Cutting Calories Makes it Harder to Fight Flu

(November 27, 2008) - You've heard the expression feed a cold, starve a fever. Or is it the other way around? In any case, according to new research, you shouldn't starve anything. Dieters or those who consume fewer calories during flu season could have a harder time fighting off the flu virus (Read about "Influenza"), according to the study.

The study showed that mice with a calorie-restricted diet were more likely to die during the first few days of infection than mice with a normal diet. Caloric restriction is the practice of reducing the intake of calories to 40 percent of a normal diet, while maintaining adequate vitamins and minerals.

"If you are exposed to a new strain of influenza, to which your body has not made adequate antibodies to protect you from infection, your body must rely on cells that will kill the virus," lead researcher Elizabeth Gardner said. "The natural killer cells are important in controlling the early stages of virus infection, because they act quickly once they encounter virus-infected cells. Our studies show that calorically restricted mice have increased susceptibility to influenza, and their bodies are not prepared to produce the amount of natural killer cells needed to combat the stress of fighting an infection." (Read about "The Immune System")

In Gardner's research, both regularly fed mice and calorically restricted mice exposed to the virus exhibited decreased food intake as they tried to fight off the infection. Yet the mice on calorically restricted diets took longer to recover and exhibited increased mortality, weight loss and other negative effects. Even though both sets of mice had a diet fortified with appropriate vitamins, the mice consuming normal amounts of food had their appetites back sooner and recovered faster.