Researchers at the University of Maine have identified a gene that is linked to high homocysteine and lower cognitive performance.
A link between high levels of the amino acid homocysteine in the blood and lower cognitive performance has already been established.
Now, the new study has provided evidence that the presence of a particular variant of a neuron-repairing gene may increase the risk of lowered cognitive performance.
Merrill F. 'Pete' Elias, Michael A. Robbins and Penelope K. Elias,professors in the department of psychology at the University of Maine, and their co-researchers looked at the relationships among the gene ApoE, homocysteine concentrations, and cognitive performance.
They discovered that stroke and dementia-free people with higher homocysteine levels, in addition to carrying one or more of the ApoE-å4 alleles, performed at lower levels on multiple measures of cognition than people with other variations of the ApoE-å4 gene.
An allele is any one of several possible gene variants.
"The importance of our recent paper in Neuroscience Letters is that we find that the combination of elevated homocysteine and the presence of the ApoE-å4 allele represent a higher degree of risk for lower cognitive performance than the presence of either risk factor alone," says Merrill Elias.
Elias noted that carriers of the ApoE-å4 allele 'might be thought of as having a less effective neuronal repair capability. There currently is no practical way that one can modify the ApoE-å4 alleles so that they do a better job of repairing brain cells."
"But there is hope for prevention and reversal of cognitive deficit related to elevated homocysteine by reducing homocysteine levels," he added.
Robbins added that vitamin supplementation might be among the important ways of achieving these goals.
The study is published in the January 2008 issue of Neuroscience Letters, a peer-reviewed science journal.