THE VIRGINIAN-PILOT
Copyright (c) 1995, Landmark Communications, Inc.
DATE: Thursday, August 10, 1995 TAG: 9508090044
SECTION: FLAVOR PAGE: F1 EDITION: FINAL
SERIES: Fitness Quest
SOURCE: BY MARY FLACHSENHAAR, SPECIAL TO FLAVOR
LENGTH: Long : 146 lines
THE HEADLINES come at us faster than we can digest them.
Maybe it's just as well. News flashes about food can be so confusing and contradictory that the consumer who tunes in to every sound bite is likely to wind up with indigestion.
On the advice of experts, we shunned eggs and red meat for a long time. Now these foods are making a comeback, with the experts' blessing.
Margarine is better than butter, we were told - until recent stories educated us about the evils of the other spread.
We've read that pasta makes us skinny. That pasta makes us
We've been told to beware of Chinese and Mexican food. Popcorn. The sandwich.
We've been tempted by the alleged powers of garlic, onions, oat bran.
We've been told food is bad for us. Except when it's good for us.
Considering the challenge of interpreting the nutrition news that is dished out to us daily, it is no wonder we all need vitamins.
Or do we?
What we need, surely, is a reliable recipe for dealing with the food and nutrition updates that have become a staple in the American way of life over the last several decades. Especially the scary stories (``hot dogs linked to childhood leukemia'') and the contradictory stories (``low-fat is good, low-fat is bad'').
Dazed and confused by the abundance of information, many Americans simply ignore it. Others devour every morsel, ready to make a grand lifestyle change at the mention of a study.
A wiser approach, say the professionals who conduct and interpret food research, lies in the conservative middle of those two roads.
According to registered dietitian and author Elizabeth Somer, consumers need to take food news with a grain of salt - keeping in mind, of course, that too much salt is a no-no. Somer and others in the field agree that the biggest mistake American consumers make is assuming that every study is definitive.
``There are no black and whites in the study of nutrition,'' said Somer, of Salem, Ore. The editor of a nutrition newsletter for medical professionals, she reads hundreds of food studies a month.
``One or two studies does not a conclusion make,'' she said. ``If you did 100 studies on a subject, some will prove a point, some will disprove it. In science, there is no such thing as a one-study approach.''
The media, however, often prefer headlines that are ``sexy and newsworthy'' rather than accurate, said Somer, who has written five books on nutrition. An example, she said, is the brouhaha about betacarotene.
``I have 100 studies in my files that say that betacarotene lowers the risk of lung cancer,'' she said. ``Then along comes one study that finds that betacarotene increases lung cancer risk.''
That headline got more attention than it deserved, she said, and much of the coverage failed to put the study in its proper perspective.
``After hundreds of studies, we have to examine where the preponderance of evidence lies,'' Somer said.
Just because one study disagrees with another doesn't mean either is bad, said Bonnie Liebman, director of nutrition for the Washington-based Center for Science in the Public Interest, a consumer advocacy group.
``The flip-flop is a common occurrence in science,'' said Liebman, citing the change of position on margarine as an example. ``Consumers need to learn how science works.''
Science works slowly, taking occasional steps backward and sideways as it moves forward, say those in nutrition science. Consumers who understand the complexity of acquiring and interpreting food research will be less likely to swallow whole every new food scare.
Nutrition research is difficult to perform, said Dr. Aaron Vinik, director of the Diabetes Research Institute at Norfolk's Eastern Virginia Medical School.
``Obtaining a uniform patient population is very hard,'' Vinik said. ``What pasta will do for an Italian, it may not do for an American. The genetic makeup and the digestive tract are just two of many differences between the the Italian and the American. These differences will factor into the findings, even though the two people are eating the same food.
And sometimes a food that seems to be the same really isn't, he added. ``In a study involving vegetables, the same vegetable is going to be prepared differently in Toronto than it is in North Carolina,'' he said.
When people are asked to recall what they've eaten in the past for nutritional research, the results are clouded by recall bias.
``But it's even hard to find out what people are eating today,'' said Dr. Susan Nitzke, a professor in nutritional sciences at the University of Wisconsin.
``I might exaggerate the amount of fruits and vegetables I've eaten if I know that's what the researcher wants to hear,'' Nitzke said. ``I might feel self-conscious about eating a brownie and not report it. When I eat at someone else's house, I don't know the recipes so I really can't tell you everything I've eaten.''
The type of study also flavors the results.
The findings of a study involving hundreds of subjects for years will be more credible than one that follows two dozen people for a couple of months. For instance, the connection between dietary fat and heart disease is undisputed because it has been demonstrated in hundreds of studies over the last 50 years.
Animal studies, while more useful than test-tube studies, can't always be applied to humans. And sometimes, potentially harmful substances are involved.
Epidemiological studies, those that track disease in a certain population, are important but shouldn't be accepted as the final word on a subject. For example, Nitzke said, the fact that Japanese women eat less fat should not be interpreted as the reason they have less breast cancer until other types of more controlled research, in science labs and clinical trials, make the same connection.
Three recent studies connected consumption of hot dogs to childhood cancer, but most nutritional researchers caution that it is too early to tell whether the hot dogs are responsible for the higher incidence of the disease.
``It might be something else in the eating habits or lifestyle of children who eat lots of hot dogs,'' said Somer, the Oregon dietitian. ``Maybe they drink more pop. Or watch more TV.''
Said Dr. Elisabeth Schafer, a professor of nutritional biochemistry at Iowa State University: ``People are always looking for simple, single cures.''
There aren't any, she said, adding: ``The most important thing to remember is that scientific truth is built up piece by piece and requires an accumulation of evidence.''
The public has to learn to distinguish between the latest bulletin and information based on years of study, said CSPI's Liebman.
``It's important to remember that most sound dietary advice hasn't really changed much over the last couple of decades,'' Liebman said. ``Virtually every health authority will tell you to eat more fruit and vegetables and whole grains, to cut back on fat and salt.''
That is the type of sensible advice given by government agencies such as the National Cancer Institute and large private groups like the American Heart Association, Liebman said. These groups are conservative and unbiased and have looked at years' worth of research before drawing conclusions.
``At the other end of the spectrum is a story by so-and-so from Podunk Institute reporting on one rat study in a journal nobody ever heard of,'' said the University of Wisconsin's Nitzke.
A headline about the USDA's Dietary Guidelines might not be as seductive as the supermarket tabloid that promises licorice will prevent heart disease.
But it will be a lot closer to the truth. MEMO: The Virginian-Pilot's Fitness Quest is a six-month project to inspire
our readers to adopt a healthier lifestyle. Through the end of the year,
we are focusing on health, exercise and diet, as well as reporting
monthly in the Real Life section on four people's quest for fitness. To
learn more about Fitness Quest, call Infoline at 640-5555 and then press
BFIT (2348).
ILLUSTRATION: Color staff drawing by John Earle
by CNB