" 
 :The apparent conflict in results is discussed in Parkin & Boyd 2011  (see the Discussion section). The Key result is directly addressed. The heterogenaety of some of the groups is thought to have masked effects. Treating all fruits and vegetables as equivalent was not helpful, particularly as the best candidate components are not common. Indeed for mustard oils and garlic oils, their strong flavours tend to be polarizing factors: some people love them, others hate them. (It's almost sterotypical that some children would rather go to bed hungry than eat brocolli, brussel sprouts, or cabbage.)   "