Antioxidant-Rich Diets Linked to Sharply Lower Lung Cancer Risk in Two Large Studies

A diet packed with antioxidants may do far more than support general health. According to a new study published in the European Journal of Epidemiology, people whose overall diets rank highest in antioxidant capacity face a dramatically lower risk of developing lung cancer than those whose diets rank lowest. The finding, drawn from two independent populations on two continents, adds weight to a long-standing but contested idea in cancer prevention: that the combined, food-based action of vitamins and minerals against oxidative stress may matter more than any single nutrient taken in isolation.

The research team, led by Tong Sun and Xifeng Wu of Zhejiang University School of Medicine in Hangzhou, China, set out to address a persistent gap in nutritional epidemiology. Individual antioxidants such as vitamins A, C, and E have each shown hints of protective potential against cancer, but trials of single-nutrient supplements have repeatedly disappointed, and the US Preventive Services Task Force has cautioned against using vitamin and mineral supplements for cancer prevention. What has remained unclear is whether the total antioxidant load of a whole diet, delivered through food rather than pills, is associated with lung cancer risk in a way that can be measured and replicated across populations.

To answer that question, the investigators designed a two-pronged study. The first component was a case-control analysis nested within the Healthy Zhejiang One Million People (HOPE) study, a large cohort established in China, with participants enrolled between 2022 and 2024. Lung cancer patients were compared with cancer-free control participants drawn from the same source population. The second component was a prospective cohort analysis of participants in the UK Biobank, a vast biomedical database of half a million British adults. Baseline dietary and health data for the UK Biobank participants were collected between 2009 and 2010, and the researchers followed them for disease outcomes through December 19, 2022. Using two different populations, two different study designs, and two different statistical frameworks gave the team a way to test whether any observed association would survive independent scrutiny.

The technical heart of the study lies in how dietary antioxidant exposure was quantified. Rather than examining nutrients one at a time, the researchers constructed two composite indices from the intake of six vitamins and minerals, as reported on food frequency questionnaires. The first, the composite dietary antioxidant index (CDAI), aggregates standardized intake values of several antioxidant nutrients into a single score reflecting the overall antioxidant capacity of the diet. The second, the dietary antioxidant quality score (DAQS), takes a different approach, evaluating whether participants meet recommended intake thresholds for key antioxidant nutrients. Both indices were divided into tertiles, allowing the researchers to compare people in the highest third of antioxidant intake with those in the lowest third, while adjusting statistically for total energy intake and other potential confounders.

The results were striking in their consistency. In the HOPE case-control study, participants in the highest tertile of the CDAI had 57 percent lower odds of lung cancer than those in the lowest tertile, with an odds ratio of 0.43 and a 95 percent confidence interval of 0.28 to 0.65, a statistically significant result. The DAQS told a similar story in the same population: the highest tertile carried an odds ratio of 0.54, meaning 46 percent lower odds, with a confidence interval of 0.36 to 0.82. In the UK Biobank cohort, where the researchers used Cox proportional hazards models to account for the passage of time, the pattern held. High CDAI was associated with a hazard ratio of 0.59, and high DAQS with a hazard ratio of 0.56, both statistically significant. In other words, across both indices and both populations, people with the most antioxidant-rich diets developed lung cancer at roughly 40 to 60 percent lower rates than those with the least.

The biological rationale for such an association rests on the role of reactive oxygen species in carcinogenesis. Oxidative stress arises when the production of reactive oxygen species outpaces the body’s antioxidant defenses, damaging DNA, lipids, and proteins. In lung tissue, this damage can create DNA adducts and mutations that initiate and drive malignant transformation, and oxidative stress is also entwined with chronic inflammation, another recognized cancer-promoting process. Dietary antioxidants, including vitamins A, C, and E along with trace minerals such as selenium, zinc, manganese, and copper, function as cofactors and radical-scavenging agents in the enzymatic and non-enzymatic systems that keep oxidative damage in check. Because these nutrients interact, sometimes synergistically and sometimes antagonistically, many researchers argue that their combined dietary presence, rather than any single compound, determines their net effect on cellular redox balance.

Importantly, the associations were robust to the team’s sensitivity and subgroup analyses. The researchers examined whether the relationship differed across strata of the study populations and whether alternative analytical choices changed the conclusions, and the protective pattern remained consistent throughout. This kind of internal stability matters in nutritional epidemiology, a field notorious for findings that evaporate under scrutiny. The convergence of a case-control design, which is efficient but vulnerable to recall bias, with a prospective cohort design, in which diet is measured before disease develops, provides a form of triangulation that neither design could achieve alone. The fact that two distinct composite indices, built on different scoring logic, pointed in the same direction further strengthens the signal.

Still, the authors and outside observers alike must weigh the usual caveats of observational research. Food frequency questionnaires depend on self-report, and people who eat more antioxidant-rich foods, typically fruits, vegetables, nuts, and whole grains, tend to differ from other people in many ways that influence cancer risk, including smoking behavior, physical activity, and socioeconomic circumstances. Although the study applied multivariable adjustment to account for such factors, no statistical model can eliminate confounding entirely. Reverse causation is a particular concern in the case-control component, since lung cancer patients may have altered their diets before enrollment. The prospective UK Biobank analysis mitigates that concern, but even there, unmeasured lifestyle differences could contribute to the observed gradient. The findings establish association, not causation, and the authors note that the data supporting the work are available from the corresponding author upon reasonable request.

What the study does offer is a reframing of how dietary prevention might be approached. Rather than chasing individual supplement trials that have largely failed to deliver, the composite-index approach captures the antioxidant profile of the whole diet, aligning with the broader evidence that overall dietary patterns, such as the Mediterranean diet, are more predictive of health outcomes than isolated nutrients. For clinicians and public health planners, the results suggest that encouraging at-risk individuals, including smokers and former smokers, to build diets naturally rich in antioxidant capacity could be a meaningful component of lung cancer prevention strategies. The researchers emphasize that elevated dietary antioxidant consumption should be viewed as a protective factor worth reinforcing, while acknowledging that diet is one strand in a web of risk that includes tobacco exposure, occupational carcinogens, air pollution, and genetic susceptibility. As lung cancer remains one of the deadliest malignancies worldwide, a low-cost, food-based intervention that correlates with a reduction in risk of this magnitude will demand closer attention, and ideally, further prospective validation in additional populations.

Subject of Research: The association between overall dietary antioxidant capacity and lung cancer risk in two observational cohorts

Article Title: Association between overall dietary antioxidant capacity and lung cancer risk: findings from two observational studies

Article References: Sun, T., Zhang, L., Luo, X., Wang, L., Xue, Q., Song, W., Li, W., Tu, H., & Wu, X. (2026). Association between overall dietary antioxidant capacity and lung cancer risk: findings from two observational studies. European Journal of Epidemiology. https://doi.org/10.1007/s10654-026-01474-3

Image Credits: AI Generated

DOI: 10.1007/s10654-026-01474-3

Keywords: lung cancer, dietary antioxidants, composite dietary antioxidant index, UK Biobank, HOPE cohort, oxidative stress, cancer prevention, nutritional epidemiology, case-control study, prospective cohort, vitamins, selenium