Oat bran is out, olive oil is in, at least for this week. And coffee is either bad for your stomach or good for your sex life, depending on which study you believe. Oh, and watch out for peanut butter--seems it contains natural toxins that may cause cancer.
If you're tired of trying to keep up with all the research on which foods cause health problems and which can solve them, you're going to love Dr. Grant Gwinup.
Relax, says Gwinup, an endocrinologist and professor of metabolism at UC Irvine's California College of Medicine. If you have no specific health problems such as diabetes or heart disease, he says, you really don't need to worry about what you eat, as long as you don't eat too much.
"The problem in this country is not that we're missing something, but that we're all overeating," he says.
Be it burgers and fries or yogurt and wheat germ, food is just food, Gwinup says. It can't solve all our problems any more than it can cause them.
"We tend to expect too much from nutrition," Gwinup says. "It goes with the whole history of medical quackery. When chemicals were discovered, there were all these medicine men out there selling magic potions that were supposed to cure all ills.
"Then when electricity came in, people would go and get electrodes put on their bodies. Then it was radiation. I grew up in Colorado and I remember people who used to go sit in the radium mines because they believed the radiation would help them.
"Now the in thing is 'natural.' And along with that goes this craze for finding foods that will do certain things for you. It's been tremendously oversold," he says.
"These things come in and go out like crazy. Awhile back, a lot of people in Newport Beach were drinking wheat tea, because it was supposed to purify the blood. But there's no evidence to back that up.
"You are what you eat is a popular concept," he says. "But you really aren't. Too many people think that if they feel bad this way or that way, they can find some food, or some distillate of food, that will make them feel better."
While he acknowledges that chocolate "does pick you up a little" because it has some of the same caffeinelike chemicals as coffee and tea, the effect on most people isn't all that pronounced.
Chocolate does contain "a minute amount" of the amino acid phenylalanine, Gwinup says, as well as other amino acids. But he adds that there is no scientific evidence that phenylalanine is a "mood elevator" or that calcium and magnesium have "a calming effect," as dietitian Debra Underwood said in a recent Health & Fitness column on "mood foods."
"You'd get 10 times as much phenylalanine if you ate a hamburger," Gwinup says.
Food in general, Gwinup says, "has an energizing property. If you're feeling down, it's almost universal that food makes you feel better."
Gwinup loves the scene in the Woody Allen movie "Sleeper" in which Allen's character--the owner of a health-food store who is frozen after a botched hernia operation--awakens 200 years in the future and asks for wheat germ. The doctors who revive him are puzzled until someone explains that in the old days, "They thought that stuff was healthy." The doctors then explain that chocolate, fat and sugar have been found to be the healthiest foods.
"That isn't so far-fetched," Gwinup says.
The author of more than 50 scientific articles on obesity and other metabolic diseases, Gwinup received his specialist training in metabolism at the University of Michigan under the auspices of the National Institutes of Health. He has written two books for general audiences, "Energetics" and "The Gwinup Report: The Only Way to Lose Weight Without Dieting."
Mood foods aren't the only subject on which Gwinup disagrees with popular opinion. Take cholesterol, for example.
"The whole cholesterol thing is so silly. If you lower your cholesterol, you're less likely to die of a heart attack. But you may be more likely to die of other things," he says. "All the big studies show no change in total mortality no matter what the cholesterol level. Most people I know would just as soon die of a coronary event as cancer. I know I would."
Gwinup says it may be no coincidence that Nathan Pritikin, one of the best-known campaigners against cholesterol, died of cancer.
In one study conducted with women in a Scottish nursing home, those who lived longest were those with the highest cholesterol levels, Gwinup says.
People with a family history of heart disease, he says, may want to lower their cholesterol levels to reduce the risk, but they may be increasing the risk of other problems.
Then there's hypoglycemia, or low blood sugar, a popular self-diagnosis of a decade ago.
"It's a non-disease," Gwinup says. "None of the studies shows that these people are really hypoglycemic. We don't even call it hypoglycemia any more. Now it's idiopathic postprandial syndrome. We really don't understand what's wrong with them, but it's not hypoglycemia."