February 20, 2006
Diet Study Confusion Will Not Change Habits
By Nichola Groom
LOS ANGELES -- New studies indicating a low-fat diet does not reduce the risk of cancer and calcium supplements do little to prevent broken bones are unlikely to change consumers' habits and may only add to confusion about the link between diet and health.In the last year, researchers have released a series of medical studies that fly in the face of conventional wisdom, which holds that weight loss, nutritional supplements and diets low in fat and calories help fight disease and prolong life.
But three studies in the Journal of the American Medical Association published earlier this month showed that women who ate less fat and more fruits and vegetables did not reduce their risk of cancer or heart disease. And Wednesday's New England Journal of Medicine found that calcium and vitamin D supplements were unlikely to prevent broken bones in women as they age.
The research comes on the heels of statistics published last year that questioned the U.S. government's assertion that obesity causes nearly as many deaths as smoking.
The studies prompted headlines suggesting consumers would take the news as carte blanche to eat as they please, but experts said that was unlikely.
"Consumers are used to the fact that there are often multiple medical studies coming out that often have conflicting findings," said Michael Allenson, a principal at food industry consulting firm Technomic. "Until they see a greater consistency ... they are likely not to make a change."
Consistency, however, appears to be a long way off as theories about diet and health are constantly changing. In the last two decades, fats and carbohydrates have alternately been praised and demonized by health experts. Most recently, fear of carbohydrates like pasta and bread led to a boom in low-carb, high-protein diets in 2004 that quickly vanished.
The headline-grabbing studies against a background of diet trends like low-carb, low-sugar and low-fat forces consumers to sift through masses of conflicting as well as confusing information and ultimately draw their own conclusions.
"The public gets information in little, fragmented pieces through the news," said Dr. Walter Willett, a nutrition professor at Harvard University's School of Public Health. "If that's really all they are getting, it is extraordinarily difficult to make some sense out of what's there."
Adding to the confusion, according to some, is that while some consumers take their long-term health into consideration when eating, those concerns are typically outweighed by a preoccupation with saving time and money.
"The real problem with health is that there is no immediate payback," said Harry Balzer, vice president with The NPD Group, which tracks consumer eating trends. "If I have low-fat milk today, what do I get? Did it save me time, did it save me money? The feedback is going to get to you 40 years from now."
In addition, Allenson said, consumers usually go on diets so they can lose weight, not so they can prevent disease.
"That's not the only reason why people go on diets or eat low-fat foods," Allenson said. "A lot of people are looking to lose weight because they do feel better about themselves."
In the meantime, while researchers duke it out over the long-term benefits of diet and exercise, experts said consumers can rest assured that the conventional wisdom about maintaining a healthy weight and eating a balanced diet is more likely to help than hurt.
"What we know about diets hasn't changed. It still makes sense to eat lots of fruits and vegetables, balance calories from other foods, and keep calories under control," said Marion Nestle, a nutrition professor at New York University. "That, however, does not make front-page news."