New Study Finds that Obesity Protects Against Malaria in Mice

A new study finds that obesity protects against cerebral malaria in mice. The study, titled "Malaria and obesity: obese mice are resistant to cerebral malaria" was published in Malaria Journal. Researchers discovered that contrary to conventional wisdom, obese mice were better able to fight malarial infection than healthy weight mice. After receiving an injection of malaria, healthy weight mice succumbed to fatal infection an average of six days after exposure, while obese mice lasted an average of eighteen to twenty five days.

The relationship between obesity and malaria has not been well studied. In part this is due to the tropical countries where malaria is most prevalent have historically been third world countries which did not experience high levels of obesity. However, as the global obesity epidemic spreads across the planet, many third world countries are now experiencing increasing levels of obesity, which in some cases are approaching those of the developed world. This has led to a greater focus on combating obesity in third world countries, including tropical countries where malaria is a major health hazard.

Although differences found in mice do not necessarily apply to humans, the results of the study are striking and warrant further research. If a link between obesity and malaria resistance is found for people, this study will join other recent examples that demonstrate the complicated factors that determine sickness and health. In the human body, many conditions like obesity that are linked with increased risk for fatal disease can themselves protect against other forms of sickness. For instance, studies have shown that obese women are less likely to experience osteoporosis, which is a significant cause of injury, mortality, and decreased quality of life for elderly women.

Of course, just because obesity can result in health benefits does not mean that the risks of obesity are reduced. The challenge for researchers is to determine the cause of the positive effect and separate it from the negative factor. For instance, perhaps obese individuals store reserves of particular nutrients in fat that can be called upon to fight a malarial infection. On average, malaria kills between one and three million people annually. The most common victims of malaria are young children in sub-Saharan Africa. Obesity, on the other hand, has been linked to around four hundred thousand deaths per year, and most commonly affects adults in industrialized nations. By capturing the mechanism which protects against malarial infection, perhaps researchers will be able to reduce the risks of malaria without introducing the risks of obesity to new populations.