Young blood has been given to people with Alzheimer’s in a very small clinical trial to see if it helps treat the condition. No, this is not a macabre Halloween joke but a real, if somewhat controversial, study about the impact of parabiosis in curing the degenerative disease.

The motivation for the study was based on recent findings that this young blood trick worked in rejuvenating the brain tissue of older mice. Those findings are not easily translatable into an “Alzheimer's cure”, especially since this approach doesn’t take into account what is believed to be the cause of the disease – brain plaques and tangles due to an accumulation of certain molecules.

“Alzheimer’s patients don’t want to wait until the exact mode of action is discovered,” team co-leader Professor Tony Wyss-Coray, from Stanford University, told Nature.

The findings of the trial will be officially announced on November 4 at the 10th Clinical Trials on Alzheimer’s Disease conference in Boston, Massachusetts. But the results in humans are not as groundbreaking as one might have hoped. There were no significant changes in cognitive skills, but daily living skills may have improved somewhat. The test did show that the trial was at least safe, with none of the 18 participants suffering any adverse effects.

The goal of the trial was to increase the level of growth differentiation factor 11 (GDF11) in older people. GDF11 is a protein found in blood plasma and its decrease (in both humans and mice) is claimed to be linked to aging.

“The scientific basis for the trial is simply not there,” Professor Irina Conboy, a neurologist at the University of California Berkeley, added in the Nature piece. “The effects of young blood on cognition have not been replicated by an independent group, and there has never been a test with a mouse model of Alzheimer’s."

The medical trial was conducted on 18 people, aged between 54 and 86, with mild to moderate Alzheimer’s disease. They received a weekly injection for four weeks of either saline solution (for the control) or plasma. The plasma was given by blood donors aged 18 to 30. New Scientist reports that several particpants dropped out, with other scientists questioning the validity of the results.  

This is not the first trial to study the effect of young blood to halt or reverse aging in humans. One last year asked participants to pay $8,000 dollars to be involved.

[H/T: Nature]