New Rx: Food That Can Heal
The diet of the future will not be designed to lose weight, but to cheat death.
Within the next few years, scientists hope to meld increasing knowledge about the genetic makeup of the human body with the equally promising use of food as medicine to customize diets that can forestall, treat or even prevent disease.
Once all of the genes in the human body are identified, and their functions understood--a task expected to be completed by 2003--researchers say they will be able to identify individuals with specific medical vulnerabilities, and give them “prescriptions” to eat.
A baby diagnosed with sickle cell anemia could be placed on a special high-nutritional diet from birth that could prevent the developmental deficits often associated with the disease. Individuals genetically found at risk of developing blood clots could be directed to eat foods that contain natural blood thinners. And those who suffer from chronic allergies, migraines or arthritis could get a steady diet of foods that counter those illnesses.
Already, researchers are studying the beneficial effects of foods on certain cancers, heart disease, menopause and other conditions, with encouraging preliminary results.
“In this generation we will be able to deliver ‘designer diets’ to individuals based on their own personal risk profiles,” said Linda Van Horn, professor of preventive medicine at Northwestern University Medical School. “We are standing on the precipice of jumping into a whole new area of medicine. This is exactly what they must have felt like 100 years ago when they discovered that vitamin C cured scurvy.”
Tantalizing reports of new food findings are emerging at a breathtaking pace--thanks, in part, to advances in lab and computer technology that have made it possible to quickly identify substances, measure them and see how they behave when combined with human cells.
“We have now incredibly powerful tools to allow us finally to ask the question: Are there things in nature that in and of themselves alter the risks of a disease?” said Dr. John Glaspy, a researcher at UCLA’s Jonsson Comprehensive Cancer Center. “Would fish oil supplementation of the American population do for breast cancer risk what fluoridating water did to tooth decay risk?”
Glaspy is chief among those trying to find out. Noting that Japanese women tend to have a lower incidence of breast cancer than Americans, he is testing their traditional diet--heavy in the omega-3 fats found in fish, and soy products--on a group of American breast cancer patients who have been treated and are currently cancer-free.
It is but one of a growing number of experiments underway in the newly emerging science of “nutraceuticals,” a field of medical research that has moved beyond studying the nutritional benefits of foods to examining their precise therapeutic effects.
Components in many foods under study--a group that ranges from blueberries to chocolate and from alcohol to garlic--already have shown evidence of lowering cholesterol, neutralizing cancer-causing substances, reducing blood pressure, soothing the symptoms of menopause, and preventing the growth of new blood vessels that feed tumors. Some may even boost the immune system.
Not waiting for final proof, some experts are already espousing the medicinal power of certain foods to some patients. They are advising menopausal women to drink soy milk, which is thought to ease hot flashes and other symptoms. They are suggesting fish high in omega-3 oils, like salmon, herring and mackerel, to patients at risk of cardiovascular disease or breast cancer. And for men fearing prostate cancer, they are advising consumption of more tomato-based products, such as spaghetti sauce--because tomatoes are high in lycopene, thought to reduce the risk of this disease.
But experts caution that final evidence is still years away--and that early conclusions are sometimes later proved wrong.
Old Theories Being Discarded
Researchers no longer subscribe to the theory that eliminating salt helps lower blood pressure, for example, and a recent study suggested that eating an egg a day does not increase the risk of coronary heart disease or stroke among healthy people.
Also, other recent research has cast doubt on whether a low-fat diet can prevent breast cancer--researchers now believe the answer may lie instead in the ratio between two different types of fat eaten--or whether fiber intake can prevent colon cancer.
“Nobody knows enough yet to definitely say do this or don’t do that--we don’t know what, how much, when and if there are any long-term effects of treating with nutrition,” said Dr. Carol Letendre, an official at the National Heart, Lung and Blood Institute.
But if the current studies prove the therapeutic powers of foods, many Americans will likely embrace the idea of eating for health. In recent years, a growing number have shown enthusiasm for more natural approaches to maintaining good health--consuming organic foods and dietary supplements and turning to less invasive procedures, such as acupuncture or homeopathy, to treat ailments.
And the food industry--recognizing a potential market--is showing similar enthusiasm, already starting to fortify cereals, soups and other products with herbs and other substances--so-called functional foods--even before science proves their effectiveness.
“Ours is the first generation of Americans seriously taking their health into their own hands,” said Beverly Clevidence, who directs the U.S. Department of Agriculture’s phytonutrients laboratory in Beltsville, Md., where researchers are cultivating a special type of the dark leafy vegetable called kale to test for nutritional properties. “They can go to their grocery stores or gardens to maintain health and prevent disease, and it can go hand-in-hand with conventional medicine.”
Thus, she and others predict that for the next generation, “dieting” will take on a whole new meaning.
“Right now when children are born we screen for 20 or 30 different diseases with one drop of blood,” said Letendre, deputy director of the institute’s division of blood diseases.
In the future, the same drop of blood could also tell new parents what to feed their child to stave off potential developmental deficiencies or other disorders predicted by the child’s genetics.
Not everyone thinks individually tailored diets will be all that popular. After all, one cannot live by broccoli alone. Once a food substance is identified as a potent agent against disease, drug manufacturers may turn it into a pharmaceutical. And, some argue, this would be an easier, safer and more efficient way to deliver these chemicals to consumers.
“If we found an ingredient in a fruit or vegetable that really did reduce the rate of metastasis in a tumor, the more efficient way to deliver that would be in a drug,” said Dr. Barbara Howard, president of Medlantic Research Institute, which conducts research for seven large nonprofit hospitals in the Washington-Baltimore area. “If you definitively found this XYZ chemical in peaches, then you would most likely purify it. I think it would be hard to get people to eat too much of one thing without affecting the rest of diet.”
It still isn’t known, though, whether the same health effects can be obtained from a processed supplement as from the whole food; some researchers believe that there may be additional factors working in combination with the chemical that convey the benefits.
While fresh vegetables have long been extolled for their healthful benefits, experts are now beginning to hone in on the scientific reasons why. They think that the class of compounds known as “phytonutrients” found in plants holds great promise for warding off breast and prostate cancers and for reducing the risk of heart disease and an age-related eye disorder called macular degeneration.
The nutrients sound like something cooked up in a test tube on a Bunsen burner--carotenoids, flavonoids, isoflavones, glucosinolates and phenols--but no lab could concoct chemicals as beneficial as those that occur naturally and can be cooked up in a kitchen, experts say.
They work by revving up the body’s natural defenses and are found in many “colorful” vegetables--those that are dark green, deep yellow and orange--and in fruits such as tomatoes and blueberries.
Researchers at Johns Hopkins University Medical School have determined that broccoli sprouts contain high concentrations of sulforaphane, an organic compound that spurs cells to produce cancer-blocking enzymes.
And scientists at the University of Wisconsin recently reported that two compounds present in fruit, vegetables and cereals can reduce the growth of some forms of cancer.
The first, gamma-tocotrienol, slows the growth of leukemia and breast cancer cells. The second, beta-ionone, also suppresses the growth of both forms of cancer, as well as colon cancer.
‘Hugely Promising’ Human Studies
At USDA’s Beltsville facility, scientists are running human studies, asking people to consume everything from fruits and vegetables to pure grain alcohol--the latter believed to lower the body’s “bad” cholesterol and raise the “good.”
In these various feeding studies, volunteers show up for breakfast and feast upon kale, sweet potatoes (yes, for breakfast) and tomato juice. Depending on the study, they would come back for lunch or dinner, and take food with them for the third meal; the USDA center has its own kitchens and dining areas and a staff of cooks and dietitians.
While the work is still in its earliest stages--at this point, they are only measuring levels of the substances in the body, such as in blood--”it’s hugely promising,” Clevidence said.
She is excited about the kale experiment being cultivated on the government’s 7,000 acres of land because it will enable scientists for the first time to see exactly where and how long the vegetable’s components remain in the body.
In the meantime, Americans can fall back on an old bromide--which Van Horn and others say is still “a good start”--mother’s advice to eat a balanced diet containing plenty of fruits and vegetables.
“I’ve been in this field for 20 years, and I continue to be incredibly amazed at how intricate the nutrients are in our food supply, and how they might serve our biological needs,” said Van Horn, who currently is studying the effect of soy on the blood lipids and hormones of premenopausal women and on cardiovascular disease in post-menopausal women. “I think God really knew what he was doing in creating the food supply.”
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It’s Good for You
Scientists believe that certain foods have health benefits for specific diseases. Among those being studied: Common Food: Kale
Key Component: lutein
Believed to LowerRisk of: age-related blindness
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Common Food: Tomatoes
Key Component: lycopene
Believed to LowerRisk of: prostate and cervical cancer
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Common Food: Sweet potatoes
Key Component: beta carotene
Believed to LowerRisk of: lung cancer
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Common Food: Broccoli sprouts
Key Component: sulforaphane
Believed to LowerRisk of: cancer
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Common Food: Apples, onions, red wine, tea
Key Component: flavonids
Believed to LowerRisk of: heart disease
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Common Food: Fish oils
Key Component: omega-3 fatty acids
Believed to LowerRisk of: breast cancer
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Common Food: Green tea
Key Component: epigallocatechin-3-gallate
Believed to LowerRisk of: cancer
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Common Food: Soy, tofu, soy milk
Key Component: soy
Believed to LowerRisk of: breast cancer, heart disease
Source: LA Times, other news reports Compiled by: Times Researcher Tricia Ford
