Tea's potential health benefits have made it the new hot drink of choice
No, thanks, you say?
If so, the makers of an unusual new tea hope you'll reconsider. Brassica Tea, they assert, teams the antioxidant powers of green or black tea with those of broccoli, for a brew that claims extra oomph on the health front. And, no, it doesn't taste like broccoli.
Brassica, which recently arrived in some local stores, has joined a flood of teas clamoring for your attention as possible disease fighters.
Green tea has been the darling of health honchos for the past few years. Now, it's being challenged by white tea and by rooibos, or red tea, as well as Brassica (a brand name). And black tea is getting more respect.
All of this "absolutely" is heating up interest in tea, says Julee Rosanoff, co-owner of Seattle's Perennial Tea Room.
"What I get are many more questions about which are the teas that have the antioxidants and which are supposed to be healthier," Rosanoff said.
"I've even had people who have cancer" ask which are the cancer-fighting teas, though Rosanoff says she makes no health claims for the teas she sells.
At The Teacup, a tea shop on Queen Ann Hill, at least 20 customers a day, and sometimes as many as 50, ask about those benefits, said owner Elisabeth Knottingham.
In coffee-guzzling Seattle, sales of tea, especially green tea, are rising like steam from a tea kettle, sellers say, giving health news much of the credit.
Across the country, Americans still overwhelmingly choose coffee over tea. Yet tea sales have climbed from less than $2 billion in 1990 to more than $5 billion a year now, says Joe Simrany, president of The Tea Council, a national trade organization.
Today, tea gets star billing at some 1,200 to 1,500 specialty tea shops nationwide versus a couple dozen or so a decade ago, said Simrany, also crediting the health news.
For anyone who loves tea, its chief appeal may have nothing to do with antioxidants and a lot to do with flavor, aroma, warmth and the soothing ceremony of preparing and sipping this ancient beverage. Still, knowing it might boost health is, at the least, an attractive bonus.
Despite its possible benefits, tea is not a health panacea, advises the University of California, Berkeley, Wellness Letter. An overall healthy diet, including lots of fruits and vegetables, is essential no matter how much tea, or what kind, you drink.
All true tea, as experts define it, comes from the same warm-climate bush, Camellia sinensis. Black, green, oolong and white teas all are all made from its leaves but differ in the way they're processed. White tea also has the distinction of being made from younger leaves and buds plucked from the branch ends.
Herbal teas are made from the leaves, roots, bark, seeds or flowers of numerous other plants. Though aficionados say these are more accurately called "tisanes," not teas, this article will use the more familiar term "herbal tea."
Most of the teas spotlighted here are true teas, chosen because more controlled studies have been done on these than on herbal teas, though many herbal varieties also claim health benefits.
The exception here is red, or rooibos, tea, an herbal variety receiving growing scientific attention.
All but one of the following teas are available both loose and in tea bags and can be found in both supermarkets and specialty tea shops, in one form or another, though white tea is less commonly available. The exception is Brassica, available only in tea bags and at certain supermarkets.
Red, or rooibos, herbal tea
This herbal tea steeps to a pretty, red color and has a fruity, slightly sweet flavor. Unlike true teas, rooibos (pronounced ROY-boss) — also known as red or red-bush tea — is naturally free of caffeine.
Its source is the rooibos plant, a shrub native to South Africa, where people have made tea from it for hundreds of years. Made from the plant's dried, needle-like leaves and stems, rooibos looks like a collection of tiny twigs in its loose-tea form. These can be strained out after steeping. It's also available in tea bags.
Rooibos tea boasts an array of antioxidant compounds called polyphenols, which include flavonoids, writes science writer Laurie Erickson in her recent review of studies on rooibos for the Journal of the American Botanical Council. The article is widely considered authoritative.
Like other antioxidants, flavonoids may help ward off certain cancers, heart disease and stroke, scientists say.
Two particularly potent flavonoids, quercetin and luteolin, are found in rooibos tea, but it's not yet clear they're plentiful enough to benefit health, according to Erickson's review.
Rooibos also contains phenolic acids, antioxidants also found fruits, vegetables and whole grains.
The final word isn't in on whether rooibos has more or less disease-fighting power than green or black tea.
In looking at the studies, Erickson found that rooibos tea has less total polyphenols than the same-size serving of the those teas, but the polyphenols in rooibos are different from the ones in green or black tea, complicating the comparison.
Leaning toward green or black tea is John Weisburger, a scientist with the Institute for Cancer Prevention in New York state and one of the country's leading researchers on tea and health. Those teas edge out rooibos in antioxidant properties, he said.
Still, with all the antioxidants rooibos does have, plus no apparent adverse side effects, no caffeine and a pleasant taste, you may find this tea worth trying.
If you're not sure whether a product labeled "red tea" is rooibos, check the ingredients for rooibos. You're more likely to find loose-tea versions at specialty shops, while the tea bags are available at supermarkets.
Green tea
A bit of trivia: It was green tea that the American colonists tossed into the harbor during the Boston Tea Party to protest British taxes.
If they'd known about antioxidants, the protesters might have re-thought their actions over a cup of tea. Green tea is loaded with these compounds.
Of the true teas, all from the Camellia sinensis plant, green is nearly the least processed, after white. This may be why green tea has more antioxidant polyphenols than black tea. To make green tea, the leaves are dried and briefly steamed.
The two leading teas, green and black, contain about equal amounts of caffeine — about half that of coffee. They're also available decaffeinated.
Green tea may help protect against certain cancers, particularly prostate, stomach and esophageal cancers, says the American Cancer Society. Studies on humans are mixed, however, and more research is needed.
A tongue-twister called epigallocatechin-3-gallate (EGCG), found in green tea, is believed to block production of an enzyme required for cancer-cell growth, says the ACA. Again, more research is needed.
Tea has long been used to ease cold miseries. Now, scientists are trying to determine whether it really works, and why. A variation of EGCG found in tea may help reduce sneezing and coughing, according to some research.
Herbalists have used green tea and extracts from its leaves to ease stomach problems, vomiting and diarrhea and to lower blood pressure, cholesterol levels and the clogging of heart blood vessels, reports the ACA. Studies are examining these claims.
One study, published in the Journal of Clinical Nutrition in 2001, looked at catechins, which are flavonoids and a major part of green tea. Catechins account for nearly one-third of the dry weight of green tea and 9 percent of black tea's dry weight, said the authors.
The researchers found that elderly Dutch men who consumed lots of catechin had lower rates of heart disease. However, the catechin came from many sources in the men's diets, including fruits and vegetables as well as tea, and the researchers said more studies are needed to pinpoint tea's impact on heart health. Other studies also have linked green-tea drinking to reduced heart-disease incidence.
Of all the possible benefits of green tea, however, one may hold special appeal for overweight Americans: potentially faster burning of body fat.
"Green tea increases a person's metabolic rate," possibly aiding weight control, said Weisburger.
Black tea and white tea
Though green tea has been the big attention-getter for its possible health benefits, black tea also has merit, research indicates.
Of the true teas, black is the most processed, its leaves fermented to produce its milder taste. Black tea has been studied less than green tea, so its possible benefits are less well understood.
While black tea has less of some antioxidant compounds, such as catechins, than green tea, it appears to have more of others, according to some experts.
Drinking black tea may improve cholesterol levels, according to a study by the U.S. Department of Agriculture. Published last year, the study found that levels of LDL cholesterol ( the "bad" cholesterol) fell between 7 and 11 percent in people who drank five cups of black tea a day for three weeks, while a control group drank colored water that tasted like tea.
The researchers concluded that regularly drinking tea could be beneficial if consumed as part of a varied diet, according to a Reuters News Service report. The blind study was relatively small, however, involving 15 subjects.
Black-tea drinkers in Europe had lower heart-disease rates in epidemiological studies reviewed by Weisburger, whose review will appear as a chapter in a book by another researcher. The exact reason for the health differences is not certain, however.
Other studies have found that heart disease decreased by 11 percent with intake of three cups of tea a day, Weisburger writes.
Like green tea, black tea also appears to have anti-cancer properties, he says. In laboratory studies, for example, adding polyphenols from either black or green tea to ground meat during frying has prevented certain carcinogenic compounds from forming.
Black tea also appears to reduce pre-cancerous damage to the colon from oxidation of cells, Weisburger writes.
White tea, the least processed tea from the Camellia sinensis plant, is less widely used, more expensive and less studied than the other true teas. However, studies suggest that it, too, may have health benefits.
In laboratory tests, researchers at Oregon State University's Linus Pauling Institute found that white tea was generally more effective than green tea in inhibiting precancerous cell mutations in bacteria.
The researchers also found beneficial polyphenols in higher concentrations in white tea than in green tea brewed the same way.
Weisburger, however, believes white, green and black teas are about on a par, healthwise.
Interestingly, caffeine, which many people try to avoid, may play a role in the health benefits of white and other true teas, some scientists say.
For example, in animal studies, white tea appeared to block precancerous cell changes in the colon, but it's unclear whether that was due to its antioxidants or to its caffeine content, which is higher than that in other teas, said a Linus Pauling Institute report. The scientists also noted that results might be different in humans and said they plan further white-tea studies on people as well as animals.
Brassica tea
Brassica is the brand name of a trademarked tea that grew out of research at Johns Hopkins University. Its key feature: the compound sulforaphane glucosinolate (SGS), an apparently powerful antioxidant found in broccoli.
The developers of Brassica Tea added an extract of SGS from broccoli sprouts to green tea, black tea and rooibos tea, to combine the antioxidant force of broccoli with that of tea. (No broccoli flavor comes through.)
Broccoli has long been considered a star among vegetables for its high antioxidant content and possible protection against certain cancers and other chronic diseases. Researchers at John Hopkins University discovered that broccoli sprouts are particularly rich in SGS.
The tea's developer, Brassica Protection Products, says a cup of their tea contains as much SGS as a serving of mature broccoli.
The company has a direct link to the Johns Hopkins research: Chief executive officer Tony Talalay is the son of Paul Talalay, one of the Johns Hopkins scientists who has studied SGS. The university holds a patent on BroccoSprouts, which are sold in stores and from which the SGS is harvested.
The researchers say their studies, as well as those of others, point to SGS's anti-cancer powers, which they say activate the body's own antioxidant system. They say a French study also suggests SGS may also destroy pre-cancerous cells.
Studies also indicate SGS may help prevent macular degeneration, a cause of blindness, according to the Johns Hopkins researchers.
Whether tea with added SGS can deliver these claimed benefits is another question. The close connection between university researchers and a commercial product may also cause some consumers to pause (though such links are becoming increasingly common nationwide).
The Johns Hopkins researchers say that, in years of doing studies, they've seen no adverse side effects of large doses of SGS.
Judith Blake: jblake@seattletimes.com or 206-464-2349.