According to the latest research, there are about 45 nutrients that humans can't live without, and which their bodies can't manufacture: 21 minerals, 13 vitamins, eight amino acids and two essential fatty acids. No single food has them all. But when a food is discovered that is a rich source of several essential nutrients, such as hemp seed, it makes nutrition news.
Its promoters bill hemp seed as the soybean of the new millennium. In addition to containing vitamins and minerals (calcium, iron, thiamine, niacin and riboflavin), hemp seed, like the soybean, is a vegetable source of complete protein, having all eight amino acids. Hemp oil (pressed from the hemp seed) is, according to many, the best source of the two essential fatty acids (or EFAs) we can't live without: omega 3 alpha-linolenic acid and omega 6 linoleic acid.
What makes it the best source? Although other vegetable oils (flax, canola, soybean and walnut, for example) contain these same fatty acids, hemp seed oil contains them in an optimum ratio of 1 to 3 (one omega 3 to three omega 6s).
In addition, hemp is the only edible seed oil that contains omega 6 gamma-linolenic acid. In "Fats that Heal, Fats that Kill," Udo Erasmus writes that hemp seed oil's "unusually well-balanced profile means that one could use it for a lifetime without ever suffering EFA deficiency.
"The emphasis on reducing fat in our diets (the just-updated USDA guidelines say fat should supply only 30 percent of daily calories) and the sudden increase in low-fat and fat-free food products can make it hard to get enough essential fatty acids.
"We can go overboard and get our fat intake too low, so the challenge is to reduce fat but keep our essential fatty acids up," says Bruce M. Chassy, assistant dean at the College of Agricultural Consumer and Environmental Sciences at the University of Illinois at Urbana-Champaign.
Chassy agrees that "hemp oil is an excellent source of essential fatty acids." But no food is perfect, Chassy says. Hemp oil is cold-pressed (extracted at low temperatures) and must be refrigerated (or frozen) and consumed quickly or it will become rancid. In addition, hemp oil cannot be used for frying or sauteing, because heat destroys the oil's nutritional components and can make it indigestible.
Fresh hemp oil is green (from chlorophyll and carotene) and has an appealing nutty flavor. As for hemp seeds themselves (often called "hemp nuts"), Chassy is reserving judgment.
"I have a hunch it's a fairly decent protein, and this stuff is not unfairly billed as nutritious," Chassy says. "But we have not been eating this long enough to know if there are any anti-nutritional factors. That's a reasonable question to ask of any new food, and we need research to answer it.
"Proponents of hemp seed cite its high-quality protein and its digestibility. It is incorporated into granolas as well as snack chips.
Before people started marketing hemp seed oil and hemp nuts, there was hemp rope for the world's navies and, of course, marijuana, which has unfairly contributed to hemp products' image problems. Edible hemp comes from a different plant than the intoxicating variety.
Hemp seed is the fruit of the cannabis plant, which includes three main varieties: Cannabis sativa, C. indica and C. ruderalis.
C. sativa,or hemp, is grown for its fibers and seeds, and can be used to make more than 25,000 different products including textiles, paper, paint, biofuel, particle board, cordage, cosmetics and food. It has little to no tetrahydrocannabinol, or THC, the intoxicating substance. C. indicais another story: Its dried leaves and flowers are smoked for their narcotic effect; hashish is extracted from the resin of this Indian hemp. C. ruderalishas varying amounts of THC.
GINGERED HEMP OIL VINAIGRETTE
Yield: About 1/4 cup, enough for 4 cups mixed greens
Developed for the Tribune by Nancy Ross
Preparation time: 10 minutes
3 tablespoons cold-pressed hemp oil
1 tablespoon rice vinegar
1/4 teaspoon each: pureed ginger, pureed garlic
1 tablespoon soy sauce
Whisk together all ingredients in small bowl until thick and uniform. Toss with greens to coat.
By Nancy Ross Ryan
The Chicago Tribune
July 12, 2000