A number of different metals occur in food, some of which – like copper, chromium, selenium and zinc – play an important health role but are toxic at high levels. Others play not useful function for humans.
The metals end up in food through a variety of routes, be it environmental through pollution, agricultural practices, or manufacturing and packaging practices.
The study, which was conducted by the Food Standards Agency’s Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) in 2006, studied 24 elements including metals in samples of 20 different food groups, bought in 24 randomly selected UK towns.
The aim was to estimate the dietary exposures of the elements for UK consumers.
The COT concluded that there were no specific health concerns associated with the findings, which showed that levels of most of the elements were the same or lower than in 2000, the last time the study was done.
However it did note a need for more research on specific metals of concern – aluminium, barium and manganese.
The COT’s specific recommendations were that future research should take in information on the different forms of aluminium in food and how bioavailable they are.
After noting a large variability in alumium in foods, they said this should be “clarified,” and consideration should be given to whether this represents an increasing trend.
As for barium, the committee recommended an assessment of the bioavailability of barium in nuts, as compared to barium choloride in water. A long-term human study is needed, they said, to establish the effect of barium on blood pressure, and to investigate the effects of barium in drinking water on the renal system.
This, they said, would “allow a TDI [tolerable daily intake] to be set with more confidence”.
Finally, the COT expressed the need for more information on the bioavailability of manganese – especially when coming from manganese, since that was seen to be the main contributing food group.
The FSA had not responded to an enquiry as to whether it would initiate or fund the required research, prior to publication of this article.
Arsenic and lead
Moreover, it “stressed that efforts should continue to reduce dietary exposure to inorganic arsenic and lead”. Arsenic occurs naturally, but inorganic arsenic is the most toxic form. It tends to accumulate in certain kinds of foods, such as fish, cereals and poultry. The major sources of lead, meanwhile, are down to industrial pollution and other human activities.
The full list of elements analyses is: aluminium, antimony, arsenic, barium, bismuth, cadmium, chromium, copper, germanium, indium, lead, manganese, mercury, molybdenum, nickel, palladium, platinum, rhodium, ruthenium, selenium, strontium, thallium, tin and zinc.