simonineaston wrote:A mate of mine has always made a wry comment when offered marg., which is, "No Thanks - I'm not putting anything in my tummy that's just a couple of molecules away from plastic!" I always thought she was using artistic licence, so I'm amused to learn she has been right all this time...
That assertion is fairly meaningless though and could be applied to a lot of natural products we eat (and marg is still derived from a natural product). Plastic or polymer chains are essentially complex chains of lipids so what separates plastics from the oils that we eat are a few chemical bonds. What's said about marge could be generalised to any oil or fat.
Food scientists have tried to use this feature to make calorie free cooking oil. Our digestive tract has evolved to digest what nature produces so by tweaking the orientation of one or two chemical bonds it is possible to produce an oil we can't digest but still behaves with the same physical properties as a cooking oil, and still tastes the same as a cooking oil.
Food scientists did in fact succeed but their product had unfortunate unintended side effects. An oil that passes unchanged through the digestive tract must eventually emerge at the other end. I'll leave the rest to your imagination.
For a successful technology, reality must take precedence over public relations, for nature cannot be fooled - Richard Feynman