Fruit and vegetables are on top of any list that identifies good foods for sound and diseases-free health. Presence of health boosting nutrients, dietary fiber and phytochemicals make them unique compared to many other staple foods. It is a universally accepted norm that for maintaining good health one must take 4-6 servings of fruits and vegetables daily. True, fruits are also rich in sugars like sucrose, fructose, glucose and organic acids like citric, malic, maleic etc which so far have been considered safe when consumed regularly. The sugar content in fruits can vary from a low of 7% to a high of more than 15% depending on the variety. Fruits like Banana (16%), Grapes (18%), Mango (15%), Apricots (13%, Pineapple (12%) are considered high sugar foods, most others like Watermelon, Cantaloupe, Grapefruits, orange, peach, plum etc having less than 10% sugar.
Sugars in fruits can be a mixture of mostly sucrose, glucose, fructose and maltose. Apricot, Banana, Jack fruit, and Mango are sucrose rich while Sweet Cherries, Grapes and Pomegranate contain more glucose. Fructose rich fruits include Apple,Grapes, Cherries and pears. Does the nature of fruits consumed make any difference as far as the consumer is concerned? Obviously it does, according to some studies recently published from Israel. It appears that consumption of even two servings of fruit juices a day has the potential to cause long term liver damage, attributed to the presence of fructose. Probably the fact that metabolic route of fructose, different from that of glucose, is supposed to explain the basis for such a finding. Fructose is metabolized only in the liver and too much of it may produce fat, causing non-alcoholic fatty liver. First observed with fizz drinks based on HFCS, freshly squeezed fruit juices were also found to cause liver damage if taken in 'large' quantities, about two glasses a day.
Studies such as the above raises more questions regarding the age old practice of drinking fruit juices for good health. If fructose is the real culprit, juices from such fruits like Apple, Grapes, Pears etc, which are rich in this sugar could be more dangerous if consumed regularly! Also not clear is whether only juices cause this problem or even eating whole fruits could be potentially hazardous. Fructose has a low GI of about 19 compared to 100 for glucose and it is doubtful whether human liver does not have the capability to handle low influx of fructose caused by drinking fruit juices. Besides, fructose is a component in sucrose and why the normal consumption of sucrose in the diet should not cause the same problem?
World consumption of sucrose from sugarcane and beets jumped from 11 million tons (mt) at the beginning of the lat century to 130 mt by beginning of this century and the per capita annual consumption is in the range of 16-18 kg in Asia and Africa while North American figure is around 36 kg and in South America it is 47 kg. This works out to an average intake of 50 to 150 gm a day but the proportion of population consuming much above the average figures can be substantial. Are they compromising the health of their liver by taking sugar equivalent to 2 to 6 servings of fruit juices every day?
These findings are bound to cast a shadow on the fruit juice industry and it is unfortunate that a high nutrient product like fruit juice is being bracketed with fizz drinks. Unless more exhaustive studies confirm the claims by the above report from Israel, there is no place for any panic.