Written by Dr. Clara Sartor, NMD, DAc, LAc, BSc. In this cross-sectional study, Qi et al. explored the relationship between dietary intake of carotenoids and biological aging indices in adults. Results indicated that higher total carotene intake was associated with lower prevalence of hypertension, cardiovascular disease, and diabetes. A negative association between dietary intake of carotenoids and biological aging indices was established. β-carotene resulted as highly contributory to phenoAge and to lowering homeostatic dysregulation.

Aging can be defined as progressive changes in metabolism and physicochemical properties in cells that result in damage in ability to self-regulate, self-renew, and ultimately can cause structural and functional injury¹. From 2010-2020, the U.S. population dynamics saw a noticeable increase in the aging population; in 2020, the population of adults aged 65 or older was 16.8%, the fastest growth rate since 1880-1890².The World Health Organization reports that this trend followed suit on a global scale with those aged 60 and older outnumbering those younger than age 5 in 2020 and with the proportion of those aged greater than 60 expected to almost double from 12 to 22% between years 2015 and 2050³. Giving the ever growing aging demographic, understanding how to best support graceful aging remains central to the public health focus.

Carotenoids represent potential for helping to support graceful aging. While these pigments are found in various plants and microorganisms, they are not synthesized in animals; dietary intake prevails as a primary way for introducing them to the human microbiome⁴. Some carotenoids act as provitamins as about 10%, can change into vitamin A once in the body^5,6. These antioxidants exhibit antiaging effects on cells such as a reduction on cancer and cardiovascular disease risk, two age-associated diseases, by mechanisms including modulation of cellular growth, gene expression, and immune response⁴. Their abilities to scavenge for free oxygen radicals and upregulate certain immune pathways have also been touted to play a role in addressing cancer, neurological conditions, and diabetes⁶.

Cross-sectional data from the years 1999-2018 from the National Health and Nutrition Examination Survey (NHANES) were utilized in the Qi et al. study. To meet the inclusion criteria, adults must have been non-pregnant and have maintained a standard daily caloric intake of 800-4200 for males or 500-3500 for females. The team collected two 24-hour dietary recall questionnaires via NHANES with the first collected in person and the second via telephone 3-10 days later. Carotene intake was calculated by adding the consumption of α-carotene, β-carotene, β-cryptoxanthin, lycopene, and lutein + zeaxanthin. Markers for evaluating biological aging indices included systolic blood pressure and blood markers such as albumin, c-reactive protein, and lymphocyte percentage. Allostatic load (AL), a measurement of the effects of long-term stress and life events on physiological health, was calculated on a 0-1 scale. Other tracked outcomes for predicting biological aging and the risk of age-related diseases included homeostatic dysregulation (HD), Klemerae-Doubal Method (KDM), and phenoAge (PA).

Significant findings of the study were as follows:

• Participants with higher total carotene values tended to be male, older, imbibed in alcohol, and participated in lifestyles with higher physical activity levels, socioeconomic status, alternative healthy eating indices, energy intake levels, retinol intake levels, and lower body mass index and prevalence of hypertension, cardiovascular disease, and diabetes.
• Those with the highest intake of total carotene resulted with the lowest AL, HD, KDM, and PA scores. Higher intakes of α-carotene resulted with significantly lower AL, KDM, and PA The same was true for β-carotene regarding lower AL, HD, KDM, and PA scores, for β-cryptoxanthin regarding lower AL, KDM, and PA scores, for lycopene regarding lower AL, HD, KDM, and PA scores, and for lutein + zeaxanthin regarding lower AL, HD, KDM, and PA scores as compared to those with the lowest intake.
• A linear relationship was demonstrated between total carotene intake and lower AL and KDM results as well as α-carotene and AL, HD, and PA, β-carotene and AL, HD, and KDM, lycopene and AL, KDM, and PA, and lutein + zeaxanthin and AL.
• Weighted quantile sum (WQS) regression and Quantile g (QG)-computation differed somewhat in their results. In the WQS regression model, lutein + zeaxanthin and α-carotene demonstrated the main two contributors for AL and KDM, however for QG-computation, α-carotene and lycopene emerged as the two carotenoids with the most significant contribution to AL acceleration, and β- and α-carotene were most contributory to KDM. For both models, β-carotene and lycopene were most contributory to HD acceleration. Both models also demonstrated that β-carotene and lutein + zeaxanthin were the two carotenoids most contributory to PA.

Limitations to the study should be discussed. As a cross-sectional, observational design, direct causality cannot be established, only correlation. Failure to include other aging biomarkers, such as leukocyte telomere length and potential for recall bias must be noted. Potential for conversion of carotenoids should be considered when interpreting quantification of serum levels post dietary intake. An independent population group was not utilized for comparison. Despite these considerations, the study demonstrated a strong and significant negative association between dietary intake of carotenoids and biological aging indices. Across models, lutein + zeaxanthin and β-carotene stand out as consistent contributors to these findings. Further studies are needed to better elucidate the functions of these antioxidants and the mechanisms behind which dietary carotenoids affect biological aging.

Source: Qi, Xiang, Xuanyang Wang, Licheng Cheng, Yue Li, Keke Dang, Shuo Yang, Yina Wang, Runyi Zhou, Can Zhang, and Ying Li. “Dietary carotenoid intakes and biological aging among US adults, NHANES 1999–2018.” Nutrition Journal 24, no. 1 (2025): 9.

© The Author(s) 2025. Open Access

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Posted July 29, 2025.

Clara Sage Sartor NMD, LAc, DAC, BSc is a licensed naturopathic medical doctor and licensed acupuncturist who focuses on metabolic conditions, hormone optimizing, and inflammation reduction. She earned her naturopathic medical degree from Southwest College of Naturopathic Medicine (now Sonoran University of Health Sciences) and is completing her Chinese herbal doctorate at Phoenix Institute of Herbal Medicine and Acupuncture. Dr. Clara also works as a monograph writer on diverse plants, and in her free time she helps instruct kung fu at 5 Elements Kung Fu and is the team secretary for the Golden Phoenix Lion Dance team. More information can be found at www.integrative-wellness-clinic.com

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