The media constantly tell us about the latest wonder foods but do they really work? Well some do and others don't.
Yes they do
Kale: a member of the cabbage family, with high levels of vitamins and minerals. ## It lowers blood cholesterol and its good for blood clotting. ## It also contains two pigments we need but cannot produce ourselves - lutein and zeaxanthin. These pigments help protect the macula at the back of the eye. Roughly one in ten of us will suffer from macular degeneration.
Kefir: a fermented milk drink containing probiotics, minerals, vitamins and essential amino acids. ## Good for a healthy gut. Most probiotics contain just one type of bacteria, whereas kefir can have up to 20 different types. Despite having to survive stomach acid, kefir is effective.
Xylitol: a sugar alcohol derived from fruit and vegetables. ## Xylitol helps prevent tooth decay by starving bacteria in your mouth and promoting saliva production. In Finland, most people use it every day and children at nursery school are given it after every meal. Dental records show it has made an impact. You can find it in brands of chewing gums and peppermint sweets.
Blackcurrants: summer fruit high in antioxidants, vitamins and minerals. ## Blackcurrants have 6 to 8 times more antioxidants than blueberries. Blackcurrants work on the cardiovascular system, so good if you are exercising.
Broccoli: member of the brassica family, rich in phytonutrients, flavonoids, vitamins and minerals. ## Some evidence that a particular type, containing high levels of glucoraphanin, helps treat cancer. As glucoraphanin is extremely bitter, a new variety has been bred to get rid of the taste and boost the glucorphanin. It's called Beneforte and available in supermarkets.
Quinoa: gluten-free South American grain containing nine essential amino acids, B vitamins, vitamin E, calcium, magnesium and manganese. ## Very nutritious, it contains protein and a lot of iron and magnesium. Good at regulating blood sugar as it is a slow release carbohydrate. White rice will make your blood sugar go into overdrive, followed by a sugar crash. Quinoa produces a tiny rise in blood sugar level and then returns to normal.
Kippers: smoked herring, a protein rich fish high in Omega 3 fatty acid, calcium and vitamin D. ## We should be eating two portions of oily fish a week and kippers are one of the best sources (after mackerel). The fattest herring are used to make kippers, so you get a good portion of these nutrients.
Spirulina: a nutrient rich algae containing minerals, vitamins and esssential amino acids, and a complete protein. It is a pond algae (not a seaweed). ## It's so nutri-dense that just one spoonful a day gives you enough iron for the day, lots of protein and your daily requirement of B vitamins. It also has anti-inflammatory properties so can alleviate chronic hay-fever.
Sweet potato: a root vegetable high in nutrients including vitamins B, C and D, iron, magnesium, potassium, beta carotene and other carotenoids. ## One sweet potato gives you your daily vitamin A requirement - much more than in carrots. To help your eyesight, eat sweet potatoes twice a week instead of ordinary potatoes as they have 2,000 times as much vitamin A and twice as much vitamin C.
Not effective in normal amounts
Grapefruit: citrus fruit high in vitamin C and the antioxidant lycopene. ## Grapefruit contains naringenin, a compound which flicks a switch in our metabolism to start fat-burning. But to get enough naringenin to do that, you'd have to eat 40 grapefruit in a single sitting.
No they don't
Wheatgrass: young grass of the wheat plant, a natural source of vitamins and minerals. ## Marketed as good for blood oxygenation and energy, it is no better than other vegetables and you are better eating broccoli and kale.
Activated charcoal: specially processed carbon. ## Sometimes found as an ingredient in juice bars, sold as a hangover cure on the basis it is supposed to absorb toxins which are then excreted in your poo. In A&E departments, it is part of conventional treatment for overdoses if administered within an hour of the overdose. The amount given as medical treatment is huge; what you get in a juice bar is negligible.
Feature in Radio Times, 27 June - 3 July 2015 (accompanied a documentary)
