Researchers in Japan found that cocoa can provide strong protection against the influenza virus. In the study published in the Journal of the Science of Food and Agriculture, the researchers examined the protective effect of cocoa on the influenza virus using both laboratory testing and clinical trials.
Cocoa has been known to contain biologically active ingredients that have antimicrobial activity, such an inhibitory effect on influenza virus infection.
For the study, the researchers prepared a cocoa extract by treating defatted cocoa powder with boiling water.
They used the extract to treat Madin–Darby canine kidney (MDCK) cells infected with human influenza virus A (H1N1, H3N2), human influenza virus B, and avian influenza viruses (H5N1, H5N9).
They also used the extract in mice administered with a lethal dose of influenza virus.
In human intervention trials, one group of participants consumed cocoa for three weeks, while the other did not.
In the MDCK cells, the extract inhibited viral adsorption.
In the animal experiments, the cocoa extract significantly improved survival in mice.
In human intervention trials, the consumption of cocoa increased neutralizing antibodies against the influenza virus, as well as natural killer cell activity.
The findings of the study suggested that consumption of cocoa activates the body's natural immunity and enhances immune response, providing stronger protection against influenza virus infection and diseases.
Kamei M, Nishimura H, Takahashi N, Inokuchi K, Mato T, Takahashi K. ANTI?INFLUENZA VIRUS EFFECTS OF COCOA. Journal of the Science of Food and Agriculture. 2 April 2015. DOI: 10.1002/jsfa.7197