One of the most important genes you should know about is your ApoE gene. ApoE is an acronym that stands for apolipoprotein E, which is a protein that combines with fat to make a lipoprotein. A lipoprotein transports fats such as cholesterol and triglycerides that are in your bloodstream to their destination, which is usually the liver or fat stores. Variations in your ApoE genes can predict your risk for heart attack or stroke. They have also been associated with developing late stage Alzheimer’s disease and some other chronic illnesses.
To better understand the effect genes have on our health it is important to review genetics 101. The body has trillions of cells and each cell contains a code called deoxyribonucleic acid (DNA). DNA is a set of instructions that runs the body. If you think of DNA as a cookbook, then your genes are the recipes that your body uses to function and make you look the way you do. For instance, one recipe may give you curly hair and another recipe may make brain cells or blood cells. One complete set of DNA is called its genome and every cell in your body contains a complete set of DNA instructions. Everyone inherits one strand of DNA from each of their parents and therefore has two strands of DNA in each cell. Because of this there are numerous combinations of DNA that can be inherited when born.
As we age cells divide and replicate throughout our lifespan. When cells divide, they copy the DNA instructions for the new cell. But sometimes mistakes occur in these copies, leading to variations in DNA. These “typos” are called single nucleotide polymorphisms (SNPs – pronounced snips). SNPs are altered recipes that can confirm how closely related people are and influence risk for a disease or response to a drug.
So ApoE genes control the metabolism of cholesterol and triglycerides. There are 3 common SNPs of the ApoE gene – ApoE2, ApoE3, and ApoE4. Each person carries 2 copies of the ApoE gene and can have one of 6 possible ApoE combinations. ApoE3 is the most common SNP and most people have an ApoE3/ApoE3 combination. However, different SNP combinations can occur. For example, having a combination of ApoE4/ApoE4 increases a persons risk for late-onset Alzheimers disease by 25%. For those who already have Alzheimer’s disease and take medications to manage it, lacking at least one ApoE4 SNP makes this drug ineffective in their treatment.
Combinations of ApoE SNPs can also confirm the best type of diet an individual should be eating. For instance, individuals who have the combination of ApoE2/ApoE4 show an increased risk for heart attack if they eat a high fat diet. Other combinations decrease their risk when eating a high fat diet. Knowing your ApoE genes and working with a registered dietitian who is skilled in functional and integrative nutrition can guide you to eat the right diet for your genetic make-up. Testing for ApoE is a simple blood test and widely available. So at your next check up talk to your doctor about learning about your ApoE genes.