"Researchers at the Osaka Institute of Public Health in Japan gave volunteers over forty years of age 50 mL of a spirulina extract and measured the activity in the blood of interferon gamma and natural killer cells. For one to two weeks following the participants' ingestion of spirulina, the activity of these substances was found to increase, and this increased activity continued for twelve to twenty-four weeks."

Cut Your Cancer Risk with Spirulina

This supplement boosts your immune system and may reverse signs of aging.
Health Claims

Researchers say spirulina (Spirulina platensis) may ward off cancer and protect your brain from age-related mental decline.

SPIRULINA, A SPECIES OF BLUE-GREEN algae, grows naturally on the surface of lakes, but most supplement manufacturers grow it under controlled conditions. The Aztecs consumed spirulina centuries ago. More recently, the Japanese began to add spirulina to food because it provides protein, vitamins, minerals, antioxidants, and heart-healthy fatty acids. Spirulina is sold in America as a supplement and is often added to juices and energy bars to boost their nutritional value.
How It Works

Carbohydrates in spirulina may prompt immune cells to destroy cancer cells. One carbohydrate, calcium spirulan, may also prevent tumor cells from attaching to body tissue. Phycocyanin, the antioxidant pigment that gives spirulina its blue-green tint, appears to scavenge the free radicals that can cause cancer and the age-related brain inflammation that impairs memory and motor skills in older adults.


Most spirulina studies have been done on animals or in test tubes.

In one human study published in a Dutch journal last year, researchers gave approximately 2 ounces of spirulina extract daily to 12 healthy men aged 40 to 65. After four weeks, more than half the men showed increased cancer-fighting immune cell activity.

In a controlled study published in the Journal of Medicinal Food in 2000, scientists treated blood from 12 healthy volunteers with a saline solution that contained spirulina. After 72 hours, the treated blood contained 13 times more cancer-fighting immune cell proteins than untreated blood.

In a controlled study published last year in the Journal of Neuroscience, researchers fed old rats diets enriched with spirulina. After 14 days, the researchers compared their brains to those of old and young rats fed no spirulina. The old rats that ate spirulina showed significant improvement in the brain activity that affects motor learning. Spirulina also reversed free radical damage in their brains to the levels found in the young rats.

How to Take It

Spirulina comes in capsule, tablet, and powder form. You'll find it in most natural food stores.
To boost your immune system, take 3 to 5 g of spirulina in capsule or powder form (mixed with water or juice) on an empty stomach, suggests Paul Dompé, N.D., a naturopath at the Bastyr Center for Natural Health in Seattle. Take the dose all at once or in increments throughout the day.

To keep your brain young, take 2 g a day, says Paula Bickford, Ph.D., senior researcher at the James A. Haley Veterans Hospital in Tampa, Fla.


To avoid toxic heavy metals and unwanted microorganisms, buy spirulina supplements grown in a controlled environment, Dompé says. When in doubt, ask the manufacturer how its spirulina is grown and request a copy of contamination test results.

Spirulina appears safe for everyone, including women who are pregnant or nursing.
The Bottom Line More human studies are needed to confirm spirulina's health benefits.
PHOTO (COLOR): Any way you take them, blue green algae provide powerful antioxidants.
By Rachel Dowd, A research intern at Natural Health.

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