McCartney says that anxious people often contact her, saying they wished they hadn’t done the tests. “These companies often say that it’s worth it for the helpful advice. But I can give you really good advice right now without seeing a single test result: be active, have lots of social networks, do work you enjoy, try not to smoke or drink too much, don’t be overweight or underweight, eat lots of fresh fruit and vegetables. Nobody needs to get tests done to get that kind of basic lifestyle advice.”
To prepare to take a cheek swab sample, you also have to refrain from eating for about an hour before. Swab kits generally contain more components, including one or two swabs and containers to protect the used swabs from contamination. We found it easiest to organize all the pieces first, to prevent any fumbling with a sample collection swab in hand. Some cheek cell kits put a stabilizing liquid in the sample containers, which required extra caution to prevent spilling.
More controversially, some of these kits profess to tell you your biological (as opposed to actual age) by measuring the length of your telomeres (in basic terms, the caps at the end of each strand of DNA that protect chromosomes, like plastic tips at the end of shoelaces). Other tests, such as 23andMe, predict higher risks of developing serious conditions, such as multiple sclerosis, Alzheimer’s and Parkinson’s, including the test for BRCA1/BRCA2 (breast and ovarian cancer) that Angelina Jolie famously underwent, going on to have a preventative double mastectomy and surgery to remove her ovaries.