I did some research for these during senior year of undergrad Biology degree. That was 10 years ago. At the time they were very scammy. For example, they might say you had an increased risk of esophageal cancer because of some gene they found. but the study of studies they based this on would be on a group of people in rural China that had a higher than normal rate of esophageal cancer. Not really applicable to standard American. Really making dubious connections was the baseline.