What are anti-vitamins? We are all taught about vitamins, right? I mean how many of us don't know that we need certain vitamins (and minerals) to stay healthy? It can't be that difficult. Just eat a diet rich in fresh fruit and vegetables with a good number of those being raw, and we are well on our way to vibrant health. However, there is one thing that can throw a spanner in the works. They are the anti-vitamins. Antivitamins can be defined as anything that interferes with the beneficial effects of a vitamin in the human body. Back in 1948, Sir Edward Mellanby chaired the fiftieth scientific meeting of the Royal Society of Arts, to discuss Antivitamins in food, so it's not a new concept. In fact, investigations on the effects of anti-vitamins go back to the late 1800s, where investigations on beriberi in the hen showed that an excess of carbohydrates in the diet was the problem which could be counter-acted by additional vitamin B1 in the diet. In this case, the excess carbohydrate in the diet was an anti-vitamin, working against B1. You can read more about the meeting on antivitamins in the 1949, Volume 2, Issue 04 edition of the British Journal of Nutrition. So why aren't we taught about them in schools? I cannot answer that, but I can tell you about some of the important anti-vitamins that we know about today. Phytic acid is found in many different foods including wheat, oats, rye germ and fiber-rich vegetables. Unfortunately phytic acid binds to various minerals like calcium and zinc, making them insoluble in water. It also binds to vitamin B1, preventing its abdorption into the blood. In fact, if corn is improperly stored, a mold can grow which compunds the issue, binding so much B1 that communities reliant on the corn can develop a B1 deficiency leading to a disease called Pellegra. Fermented grains have less (or no) phytic acid so is one way to get around the problem. Another common antivitamin is a group of chemicals called nitrosamines. These are formed in the stomach when we eat nitrates (often used in preserving meats). It's also in beer and cheese. Nitrosamines deplete levels of vitamin A in the liver and this can lead to dry skin. Avidin is a substance found in egg whites. Avidin is a biotin anti-vitamin (and has an important role as such in the developing chick embryo), though it can be destroyed by cooking the egg. As well as these naturally occuring antivitamins in the foods we eat, pharmaceutical drugs can also be causes of vitamin depletion, e.g. * arthritis medications often deplete folic acid.
* blood-thinning medication, including aspirin can destroy vitamin A in the body. * antiobiotics can reduce vitamin K levels. * smokers have lower levels of vitamin C so something in the smoke is a vitamin C antagoonist. I've only really scratched the surface with this discussion, but I am sure you'll agree, we should all be taught this type of nutritional information at school. Further reading: http://juicingtherainbow.com/780/vitamins/antivitamins/