Use Ancestry.com instead. Ancestry asks if you want to be part of x y z. Say no to all. Also opt for Ancestry to destroy your sample. Once your test is completed, download the raw data file. Then request your data and account to be deleted.

You can then use services like Promethease to give you information on any potential genetic issues.

I don't know if 23 and me offers the same level of privacy as only have experience with Ancestry.com.

Make sure whichever service you use, you read the privacy statement.