Wines from 13 different countries contain potentially hazardous levels of metals, according to a chemical analysis by British scientists.

The findings suggest that the health benefits of drinking red wine may often be counter-balanced by risks posed by excessive levels of metals such as copper, manganese and vanadium, researchers at Kingston University said.

Wines whould also be labelled with their ion metal content, and manufacturers need to introduce new methods to remove the potentially hazardous material from their products, they said. Metal ions are charged atoms, which play an important role in body biochemistry but which can also be hazardous in excess amounts.

The study, by Professor Declan Naughton and Andrea Petróczi, used a system of risk assessment known as target hazard quotients (THQ), developed by the US Environmental Protection Agency, to examine the risks from metal ions in wine.

The THQ gives an indication of risk based on published upper safe limits for chemicals, and probable levels of consumption and body weight. A value of one is considered safe, though higher scores may also pose no risk because the system is designed to avoid underestimating hazards.

Only wines from Italy, Argentina and Brazil did not exceed the threshold risk THQ of one, the scientists reported. Wines from other countries, including popular producers such as France, Germany, Austria and Portugal, regularly exceeded this.

Typical THQ values ranged from 30 to 80, while Huungarian and Slovakian wines reached as high as 300. Both red and white wines scored poorly in the survey. Details of the research are published in Chemistry Central Journal.

“These values are concetning, in that they are mainly above the THQ value of 1.0,” Professor Naughton said. “Excess intake of metal ions is credited with pathological events such as Parkinson’s disease.

“In addition to neurological problems, these ions are also believed to enhance oxidative damage, a key component of chronic inflammatory disease which is a suggested initiator of cancer.”

The health-enhancing properties of red wine are generally attributed to the presence of antioxidant chemicals, which can fight oxygen damage to cells. Metal ions, however, can promote this oxidative process, and excessive amounts may thus counteract any health benefit of drinking wine.

The scientists said: “The results from this study also question a popular belief about the health-giving properties of red wine: that drinking red wine daily protects you from heart attacks is often related to levels of anti-oxidants. However, the finding of hazardous levels of metal ions, which can be pro-oxidants, leads to a major question mark over the protective benefits of red wine.

“Levels of metal ions should appear on wine labels, along with the introduction of further steps to remove key hazardous metal ions during wine production.”

In a separate study, published in the journal Nature, scientists have found that eating red meat could “prime” the body for infection by the food-poisoning bacterium Escherichia coli.

esearch led by Professor Ajit Varki, of the University of California, San Diego School of Medicine, has found that red meat releases a type of sugar molecule called Neu5Gc that is not normally found in human cells. This sugar is targeted by a potent bacterial toxin produced by E. coli, and may thus make infections more likely and more virulent.

Professor Varki said: “Ironically, humans may set themselves up for an increased risk of illness from this kind of E. coli bacteria present in contaminated red meat or dairy, because these very same products have high levels of Neu5Gc.”

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