On average the organically grown vegetables were 10 times higher in minerals than the supermarket samples. Some were higher and the zinc level in silverbeet was 228 times higher.

So how important are these higher levels of minerals? The Natural Health Society of Australia opinions that even on a good diet, low in junk foods, many people will not be getting sufficient minerals unless the foods are organically grown.

Plants require over 20 minerals, more than are supplied by chemical fertilisers. Artificial fertilisers tend to inhibit the uptake of other soils nutrients and the unbalanced nutrient supply can cause deficiencies, eg: increased potassium uptake can depress magnesium levels.