Spinach (Spinacia oleracea) is known for its deep green and succulent leaves that are often added to salads. Spinach leaves are nutritionally packed full of essential nutrients including magnesium, vitamin C, vitamin B6, vitamin K, folic acid and iron. In addition, spinach is also a good source of phytochemicals including the carotenoids beta carotene and the xanthophylls lutein and zeaxanthin. These phytochemicals contribute significantly to the antioxidant capacity of the leaves. The beetroot plant (Chenopodiaceae) is related to spinach and its leaves are of a similar nutritional quality and are a useful alternative for salads. Like spinach leaves, beetroot leaves also contain high concentrations of phytochemicals including a number of carotenoids. Magnesium, folic acid, vitamin B6, vitamin C and iron also characterise the nutritional profile of beetroot leaves. Beetroot consumption has traditionally been associated with improvements in bowel function and liver detoxification.
However, beetroot also contains an edible root attached to its edible leaves, and this makes almost the entire plant available for consumption. The carbohydrate content (10 grams) of beetroot comprises mainly of sugar (8 grams), however the presence of high amounts of fibre and a high water content nullify any negative health effects associated with simple sugars. The purple colour of the root is due to the presence of betalains, pigments present in a number of plants (including beetroot, carnations and cacti) that replace the normal purple anthocyanin pigments common to most plants. Betalains differ from anthocyanins in that the former contains a nitrogen within their structure. Betalains can be further split into the subclasses betacyanins and betaxanthins. Evidence suggests that antioxidant effects of betacyanins may explain the ability of beetroot to protect from colon cancer. Betacyanins may also be able to lower plasma cholesterol levels.