Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: WEDNESDAY, January 6, 1993 TAG: 9301050211
SECTION: EXTRA PAGE: 1 EDITION: METRO
SOURCE: DAVID JACOBSON THE HARTFORD COURANT
DATELINE: LENGTH: Long
DESIGNER FOODS MAY ACTUALLY FIGHT CANCER
When it comes to nutrition and cancer, the bad guys are pretty well known. To hear some scientists tell it, the average American diet, full of fat and low in fiber, seems almost designed to yield some of our most common and deadly forms of cancer.But fruits and vegetables, the good guys in this nutritional battleground, may not be as well understood. It's known that people who eat a variety of fruits, vegetables and grains are at lower risk for getting cancer.
Obviously, the fact that these dietary good guys are low in fat and high in fiber helps. But even if fat intake and vitamin intake remains the same, "You still get an independent protective effect from fruits and vegetables," says Carolyn Clifford, chief of the diet and cancer branch of the National Cancer Institute.
So what else in fruits and vegetables makes them such potent cancer fighters? Recent research funded by the cancer institute has focused on the role of phytochemicals (literally meaning "chemicals from plants").
Little known to the public, these substances have been considered nutritionally "non-essential," as opposed to "essential" minerals and vitamins, such as vitamin C.
But "some of these non-essential components, when fed to animals in a purified chemical form, have been shown to have . . . anti-carcinogenic activity," Clifford says.
Indeed, some researchers even argue that our foods should be enriched with increased amounts of phytochemicals, or at least given standard quantities, to create so-called designer foods for cancer prevention.
Clifford emphasizes that the cancer institute's research projects "are in their infancy" and are not aimed at this stage at developing designer foods.
But, she adds, "The technology is available to modify the composition of foods and the levels of various chemical compounds in foods. The science is lagging behind in being able to tell people in plant breeding, food processing, etc., as to what compounds are effective and at what levels they are effective. The [institute] is trying to increase the scientific base."
As a toxicologist and program director at the National Cancer Institute in the late '80s, Herbert Pierson spent three years analyzing reports of anti-carcinogenic phytochemicals in American and European medical literature.
His research turned up groups of phytochemicals such as flavonoids, which are found in oranges. "The major [flavonoids] have been studied in animals against powerful chemical carcinogens," he says.
dreds of chemical pieces in the orange juice puzzle by mixing it with different solvents and spinning it in centrifuges. Chemicals were further sorted by their different boiling points.
But, Miseo notes, "The phyto-chemicals we were looking for changed over time. The concentrations of some of them decreased, and the concentrations of some of them increased. Enzymes are . . . affected by oxygen, so chemical reactions are still occurring in that stuff . . . in your refrigerator."
In the case of some of the targeted, potentially helpful phytochemicals, "after a while the concentration drops off, so you'll have to start drinking a gallon of juice as opposed to a glass" to get the same amount, Miseo says.
Also, "the concentrations of those phytochemicals are different depending on what [strain] of oranges you look at."
New institute-sponsored studies are comparing how well fruit and vegetable fiber alone protects laboratory rats against chemically induced cancer. Effects of the fiber are being compared with the effects of whole fruits and vegetables, presumably with phytochemicals and essential nutrients intact.
Pierson, meanwhile, has left behind what he describes as infighting and constraints in the government bureaucracy to be a consultant to the food industry.
"We've got more information staring us in the face that we need to put into applications than we've ever had before," he says. "These materials should be formulated into our everyday foods."
Given our rising preference for the quick and convenient, he argues for "well-designed food as supplements of a total healthy diet."
"Imagine a 5 1/2-ounce food bar that would have in it the [phytochemical equivalent of] the government's [recommended] five half-cup servings a day" of fruit and vegetables, he says. "You hop in the car and eat the bar on your way to work. I've had more offers from industry to develop such a food bar than I know what to do with."
At the least, Pierson advocates developing foods that would standardize the level of phytochemicals in our diet.
"What the government says is, `Eat a wide variety of things,' and it's like, `Hopefully, you'll eat something good today.' . . . That's too random for what I want to do with my own body and my family's.
"I want to have stuff standardized so that each day I'm getting [phytochemical] levels in my system, and therefore I'm building blood levels that are going to bathe the tissues and do what all the thousands of reports say they're going to do - and that's protect me."
But others, while supporting further research, are not so sure designer foods are warranted just yet, especially until effective and safe levels are determined.
"The bottom line . . . is that a lot of this evidence is still preliminary," says Bonnie Liebman, director of nutrition at the Center for Science in the Public Interest.
"I'm not sure I want them putting flavonoids in pizza five years from now."
In the meantime, most American consumers could increase their intake of phytochemicals and improve their overall diet by eating the five daily half-cup servings of fruits or vegetables recommended by the National Cancer Institute.
Nearly four of five Americans failed to meet that recommendation, the institute's August 1991 survey, the most recent, indicates.
"These phytochemicals are available today, at least in some quantity," Liebman says, "in the produce section of your supermarket."