According to a thesis from Sahlgrenska Academy the intake of fatty food can worsen the fighting capacity of the immune system. The trial was carried out on mice who were fed for a long duration of time, a lard-based diet where 60 per cent of their total calories were derived from fat. These mice were compared with other mice that were fed a low-fat diet where no more than ten per cent of their calories came from fat and as expected the mice on the high-fat diet showed increased obesity.
The researchers were surprised when they noticed that the immune system in the mice with high fat diet was less active and that the white blood cells got worse at dealing with bacteria in the blood which could have contributed to many dying of sepsis.
Doctoral student Louise Strandberg said that obesity is usually associated with inflammation that does not result from an infection, which simply means that the immune defenses are activated unnecessarily; but in this study, the results showed the reverse as the immune system of obese mice was less active when it should really be more active. This implies that obese people are also at a greater risk of acquiring an infection. It is clear from the results of this trial that fatty food is responsible rather than obesity in itself for the reduced ability to fight off sepsis caused by bacteria.