By Lynne Peeples
NEW YORK (Reuters Health) - Reducing the price of healthy foods could land more whole grains, carrots and bananas in shopping carts, even months after the discounts are removed, according to a new study.
"Traditionally there has been a reliance on nutrition education to promote healthier diets," the study's lead researcher Dr. Cliona Ni Mhurchu of the University of Auckland in New Zealand, told Reuters Health by email. "These results highlight the importance of adding regulatory interventions to the mix rather than relying too heavily on personal responsibility."
As rates of obesity continue to rise in much of the developed world, so does the urgency to improve people's food choices. Ni Mhurchu and her team conducted a six-month trial across eight New Zealand supermarkets to determine the effects of two strategies: price discounts and nutrition education.
A total of 1,104 shoppers were randomized to receive a price discount on healthy foods, tailored nutrition education, a combination of the two or no intervention. Healthy foods, as recognized by New Zealand's Heart Foundation, were 12.5 percent cheaper for those randomized to receive discounts. Participants assigned to nutrition education received monthly packages of food-group-specific information, which were tailored to their shopping history. Handheld barcode scanners recorded all supermarket purchases.
According to a report in the American Journal of Clinical Nutrition, after six months of intervention, participants receiving price discounts bought approximately 1.7 more pounds (790 grams) of healthy food per week compared with those not randomized to pay the lower prices.
This was an 11 percent increase from purchases made prior to the study and included just over a pound (480 grams) more fruits and vegetables per week, or about six servings. The total difference dropped to around 0.8 pounds (380 grams), but remained significant, six months after the study was over. No consistent differences were found between the groups in the amounts of purchased saturated fat or other nutrients.
The fact that nutrition education was unsuccessful in improving food choices initially surprised Ni Mhurchu, especially since previous research had shown positive effects. Most of those studies, however, used self-report rather than the more objective supermarket sales data. Still, she said, her study participants were generally more informed and interested in healthy eating than average individuals, which could have masked education's true impact.
Nutrition enthusiast or not, everyone likes a bargain. "The price reductions may have provided an additional incentive over and above health to buy healthier foods," explained Ni Mhurchu. And although these reductions didn't change the quantity of unhealthy food purchased, almost two thirds of the additional healthy purchases were fruit and vegetables -- low caloric foods that Ni Mhurchu thinks most people need to consume more of anyway.
"We believe that regulatory options to reduce the price of healthy foods have an important role to play and deserve more consideration," said Ni Mhurchu, noting that the price reduction reflects the likely effects of removing taxes from healthy foods.
"Other pricing options to improve diets include subsidies on healthier foods, subsidies targeted to low-income populations, or working more closely with the food industry to produce cheaper healthy foods," the researcher noted.
SOURCE: American Journal of Clinical Nutrition, January 27, 2010.