The problems comes from a type of sugar that is found in fruit – fructose. Research is now showing that fructose may not be as healthy as once thought and may actually cause more harm than good.
A study published in the journal Cancer Research found that refined fructose caused cancer cells to proliferate (not good) – however not directly attributed to fruit consumption but to high fructose corn syrup (more on this later). Fructose consumption has also been linked to a condition known as fatty liver – like that seen in alcoholic liver damage. Research is showing that high carbohydrate diets and not high protein or high fat diets can actually lead to this fatty liver disease (although this research was carried out in mice not humans).
The American Heart Association have demonstrated that 200g of fructose on top of a normal diet demonstrated notable changes in triglyceride levels, insulin levels and measures of insulin resistance, as well as lowering in supposedly ‘healthy’ HDL levels. All of this is not good.
What seems to be the problem here is a substance called high fructose corn syrup – a cheap form of processed sugar made from corn. This gets added to foods as a sweetener but it really is the worst possible thing you could.
Now back to fruit, although good for you it’s probably not a wise idea to be eating unlimited portions of fruit per day as this will lead to excess fructose consumption and some of the deleterious health effects. Experts are suggesting that most sedentary people consume no more than 5g of fructose per day which is roughly 2 portions of fruit (i.e. and apple and a pear, or a banana and a serving of berries for example). If you are more active you might be able to eat 3 potions a day. But the take home point from this is to consume more portions for vegetables to get you “5 a day” (what should actually be your” 7-9 a day”).
Tomorrow I’m going to talk about fruit juice.