October 1, 2009

Can Multivitamins and Antioxidants Slow the Aging Process?

Reference

Xu Q, Parks CG, DeRoo LA, Cawthon RM, Sandler DP, Chen H. Multivitamin use and telomere length in women. Am J Clin Nutr. 2009;89(6):1857-1863.
 

Design

A cross-sectional analysis of data from 586 women
 

Participants

Five hundred eighty-six female participants (34 y-74 y of age) in the Sister Study, an ongoing risk-enriched prospective cohort of the healthy sisters of breast cancer patients
 

Study Parameters

Enrollment in the study included a home visit for blood and urine collection, a 90-minute computer-assisted telephone interview, and several self-administered questionnaires. Multivitamin use and nutrient intakes were assessed with a 146-item food-frequency questionnaire. Relative telomere length of leukocyte DNA was measured by quantitative polymerase chain reaction (PCR).
 

Main Outcome Measure

The primary aim of this study was to determine whether telomere length could be correlated with multivitamin use. 
 

Background

Telomeres are the TTAGGG tandem repeat sequences and their corresponding binding proteins that are found at the ends of chromosomes to prevent detrimental recombination and degradation of the chromosomes. They effectively act like the tips on the ends of shoelaces to keep the chromosomes from unraveling. It is theorized that the steady shortening of telomeres with each replication in somatic (body) cells may have a role in senescence (biological aging). This is because the telomeres act as a sort of time-delay “fuse,” eventually running out after a certain number of cell divisions and resulting in the eventual loss of vital genetic information from the cell’s chromosome with future divisions.
 
A person’s systemic telomere length is predominantly genetically determined but has several other known determinants: age (shorter telomeres in older people), paternal age at birth (longer telomeres in subjects with older fathers at their birth), and sex (shorter telomeres in men, probably due to a faster telomere attrition). Evidence suggests that elevated levels of oxidative stress and inflammation further increase the telomere attrition rate. In this study, systemic telomere length was measured by a PCR-based telomere assay of peripheral blood leukocytes. Leukocyte telomere length (LTL) decreases with each cell cycle and with increased oxidative stress and inflammation. LTL has been previously used in studies as a predictor of age-related disease.
 

Key Findings

Daily users of multivitamins had on average 5.1% longer telomeres. In this study, it was found that 65% of the participants used multivitamins at least once per month and most users (74%) took multivitamins on a daily basis. About 89% of the users took once-a-day type multivitamins, 21% took antioxidant combinations, and 17% took stress-tabs or B-complex vitamins. Among users, multivitamins represented a major source of total vitamin and mineral intakes, contributing >50% of the total intake for vitamins C, E, D, B6, B12, folate, iron, and zinc, and 30% to 50% for vitamin A, beta carotene, and calcium.
 
As for single nutrients, vitamin B12 supplement users (n=52) had a longer telomere length than did nonusers (n=518) and iron users (n=41) had a shorter telomere length than nonusers (n=527). Micronutrient intake from foods was generally not related to telomere length, except for vitamins C and E. Higher dietary intake of these 2 antioxidants was associated with longer telomere length in a dose-response manner even after multivitamin use was adjusted for. Among women who did not use multivitamins (n=203), higher dietary intakes of beta carotene; folate; magnesium; and vitamins C, E, and A were each associated with longer telomere length.
 

Practice Implications

No one would argue that only 1 factor is implicated in aging. The aging process is certainly multifactorial; however, it is of great interest to study what the important variables are in senescence and how we can manipulate these in the quest for greater quality and quantity of life. Telomere attrition in human somatic cells and its association with aging has been an incredibly interesting field to watch over the past 5 years. Studies have demonstrated that shorter telomeres are associated with oxidative stress and inflammatory reactions, both of which are associated with poorer prognosis in many chronic disease states. This epidemiological study is likely the first of its kind to demonstrate the effect that multivitamins, and more particularly dietary vitamins C and E, have on telomere length. This provides some interesting clues and a deeper understanding as to how these antioxidants work in the body and provides compelling support for nutritional supplementation.
 
A study from 2007 has already shown that higher vitamin D concentrations are associated with longer leukocyte telomere length.1 Vitamin D is a potent inhibitor of the proinflammatory response and thereby diminishes the turnover of leukocytes. Serum vitamin D concentrations were measured in 2,160 women aged 18 to 79 years (mean age: 49.4 y) from a large population-based cohort of twins. LTL was measured by using the Southern blot method—that’s a different method than what was used in the multivitamin study, but the 2 methods have been shown to be highly correlative. As expected, age was negatively correlated with LTL. Serum vitamin D concentrations were positively associated with LTL, and this relation persisted after adjustment for age and other covariates (age, season of vitamin D measurement, menopausal status, use of hormone replacement therapy, and physical activity). The difference in LTL between the highest and lowest tertiles of vitamin D was 107 base pairs, which is equivalent to 5.0 years of telomeric aging. This difference was further accentuated by increased concentrations of C-reactive protein, which is a measure of systemic inflammation.
 
In conclusion, these combined findings suggest that supplementation with multivitamins increases leukocyte telomere length, especially when these include vitamins D, C, B complex, and E, and underscores the potentially beneficial effects of these vitamins on aging and age-related diseases. 

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References

  1. Richards JB, Valdes AM, Gardner JP, et al. Higher serum vitamin D concentrations are associated with longer leukocyte telomere length in women. Am J Clin Nutr. 2007;86(5):1420-1425.