In the news: Carotenoids Linked to Lower Systemic Inflammation

Carotenoids Linked to Lower Systemic Inflammation

Results of a new study(1) from medical researchers at several collaborating Chinese Universities provides critical evidence supporting the health benefits of consuming carotenoid-rich fruits and vegetables.

Evidence suggests that chronic systemic inflammation is an underlying factor in the development or progression of many chronic diseases. Previous studies have shown inflammatory markers to be associated with the incidence of diabetes, CVD, neurodegenerative disorders, and certain cancers.

Carotenoids are known for their antioxidant and anti-inflammatory properties and are thought to be protective against various chronic diseases. A meta-analysis of longitudinal studies, for example, found the concentration of total and various carotenoids to be inversely related to all-cause mortality(2).

In the new study, researchers set out to investigate the relationship between serum carotenoids and inflammatory markers. The results of several earlier studies suggested that carotenoids may confer anti-inflammatory effects, but the studies had small sample sizes.

The current investigation is unique for several reasons. First it was conducted in over 15,900 participants in the National Health and Nutrition Examination Survey (NHANES). NHANES is a nationally representative sample so that the outcome reflects the national population.

Secondly, the researchers utilized the Systemic immune-inflammation index or SII, a novel index that serves as a reliable inflammatory marker.

Unlike other inflammatory indices, the SII reflects the balance between inflammatory and immune responses. The SII is also becoming recognized as a prognostic biomarker for various diseases including cancers, cardiovascular diseases, and hepatic steatosis.

The analysis focused on the most commonly consumed carotenoids: alpha carotene, beta carotene, beta cryptoxanthin, lutein / zeaxanthin, and trans lycopene. Higher serum levels (the highest vs. lowest quartiles) of these carotenoids were significantly associated with lower SII values.

Additionally, nonlinear relationships were observed between certain carotenoids – beta carotene and trans lycopene – and SII. Beta carotene displayed an inflection point at the concentration of 6.90 µg/dL, while the inflection point for trans lycopene was 4.01 µg/dL.

Subgroup analyses found that several variables such as age, race and alcohol consumption could modify the effects of carotenoids on SII. Older people or current drinkers, for instance, may experience different associations between serum carotenoid levels and systemic inflammation.

The results of this study support previous findings that a diet rich in carotenoid containing fruits and vegetables likely play a role in reducing the risk of chronic diseases associated with inflammation.

This is the first study to examine the relationship between these specific, frequently consumed dietary carotenoids and the SII, according to the study authors. The authors also point out that, as a cross-sectional Investigation, the results cannot establish cause and effect and should be confirmed by future longitudinal studies.

References

1. Yan S-H, et al. Association of serum carotenoids and SII among general people, based on NHANES 2001-2006. Nature Sci Reports. 15:10107, 2025.
2. Aune D, et al. Dietary intake and blood concentrations of antioxidants and the risk of cardio -vascular disease, total cancer, and all-cause mortality: A systematic review and dose-response meta-analysis of prospective studies. Am J Clin Nutr. 108:1069-1091, 2018.