`Superfoods' to fight cancer

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The National Cancer Institute is now trying to harness nature's most powerful preventives

EAT YOUR FRUITS AND veggies and you can decrease your chances of getting certain kinds of cancer. We've been saying it for years. Now the National Cancer Institute (NCI) is poised to go us one step better. Recently they launched the Designer Foods Research Project with one aim in mind: to hunt down nutrients known as phytochemicals locked inside common fruits, vegetables and other edible plants (like herbs, grains and spices), and find some way to concentrate these natural cancer preventers into new foods-- superfoods with super potential. You could call it Prevention Cuisine in a lab coat.

When they've completed their work, the NCI may very well have in their hands the future's first cancer-prevention menu--a full-blown attempt to stop the disease before it starts. Here's the strategy:

1. Identify the most powerful cancer-fighting substances found in fruits, vegetables, herbs and other edible plants.
2. Calculate their ideal concentrations and most potent forms.
3. Then test them in controlled trials with high-risk or cancer patients to see if they really can stop the disease.

The mission is to stamp out the unpredictable. "Foods are complex substances," says Herbert Pierson, Ph.D., an NCI toxicologist and director of the five-year study. "A food grown in one part of the country may have significant chemical differences from the same food grown in a different location. How it's then extracted, processed or prepared also plays a big role." Because of these inconsistencies in composition, it's difficult to determine how a fruit or vegetable may affect someone's health, he says. The cancer-fighting nutrients targeted in this program, however, would be engineered into their purest and most powerful form-- approaching the same beneficial consistency of a mass-produced, heavily researched therapeutic substance. Newly designed, they may become edible medical missiles aimed at preventing cancer.
DIETS BY DESIGN

Phytochemicals are simply chemicals found in plants that may protect them against stresses (like being eaten by animals), climate and infection. Some vitamins and many organic molecules are collectively referred to as phytochemicals. Researchers think theirprotective power may not be limited to just plants, however--humans may have something to gain from them too.

"We're going after common foods plus some ingredients that peopledon't know much about but have been eating for years," says Dr. Pierson. "Human safety and potential anticancer activity are the major criteria."

Right now the Designer Food Project is in the diaper stage--researchers are busy trying to find and fingerprint the phytochemicals while attempting to understand how they work and if they have anticancer properties.The territory's fresh, but the NCI researchers believe these nutrients may help armor the body against cancer through three mechanisms:

* by blocking E2 prostaglandin's tumor-promoting power. This prosta-glandin is one of a group of fatty acids that perform a variety of hormonelike actions in the body. "Even though this prostaglandin is essential for the body, somehow it gets deregulated, becomes harmful and gathers in cancerous tissues," says Dr. Pierson.
* by shunting estradiol, the major estrogen in a woman's body, away from tissues at risk like the breast and uterus. "When estradiol is activated, it too can act as a tumor promoter," says Dr. Pierson.
* by hastening detoxification of certain foreign, harmful chemicals sothey leave the body faster.

THE FOOD 'PHYTERS'

The NCI will look at an array of familiar foods--and the not-so-familiar substances inside them. Some sport names that could unravel a spelling-bee judge. Here's a quick rundown on some of these key players on the NCI Designer Foods research lineup:

Garlic Evidence concerning garlic's anticancer benefits in people is preliminary but has been mounting steadily. Mark Bricklin's column, in October last year, told you about three different studies looking at garlic consumption and cancer risk. One found much lower stomach-cancer rates in people with high garlic consumption, while another found lower stomach-cancer rates from the same healthy-eating habit. The third study reported high consumption of garlic being linked to lower incidence of colorectal cancer.

How might this odoriferous little package play a role in all this? Take a whiff of the stuff and you've alreadyhit on a clue. The sulfur-containing substances that give garlic its pungent, elevator-clearing aroma are also what give it its anticarcinogenic activity.

"Research in mammals suggests that the sulfur compounds in garlic can inhibit prostaglandin metabolism," says Dr. Pierson. "They may also enhance parts of our immune system and intercept carcinogens when they're activated in our body--preventing them from damaging our cells."

Creating the right recipe that highlights the most powerful phytochemicals in garlic will take time, though. "The actions of these compounds may depend on how the garlic's prepared," says Dr. Pierson. "Raw garlic would contain a compound that does one thing, while garlic sauteed in a spaghetti sauce would contain another compound that does something else.

Flaxseed Inside flaxseed lurk two major classes of compounds that have been linked to cancer-preventive activity. One is the lignans, a type of fiber that may interfere with potentially dangerous estrogen activity on tissues vulnerable to cancer.

"Reports indicate that women who are vegetarians most of their lives have the lowest rates of breast cancer," says Dr. Pierson. "The high urinary lignan levels in vegetarians are thought to be derived from their fruit-and-vegetable diets. Research indicates that lignan levels in people who eat flaxseed approach those of vegetarians." Further research will help determine if the key anticancer factor in the vegetarian diet is low-fat food intake (which has been linked to lower breast-cancer risk) or substances like lignans or other phytochemicals. Several types of lignans from other medicinal plants have been used in cancer chemotherapy, he says.

Flaxseed is rich in alpha-linolenic acid, one of the omega-3 fatty acids. "It's essentially a plant version of fish oil," says Dr. Pierson. "Research suggests it may block the action of cancer-promoting prostaglandins."

And in Canadian studies done in animals, certain kinds of flaxseed have been shown to significantly block breast and colon carcinogens.

Licorice The licorice the NCI is chewing on isn't the candy-store kind (which is related to parsley), but rather the root originating from the Legume family. Preliminary test-tube research suggests that one class of phytochemicals called triterpenoids, along with other compounds, may stifle quick-growing cancer cells, block prostaglandin production, and cause some precancerous cells to return to normal growth--in a sense heading cancer off at the pass. "It may also help regulate the way we detoxify and get rid of foreign materials from our body," says Dr. Pierson.

Citrus "Chemically speaking, citrus stands out as a rich source of natural products that have been indicated as cancer preventives in much of the literature," says Dr. Pierson.

To track this wide and somewhat woolly spectrum of chemicals inside citrus fruits, Dr. Pierson is prepared to conduct basic research on how the phytochemicals are absorbed into the blood and how they might affect metabolism in humans. "The beauty of citrus, however, is that several classes of phytochemicals are highly likely to act more powerfully when they are present as a natural mixture than when they appear separately," he says. Research may evolve around different blends of citrus fruits developed into a combination food, which will then be tested in a clinical trial. Some of the phytochemicals Dr. Pierson is looking at include flavonoids and carotenoids, found in citrus fruits. "Both help to protect cells in the body because as antioxidants they help fight free radicals," he says. Free radicals are destructive oxygen molecules formed in the body by anything from body processes and infections to cigarette smoke and pollution. Beta-carotene and vitamin C, both free-radical-quenching antioxidants, are linked to cancer-preventive activity. Other phytochemicals found in citrus, called terpenes, may also help head off cancer-causing agents, suggests Dr. Pierson.

Cruciferous vegetables These contain indoles and include cabbage, broccoli and kale. Indoles may inactivate tumor-causing estrogen that targets the breast. And in animal tissues, they've been shown to switch on enzymes that prevent exposure to carcinogens.

Umbelliferous vegetables The key cancer fighters here might include celery, parsley, parsnips and beta-carotene-rich carrots. "We're interested in these vegetables because they contain a great variety of phytochemicals," says Dr. Pierson. "To harness anticarcinogenic activity, a combination of these vegetables would probably work best."

Soy "Soybeans contain compounds called isoflavones, which have a natural affinity for inhibiting an enzyme that gets overproduced in precancerous stages," says Dr. Pierson. "Soybeans are also extremely rich in other phytochemicals that may have anticancer properties."

Green tea "Many constituents in green tea are capable of blocking cell mutations," says Dr. Pierson. "The Japanese, by drinking three to five cups a day, deliver a gram of flavonoids into their bodies each day." The green-tea flavonoids have demonstrated significant cancer-preventive activity in laboratory animal models of human cancer. Evidence suggests the dietary habit of routinely drinking green tea may be one factor linked to a decreasing incidence of gastrointestinal cancer in Japan, he says. The tea also contains a wide variety of other antioxidants.
TODAY'S DIET, TOMORROW'S DRUG

According to Dr. Pierson, it's too soon to expect doctors to write out prescription recipes straight from the produce section. None of the phytochemicals under investigation has yet been shown to block the formation of cancer in humans. "But once we arrive at initial conclusions, it might be possible to target people at risk for breast, uterine, colon and perhaps even lung cancer, for more detailed studies."

Until then, you shouldn't put off helping yourself to the arsenal of potential disease-fighting weapons you've come to know well within these pages. And in a few years, it may besecond nature to pick up a bottle of carrot juice chock-full of cancer-beating nutrients and phytochemicals.

Says Dr. Pierson, "Isn't it time for us to protect ourselves as we develop from youth to old age? This program is the first step in that direction."

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By Greg Gutfeld

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