Information About Nutrients and Herbs - Uses, Benefits
GABA (GAHHA-AHINOBUTYRIC ACID)
an amino acid supplement that is gaining popularity for its anti-anxiety effects, GABA is produced in the body from glutamic acid and acts as an inhibitory neurotransmitter. That is, it slows down activity in the part of the brain called the lymbic system, which is our emotional alarm bell. Thus, GABA is able to help reduce stressful feelings such as anxiety, fear and panic. As a natural tranquillizer, GABA can partially replace valium by binding to the same brain receptors, providing tranquillization. It is also reported to help reduce frequent night-time urination by suppressing the hormone prolactin, which stimulates urination. Available from health food stores.
As an ester of ferrulic acid, gamma oryzanol is an antioxidant within plant cells that is widely distributed in foods such as rice, wheat, barley, oats, vegetables, olives, tomatoes and citrus fruits. Found mainly in the bran part of grains, it promotes their growth. Gamma-oryzanol was isolated from rice-bran oil and was first used by the Japanese to treat anxiety. It is now used mainly to treat the hot flushes of menopause, high cholesterol levels and digestive disorders such as ulcers, gastritis and irritable bowel syndrome. As a potent antioxidant, gamma-oryzanol can help to counter the damaging effects of radiation and chemotherapy. Animal studies have shown that it can also have anti-cancer effects. Many bodybuilders believe that gamma-oryzanol increases the secretion of growth hormone, since it acts on the hypothalamus and the pituitary gland, the sources of this hormone. Gamma-oryzanol is considered to be a safe, natural substance and its normal total daily intake is estimated at 300 mg.
Garlic, a pungently flavored bulb of the onion family, is a classic example of a combination of food and folk medicine. It contains various potent sulphur compounds such as alliin and allicin, which boost immunity to diseases and which have antibacterial, antifungal and antithrombic effects. Allicin extract in cream form was recently found in clinical trials to kill the so-called 'super bug' (MRSA), which is resistant to antibiotics in treating skin disorders such as eczema and acne.
Garlic is extensively used to prevent and treat colds and flu. It has been found to lower blood pressure and reduce blood stickiness, thus preventing coronary thrombosis, heart attacks and strokes, and has also been found to be beneficial in inhibiting the growth of cancerous tumours, and treating diabetes, yeast infections, allergies and stress. The long-term use of garlic can benefit people who are predisposed to conditions such as heart disease, cancer or diabetes, or have a family history of them. As a strong anti-fungal, garlic has long been a folk remedy for children with intestinal parasites such as pinworms or tapeworms. It has also been used in the treatment of athlete's foot and yeast overgrowth. The strong odour of the herb can be suppressed by eating fresh parsley along with it. There are also many brands of odourless garlic oil capsules available in health food shops.
GENETICALLY MODIFIED FOODS
An recent years, genetic engineering has been applied in farming with the purpose of improving certain characteristics in plants. Genetic modification consists of splicing a gene with a desired quality from one plant and inserting it into another. In nature, only closely related plants are able to mix genes, but in genetic engineering it is possible to mix genes of entirely unrelated plants or organisms. For example, a variety of tomato was made frost-resistant by the insertion of an 'antifreeze' gene from an arctic fish. However, there has been concern among many people that once new genes enter the DNA chain, they can cause genetic damage with unpredictable results. For instance, in 1989, a batch of genetically engineered L-tryptophan, a calming amino acid, caused the death of 30 people in the United States and afflicted thousands of others with a rare blood disorder. This subject eventually became a public controversy when it became known that staple grains such as soybeans and maize, for example, were being genetically modified to resist herbicides as these grains are widely used in many human foods and also in animal feeds. Scientists became concerned that GM foods could compromise the treatment of disease in animals and humans by increasing resistance to the commonly used antibiotic ampicillin, which could lead to the creation of drug-resistant bugs. It is also feared that GM plants will cross-pollinate with adjacent fields and pose a threat to wildlife. Consumer groups and supermarkets have demanded clear labelling and the segre-gation of GM foods, in the hope that the GM foods of today do not become the BSE-type problem of tomorrow.
A naturally occuring isoflavone which is mostly prevalent in soy beans, alfalfa and clover, genistein was recently introduced in health food stores as a natural food supple-ment due to its significant cancer-preventing effects.
A recent study done by Catherine Rice-Evans at Guy's Hospital, London, has confirmed that the soy isoflavone genistein (and to a somewhat lesser degree daidzein) is a powerful antioxidant in its ability to quench free radicals.
Genistein is also a phytoestrogen (plant estrogen) with both oestrogenic and anti-oestrogenic activities, a paradox that is the key to its cancer preventive properties. Compared to hormone replacement therapy (HRT), the oestrogenic activity of genistein is much milder and safer. It has been known for some time that people who consumed large amounts of soya beans and soy products such as soya drinks, tofu or miso, have a lower incidence of various cancers. Breast cancer, which according to recent statistics affects one woman in eight, is linked to higher levels of oestrogen. Genistein was found to bind to oestrogen receptors in cells, inhibiting the harmful action of excess oestrogen or cancer-causing pesticides and thus reducing the risk of breast cancer
Germanium is a much-acclaimed trace element. It is a semi-metal and semiconductor, and was once used to make tran-sistors. Nutritionally, organic germanium boosts the immune system by stimulating the production of interferon and other immune cells, increasing resistance to variousdiseases. Organic germanium also lowers the oxygen requirements of body organs and is a powerful antioxidant, reducing peroxidation damage, and helping prevent the debilitating diseases of ageing. As such, it was found to have a beneficial effect on ovarian malignancies, colon cancer and Hodgkin's disease. Organic germanium was also found to have anti-arthritic properties. Trace amounts of germanium are present in most foods, but richer amounts are found in ginseng, garlic, aloe vera and comfrey, which may partially explain the health- promoting effects of these foods. Germanium is also available as a supplement in health food stores.
A tree existing for millions of years, its leaves were found to contain substances capable of reversing the ageing of the brain. Powerful antioxidant compounds such as flavonoids and terpenes, gingkolides and bilobalides, which make up 47 per cent of the ginkgo extract, are considered to halt lipid peroxidation in the brain and protect brain cells.
Since ginkgo increases the supplies of both blood and oxygen to the brain, it can benefit sufferers of degenerative diseases such as dementia in the elderly, which can be a result of poor flow of blood and oxygen to the brain. Indeed, various studies have shown that ginkgo biloba extracts not only benefit cases of Alzheimer's disease, but can also improve short-term memory in students and act as an effective memory aid for all ages.
Ginkgo's ability to improve blood supply was recently found to be beneficial in other conditions, such as male erectile dysfunction and male impotency, senile macular degeneration, hearing loss in the elderly and tinnitus.Ginkgo biloba extract capsules are widely available in health food stores. A minimum usage period of three months is normally necessary to achieve benefits.
GINGER (ZINGIBER OFFICINAUS)
A perennial plant grown in most of the tropical regions of the world, its powdered root has been used for centuries as a culinary spice and in infusions. Ginger is a stimulant that relieves flatulence, discharges mucus, strengthens digestion, stimulates glandular secretions and relieves vomiting. Blended with cinnamon powder, ginger makes a pleasant tea and ginger root powder taken in doses of 250 mg four times a day can reduce morning sickness of pregnancy. In some African cultures, ginger is considered to be an aphrodisiac.
GINSENG (PANAX GINSENG)
Ginseng is the most widely used herb of Chinese medicine, hence its name, panax, which means' care-all'. It is a small perennial plant, native to Korea but also cultivated in China, Siberia and the USA. Ginseng is grown for its root which is said to abound with healing properties and which is used mainly as a tonic. Its many uses, however, include treatment for a great variety of disorders, from hypertension, fatigue and stress, to weak memory, arthritis and impotence. The root contains glycosides, called ginsenosides, with vitamins and minerals that modify the immune system, increasing resistance to various diseases, and promoting physical and mental vigour. Ginseng is available from health food shops as teas, capsules and extracts.
Eating raw animal glands, such as the liver, is a practice that has been followed since ancient times to invigorate the body and fight disease. The therapeutic value of endocrine glands, which secrete hormones and enzymes, has recently been gaining increased scientific recognition, and following the development of safe production methods, such as freeze-drying, which preserve the nutrients of the glands, glandular supplements have become available. The principle underlying glandular therapy is that 'like cures like'. For example, a person with a weak liver or liver disease can benefit by eating animal liver. Indeed, science has confirmed that extracts of various glands such as those of the thyroid, adrenal, thymus, pancreas or pituitary, are quite effective when taken orally because of their active hormone and enzyme content. Pancreatin, for example, is a popular digestive aid made from the pancreas gland, which contains a comprehensive range of digestive enzymes. The adrenal gland is rich in hormones and its extracts are used to overcome stress and many other ailments, such as asthma, heart disease, flu, depression, headaches, irritable bowel syndrome, diabetes, PMS and arthritis. Glandular extracts are now available in health food shops in various combinations, on their own, and included in multivitamin preparations.
These are food additives, such as beeswax or shellac, which are used by the food industry to give foods a shiny appearance or a protective coating.
Agum, which is derived from a plant tuber, it acts as dietary fibre by absorbing water and, in the intestines, can expand to 60 times its weight. It is also a fat mobilizer, combining with fat to removes it from the colon. Thus, glucomannan can be used to treat constipation, curb appetite, normalize blood sugar levels, help with weight loss, reduce cholesterol levels and treat diabetes.
Glucomannan is sold in capsules, and for best results, 2 - 3 capsules should be taken with a large glass of water half an hour before meals.
These are mineral complexes bound with gluconic acid. Gluconic acid is naturally produced by the body and used as a source of energy. The gluconate complex enables minerals to cross the intestinal wall and be absorbed into the blood stream more efficiently. Mineral gluconates, sold in health food shops, include iron, zinc, calcium, magnesium, potassium, manganese and copper.
Also known as blood sugar, it is the form of sugar that is produced in plant and animal tissues and is used to provide Nnergy. It is the end product of assimilated foods, and a feeling of well-being and high energy levels depends upon the maintenance of normal levels of glucose in the blood, cells and muscles. The brain is particularly dependent on glucose as its energy source: a drop in the brain's glucose level immediately releases hormones, such as adrenaline and glucagone, to restore it. A chronic condition of low blood glucose levels is known as hypoglycaemia, while its opposite -chronic high glucose levels - is diabetes. Glucose is found naturally in fruits, grains and plants.
This is standard laboratory test for detecting hypoglycaemia or diabetes. To check for diabetes, the patient is normally given a solution of 100 g glucose to drink first thing in the morning, on an empty stomach, and blood samples are then taken after 30 minutes, and again after an hour, to check the glucose levels. The most reliable GTT for hypoglycaemia is one that lasts for 5-6 hours, with blood samples being taken each hour.
GLUCOSAMINE SULPHATE (GS)
Glucosamine sulphate is a compound that occurs naturally in the joints. It is made up of glucose, an amino acid (glutamine) and sulphur. Its main function is to stimulate the growth of cartilage, by serving as a building block for its production. GS provides proteoglycans (PAS), proteinand sugar molecules that attract and hold water, and produces a group of gelatinous compounds known as glycosaminoglycans (GAGs), which bind water in the cartilage matrix and help prevent cartilage from breaking down. GS also promotes the incorporation of sulphur into the cartilage, which means that GS is necessary not only for joint function, but also for stimulating its repair. In this sense, GS works best with chondroitin sulphate (CS) to repair cartilage damage, preventing osteoarthritis. While GS holds water in the cartilage, CS acts more like a 'water magnet'. In many people, the production of GS in the body declines with age, as cartilage loses its flexibility and thus its ability to act as a shock absorber and the result is osteoarthritis, the most common form of arthritis, which affects millions of elderly people. It has been suggested that GS deficiency is the major causative factor in osteoarthritis and, as a result, GS supplements have been tried and found successful in the treatment of the disease. GS is now widely available in health food stores as a dietary supplement. Taken orally, it is efficiently absorbed and tolerated with no known contra-indications or adverse interactions with drugs. In some cases of nausea or heartburn, it is advised that GS should be taken with meals. The standard dose is 500 mg, 3 times a day, but overweight people may require more, depending on their body weight, the guide lines being 20 mg per kg of body weight a day.
GLUTAMINE AND GLUTAMIC ACID
Glutamic acid is a non-essential amino acid that has been dubbed 'the brain fuel'. It is usually supplied by food and is the most prominent amino acid in wheat. Glutamic acid combines with poisonous ammonia in the brain and detoxi-fies it, producing glutamine, the actual brain booster. As a supplement, glutamine improves brain function, alertness and mood, and can help in the treatment of alcoholism and migraine, and also to overcome a sweet tooth. Glutamic acid, by helping produce GADA (a calming neurotransmitter) in the brain, has an indirect calming effect. Studies during the 90s revealed that glutamine is the primary fuel for the growth of immune cells, especially intestinal lining cells. It is therefore used now in the treat-ment of the leaky gut syndrome, Crohn's disease, irritable bowel syndrome and ulcerative colitis. Glutamine is a liver detoxifyer and is also indicated for allergies and arthritis. A daily supplement of 3-5 g of glutamine powder or capsules is a normal protective dose. Higher therapeutic doses should be taken under nutritional or medical supervision. Being heat-sensitive, glutamine is best kept in the fridge.
A potent antioxidant, it is a peptide produced in the body from three amino acids, glycine, glutamic and cysteine. Glutathione helps to prevent many of the degenerative diseases of ageing, such as heart disease, cancer and arthritis, and it is also thought to increase life-span. This is a result of its participation in various enzyme systems, such as glutathione peroxidase and glutathione reductase, that neutral-ize free radicals and reduce their oxidative damage. Since glutathione is abundant in the lens, it is especially helpful in preventing the progression of eye cataracts. It also provides protection from the effects of pollution, smoking and radiation and is a detoxifier of toxic metals, metabolic by-products and hormonal waste. Glutathione can thus improve detoxification of the liver by neutralising toxins and, as an antioxidant, it protects the heart by preventing cholesterol oxidation. Its levels in the body can be raised by eating more fresh fruit and vegetables and by supplements of glutamine, cysteine, vitamin C and selenium. It is available from health food stores.
This is the major wheat protein, containing sub-divisions such as gliadins and glutenins. Gluten is high in the amino acids glutamine and proline, but low in lysine. It is also found in rye, oats, barley and buckwheat. Gluten is the main allergy-causing ingredient in bread and the allergy can be manifested in a variety of symptoms. An intolerance to gluten is the cause of coeliac disease, which is an intestinal malabsorption syndrome, characterized by diarrhoea, weight loss, bleeding tendency and low calcium levels. The only treatment for coeliac disease is the maintenance of a strict gluten-free diet; this is usually high in rice and maize, and should be devised by a dietician or nutritionist. Food labels must be read carefully to avoid coeliac-causing ingredients. Recent reports also implicate gluten in gastrointestinal disorders in people with sensitive digestion, and it is also suspected to be a causative factor in schizophrenia.
GLYCAEMIC INDEX (GI)
As the prime suppliers of energy, various carbohydrates raise the blood sugar level at various rates: sugars like glucose and sucrose are the quickest to raise blood sugar level while complex carbohydrates like pasta and starchy foods are the slowest.
A non-essential amino acid that, as an inhibitory neurotransmitter, inhibits stress response in the spinal cord, together with taurine, helps to relieve spasms and contractions that are due to stress or anxiety. Glycine promotes muscle tone by increasing creatine, a source of high-energy phosphate released during muscle contraction, and its inhibitory action contributes to the prevention of epilepsy. Glycine is also reported to reduce uric acid levels, thus benefiting gout, and it is involved in the production of glutathione, the important antioxidant enzyme. As a major component of collagen, glycine can enhance the repair of injured tissue and wound healing. Available at health food stores.
GOLDENSEAL (HYDRASTIS CANADENSIS)
A small perennial herb native to North America, it is cultivated for its medicinal uses. It has a wide range of therapeutic properties which are attributed to its high content of active alkaloids, such as berberine, hydrastine and canadine. It was traditionally used by the American Indians to treat a variety of conditions, especially infections. More recently, it has been well-documented as an antibiotic and a booster of the body's immune system, thus useful in fighting diseases. Goldenseal is also known as an antiseptic, diuretic and tonic. An infusion of goldenseal can be used as a vaginal douche and as an antiseptic mouthwash. It is also particularly helpful in treating mucous membranes, making it useful for colds and catarrhal conditions. Goldenseal is available from health food stores on its own as a powder, tinctures and extract and is increasingly included in many nutritional formulas.Caution: The herb must not be eaten fresh as it can produce ulceration of the digestive tract.
GOTU - KOLA (HYDROCCHYLE ASMTICA, CENTEILA ASMTICA)
A native of India and Asia, gotu-kola is a mildly bitter herb that stimulates the central nervous system. It contains several active ingredients, such as saponins and triterpenes, which are known to improve memory and learning ability and, in addition, the herb is now being used to alleviate fatigue and depression, increase sex drive, treat rheumatism, increase urination, treat heart conditions and accelerate the healing of wounds. In Europe, gotu-kola is used to promote the self-healing of skin ulcerations or bedsores from prolonged confinement to bed. In addition, in combination with cayenne and ginger, gotu-kola has been found to be an effective energy booster. This combination can be found in health food shops under different brand names, while gotu-kola is available on its own in capsules containing the powdered herb. A normal daily dose of the extract is 120 mg.
Grains are a primary nutritional source of complex carbohydrates, which are mainly starch. Whole grains, and their products, also contain large amounts of fibre, -vitamins and minerals, and as such are valuable as a nutritious source of energy. This food category includes wheat, barley, buckwheat, corn, rice, millet, oats, rye, triticale, amaranth and quinoa.
A citrus fruit, rich in vitamin A and C, the grapefruit contains smaller amounts of minerals such as calcium, phosphorus and potassium. The grapefruit comes in both white and pink varieties, but the pink variety has over five times the amount of vitamin A than its white counterpart. Juice from the fresh grapefruit harvested in September October is the richest in vitamin C, and is beneficial in colds and fevers. Grapefruit peel (rind) is rich in bioflavonoids, and has a pungent, bitter-sweet flavour. The bioflavonoid activity of the peel, combined with its vitamin C content, is useful in strengthening weak gums, arteries and capillaries. To extract the properties of the peel, a tea can be prepared by simmering fresh or dried peel for twenty minutes.Externally, a compress of this tea can be used to treat frostbite by helping to restore circulation to the damaged tissue. The bitter grapefruit seeds, especially the grapefruit seed extract (GSE), are known as a natural antibiotic and antiseptic and to inhibit bacteria, viruses and mould. As such, it is used as a mould inhibitor in various foods. GSE contains many beneficial elements such as bioflavonoids, saccharides and phenolic acids, and is used for colds and flu, sore throats, parasites and yeast infections. It is also used to relieve indigestion and treat gastrointestinal upsets. Available as capsules, tablets and powder for external use.
GREEN TEA (CAMELLIA SINENSIS)
Green tea is produced from the same plant as the common black tea that is usually consumed in western countries. However, it is not processed, as is the case with black tea, nor is it allowed to ferment after harvesting and before drying, and so it retains most of its active ingredients. Studies made largely in the 1990s found that green tea has many beneficial effects. It contains large amounts of catechins, a group of antioxidant polyphenol flavonoids with strong anti-cancer properties, and the tea has also been found to provide protection against oesophageal cancer and to block the formation of tumours arising in the skin, lungs, digestive tract, liver and breasts. In addition, it was found to reduce cholesterol levels and lower blood pressure, and it has been claimed to fight colds and flu and prevent gum disease, dental cavities and bad breath.
Green tea bags are available in health food shops. It is recommended that 3-5 cups of the tea are drunk each day in order to reap its full benefits.
GROWTH HORMONE (GH)
This hormone is secreted by the pituitary gland in the brain and is crucial for the growth and repair of body cells, as well as for stimulating the immune system. It is secreted mainly during the first 90 minutes of night sleep, and also in response to fasting and non-aerobic, peak-effort exercise. It is abundant in young people up to 30 years of age, and absent, or present in only small amounts, in older and/or obese people. GH has many important functions: it stimulates the growth of immune cells and is well-known to benefit auto-immune diseases such as arthritis; it speeds the healing of wounds; it stimulates muscle growth and increases the burning of fat to energy, aiding weight loss Supplements of several nutrients, taken on an empty stomach, can increase the release of GH in older people. GH releasers include the amino acids arginine, ornithine and the prescription drug L-dopaCaution: GH releasers should not be used by young persons who have not completed their growth or reached their full height.
GUARANA (PAUUNIA CUBANA)
A tall climbing vine native to the Brazilian Amazon, the seeds or beans of guarana are roasted and ground for use as a beverage in Latin America. Prepared in a similar way to coffee, guarana is high in stimulating alkaloids such as caffeine, saponins, tannins and guaranine. It is a very stimulating beverage that is claimed to relieve headaches and migraines quickly. Guarana also inhibits appetite and it is used as an appetite-suppressant ingredient in various slimming products. It is also used to treat arthritis and to stimulate delayed menstruation, and is reputed to be an effective sexual stimulant. It is available in a variety of forms, including tablets and as drinks.
GUAR GUM (CYAMOPSIS TETRAGONOLOBUS)
A herb for livestock feed, guar gum is now used both as a food additive and as a health -promoting nutrient. It contains mucilaginous substances which are gel-and bulk- forming and is used in the foodindustry as a stabilizer and thickening agent in the production of products such as soups, salad dressings, ice cream and tooth-pastes. Nutritionally, guar gum can contribute to weight loss. It benefits slimmers by acting as a bulking agent in the digestive tract. This delays stomach emptying and the passage of food through the intestines, promoting a feeling of fullness and reducing food cravings. The gel-forming guar gum also combines with fats and promotes their excretion. Thus, it can effectively lower high cholesterol levels. Guar gum also reduces insulin levels and is beneficial for diabetics. It is available in health food stores in capsule form.
Originating in Central America, the guava is an outstanding source of vitamin C, the pink varieties being richer in vitamin C than the white. One average fruit can provide as much as 150 mg vitamin C! Guavas are also a good source of soluble fibre and contain moderate amounts of calcium, phosphorus and niacin. They help reduce high cholesterol levels, can be useful for constipation, boost immunity and protect the heart. They are highest in nutri-ents when fresh and ripe. Canned in heavy syrup or made into a sugary guava nectar drink, they lose much of their nutritional value.
GUGGUL (COMMIPHORA MUKUL)
This is an Eastern Indian plant used for centuries by ayurvedic medicine as a treatment for arthritis. However, modern research conducted in medical research institutions in India found that guggul can also prevent heart attacks. Various studies confirmed that the oily resin of the guggul gum, which contains a mixture of biologically active compounds called guggulsterones, reduces platelet adhesiveness and lowers the levels of blood lipids such as cholesterol and triglycerides, thus reducing the risk of atherosclerosis, thrombosis and coronary heart disease. Guggulsterones were also reported to have pronounced antioxidant activity, by protecting the important free radical scavenger enzyme SOD (superoxide dismutase), and keeping it in higher levels. SOD protects the heart by scavenging the destructive superoxide radicals and preventing oxidative damage to the heart muscle. And indeed, various studies showed that guggul gum produced a marked reversal of the metabolic changes occuring in people with reduced blood supply to the heart (ischemia). Crude guggul extracts can cause side effects such as skin rashes, diarrhoea and irregular menstruation. However, guggul capsules, which are increasingly available in health food stores, are made from the purified and standardised gum of the plant and were found to be well tolerated. They usually each contain no less than 25 mg of the bioactive components, Z and E-Guggulsterones. Pregnant women should consult a qualified practitioner before using this product.
GUMS - PLANT
Plant gums are mucilaginous resins produced by various plants, usually as a response to injury. Commercially, they are produced by making a scratch in a plant or tree and collect-ing the exuding thick fluid. Plant gums are water-solubleand gel-forming and are used by the food industry mainly as emulsifiers and stabilizers. Examples of these are gum Arabic used in confectionery and karaya gum used in soft cheeses and brown sauces.