 Now, of course, when we eat food, you may think that we're most interested in the proteins, the carbohydrates, the fats, and of course the vitamins and the minerals as well. But when you eat a natural product, a plant, whether it's a tomato, bell pepper, broccoli, oats or whatever, what you often don't realise is that you're also eating all of these secondary metabolites as well. You can't avoid it. They're all parceled up together. And that partly, of course, that will come into this discussion at a certain point. And that partly, of course, is the way that we keep healthy as well because we're getting small amounts of very important chemicals, quercetin, for example, in almost every meal that we eat. So if we eat a plant-based diet, and I cannot stress this too highly, you are probably getting all the food and the medicine that you need. It reminds us, does it not, of Hippocrates' famous dictum, let food be thy medicine and medicine be thy food. So there is a very fine line between herbs and foods where this is concerned. We're going to be staying mainly on the herbal side of that line because that's what we need to know as herbal practitioners. But we can never entirely separate the two things apart, as you'll see. So what do these substances do in our bodies? They function as antioxidants. You've probably heard that term a million times. These are things which prevent oxidative damage, which causes aging, of course, and the gradual degeneration, if you like, of tissues and organs in our body. Very, very important. This is one of the big reasons for eating a plant-based diet because of the antioxidants. They regulate the cell cycle, and that's really important. At a certain point in level three, we'll be talking about cancer, and there's a thing called the cell cycle checkpoints where, as a cell divides in a natural process of repair, you know, repair of tissues, it goes through a number of stages, and at each stage it's important that something is checking what's going on to make sure that it's not mutating in some way. And it's thought that part of the mechanism of producing cancer is that these cell cycle checks don't work so well. So again, we find that many of our plant chemicals have what we call desmutagenic or anti-cancer effects and partly, perhaps, due to this ability to regulate the cell cycle. Plant chemicals also increase the detoxification of carcinogenic compounds in the body and other toxic compounds. So in other words, they're much, much involved, particularly the bitters, in getting rid of stuff that we don't need to be hanging around inside us. They reduce DNA damage, which of course is very important, again, for protecting against cancer and keeping tissues healthy and robust and well-functioning into old age. And sometimes, of course, as we'll find, they also mimic or interact with natural hormones inside our bodies. So there's a class of plant chemicals that we call phytoestrogens, that's plant estrogens, which are very, very useful in treating certain complaints, particularly of the female, but also sometimes of the male physiology.