How Lifestyle Shapes Genetic Risk For Alzheimer’s
Good news for ApoE4 carriers
Hello, everyone. All this month on BHK we have been discussing the Alzheimer’s risk gene ApoE4. Based on your comments, emails, direct messages on Instagram (and even a few phone calls!) I can tell this topic is hitting home in our BHK community.
Today we are talking about how one’s environment and lifestyle shape genetic risk for Alzheimer’s. For example, Why do ApoE4 carriers who live in Southern Italy and Nigeria have no increased risk of Alzheimer’s…unless, that is, they move to the U.S.? Is it possible to improve the cognitive health of people carrying ApoE4 with lifestyle interventions? And, are there any habits that ApoE4 carriers should be especially careful to avoid?
We’ll get into that, below, and look at how people with ApoE4 fare out in the real world. Plus, don’t miss the paying subscriber discount codes I’ve been sharing this month on organic groceries, my top omega-3 + brain healtlh supplement, fave mushroom matcha and zero-proof drink. I’ve listed them at the end of this post.
Refresh your knowledge about ApoE4 basics here.
You’ll find my takeaways from the recent Nature ApoE4 study here.
Read the full list of 21 Things You Can Do To Lessen The Impact of ApoE4 here.
Epigenetics 101
Epigenetics, in a nutshell, is the study of how genetic material (DNA) behaves in response to environmental factors. By environment, I mean not just where you live but what you eat and your daily habits. In the case of the ApoE4 risk gene, certain habits amplify its activity while others silence it. The idea that genes can get turned on or off, up or down is nothing new—I first learned about epigenetics in medical school over 40 years ago. But the medical field’s understanding of how this applies to risk genes like ApoE4 is really evolving.
Here’s an example of how a simple habit impacts DNA activity at the cellular level. You whisk up a cup of matcha green tea and sip it slowly while you take a break from work. Matcha is a type of green tea that is especially rich in polyphenols. Within minutes your bloodstream is flooded with matcha’s predominant polyphenol—EGCG—which activates the production of methyltransferase enzymes that change DNA activity. When these enzymes go up, DNA gets tagged with a methyl group.
This “methylated DNA” now behaves differently; it no longer “expresses itself” by cranking out certain proteins. In other words, the gene sequence is the same but its activity has been altered. It has become less likely to engage in cellular reactions that are harmful to the brain.
Epigenetic actions can have negative consequences, too, that kick off a cascade of harmful cellular reactions. Both positive and negative epigenetic factors are constantly at work on these specific aspects of brain health:
the production of amyloid and tau proteins
brain inflammation
synaptic function
Think about all the brain-healthy habits you choose throughout the day.
Each time you choose a stress-reducing activity, like hanging out with friends, taking a walk, snacking on berries instead of corn chips, or sipping on coffee, it sets off a cascade of chemical reactions at the cellular level. Your genetic activity is not set in stone like the words printed in a book. It’s more like a document on your computer that is constantly being shaped by tiny edits over time. This pliability of the ApoE4 gene may explain why people who carry it fare differently depending on their environment.
How do people with ApoE4 do out in the real world?
You may recall that the Nature study we discussed recently measured biological Alzheimer’s, not clinically-diagnosed Alzheimer’s. That’s great for trying to develop a drug that targets plaques and tangles in a research setting, but not as helpful to determine the risk of actually getting dementia. I am giving you the takeaways up top; read on to learn about the five studies that evaluated the impact of lifestyle on ApoE4s.