Wednesday, October 21, 2009

Food additive that destroys your vitamin E

Sodium Bisulfite as food additive number E 222. It is a very common preservative, it is found in nearly all wines as it is added to halt fermentation, and prevent the wine going off. It is also used in dehydrated fruit to stop them browning, hence why some dried apricots are bright orange and others brown. The bright orange ones have been processed with sodium bisulfite. It is also found in things such as sauces, gravys jams and preserves though to frozen food pastries. So you can see that this is found in a large range of food stuffs. Further foods containing sodium bisulfite can be found here.

How does this relate to vitamins? Good question, when  vitamins were first studied they used laboratory animals to recreate the vitamin deficiency so that they could study the signs and effects of the vitamin deficiency. The animals were also used to test vitamin levels in various foods. Once the proposed vitamin had be extracted from food, or artificially created in a lab it could be fed to the animal to determine if this compound reversed the deficiency disease thus allowing the chemical structure of the vitamin to be found. One of the problems with this method is that it took a long time for the animal to use up there reserves of the vitamin and show clinical deficiency signs. For example vitamin B deficiency showed up quickly, but it was still 1 - 3 months before it showed up. For fat soluble vitamins who's body storage is much higher than B vitamins, it could be 10 months or more before they showed signs of deficiency disease. The photograph below is a swan that has vitamin E deficiency, as you can see it has trouble holding its head up in the right spot.

Clearly it is difficult to study something if you are waiting 10 months before you can start your experiment and if you have trace amounts of the vitamin still in the animal food you might not get deficiency disease at all and you would have to wait a year to figure this out. Therefore it became important to have ways to accelerate the vitamin loss. In 1955 they found such a thing. They found that sodium bisulfite accelerated the time taken for chicks to show signs of vitamin E deficiency.

I am amazed that sodium bisulfite is allowed into our food. This is because vitamin E is the hardest vitamin to get your RDI intake. And we are allowing a chemical into our food that destroys our vitamin E. If this is not a sign of madness I don't know what is.   

References:
Miller et al Studies on the effect of sodium bisulfite on the stability of vitamin E, Journal of Nutrition vol 55 no 1 1955
McCarthy and Cerecedo Vitamin deficiency in the mouse Journal of Nutrition
McCarrison Studies in Deficiency disease Oxford Medical Publications 1929

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