What are the health benefits of red onions? These little beauties find their way in to many of the dishes that I cook. Not only do they provide the ideal base not flavours for almost any savoury dish, but they also have some wonderful health benefits too!
Red onions are very rich in a group of compounds called flavonoids. These are part of the chemistry that gives them their vivid purple colouration. These compounds are beneficial for the health of the cardiovascular system. This is because they have an effect upon the endothelium – the highly physiologically active inner skin that lines our blood vessels. Flavonoids get taken up by the endothelial cells that make up the endothelium, and cause metabolic distress within these cells. When this happens, the endothelial cells are stimulated to release something called Nitric Oxide. This is something they release naturally for regulating blood pressure, but flavonoids almost force the process. Nitric Oxide, when released by endothelial cells, moves out into the musculature of the vessel walls and causes these muscles to relax. As these muscles relax, the vessel gets bigger. As it gets bigger, the pressure within it drops. In short – flavonoids can have a temporary lowering effect upon blood pressure. Flavonoids can also help to increase the resilience of the endothelium against inflammatory damage. Damage that can set the stage for heart disease.
Digestive system health
Onions, like all of the Alliums, are rich in a compound called inulin. It is a potent prebiotic. This basically means that it works as a food source for the good bacteria that live in our gut. These bacteria are involved in so many processes it is almost unbelievable. The most obvious is their role in digestion. They help to regulate peristalsis, breakdown components of our food, and even synthesise certain micronutrients. Probably the most exciting benefit that is now becoming more widely understood is their influence on immunity. Our gut contains a great deal of lymphatic tissue filled with white blood cells. These areas of lymphatic tissue are like surveillance stations, continually monitoring gut contents and then relaying messages, via chemicals called cytokines, to the rest of the immune system. Our inherent gut flora can interact with this local white cell population and influence the immune system systemically. So, nurturing our gut flora is pretty darn important. When gut bacteria feed on inulin found in foods such as onions, they start to reproduce and increase in numbers. As they feed on it and ferment it, they also secrete compounds that help repair the gut lining and regulate movement through the gut. One of the main byproducts of this fermentation is a substance called butyric acid. This can stimulate repair mechanisms within gut tissue.