You should be careful taking the conclusions of single studies too seriously. Due to the methods underlying statistical significance testing, results from signal studies are highly unreliable and should be taken with a large grain of salt.
Additionally, the study you linked is not an intervention, therefore there is a high likelihood that unknown covariates had an impact on the observed group differences.
Of course, one's scepticism should be in proportion to an intervention's risk, and eating more fruit and vegetables seems, naively, quite low risk.
It might stop them from unleashing anticommunist terrorism all around Europe (e.g. gladio in Italy).