low-fat diets was noted among older, female, and non-white participants, with educational status being a significant factor in diet adherence.
During the 8.83-year follow-up, 1,642 participants developed lung cancer, with 1,408 cases of NSCLC and 234 cases of SCLC. The study found that high intake of saturated fatty acids (SFAs) correlated with the highest lung cancer risk, while monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) did not show similar associations. Interestingly, the protective benefits of PUFAs were most significant among smokers, who are at the highest risk of lung cancer.
Conclusion
This extensive study underscores the importance of dietary fat composition in managing lung cancer risk among older adults. A higher adherence to low-fat diets was linked to a reduced risk of lung cancer, particularly among smokers. While SFAs were associated with increased cancer risk, MUFAs and PUFAs did not exhibit the same detrimental effects. These findings highlight the potential of dietary interventions in cancer prevention strategies, emphasizing the need for public health initiatives to promote low-fat dietary patterns, especially in high-risk populations such as smokers.