I bought a book entitled "What color is your diet?" last year. Written by the director of the UCLA center for human nutrition, it contains lots of useful information on the properties of foods and how they impact the body. It explains the major differences in diets across the world and how these influence the incidence of cancer, heart disease and other health problems.
The book suggests that to stay healthy and reduce the risk of cancer etc we should eat not 5, but at least 7 portions of fruit and veg each day. It presents 7 colour categories and provides a list of fruit and veg that fall into each category. Each colour is important for a different reason and the book recommends that we eat at least one item of each colour every day.
At present I do not eat the 7 colours or even 7 portions of fruit and veg each day, but I do consider this to be my goal. Even ignoring the possible health benefits it will make for a varied and interesting diet and encourage me to grow some more unusual fruit and vegetables.
Each recipe that I post contains the number of colours that it includes in brackets.
THE RED GROUP
The red colour group contains no vegetables and only four fruits. However, it is probably one of the easiest groups to eat every day as it contains what is often a staple food in cooking: the tomato. Also in the red group are watermelons, pink grapefruits and red papayas.
Each of these fruits contain the powerful antioxidant lycopene. Lycopene has been considered a potential agent for the prevention of some types of cancers, particularly prostate cancer. It is more available from cooked tomato products and juices than raw tomatoes and over 80% of lycopene in the American diet comes from just four products: tomato soup, pasta sauce, tomato ketchup and tomato juice. Lycopene is now also available as a dietary supplement.
THE WHITE/GREEN GROUP
The white/green colour group includes garlic, onions, spring onions, leeks, celery, pears, white wine, endive, artichokes, asparagus and chives. Plants in the onion family contain allicin, which has been shown to have anti-tumour effects. Foods in this group are also rich sources of flavonoids, which when consumed result in a reaction by the body involving an increase in the antioxidant capacity of the blood. This in turn plays a role in the prevention of cancers and of cardiovascular disease.
THE ORANGE GROUP
The orange colour group provide alpha- and beta-carotenes. Foods in the orange colour group include carrots, pumpkins, sweet potatoes, acorn squash, winter squash, cantaloupe melons, mangos and apricots (but not oranges!).
Of these, carrots and sweet potatoes can be considered "star foods" from a health-perspective. Carrots are high in antioxidants and protect the body from certain types of cancer. They boost the immune system and are useful in treating a range of ailments, from poor night vision to stomach ulcers. I shall write a separate post about the sweet potato another time.
THE ORANGE/YELLOW GROUP
The orange/yellow colour group includes oranges, orange juice, tangerines/satsumas/clementines, kumquats, guava, lemons, nectarines, papayas, peaches, pineapple, starfruit, yellow grapefruit and yellow passionfruit. These provide beta-cryptothanxin, a a carotenoid that helps with vitamin and mineral exchange between cells.
THE RED/PURPLE GROUP
The red/purple group contains a huge array of fruits including cherries, figs, lychee, plums, prunes, purple passionfruit, pomegranates, red apples, red grapes (and red wine), red pears and a number of berries including cranberries, blueberries, blackberries and strawberries. It also contains aubergines, beetroots, red cabbage, red onions and red peppers. These contain anthocyanins, powerful antioxidants that may have a beneficial effect on heart disease.
THE GREEN GROUP
The green group contains only vegetables and includes broccoli, Brussels sprouts, cabbage, chinese cabbage (bok choi), cauliflower, kale and swiss chard. These stimulate the genes in your liver to turn on the production of enzymes that break down the cancer-causing chemicals in the body.
THE YELLOW/GREEN GROUP
The yellow/green group contains mostly vegetables, but also includes kiwi fruit, avacados and honeydew melons. The vegetables include courgettes, cucumber, green beans, green peppers, peas, romaine lettuce, spinach, sweetcorn, yellow peppers and mustard or turnip greens. These contain carotenoids that contribute to eye health. Lower intakes have been associated with cataracts and a condition that causes blindness.