Aside from conventional vitamin and mineral supplements, health food companies also market supplements in the form of tonics and elixirs, often made from plant extracts. While some of the plants used to make these tonics have a proven track record in traditional herbal medicine, others rely purely upon anecdotal evidence about their efficacy. Some nutritionists do not consider these to be food supplements. The following have established themselves as popular supplements – although some still wait for science to prove or disprove the claims that are made for them. It is advisable to consult a qualified practitioner to ensure that the supplement is appropriate.
Evening primrose oil
This oil is extracted from the seeds of the evening primrose herb, and contains a type of fatty acid called gamma-linolenic acid (GLA) which is involved in the production of hormone-like substances called prostaglandins. These regulate many functions, including blood pressure, inflammation and the menstrual cycle. Although GLA is made naturally in the body from linoleic acid (found in vegetable, seed and nut oils), this conversion may not be very efficient in some people, resulting in low levels of GLA and prostaglandins.
It is claimed that evening primrose oil can help relieve some of the symptoms of pre-menstrual syndrome (PMS), such as breast soreness and abdominal pains. It has also been used tp treat skin complaints, such as eczema and dermatitis, and inflammatory diseases, such as rheumatoid arthritis. There is some medical evidence that evening primrose oil supplements benefit people with these conditions. Another good source of GLA is starflower (borage) oil supplement.
This herb is extracted from the leaf of the maidenhair tree, native to China, and has been used in Chinese medicine for around 5000 years. The leaves contain substances called ginkgoloides and bilobalide – complex organic compounds believed to fight disease. They also contain flavonoids that act as antioxidants.
Ginkgo biloba is said to have multiple benefits. Its leaves are known to be effective in improving circulation and stimulating blood flow to the brain, making it potentially useful in the prevention of stroke and the treatment of some dementias, Alzheimer’s disease and memory loss. Studies have shown that patients with mild to moderate age-related memory impairment and changes in mental functioning, for example, show significant improvement in memory and concentration after taking the herb. Its antioxidant action is thought to help protect cells and slow down the ageing process. Research is also taking place to establish the effects of ginkgo biloba on the cardiovascular system.
The strongly flavoured garlic plant is closely related to the onion plant and it has been cultivated for at least 5000 years. Research suggests that garlic may reduce levels of unhealthy blood cholesterol, boost the immune system, help prevent cancer and act as a natural antifungal and antibacterial agent. The active ingredients in garlic are thought to be a number of different sulphur compounds.
Different brands of garlic supplements are prepared using various techniques and this may affect the type of sulphur compound yielded. This in turn is thought to affect the quality of a supplement. In general, supplements prepared from freeze-dried garlic are thought to be the most effective – if in doubt, consult a nutritionist who can recommend a specific brand.
The aloe plant originates in tropical Africa; the gel from the eaves has long been used for treating skin conditions such as burns, itchiness and eczema. Aloe vera can also be taken internally – powdered leaf capsules can be used as a laxative, and the juice has become a popular all-round tonic. It is claimed that aloe is a natural detoxifier that works throughout the digestive system, flushing out dead cells and encouraging new growth. It may also help to heal ulcers and gastrointestinal inflammation, and boost the functioning of the immune system.
Although an impressive body of folklore supports aloe vera’s efficacy, the scientific evidence is less conclusive and research has yielded mixed results. Prolonged or excessive internal use may cause haemorrhoids. Pregnant women should not take aloe vera internally.
This herbal product is made from the root of a plant grown in Asia, and has been used for centuries as a general tonic. Korean or Chinese ginseng (also know as Panax ginseng) is said to strengthen the immune system and help combat physical and mental fatigue. Siberian ginseng is the Russian relative of its Oriental cousin, and is said to confer the same benefits.
Considerable research into ginseng has been carried out, and many researchers agree that the herb offers anti-stress benefits by helping the body to cope with anxiety and ward off illness. It is considered to be an ‘adaptogen’, which means that it will affect each person differently according to their individual needs; it may help to calm a stressed person or it can stimulate someone who is suffering from fatigue.
Ginseng is available in many forms of varying quality, including chewing gum, capsules, powder and tea. People who take ginseng supplements on a long-term basis may suffer negative health consequences such as high blood pressure, skin eruptions and diarrhoea. Postmenopausal women may also experience vaginal bleeding and breast pain. Ginseng should not be taken byor anyone suffering from cardiovascular disease.
This South American herb comes from the seeds of a shrub called Paullinia cupana, native to the Amazon forest. The active ingredient is known as guaranine. It is taken in capsule or powder form, or as an elixir or a tea to refresh the mind and body. Although pharmacists believe that guaranine is identical to ordinary caffeine, an alternative view is that it is a close relative of caffeine which also acts as a stimulant. There is currently no evidence for any health benefits.
Edible algae have been consumed for centuries. These simple plants are grown in wild lakes or man-made ponds, and cultivated as a concentrated source of immune-strengthening nutrients that are easy to digest and absorb.
Algae is rich in chlorophyll (the substance that makes plants appear green), protein and the antioxidant betacarotene, as well as magnesium, iron, iodine and calcium. Spirulina, a microscopic blue-green algae, is one example of an algae supplement – as well as being rich in beta-carotene and chlorophyll, it also supplies small amounts of the unsaturated fatty acid, gamma-linolenic acid (GLA). Claims that algae can boost the immune system, enhance wellbeing and increase energy have not been scientifically verified.
One of the essential amino acids required to make proteins is called lysine. It is found in red meat, poultry, eggs, fish and milk, and relatively low levels are present in non-animal foods, such as potatoes, peanuts and soya beans. It can also be taken in supplement form.
There is some evidence that lysine supplements (particularly when they are combined with magnesium and vitamin B6) lessen the frequency and severity of herpes outbreaks in individuals who are infected with the virus.
Produced by worker bees to feed the larvae of future queen bees, royal jelly is a popular supplement. The power of royal jelly has been recognized in China and other Eastern countries for centuries, and in China today, it is injected as a cure for arthritis.
Royal jelly is a rich source of pantothenic acid, a B vitamin which plays a vital role in energy production and is important in the production of the neurotransmitter acetyl-choline (important for memory). Royal jelly, most often found in capsule or tablet form, is sometimes recommended for fatigue, but is most commonly used as a general tonic to enhance energy levels and general wellbeing. There is, however, no current scientific evidence for its efficacy and reports of its effects may be exaggerated.
Essential fatty acid supplements
Contrary to popular belief, some fats are essential for good health. These include the omega-3 and omega-6 essential fatty acids, which are found in some foods but may also be taken as supplements.
Omega-3 supplements take the form of capsules containing either flax oil or fish oil. Fish oil supplements reduce inflammation – for example, in people suffering from arthritis – and reduce the risk of heart disease. They may also improve intellectual development in early childhood. Some precautions are necessary, however: pregnant women and people with diabetes, asthma, high blood fat or blood cholesterol levels should not self-supplement. In addition, cod liver oil is a concentrated source of vitamins A and D; these fat-soluble vitamins are stored in the body so it is possible to overdose on them and experience symptoms such as headaches, blurred vision, nausea and even liver or kidney problems. Pregnant women should avoid an excessive intake of vitamin A.
Omega-6 supplements take the form of evening primrose or starflower (borage) oil capsules.