The findings, reported by Chinese researchers in the journal Frontiers in Nutrition, show only correlation and not causation, and therefore some caution must be exercised when interpreting the data.
However, this is not the first time that researchers have used data from the National Health and Nutrition Examination Survey (NHANES) to explore a potential anti-aging benefit for carotenoids. A 2016 study indicated that doubling levels of alpha-carotene, beta-carotene and beta-cryptoxanthin was associated with 2% longer telomeres. This study did not limit its analysis to overweight and obese subjects.
Another study published earlier this year linked lutein/zeaxanthin and beta-carotene to improvements in a range of biological aging indices, but that study did not assess telomere length.
“Our study found that increasing serum carotenoid levels were significantly associated with longer telomere lengths in overweight or obese U.S. populations,” the Chinese researchers wrote. “The increase in carotenoid levels had a more significant effect on telomere length in obese individuals compared to overweight individuals.”
Interestingly, they did not find a relationship between carotenoids concentrations and telomere length in non-overweight or non-obese individuals. No benefits were associated with levels of alpha-carotene, lutein/zeaxanthin and trans-lycopene.
Hallmarks of aging
Telomeres, DNA sequences at the end of chromosomes that shorten as cells replicate and age, do not always correlate with chronological age, and there is evidence to suggest telomere shortening may be modifiable by lifestyle factors.
The aging and lifespan of normal, healthy cells are linked to the so-called telomere shortening mechanism, which limits cells to a fixed number of divisions. During cell replication, the telomeres function by ensuring the cell’s chromosomes do not fuse with each other or rearrange, which can lead to cancer.
Elizabeth Blackburn, a telomere pioneer at the University of California San Francisco, likened telomeres to the ends of shoelaces, without which the lace would unravel.
With each replication the telomeres shorten, and when the telomeres are totally consumed, the cells are destroyed (apoptosis). Telomere shortening or attrition was listed as one of the nine hallmarks of aging in a seminal paper published in Cell in 2013 by Carlos López-Otín et al. This list has since been expanded to 12 hallmarks of aging, outlined in a 2023 review by Professor López-Otín.
Oxidative stress and chronic inflammation are reported to increase telomere shortening, both of which are exacerbated by obesity.
“Therefore, obese individuals may have shorter somatic telomere lengths and are more susceptible to premature aging and reduced cell lifespan,” the Chinese researchers noted. “Our findings support this trend, with lower BMI associated with longer telomeres across all populations included.”
Study details
The new analysis included data from 2,353 overweight or obese people participating in the 2001–2002 NHANES and found that every unit increase in beta-carotene levels was associated with increases in telomere length of 1.7 base pairs (bp) and 2.6 bp in overweight and obese individuals, respectively.
“This investigation indicates that higher serum β-carotene concentrations are linked with extended telomere length in overweight and obese populations in the United States,” the researchers concluded. “These findings warrant further validation through prospective studies.”
Source: Frontiers in Nutrition, Volume 11. doi: 10.3389/fnut.2024.1479994. “Relationship between serum carotenoids and telomere length in overweight or obese individuals”. Authors: J. Wang, et al.