Key Takeaways
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June is Alzheimer’s and Brain Awareness Month, and there’s a lot to talk about. Around 7.4 million Americans age 65 and older are living with Alzheimer’s disease and other dementias. At the same time there has been a lot of new research into the genetics of the disease and how the choices you make can help shape your risk. Here’s a closer look at what’s new.
The importance of APOE
The APOE gene remains a large focus in Alzheimer’s research. There are three common variants of the APOE gene: e2, e3 and e4. Of the three, e4 carries the highest known genetic risk for late-onset Alzheimer’s disease. However, researchers are still actively exploring the nuances of each variant, and some recent findings are prompting the field to rethink assumptions that have stood for decades.
A recent study looked at exactly how much Alzheimer’s disease can be traced back to APOE. Using those with two copies of the e2 variant as the comparison point, researchers found that more than 70% of Alzheimer’s cases were attributable to carrying at least one copy of e3 or e4.
A separate study looked at people who carry two copies of the e4 variant and saw they tend to show biological signs of Alzheimer’s earlier in life, and the path the disease takes is more predictable than in those with other APOE variants. While this study has limitations (including a lack of participants from diverse ancestries), the authors make the case that having two e4 variants is a distinct genetic form of Alzheimer’s, which could mean people with this genetic result might benefit from prevention strategies, clinical trials and treatments built specifically for them.
Towards simpler, earlier Alzheimer’s detection
For a long time, the only way to look for biological signs of Alzheimer’s in the brain was a PET scan or a spinal tap. Both are expensive, hard to access and, in the case of a spinal tap, invasive. But last year a new blood test was approved that changes this.
This blood test measures two well-known hallmarks of the disease called phosphorylated tau (p-tau; a sticky protein that builds up inside brain cells) and amyloid beta (a protein that forms plaques outside brain cells). As treatments and prevention strategies continue to improve, easier testing makes a real difference. The earlier Alzheimer’s can be identified, the more options people have.
What you can do: new research in Alzheimer’s treatment and prevention
For years the message around Alzheimer’s was that there was nothing you could do to prevent it. New research is changing that message.
First, several antiamyloid medications have been approved by the FDA. These drugs can slow Alzheimer’s progression by 25% to 30% when started soon after symptoms appear. However, genetics may play a role in potential side effects from these drugs. People with two copies of the e4 variant in the APOE gene may be more likely to develop side effects including brain swelling or bleeding. Because of this, genetic testing to check for the e4 variant is recommended before starting antiamyloid medications.
In addition to new treatments, a growing body of research suggests that everyday choices can meaningfully shape your risk. The U.S. POINTER study showed that physical and cognitive exercise, diet and regular check-ins on blood pressure and other routine lab results can help slow or prevent cognitive decline.
Diet research is moving fast, but it’s also where the science is still settling. Recent studies have linked specific foods (for example red meat and eggs) to lower Alzheimer’s risk. These are early findings and they don’t always agree with one another, so any single food headline is worth taking with caution. That being said, a diet with plenty of green leafy vegetables, fruits, whole grains and healthy fats such as those found in fish, nuts and olive oil is associated with a reduced risk of developing Alzheimer’s disease.
Some of the stronger recent findings are around vaccines. Large studies have now linked the shingles vaccine, the RSV vaccine and other vaccines to lower dementia risk. Researchers think the protective effect may come less from the specific virus the vaccine targets and more from how these newer vaccines engage the immune system overall. If you’re 50 or older, it may be worth talking to your doctor about whether the shingles or RSV vaccines are right for you.
The bottom line
Alzheimer’s research has hit an inflection point. We understand genes like APOE better than ever. We can detect hallmarks of the disease earlier and less invasively. And we have growing evidence that lifestyle and even routine vaccines may help shape your risk. The story of Alzheimer’s is now one of momentum and hope. Understanding your APOE result can connect you to that story and to the research helping shape what comes next.
While 23andMe does offer APOE e4 testing*, we believe that deciding whether or not you want to learn about genetic information that relates to health risks is a personal choice. 23andMe customers have the option to opt-in or opt-out of receiving health information, and have the further option of opting in or out of the Late-Onset Alzheimer’s Disease Report specifically. If you’re a 23andMe customer and you do not opt in to seeing this information you will not see a Late-Onset Alzheimer’s Disease Report in your account. You can change your decision at any time in your account settings.
We encourage everyone to think carefully about whether to view their Late-Onset Alzheimer’s Disease Report—ultimately, it’s up to the individual to decide. While many 23andMe customers want this information and find it helpful in their health journey, we know that not everyone feels this way. We provide access to this information for those who want it, but also provide mechanisms to ensure those who do not want this information do not have to see it.
* The 23andMe PGS test uses qualitative genotyping to detect select clinically relevant variants in the genomic DNA of adults from saliva to report and interpret genetic health risks. It is not intended to diagnose any disease. Your ethnicity may affect the relevance of each report and how your genetic health risk results are interpreted. Each genetic health risk report describes if a person has variants associated with a higher risk of developing a disease but does not describe a person’s overall risk of developing the disease. The test is not intended to tell you anything about your current state of health or to be used to make medical decisions, including whether or not you should take a medication, how much of a medication you should take, or determine any treatment.
The Late-Onset Alzheimer’s Disease genetic health risk report is indicated for reporting of the e4 variant in the APOE gene. It describes if a person has a variant associated with an increased risk of developing late-onset Alzheimer’s disease. The e4 variant included in this report is found and has been studied in many ethnicities. Detailed risk estimates have been studied the most in people of European descent.
