Refined Carbohydrate Intake Increases Alzheimer’s Risk in ApoE4 Carriers

by Amylee Amos PhD, RDN, IFMCPNews
Box of partially eaten doughnuts

It is well established in the research that genetic predisposition, including carrying one or two copies of ApoE4, plays an important role in determining the risk of developing Alzheimer’s disease. Unfortunately, that is often the only focus of talk surrounding genetics and chronic disease. However, the reality of how this works is far more complex. More important than our genetic makeup is the influence of environmental factors on these genes. Our environment, meaning our diet, exercise, and sleep habits, our stress level, and our exposure to toxins directly affects the expression of our genes, and thus affects our disease risk. This concept, known as epigenetics, refers to changes caused by modification of gene expression rather than alteration of the genetic code itself.

Epigenetics and the influence of environment on disease risk and development is being extensively studied. A studied published earlier this month in the journal Alzheimer’s & Dementia investigated the impact of glycemic load on the risk of Alzheimer’s disease. This epidemiological study out of the French National Institute of Health and Medical Research and the University of Montpellier followed 2,777 French older adults over the course of 12 years. They analyzed their diets and determined the glycemic load, a measure of how much consumption of a certain food will raise an individual’s blood glucose. They used glycemic load as a means of assessing the participants’ intake of refined carbohydrates.

Though the scientific community has established through basic science and previous research that high intake of sugar and refined carbohydrates certainly plays a part in the development of Alzheimer’s disease, in particular Type 1.5 “Glycotoxic” Alzheimer’s, the interaction between high intake of refined carbohydrates and ApoE4 were previously unclear.Researchers of this study found that ApoE4 carriers who ate an afternoon snack with a high glycemic load were twofold to threefold more likely to develop dementia or Alzheimer's disease after 12 years, compared with those who didn't eat such snacks.This correlation was independent of possible confounding factors such as energy intake, physical activity, or comorbidities. The researchers speculate that the reason for this correlation involves the metabolic complications of insulin resistance, which occurs as a result of a high refined carbohydrate and sugar diet.

This type of research is further proof that we can influence our likelihood of developing chronic diseases such as Alzheimer’s by modifying our diet and lifestyle. By understanding how our genetic variants impact our metabolism, we can personalize nutrition plans to specifically optimize our health and aid in disease prevention. Our genes do not hardwire us for chronic disease. Instead they offer a menu of what we can be under different environmental conditions. We have a choice in what we get. And every day, at every stage of our lives, we send our genes information to guide that choice- to determine which menu option we get. And those messages come from our diet, our lifestyle, our physical environment and our mental environment. While more research is always needed, this study is a great reason to lower your glycemic load by reducing your intake of refined carbohydrates and sugars, especially if you carry ApoE4!


Gentreau, M, Chuy, V, Féart, C, et al. Refined carbohydrate‐rich diet is associated with long‐term risk of dementia and Alzheimer's disease in apolipoprotein E ε4 allele carriers.Alzheimer's Dement. 2020; 1– 11.