A gene named APOE4 is the bad guy when it comes to Alzheimer’s disease, which plagues an estimated five million Americans. It is present in half of all Alzheimer’s patients, and in 15 percent of the general population, putting them at risk of this common form of senile dementia.
But it looks like there’s a way to neutralize this villain. Tel Aviv University Prof. Daniel Michaelson developed animal models to investigate the effects of diet and environment on carriers of APOE4. In experiments performed on mice, researchers in Michaelson’s neurobiology lab demonstrated that eating foods high in omega 3 oils (such as fatty fish) and low in cholesterol appears to significantly reduce the negative effects of the gene.
Good genes, bad genes
APOE, created by the apolipoprotein E. gene found in all humans, comes in two forms: a “good” APOE gene and a “bad” APOE gene, or APOE4. In differentiating between the good and bad variants, Michaelson and his team studied many variables. They provided a stimulating environment for the lab mice, with running wheels and tubes, ropes and other toys. Those mice carrying the “good” APOE gene formed new nerve connections in their brains. Surprisingly, the same environment caused the death of brain neurons in APOE4 carriers.
“Conditions that are generally considered good can be harmful if the mouse is a carrier of the APOE4 gene. Extrapolating this to the human population, individuals with the ‘bad’ APOE4 gene are more susceptible to stress caused by an environment that stimulates their brain,” says Michaelson, who has been researching Alzheimer’s disease over the past 15 years with support from the Joseph and Inez Eichenbaum Foundation of Beverly Hills. This would contradict currently accepted wisdom that a stimulating environment staves off the disease.
The neurobiologist originally wrote an article about the topic of APOE in the Journal of Neuroscience in 2008. Now, he expanded his research to study the effect of diet on the gene.
Under a joint European Commission grant, Michaelson and European colleagues constructed an experiment to see how three different dietary approaches – a “normal” diet, a “bad” diet high in cholesterol and a “good” diet high in fish oil – would affect APOE, which is a lipoprotein and known to be influenced by omega 3 oils.
“The main take-away message here is that good diets can alleviate the effects of bad genes,” says Michaelson. “Of course nutritionists have had this general idea for a while, but it’s nice to be able to show that this approach can be applied to specifically counteract the negative effects of Alzheimer’s disease-related genes.”
The results of the experiment will be presented at an international conference in Barcelona, Spain, next month.