 Back in the 1990s, a major susceptibility gene was discovered for Alzheimer's called ApoE4. If we have one ApoE4 gene, either from our mom or dad, like about 15% of the US population does, our risk of getting Alzheimer's is tripled. And if we are like one of the 1 in 50 folks who have ApoE4 genes for both parents, we may be at 9 times the risk. The highest frequency of ApoE4 in the world is in Nigeria, but they also have some of the lowest Alzheimer's rates. To understand this paradox, one has to understand the role of ApoE. What does the ApoE gene do? ApoE is the principal cholesterol carrier in the brain. So their diet appeared to have trumped their genes, their low cholesterol levels from their low intake of animal fat, living off most of the grains and vegetables. High ApoE4, but Alzheimer's are rarity thanks, perhaps, to their low cholesterol level, which any of us can achieve eating healthfully too. These findings suggest that long-term changes in plasma cholesterol can lead to changes in ApoE gene expression, just because we may have been dealt some bad genetic cards doesn't mean we can't reshuffle the deck with diet. We can't change our genetic makeup, but we can reduce or prevent high cholesterol. In the study of 1,000 people for over 20 years, ApoE4 doubled the odds of Alzheimer's, but high cholesterol nearly tripled the threat. So the risk for Alzheimer's disease, from treatable factors, elevated cholesterol and blood pressure, appears to be greater than that from the dreaded Alzheimer's susceptibility gene. In fact, projecting from their data, controlling lifestyle factors could reduce a person's risk for Alzheimer's disease, even if they had the double-barreled ApoE4 gene from both parents, from 9 or 10 times the odds down to just 2. People tend to have a fatalistic view about developing Alzheimer's disease. Look, it's going to happen if it's going to happen. But studies like this undermine such a view, which is need to emphasize the need for preventing and treating high blood pressure and cholesterol in the first place to reduce our risk for heart disease, stroke, and Alzheimer's disease, and as a result, potentially enhance quantity and quality of life. Of equal importance, these data should be comforting to anyone interested in attempting to reduce the risk for and future burden of Alzheimer's disease.