Manganese

Manganese is a trace element (needed in amounts of a few milligrams) found in many enzymes. It plays a part in the metabolism of carbohydrate, fat and protein, the formation of bone and cartilage, wound healing, and above all antioxidant defence (it is central to mitochondrial superoxide dismutase, SOD2, a major antioxidant enzyme).

The original angle (the mineral nobody notices): manganese is one of the most discreet micronutrients: it is rarely talked about, and pure deficiency is rare because it is widely distributed in plant foods (wholegrain cereals, nuts, tea, green vegetables, pulses).

Yet its mitochondrial antioxidant role is crucial: SOD2 protects the mitochondria from the free radicals they produce while making energy. Without manganese, this first line of defence is compromised, exposing the “power plants” of the cell to oxidative stress.

Tea, an unsuspected concentrated source: tea (especially green) is remarkably rich in manganese, one of the most concentrated sources in the diet. A regular tea drinker gets a significant share of their intake from it.

The paradox of toxicity by inhalation: a particularity: while excess manganese from food is rare and not very problematic (the body regulates it), excess by inhalation (industrial dust, welding) is neurotoxic and can cause a syndrome close to Parkinson’s disease (“manganism”). It is an occupational health issue, not a dietary one.

Interactions: manganese absorption is reduced by iron (the two compete), so people taking high iron supplements may absorb less manganese. The phytate in plant foods also reduces its absorption.

Sources: wholegrain cereals, nuts (especially hazelnuts and pecans), tea, pulses, spinach, pineapple, brown rice, cloves.