In the news: Telomere Length & AMD: ‘Multi’ Use Linked to Longer Telomeres in Women

Telomeres as a Marker of Biological Aging

Telomeres are the regions of repetitive DNA located at the end of chromosomes. They protect the end of the chromosome from deterioration, preventing chromosomes from fusing together or rearranging, which can lead to cancer.

Interest in telomeres arose from the observation that human cells can undergo only a limited number of divisions to produce new cells, and that telomere length may determine that limit.

In somatic (non-reproductive) cells, telomeres shorten with each cell division, eventually leading to cells that are no longer capable of dividing or to cellular self-destruction (apoptosis). Therefore, telomere length has been proposed as a marker of biological aging.

Consistent with this hypothesis, epidemiologic studies have related shorter telomeres to higher mortality, accelerated aging, and greater risk of some age-related chronic diseases including cognitive decline, dementia (1) and recently, AMD (2).

Telomere Length Linked to GA type of AMD

Researchers in China looked at the relationship of leukocyte telomere length and AMD in 197 AMD patients and 259 healthy controls using the established quantitative polymerase chain reaction (PCR) technique. Logistic regression was performed to evaluate the association of leukocyte telomere length and AMD.

After adjusting for age and sex, a significant association between AMD and telomere length was seen (OR=2.24; 95% CI=1.68-3.07; P=0.0001).
Notably, the results showed a strongly significant association between the geographic atrophy (dry AMD) subtype and telomere length (OR=4.81; 95% CI=3.15-7.82; P=0.0001), but no association was found in the wet AMD subgroup. The observed 2-fold risk of AMD and nearly 5-fold risk for dry AMD suggest that telomere shortening could play a role in the development of AMD.

‘Multi’ Use Linked to Longer Telomeres

Experimental evidence suggests that oxidative stress and chronic inflammation contribute to the gradual loss of telomeres, and that some vitamin and minerals may affect telomere length by influencing these processes. Based on these findings, researchers from the NIH examined whether multivitamin use is associated with longer telomeres in women (3).

The research team performed a cross-sectional analysis of data from 586 early participants (age 35–74 years) in the Sister Study, a prospective cohort study of healthy sisters of breast cancer patients. Multivitamin use and nutrient intakes were assessed with a 146-item food-frequency questionnaire, and relative telomere length of leukocyte DNA was determined using quantitative PCR, confirmed by duplicate assays.

After adjusting for age and other potential confounders, multivitamin use was associated with longer telomeres.
Compared with nonusers, the relative telomere length of leukocyte DNA was significantly longer among daily multivitamin users (P for trend 0.002).

Higher intakes of vitamins C and E from foods were each associated with longer telomeres, even after adjustment for multivitamin use. Further, intakes of both vitamins C and E were associated with telomere length among women who did not take multivitamins.

The associations of telomere length with AMD and of longer telomeres with multi use in women should be further evaluated. In the meantime, taking a daily multi-nutrient supplement is a prudent idea since recommendations for anti-oxidant and nutrient-rich fruit and vegetable intakes are met by fewer than 17% and 14% of US adults, respectively (4).

References:

1. Martin-Ruiz C, et al. Telomere length predicts post-stroke mortality, dementia, and cognitive decline. Ann Neurol 60:174-80, 2006.
2. Weng X, et al. Leukocyte telomere length is associated with advanced age-related macular degeneration in the Han Chinese population. Exp Gerontol 69:36-40, 2015.
3. Xu K, et al. Multivitamin use and telomere length in women. Am J Clin Nutr 89:1857-63, 2009.
4. Moore L, et al. Adults Meeting Fruit and Vegetable Intake Recommendations: US 2013. CDC Morbidity and Mortality Weekly Report 64:709-713, 2015.