Pioneering studies of post-mortem brain tissues have yielded the first evidence of a potential association between Alzheimer’s disease and the epigenetic alteration of gene function. The researchers stress, however, that more research is needed to find out if the changes play a causal role in the disease or occur as a result of it.

We already have some evidence that the risk of developing Alzheimer’s might be elevated by poor diet, lack of exercise, and inflammatory conditions such as diabetes, obesity and clogging of blood vessels with fatty deposits. The new research hints that the lifestyle changes that raise Alzheimer’s risk may be taking effect through epigenetic changes.

The idea is strengthened by the fact that the brain tissue samples studied in the new work came from hundreds of people, many of whom had Alzheimer’s when they died, and that a number of genes identified were found by two teams working independently, one in the UK and one in the US.

“The results are compelling and consistent across four cohorts of patients taken across the two studies,” says Jonathan Mill at the University of Exeter, who led the UK-based team. “It’s illuminated new genetic pathways affecting the disease and, given the lack of success tackling Alzheimer’s so far, new leads are going to be vital.”

“We can now focus our efforts on understanding how these genes are associated with the disease,” says Philip De Jager of the Brigham and Women’s Hospital in Boston, who headed the US team.

That might not be easy. Because the samples came from the brains of people who had died, the researchers cannot say yet whether the gene changes help cause the disease, or occur as a result of it. One Alzheimer’s researcher not involved in the study even wonders whether the epigenetic changes are simply a natural part of ageing.

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