Professor Richard Mithen of the National Food Research Institute, is quoted by Andrew Purvis (Food Magazine 15th May) as stating that my evidence on the decline in trace elements in food is “merely anecdotal”. I do not consider that data collected by McCance and Widdowson for the Government using robust and proper analytical methods, is anecdotal. It is factual data. You can argue as to the cause but the bottom line is less. He is also wrong to dismiss the loss of trace elements as irrelevant to health. He seems unaware that selenium, along with copper, manganese and zinc are essential components of the bodies own defence enzymes against membrane and intracellular peroxidative damage considered to be a major cause of DNA damage, cancer and heart disease.

Professor Mithen is right in saying that liver is a better source of iron than carrots. However, the people who need iron most are pregnant women. The Department of Health several years ago told pregnant women not to eat liver because of the near toxic levels in liver of vitamin A used as a growth promoter in animal feeds. He also stated that his children ate far more oranges now than his grandparents ever did – I wonder if the same applies to those children we saw in the Jamie Oliver ‘expose’ of school meals? Their intake of micro nutrients is/was near negligible. Is he suggesting they should/would eat 10 tomatoes to receive the same amount of copper as was present in 1 tomato in 1940? Lets get real! What’s happened to common sense!

David Thomas.