Wednesday, December 23, 2009

Medicinal Herbs: Rosemary

Rosemary

Overview

Rosemary (Rosmarinus officinalis) is widely used as a spice when cooking, especially in Mediterranean dishes. It is also used for its fragrance in soaps and other cosmetics. Traditionally, rosemary has been used medicinally to improve memory, relieve muscle pain and spasm, stimulate hair growth, and support the circulatory and nervous systems. It is also believed to increase menstrual flow, act as an abortifacient (causing miscarriage), increase urine flow, and treat indigestion. Almost none of these uses have been studied scientifically in humans, however.

In the lab, rosemary has been shown to have antioxidant properties. Antioxidants can neutralize harmful particles in the body known as free radicals, which damage cell membranes, tamper with DNA, and even cause cell death. Also in the lab, rosemary oil appears to have antimicrobial properties (killing some bacteria and fungi in test tubes). It isn't known whether rosemary would have the same effect in humans.

Indigestion

Rosemary leaf is used in Europe for indigestion (dyspepsia) and is approved by the German Commission E, which examines the safety and efficacy of herbs.

Muscle and Joint Pain

Applied topically (to the skin), rosemary oil is sometimes used to treat muscle pain and arthritis, and to improve circulation. It is approved by the German Commission E for this purpose. However, there is no scientific evidence that it works.

Alopecia

Historically, rosemary has been used to stimulate hair growth. Rosemary was used in one study of 84 people with alopecia areata (a disease in which hair falls out, generally in patches). Those who massaged their scalps with rosemary and other essential oils (including lavender, thyme, and cedarwood) every day for 7 months experienced significant hair re-growth compared to those who massaged their scalps without the essential oils. But the study was not well designed, and it is impossible to say whether rosemary caused the hair growth.

Improve Memory or Concentration

Rosemary is often used in aromatherapy to increase concentration and memory, and to relieve stress. One study suggests that rosemary, combined with other pleasant-smelling oils, may help reduce anxiety. However, in another study, people who inhaled rosemary said they felt more anxious than those who inhaled lavender and those who did not inhale a scent.


Plant Description

Native to the Mediterranean area, rosemary now grows widely in other parts of the world. It thrives in a warm and sunny climate. The plant takes its name from rosmarinus, a Latin term meaning "sea dew." It is an upright evergreen shrub that can grow to a height of 6-and-a-half feet. The woody rootstock bears rigid branches with fissured bark. The long, needle-like leaves are dark green on top and pale beneath. Both the fresh and dried leaves are aromatic. The small flowers are pale blue. The leaves and parts of the flowers contain volatile oil.


What's It Made Of?

The leaves and twigs of the rosemary plant are used for culinary and medicinal purposes.


Available Forms

  • Dried whole herb
  • Dried, powdered extract (in capsules)
  • Preparations made from fresh or dried leaves, such as alcohol tinctures, teas, and liquid extract
  • Volatile oil (to be used externally, not orally)

How to Take It

Pediatric

Because rosemary has not been studied in children, it is not recommended for medicinal use in those under age 18. It is safe to eat as a spice in food, however.

Adult

Listed below are the recommended adult doses for rosemary. Total daily intake should not exceed 4 - 6 grams of the dried herb. Do not take rosemary oil orally.

  • Tea: Steep 6 g of dried herb in 2 cups boiling water; strain and cool. Divide into 3 cups and drink during the course of one day.
  • Tincture (1:5): 2 - 4 mL three times per day
  • Fluid extract (1:1 in 45% alcohol): 1 - 2 mL three times per day

Topically, rosemary may be used as follows:

  • Essential oil (6 - 10%): 2 drops semisolid or liquid in 1 tablespoon base oil. Avoid contact with eyes and do not apply to an open wound.
  • Decoction (for bath): Place 50 g herb in 1 liter water, boil, then let stand for 30 minutes. Add to bath water.

Precautions

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, can trigger side effects and can interact with other herbs, supplements, or medications. For these reasons, herbs should be taken with care, under the supervision of a health care practitioner.

Rosemary is generally considered safe when taken in recommended doses. However, there have been occasional reports of allergic reactions. Large quantities of rosemary leaves, because of their volatile oil content, can cause serious side effects, including vomiting, spasms, coma and, in some cases, pulmonary edema (fluid in the lungs).

Because higher doses of rosemary may cause miscarriage, pregnant and nursing women should not take rosemary as a supplement. It is safe to eat as a spice in food, however.

People with high blood pressure, ulcers, Crohn's disease, or ulcerative colitis should not take rosemary.

Rosemary oil can be toxic if ingested and should never be taken orally.


Possible Interactions

Antiplatelet and anticoagulant drugs (blood-thinners) -- Rosemary may affect the blood's ability to clot. It could interfere with any blood-thinning drugs you are taking, including:

  • Warfarin (Coumadin)
  • Clopidogrel (Plavix)
  • Aspirin

ACE inhibitors -- Rosemary may interfere with the action of ACE inhibitors taken for high blood pressure.

  • Captpril (Capoten)
  • Elaropril (Vasotec)
  • Lisinopril (Zestril)
  • Fosinopril (Monopril)

Diuretics (water pills) -- Because rosemary can act as a diuretic, it can increase the effects of these drugs. That can raise your risk of dehydration.

  • Furosemide (Lasix)
  • Hydrocholorothiazide

Lithium -- Because of its diuretic effects, rosemary might cause the body to lose too much water and the amount of lithium in the body to build up to toxic levels.

Diabetes -- Rosemary may alter blood sugar levels and could interfere with any drugs taken to control diabetes.

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