Supplementation with an extract from Astragalus may reduce telomere shortening in healthy volunteers, says a new randomized, double-blind, placebo-controlled trial from France.
Six months of supplementation with the extract was associated with significant improvements in a range of telomere measures to an extent described by researchers as a "statistically and possibly clinically significant manner".
Scientists from the Institute of Medicine and Physiology of Longevity (Institut de Jaeger), Université Paris Cité, and the Sorbonne Université wrote: "These findings suggest that this Astragalus-based supplement warrants further investigation for its potential benefits in promoting health, extending life expectancy, and supporting healthy aging."
Telomeres
The aging and lifespan of normal, healthy cells are linked to the so-called telomerase 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.
Study details
The new study used a telomerase activator complex which the researchers referred to as ASTCOQ02. The complex was a blend of Astragalus extracts (250 mg, of which 40 mg was astragaloside IV and 25 mg was cycloastragenol), olive fruit extract (140 mg, of which hydroxytyrosol and its derivatives were 28 mg), zinc oxide (14.46 mg), and grape seed extract (160 mg).
Forty healthy volunteers with an average age of 56 were randomly assigned to receive either ASTCOQ02 or placebo for six months.
The researchers reported that all the volunteers finished the study, and there were no reports of any adverse side effects.
Looking at the telomeres, the data showed that "ASTCOQ02 lengthens both median and short telomeres by increasing telomerase activity and reduces the percentage of short telomeres (<3 kbp)", said the researchers.
Commenting on the potential mechanism(s) of action, the researchers noted that astragalosides have been reported to be metabolized to cycloastragenol, which can activate telomerase, which acts to prevent telomers from shortening and therefore protects the chromosomes.
Hydroxytyrosol from olives has also been reported to exert antioxidative and anti-inflammatory activity, which may also be contributing the observed effects, they said.
"Our study thus opens a novel and effective therapeutic pathway to control telomere length in aging and/or support the prevention of cardiovascular-related diseases," they concluded.