November 19 (HealthDay News) -- Genetic biomarkers that are highly accurate in determining physiological age have been identified by researchers at California's Buck Institute for Age Research, who said it may be possible to use these biomarkers to test anti-aging drugs.

The study, which included nematode worms, microarrays that measure changes in gene expression, and complex computer algorithms, was published in the Nov. 20 online edition of Aging Cell.

Chronological age (time from birth) and physiological age (level of function) are rarely in sync, the researchers noted. It's easy to determine chronological age simply by counting forward from birth. But physiological age is more subjective. For example, some 70-year-old people function at the level of someone in their 50s, while other 70-year-olds seem prematurely aged. The same is true of the nematode worms used in the study.

The Buck Institute team conducted individual whole-genome profiles of 104 worms and correlated the results with age-related behavior and survival. The researchers identified a suite of genes actively involved in the aging process.

"This is the first evidence that physiological age can be predicted non-subjectively. This is a first step; our results were not perfect, but we were able to predict the ages of the animals 70 percent of the time, which is far better than anything that has been done before," study author Simon Melov said in a Buck Institute news release.

In humans, being able to examine aging-related biomarkers could help determine if a person is aging faster or slower than would normally be expected. In addition, examining such biomarkers over time would provide a scientific baseline for clinical trials of anti-aging drugs.

"I am optimistic that we will be able to pursue this line of research further," Melov said. "Research into the biology of aging in humans has been hampered by the lack of irrefutable biomarkers that correlate with the aging process. I am confident that at some point, there will be a non-subjective method of determining how old someone is with a high level of confidence."

SOURCE: Buck Institute for Age Research, news release, Nov. 19, 2008