Carotenoids, vitamin C may lower lung cancer risk
High intake of carotenoids such as β-carotene and lycopene as well as vitamin C appears to be associated with decreased risk of lung cancer, according to a recent study.
“We found that high intake of β-carotene ... and lycopene were associated with a reduction in lung cancer risk among male heavy smokers, while vitamin C reduced the risk of lung cancer among female heavy smokers,” according to the researchers.
This population-based case-control study involved 1,105 incident lung cancer cases and 1,449 controls. Researchers evaluated the role of dietary intake in lung cancer and other lung cancer subtypes such as squamous cell carcinoma, adenocarcinoma, and small cell carcinoma. [Front Oncol 2017;doi.org/10.3389/fonc.2017.00023]
High daily intake of β-carotene (adjusted odds ratio [adjOR], 0.66, 95 percent confidence interval [CI], 0.51–0.84), lycopene (adjOR, 0.75, 95 percent CI, 0.59–0.95), and vitamin C (adjOR, 0.74, 95 percent CI, 0.54–0.96) were associated with reduced risk of lung cancer.
High daily intake of β-carotene was also associated with reduced risk of squamous cell carcinoma (adjOR, 0.56, 95 percent CI, 0.40–0.80) and adenocarcinoma (adjOR, 0.62, 95 percent CI, 0.45–0.85).
High daily intake of lycopene was also associated with reduced risk of squamous cell carcinoma (adjOR, 0.70, 95 percent CI, 0.50–0.98) and small cell carcinoma (adjOR, 0.65, 95 percent CI, 0.43–0.99).
High daily intake of vitamin C was also associated with reduced risk of squamous cell carcinoma (adjOR, 0.55, 95 percent CI, 0.38–0.80).
The findings were consistent with a previous study showing reduced lung cancer risk with high intake of β-carotene. [Nutrients 2015;7:9309-9324] Additionally, the high intake of lycopene and vitamin C signified a preventive effect against lung cancer, noted the researchers.
“[However], one notable exception was lycopene, which showed correlation coefficients with other micronutrients ranging from 0.34–0.50, whereas the correlation between the other micronutrients ranged from 0.52–0.94. This high level of collinearity impeded our ability to estimate the independent effect of each micronutrient on lung cancer risk, and this should be kept in mind when interpreting the results,” they said.
Overall, the findings suggest that common food sources contain dietary antioxidants that have a protective function against lung cancer, noted the researchers.
“One should therefore keep in mind that although dietary intake of carotenoids and vitamin C may help prevent lung cancer, [these micronutrients] could also be surrogates for other protective compounds found in selected fruit and vegetables,” said the researchers.