High levels of dietary manganese up fatal heart infection
Excessive intake of the mineral manganese can be toxic to the heart, according to a new study.
Manganese can be found in leafy vegetables such as spinach and kale as well as in pineapple, nuts, and tea.
A study in mice conducted by Dr Eric Skaar, the Ernest W. Goodpasture Professor of Pathology, Microbiology, and Immunology at the Vanderbilt University Medical Center in Nashville, Tennessee, US showed that high levels of the dietary manganese increase lethality and heart colonization by Staphylococcus aureus (S. aureus). The bacterium is also the leading cause of skin infections (eg, boils and furuncles), fatal bloodstream infections, pneumonia, as well as infective or bacterial endocarditis.
The researchers fed a group of mice with thrice the normal amount of manganese and compared with another group of mice fed with a normal diet. Most of the mice that received excessive manganese died from
S. aureus infection.
The researchers put forth an explanatory mechanism for their findings, which involves the immune system’s oxidative oxygen burst. During oxidative burst, oxygen-containing molecules are rapidly released by the immune cells into the site of infection. However, excessive manganese appears to counteract this process, rendering the calprotectin ineffective at protecting the heart.