Report Identifies Levels of Evidence for Safety, Efficacy of 60 Herbs

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Report Identifies Levels of Evidence for Safety, Efficacy of 60 Herbs

Newswise — Malpractice rates for gynecologic physicians are among the

highest in the field of medicine. Now, for the first time, these

doctors can obtain clearly presented data about the levels of

evidence for some of the most commonly used herbs consumed during

pregnancy and lactation.

The Report

A soon to be released report, entitled Safety and Efficacy of

Commonly Used Herbs During Pregnancy and Lactation, is the work of a

team of Canadian researchers. The team is comprised of Jacques

Dugoua, ND, Department of Clinical Epidemiology, Canadian College of

Naturopathic Medicine, Toronto, CN; Mills, PHD, MSc., Ph.D.

(Cand.), Department of Epidemiology and Biostatics, McMaster

University, Ontario, CN; Dugald Seely, ND, MSc. (Cand.), Institute of

Medical Science, University of Toronto, Toronto, CN; Dan Perri, MD,

BscPharm, FRCP©, Department of Clinical Pharmacology and

Toxicology, University of Toronto, Toronto, CN; and Gideon Koren, MD,

The Motherisk Program, Hospital for Sick Children, University of

Toronto, Toronto, CN.

Dr. Dugoua will present his team’s findings at the 20th Annual

Meeting and Convention of the American Association of Naturopathic

Physicians (AANP) http://www.naturopathic.org/. The meeting is being

held August 24-26, 2005 at the Arizona Biltmore Hotel, Phoenix, AZ.

Methodology

The researchers conducted their analysis in two phases:

Data Selection

The researchers searched seven databases for reports relating to 60

herbs, ten supplements and eight vitamins. The databases included

AMED, CINAHL, Cochrane CENTRAL, Cochrane Library, MedLine, Natural

Database, and Natural Standard. Each database was examined in

duplicate for data from its inception through June 2004. Unpublished

research and bibliographies were also included.

Assessment of the Levels of Evidence for Select Herbs, Vitamins and

Supplements

Based on the data, a level of evidence was assigned to each herb,

vitamin or supplement. Rankings were assigned to each item, in

descending order:

LEVELS OF EVIDENCE FOR HERBS

A VERY STRONG SCIENTIFIC EVIDENCE

Statistically significant evidence of benefit from one or more

systematic reviews or meta-analysis.

B1 STRONG SCIENTIFIC EVIDENCE

Statistically significant evidence of benefit from one or more

properly conducted random control trials (RCTs).

B2 GOOD SCIENTIFIC EVIDENCE

Statistically significant evidence of benefit from one or more RCTs.

The RCTs, however, are either of small sample size or have

discrepancies in their methodologies.

C FAIR SCIENTIFIC EVIDENCE

Statistically significant evidence of benefit from one or more cohort

studies or outcome studies.

D WEAK SCIENTIFIC EVIDENCE

Evidence from case series.

E THEORETICAL AND/OR CLINICAL EVIDENCE

Evidence from case reports or expert opinion or laboratory studies.

F HISTORICAL OR TRADITIONAL EVIDENCE

Historical or traditional evidence of use by medical professionals,

herbologists, scientists or aboriginal groups.

LEVELS OF EVIDENCE FOR VITAMINS AND SUPPLEMEMENTS

1a VERY STRONG SCIENTIFIC EVIDENCE

Statistically significant evidence from one or more systematic

reviews or RCTs.

1b STRONG SCIENTIFIC EVIDENCE

Statistically significant evidence from one or more cohort studies or

control study.

1c GOOD SCIENTIFIC EVIDENCE

Evidence from one or more case series.

2 FAIR SCIENTIFIC EVIDENCE

Evidence based on case reports.

3 IN VITRO SCIENTIFIC EVIDENCE

Evidence based on scientific studies conducted on animals, insects or

microorganisms or laboratory studies on human cells.

4 THEORETICAL EVIDENCE

Evidence based on scientific theory or expert opinion.

5 UNKNOWN

No available information.

Highlights of the Results

The researchers identified the following:

LEVELS of EVIDENCE OF SAFE USE DURING PREGNANCY AND LACTATION

Name

Use

Level of Evidence Rating

Cranberry

Used to treat urinary tract infection.

A

Echinacea

Used to treat upper respiratory tract infections.

A

Garlic

Reduces blood pressure cholesterol and stomach/colorectal cancer

prevention.

A

Ginger

Reduces/eliminates nausea during pregnancy.

A

Ginseng (Korean)

Diabetes type II, Improves memory, Potentiates against influenza and

the common cold, Improves cognitive function.

B1

Ginseng (Siberian)

Coronary artery disease.

B1

Horse chestnut

Used to treat varicose veins.

A

Milk thistle

Used to support the liver.

A

Raspberry

Supports and nourishes the uterus.

B1

St. ’s Wort

Helps to reduce depression.

A

Turmeric

Reduces arthritic conditions; acts as an anti-inflammatory.

B1

Valerian

Used for sleep.

B1

LEVELS of EVIDENCE FOR CAUTIONARY USE DURING PREGNANCY

Herbs

Name

Use/Contraindication

Level of Evidence Rating

Calamus

Weak evidence of use in UTI and digestive disorders Cancerous to the

liver.

3

Barberry

Used as an anti-microbial. Can aggravate jaundice.

3

Foxglove

Contains digitalis. May cause musculoskeletal malformations.

2

Goldenseal

Anti-microbial. Can aggravate jaundice in the newborn.

3

Juniper berries

Used to treat common cold. Potential abortifacient.

3

Mother’s Cordial containing blue cohosh

Used to stimulate the uterus. Can cause heart problems and lack of

oxygen to organs in newborns.

3

Borage oil

Used to treat arthritis. May be teratogenic and induce labour.

1a

Deadly nightshade

Used for irritable bowel syndrome, migraines, PMS. Teratogenic.

2

Parsley

Used as an antioxidant. Abortifacient.

1b

Pennyroyal

Abortifacient.

2

Oregon Grape root

Used as an anti-microbial for acute infection during pregnancy. Can

aggravate jaundice in the newborn.

3

Vitamins and Supplements

Vitamin A

Needed in pregnancy but not beyond 6,000 IU per day, as higher doses

can be teratogenic.

1a

Vitamin D

Prevents against rickets. Safe.

1a

Vitamin E

May prevent pre-eclampsia, decreases malformations.

1a

Vitamin K

Treats hemolytic disease of the newborn.

1a

Folic acid

Improves hemoglobin levels, prevents birth defects.

1a

B6

Reduces nausea of pregnancy. Reduces dental decay during pregnancy.

Reduces malformations. Improves oxygenation to baby.

1a

Fish oils

Reduces cholesterol, prevents heart disease, lowers blood pressure;

improves IQ in newborn; minimal risk.

1a

Probiotics

Treats diarrhea. May reduce preterm babies.

1a

Additional Findings

The researchers also found that fish oils and probiotics were safe

for use during pregnancy, and that the use of Vitamin A should not

exceed 6,000 IU per day as it may be teratogenic at higher doses.

Conclusions

This is the first time that herbs used during pregnancy have been

independently ranked according to the available evidence surrounding

the safety and efficacy of these products. The researchers hope

additional research will be conducted to enhance the clinician’s and

patient’s understanding of the effects of consumption on pregnant

women and their fetus.

The authors also urge that women not assume that herbs are safe

because they are labeled “natural.” They recommend all pregnant and

lactating women consult a licensed, health care professional before

consuming any herb.

The American Association of Naturopathic Physicians (AANP) was

founded in 1985 to provide alternative methods for healing human

diseases and disorders than have been traditionally offered in the

United States. Members of the AANP must have graduated from one of

North America’s six accredited graduate schools of naturopathic

medicine and served a clinical residency.

For more information about naturopathic physicians, log on to

http://www.naturopathic.org/.