Having found out how education or so-called cognitive stimulation slows brain degeneration, the studies from Tsai’s group bring hope of a drug therapy that could also help the process. They found that the epigenetic processes involved in Alzheimer’s can be interrupted and reversed using a chemical called sodium butyrate. This drug blocks the enzyme that removes acetyl groups from the histone proteins within chromatin, leading to increased histone acetylation levels. The results of administering sodium butyrate showed an improvement in cognitive ability and memory recall in Alzheimer mice, that was about as effective as rearing mice in environmentally enriched conditions. Even better results came from the combined use of environmental enrichment and sodium butyrate.

Paradoxically, the most recent paper by Tsai’s group discusses the beneficial effects of increasing acetyl group-removing enzyme. In theory, this would reduce histone acetylation. However, there are three distinct classes (each comprised of several types) of enzyme that carry out this task, and sodium butyrate only blocks two classes of them.  The enzyme SirT1 belongs to a third class, and stimulation of its production improves the cognitive ability of Alzheimer’s-affected mice. This enzyme is stimulated during famine or other stressful conditions and apparently activates pathways that delay aging. However, we do not yet fully understand how it works. One complicating issue is that SirT1 doesn’t only work on histones, but also other proteins, including the p53 “guardian angel” protein that regulates a cell’s life and stops it becoming cancerous. Because of this, we don’t know whether the beneficial effects occur because of a decrease in histone acetylation, or some other reason not yet known. Whatever the mechanism, the results are promising. Many natural foods contain a SirT1 enhancing molecule called resveratrol, including red grapes, cranberries and Japanese knotweed. This molecule is currently being explored by pharmaceutical companies as a potential future medicine for Alzheimer’s disease.