You can also choose to opt out of just the Alzheimer's and Parkinson's reports. Because the two neurodegenerative diseases have few treatments, getting the report could cause more anxiety than necessary.

23andMe

On these two, I opted to defer. I made the decision after speaking with representatives from patient groups in 2017, who clarified what the reports could tell me and what I might want to do before looking at them.

For both Parkinson's and Alzheimer's, age is a bigger risk factor than genetics. With Parkinson's, if I had a variant related to the disease, my risk of getting the disease would certainly be increased, but not by much.

Keith Fargo, the Alzheimer's Association director of scientific programs and outreach, told Business Insider in 2017 that the Alzheimer's report, which would tell me whether I had a mutation on my APOE gene, was more useful in the context of research than it was for predicting who might get the disease. And as I mentioned, I had allowed 23andMe to use my DNA for research purposes, so it was already getting put to use.

I also kept in mind my family history of one of these diseases. If I decide to view my results, I will plan on speaking with a genetic counselor before proceeding.

Another factor I noted was life insurance, something 23andMe's report brings up as well. While genetic testing can't prevent you from getting health insurance, life-insurance policies can use the information to deny your application. Since my results won't be changing, I decided it would make the most sense to wait to get the results until I get life insurance. As long as I don't know, there shouldn't be a way for life insurers to find out.