But surely, people ask, even if there is no evidence that increasing our intake of fruit and vegetables will help prevent disease, they remain good things to eat?
I don’t think so. If people try to add five portions of fruit and veg — let alone eight — a day to their diet, it can be counterproductive. Fruit contains high levels of fructose, or fruit sugar.
Among dieticians, fructose is known as ‘the fattening carbohydrate’. It is not metabolised by the body in the same way as glucose, which enters the bloodstream and has a chance to be used for energy before it heads to the liver.
Fructose goes straight to the liver and is stored as fat. Very few ¬people understand or want to believe this biochemical fact.
Another argument that is often put forward by dieticians on behalf of fruit and vegetables is that they are ‘a source of antioxidants’.
They believe we need to have more ¬antioxidants in our diet to counteract the oxidants that damage the body’s cells, either as a result of normal metabolic processes or as a reaction to environmental chemicals and pollutants.
But I would rather concentrate on not putting oxidants such as sugar, processed food, cigarette smoke or chemicals into my body.