Observational studies on fruit and vegetable intake may be confounded by other healthy behaviors.

“is it non-smokers non-smokers more likely to exercise more likely to be in the sun higher community higher socioeconomic status more regular doctor visits for uh for mammograms and rectal exams and colon cancer screening and so when people are doing these surveys they will often these surveys will get these epidemiology studies will often get reposted to the internet”