What Kinds Of Products Are We Concerned About?
Chronic conditions such as Alzheimer's disease, arthritis, high blood pressure, depression and problems with the prostate gland become more common with advancing age. Consequently products such as, ginkgo biloba, glucosamine, garlic, St. John's Wort and saw palmetto, are frequently promoted as treatments for these health problems.
Ginkgo biloba, L. (Ginkgoaceae). Ginkgo has been prescribed in Europe for illnesses associated with reduced blood flow in the brain in elderly persons. These include depression, short-term memory loss, ringing in the ears (tinnitus), and Raynaud's disease.
Researchers are still studying ginkgo to find out how it works. It may work as an anticoagulant (blood thinner), vasodilator (opens up blood vessels) or as an antioxidant (a chemical that has a protecting effect in the body) (Desmet). The anti-stress and anti-anxiety activity may be due to its effect on an enzyme in the brain (White, Scates, and Cooper; Letzel, Haan, and Feil).
Because of the way ginkgo may work, patients taking aspirin, anticoagulants (blood thinners, for example, Coumadin®), vasodilating agents (drugs that open up blood vessels), anti-inflammatory, or antidepressant drugs should not add ginkgo to their medicines without first consulting with their doctors. Side effects of ginkgo have included stomach upsets, headache, dizziness, and vertigo. Ginkgo seeds and fruit pulp are toxic if eaten (Pharmacist's Letter).
Clinical studies in humans for symptoms associated with decreased blood flow to the brain, used dosages of 120 to 160 mg per day of a ginkgo biloba extract, with treatment lasting for at least four to six weeks. Results showed that ginkgo may have some benefit but that this needs to be studied further. Ginkgo does not seem to be of benefit for treating tinnitus (World Health Organization).
Glucosamine. Glucosamine is a sugar derivative that occurs naturally in the body (see Figure 1). It is an essential nutrient used in the formation of specialized sugar polymers called glycosaminoglycans. These polymers are used to form bone, cartilage, heart valves, ligaments, nails, tendons, and synovial fluid (a lubricating fluid found in weight-bearing joints).
As the human body ages, cartilage, which cushions the ends of bones, begins to lose elasticity, shrinks, and cracks. Sometimes pieces of cartilage break off into joint space and irritate the surrounding tissue. This inhibits movement and causes inflammation that results in decreased movement and pain. The muscles that hold the joints together weaken due to their lack of use, and the joint may change its shape and function. After a long period the bones may rub together causing more pain and the formation of spurs. This condition is known as osteoarthritis (OA).
It has therefore been suggested that supplementation with glucosamine may relieve symptoms of OA. The usual oral dosage reported in the scientific literature is 500 mg, three times a day. Glucosamine is a by-product of the shellfish industry and obtained from the exoskeletons of crustaceans (lobsters). Pharmacists and physicians should ask the consumer if they have any allergies to shellfish. Glucosamine is well tolerated and adverse reactions or drug interactions have not been reported.
Large-scale, long-term clinical studies are needed to evaluate the efficacy of glucosamine in the treatment of OA (McAlindon et al.). It is important for the patient to understand the nature of OA, risk factors (heredity, injury to the joint, and excess body weight), and current therapy, which includes diet, exercise, and physiotherapy. Appropriate lifestyle changes may eliminate or limit the need for medications.
Serenoa repens (Bart.) or saw palmetto. In men the urethra is surrounded near its base by the prostate gland, which secretes part of the semen. When this gland enlarges, as it often does in older men, urination may become difficult. Symptoms of urinary frequency, urgency, and hesitancy are common in urinary tract infections, cancer of the prostate, or prostate enlargement. Therefore, it is very important for patients to see their doctor to find out the nature of the underlying problem.
Saw palmetto extract, has been used to treat symptoms associated with prostate enlargement ("Sabal fructus"). Clinical studies using an oral dose of 160 mg of extract twice daily indicate that it may help the symptoms associated with an enlarged prostate (Brinker). The most common adverse effects are nausea and stomach pain. Headache, increased blood pressure, urinary retention, and back pain have been reported (Nemecz).
Saw palmetto has not been shown to reduce enlargement of the prostate gland, and patients with symptoms should be encouraged to see their physician for routine checkups.