 So we now come to our third fat soluble vitamin, vitamin E, which was discovered in 1922. This was very much the age of vitamin discovery. And you'll recall that I mentioned vitamins were being discovered back then from the perspective of the deficiency disease that their absence created. And so for the longest time vitamin E was known as this vitamin in search of a disease because they couldn't find a disease present when vitamin E was deficient. And there were a few theories, possibly cardiovascular disease, maybe infant nutrition, but it wasn't until 1983 that vitamin E finally became recognized as essential for human health. We'll discuss why it's essential on the next slide. But vitamin E is effectively a two families of compounds. We have tocoferols and toco-triannols. And in each of those families or classes of compounds, we have four children, if you will, alpha, beta, gamma, and delta. Okay? Now, what's the difference between tocoferols and toco-triannols? It's chemistry basically. For those interested in that, tocoferols have a saturated tail and toco-triannols have an unsaturated tail. That's the difference. And the alpha, beta, gamma, delta has to do with where the methyl group is attached in the compound, if you're interested in that level of chemical detail. Now, of all the vitamin E compounds or let's say, vitaminers, it's alpha tocoferol that we find the most biological activity. And in fact, that's the only form of vitamin E that we find in human tissue. And it happens to be the only form that's recognized as valuable in human nutrition. Scientists kind of dismiss the other compounds. And in fact, that's where all the research is gone into. It's alpha tocoferol that gets all the research. Does that mean the other compounds aren't valuable in human nutrition? I think not, if nature provided them. But clearly it needs more research. And that kind of thing just doesn't get funding because there's not a lot of money in it. Nonetheless, it's kind of interesting to note, normally when we heat foods, we degrade some of the nutrients. And when we freeze foods, we preserve them. But in the case of vitamin E rich foods, freezing actually destroys 80% of the vitamin E. So we look at food sources, nuts and seeds, particularly sunflower seeds, almonds, very good sources and their oils as long as those oils are cold pressed. Whenever we industrialize seed oils, there's no vitamin E content to speak of. We're talking about olives, avocado oil and avocados themselves, sweet potato spinach. We're also talking about wheat germ. It's not on this slide, but wheat germ is a really high source of vitamin E. If you enjoyed this video, please give it a like and subscribe below so you don't miss any future content. To learn more about CNM or its courses, head to www.naturopathy-uk.com.