Sunday Feb 14, 2015 (foodconsumer.org) -- A. Sen and colleagues at Medical University of Graz in Graz, Austria published a study (1) to suggest that supplementation with lutein, zeaxanthin and vitamin C may help extend humans' lifespan.

The study did not examine how these nutrients affect lifespan, but found that people who had high levels of lutein, zeaxanthin and vitamin C had longer leukocyte telomere length in health elderly people.

A telomere is part of repetitive nucleotide sequences at each end of a chromatid. The telomere functions to protect the end of chromosome from deterioration or fusion with other chromosomes.  During each chromosome replication or duplication, the end of the chromosome is shortened because the duplication cannot reach the entire end of a chromosome.

A longer telomere length generally indicates that a person has a longer time to live.

The Austrian Stroke Prevention Study, a cross-section cohort study was intended to examine the effect of antioxidative micronutrients on brain aging, specifically, the leukocyte telomere length, in elderly men and women.

For the study, researchers measured serum concentrations of lutein, zeaxanthin, vitamin C (also known as ascorbic acid), and other antioxidative nutrients like β-cryptoxanthin, canthaxanthin, lycopene, α- and γ-tocopherol, α- and β-carotene, and retinol (vitamin A).  They also measured leukocyte telomere length and advanced oxidation protein products, which indicate oxidative stress.

Among all the micronutrients, higher vitamin C, lutein and zeaxanthin concentrations were found strongly associated with longer telomere length regardless of body mass index, maximum oxygen uptake, vascular conditions and advanced oxidation protein product concentrations.

The findings suggested that higher serum levels of lutein, zeaxanthin and vitamin C may render a protective effect in telomere maintenance even though the study could not explain how.

Humans cannot synthesize lutein, zeaxanthin and vitamin C and these nutrients must come from a person's foods or dietary supplements.

Vitamin C is found high in foods like bell peppers, dark leafy greens, kiwi, broccoli, berries, citrus fruits, tomatoes, peas, and papayas.  Vitamin C is known to provide many health benefits including enhancement of human immunity.

Lutein and zeaxanthin are found high in eggs, spinach, goji berry (wolfberries), green leafy vegetables like kale, turnip greens, collard greens, Swiss chard, broccoli, kiwi, corn, garden peas, and Brussels sprouts. 

Lutein and zeaxanthin are known to be protective against eye diseases.  Another study (2) found significantly lower serum levels of lutein, lycopene, alpha- and beta-carotene in patients suffering ischemic stroke who had a poor early outcome (functional decline) compared with controls.

Vitamin C, lutein and zeaxanthin are available as dietary supplements online and local health stores.  Vitamin C is very cheap while lutein and zeaxanthin are quite expensive. (David Liu, PH.D.)

References

1) Sen A, Marsche G, Freudenberger P, Schallert M, Toeglhofer AM, Nagl C, Schmidt R, Launer LJ, Schmidt H.  Association between higher plasma lutein, zeaxanthin, and vitamin C concentrations and longer telomere length: results of the Austrian Stroke Prevention Study.  J Am Geriatr Soc. 2014 Feb;62(2):222-9. 

2) Polidori MC, Cherubini A, Stahl W, Senin U, Sies H, Mecocci P.  Plasma carotenoid and malondialdehyde levels in ischemic stroke patients: relationship to early outcome.  Free Radic Res. 2002 Mar;36(3):265-8.