The blood-borne signs of aging – and indeed, perhaps the causes of aging – make three big shifts around the ages of 34, 60 and 78, a new Stanford-led study has discovered, potentially leading to new diagnostic tests and avenues of anti-aging research.
The study measured levels of nearly 3,000 individual proteins in the plasma of small blood samples from 4,263 people aged between 18 and 95, and found that 1,379 of these proteins varied significantly with a subject's age. Indeed, with information about levels of just 373 of these proteins, the researchers found they could predict a subject's age "with great accuracy," and an even smaller subset of just nine proteins could do a "passable" job.
Proteins are the body's workhorses, carrying out instructions from all the body's cells. Changes in their levels in our blood reflect the starting, stopping and changing of different biological processes. The researchers found that these changes were often quite sudden – levels of a protein would remain stable in the blood for years, and then rapidly plunge or leap, rather than showing a steady increase or decline.
What's more, these dramatic changes seemed to be happening in a synchronized fashion, with big changes in multiple proteins showing up around the ages of 34, 60 and 78, pointing to the possibility that the body is significantly changing its biological programming around these ages, and potentially opening up new avenues of research into exactly what's going on, and whether these changes can be stopped, reversed or slowed down to combat the aging process.
Another possible use for this new information could be in assessing the effects or side-effects of medications, which might be causing unintended accelerations or decelerations in these aging processes.
Other interesting findings in the study included the fact that out of the 1,379 proteins that significantly change their levels with age, 895 of them are significantly more age-predictive for one sex than the other, indicating that the aging process operates differently between men and women. This supports the National Institutes of Health in its 2016 policy to promote increased participation of female subjects in aging research, and the use of sex as a biological variable in such studies.
And naturally enough, there were outliers – study participants for whom the blood protein levels predicted much younger ages than were actually the case. And these people, including a number of famously long-lived Ashkenazi Jews, tended to show exceptionally good health, stronger hand grips and better measured cognition than folks with older-looking blood.
The study was published in Nature Medicine.
Source: Stanford