Herb

Also known as purple coneflower, echinacea is a well-documented immune system stimulant which activates T and B lymphocytes. It also has marked antiviral properties. Echinacea enhances resistance, stimulates the lymphatic system, and is often used against colds and flu. It is best taken in small, frequent doses. If used on a long-term basis, take echinacea for only six days a week, or three weeks out of four, since it is more effective if not taken continuously.

Availability: health food shops.

EDTA (edetic acid)

This is a substance which forms complexes with lead and other heavy metals and can therefore be used as a chelating agent to combine with and remove these substances from soft tissues in the body.

Availability: from specialist chelation clinics.

Eicosanoids (see Prostaglandins)

Eicosapentaenoic acid (EPA) (also see Fats)

The active ingredient in fish oil supplements. EPA can be produced from the essential fatty acid alpha linolenic acid in the body, and is then used to form series 3 prostaglandins and leukotrienes. It also forms a structural part of cell membranes. Oily fish provide a rich source of ready-formed EPA.

Fish oil supplements have become popular with individuals seeking to prevent and treat heart disease. Studies have shown that populations (mainly Eskimos) who consume particularly large amounts of EPA suffer very low rates of heart disease despite their high-fat, high-cholesterol diet. It is now thought that this is due to EPA's ability to reduce platelet adhesiveness (thus reducing the blood's tendency to clot), very low density lipoprotein (VLDL) levels, plasma triglycerides, and the synthesis of cholesterol by the liver.

Availability: Health food shops and pharmacies.

Elderberry

Herb

Elderberries are not often sold as a herbal product, but can be picked in the wild in Europe (in the autumn) and are often made into wine. They have limited use as a herb, and can cause nausea if consumed in large quantities. They also have a mildly laxative action. Elderberry juice or puree consumed regularly is considered to be a good remedy for chronic rheumatism, neuralgia and sciatica.