The green tea health claim debate continues to brew

Tue., Nov. 22, 2005

Alice Lesch Kelly and Rosie Mestel Los Angeles Times

By Daniel Costello

Los Angeles Times

Before a food manufacturer can claim on a package that a product has a health benefit, it must have permission from the Food and Drug Administration.

For years, the agency either approved or denied health claims. In 2003, however, the FDA began allowing "qualified" health claims – for when the agency believes there is some, but weaker evidence that a food or food component helps prevent a disease or condition.

Manufacturers who put a health claim on a product must post the FDA's position in its entirety (not just the favorable stuff).

Following is a partial list of foods and ingredients that the FDA has decided merit a health claim, a qualified health claim or no claim at all:

Health claims the FDA allows:

•Calcium helps women maintain good bone health and reduce their risk of osteoporosis later in life.

• Fruits and vegetables, and nutrients from these diets such as vitamin C, vitamin A and dietary fiber, reduce the risk of some types of cancer.

Qualified health claims the FDA allows:

• Selenium, which is found in beef and tuna, may reduce the risk of certain cancers.

• Eating 1.5 ounces of nuts such as almonds, hazelnuts and peanuts every day as part of a diet low in saturated fat and cholesterol could reduce the risk of heart disease.

• Green tea may help prevent breast cancer and prostate cancer, but the link is highly unlikely.

Claims the FDA denied:

•Green tea reduces the risk of gastric, ovarian and lung cancer.

•Chromium picolinate reduces cardiovascular disease in Type 2 diabetes.

Tea, to China’s 18th century Emperor Chien Lung, was more than a whistle-wetting pick-me-up: It was “that precious drink which drives away the five causes of sorrow.”

Western businesses are banking on our buying into Chien Lung’s sentiments. In addition to selling a cornucopia of loose green teas, they have distilled the brew’s essence and added it to health bars, supplements, diet aids, gum, soft drinks and skin creams – even, in Asia, to Kit Kat candy bars.

Green tea is good for us: That mantra has been chanted in the West since the early 1990s, when studies reported that the infusion, sipped for centuries in China and Japan, appeared to help fight off cancers when drunk by lab mice or rubbed on their skin. Enthusiasm intensified after other studies revealed that green tea contained certain chemicals with cancer-fighting clout. Scientists rolled up their sleeves to figure out how it works.

Today, green tea imports are soaring.

“Ten years ago, 3 percent of imported tea was green tea. Now it’s 12 percent,” says Joe Simrany, president of the Tea Association of the U.S.A.

So confident was one doctor-turned-green-tea businessman that in 2004 he decided to petition the Food and Drug Administration to permit green teas to sport cancer-fighting health claims on their packages.

The FDA’s response: tepid. At best.

In June, the agency ruled that there was “no credible evidence” green tea fights cancers of the stomach, lung, colon, esophagus, pancreas or ovary. The agency acknowledged that the evidence for tea fighting breast or prostate cancer was somewhat better, although it also said the link was “highly unlikely” because the evidence on humans wasn’t conclusive enough.

Scientists say that despite the unanswered questions green tea still shows promise, not only as a potential cancer-protector but also against other health threats, such as cardiovascular disease and possibly Alzheimer’s. But they also are mindful that many a cell in a dish has been vanquished, and many a mouse cured of cancer, from therapies that don’t ultimately pan out in humans.

“You can build your case in cell studies and animal studies but ultimately you have to do it in humans or you can’t make a case that it works,” says Balz Frei, a professor of biochemistry at Oregon State University.

Green tea is made from the dried leaves of Camellia sinensis, an evergreen shrub native to Asia. The plant is harvested and treated in different ways to produce green tea or black tea.

Green tea is made by steaming the crushed leaves shortly after harvest, destroying enzymes so that chemicals aren’t oxidized very much. Leaves used for black tea ferment for days before they’re heated, causing the leaves to blacken and many chemical changes to within them.

Those processing differences may be medicinally important. Both types of tea are abundant in certain antioxidant chemicals called flavonoids, which obstruct the action of cell-damaging free radicals. Green tea, because it doesn’t ferment, has much higher levels of a group of flavonoids called catechins. A potent catechin, epigallocatechin gallate, or EGCG, is three to four times more abundant in green tea than black.

So, what happens to humans when they drink tea? Such studies, because they’re usually not done in controlled groups, are tricky to interpret, partly because it’s hard to measure how much tea people drink, and partly because tea-drinkers do a lot of other things. For example, it’s common in China that men who drink a lot of tea also smoke, Yang says.

The few human studies that have been done have produced mixed results. But despite the complexities, some studies do look good, scientists say.

For example, in an article published in the International Journal of Cancer in 2003, scientists looked at the eating and drinking habits of more than 1,000 Chinese-, Japanese- and Filipino-American women in Los Angeles. They reported that women who drank green tea had a 43 percent lower risk of getting breast cancer compared with women who drank no tea. The more green tea the women drank, the lower their risk of breast cancer, according to the study.

Tea has been shown to do a number of heart-healthy things. In human studies it has relaxed artery walls, potentially lowering the risk of high blood pressure, heart attacks and stroke. It reduces a process that clogs arteries – the oxidation of LDL, or “bad” cholesterol – and lowers rates of atherosclerosis in animals. It increases levels of HDL, or “good” cholesterol.

Population studies also are intriguing: Last year, for instance, a Chinese study published in the Archives of Internal Medicine reported that people who drank green or black tea had a 46 percent to 65 percent lower risk for high blood pressure.

As for fighting cancer, other human clinical studies are underway in the U.S. If these find evidence that green tea prevents cancer, tea producers say they will petition the FDA again.

If stronger evidence came to light, “we’d re-evaluate the evidence,” the FDA’s Elwood says. “Science evolves.”