FOOD SUPPLEMENTS that offer health-promoting properties could also contain potentially harmful contaminants, a conference in Cork will hear later this week.
Screening has identified a number of contaminated products on the Irish market, according to Dr Martin Danaher, a senior research officer at Teagasc's Ashtown Food Research Centre in Dublin.
In particular, blue-green algae harvested from a lake in the US can be contaminated with a liver toxin, said Dr Danaher, who collaborated with Belfast company Xenosense on a screening study of about 200 blue-green algae products on the Irish market.
The project found that products with blue-green algae harvested from Klamath Lake in Oregon contained varying levels of the toxin microcystin, which can affect the liver.
"What can happen is that along with the good algae which has health-promoting properties you can also harvest toxic algae," said Dr Danaher, who will discuss the findings at the annual meeting of the Irish Society of Toxicology (IST) at Jurys Cork Hotel on Thursday.
"Generally the [toxins] make you sick. The people selling the tablets claim that this is the natural detoxification process," he said. "The levels in the tablets mean if you were taking them over a long period of time there might be cause for concern but over a short period it's probably of no significance."
The safefood-funded biosensor project also screened Spirulina blue-green algae products, which are grown under controlled conditions, and they came up clear for the toxin.
"I would say that Spirulina are safe, from our work there, no [microcystin] toxin in them," said Dr Danaher, who suggested that consumers contact the Food Safety Authority of Ireland if they have concerns.
Consumers should be wary when buying food supplements, said Christopher Elliot, professor of food safety at Queen's University Belfast, who will also speak at the IST conference.
"In many cases the products are from bone fide companies and the contents are well characterised and described. However, this is not always the case," he said. "Some products contain 'health-giving ingredients' that are not fully understood. They have shown some beneficial properties but the possible downsides of consumption have not been fully explored."
Prof Elliot described the message to consumers as straightforward: "Don't think of these supplements as a substitute for a healthy lifestyle; a balanced diet and regular exercise remain the best way to maintain your health," he said.
"While it may be wise to buy shoes and CDs over the internet, I would advise people to think twice before purchasing any food supplement with claims of wondrous properties.
