At a Science Media Centre briefing on Monday 20th February, Professor Edzard Ernst, professor of complimentary medicine at the University of Exeter, said that there was no scientific evidence to support the claims from natural products available on the Internet to protect against avian flu.
The products quoted by Professor Ernst included olive leaf extract, garlic, oregano oil, colloidal silver, aloe vera, Echinacea, and green tea.
"Nothing works," Professor Ernst is quoted as saying in the Guardian newspaper (February 21st). "Nothing that is within the umbrella of complementary medicine is of demonstrable effectiveness. Journalists ought to be very cautious when they hear this or that plant kills something in a petri dish.
You'd be hard pushed to find a plant that doesn't have antiviral or antibacterial effects," said Ernst.
This view was claimed to be "irresponsible and a danger to public health," by Dr. Damien Downing, president of the British Society for Ecological Medicine, and medical director of the Alliance for Natural Health, an international campaign organisation dedicated to protecting and promoting natural healthcare worldwide.
"I welcomed Professor Ernst's acknowledgement of the point made by the Alliance for Natural Health over a month ago that genuine caution should be exercised when using certain herbal remedies, such as Echinacea, in bird flu, but I am amazed that Professor Ernst appears to have no knowledge of the extensive literature on the essential nature of zinc and vitamin C, for example, when the body is dealing with infections," said Downing.
Downing says that a significant body of research backs the evidence that both zinc and vitamin C are essential for the immune system, but warned that less than ten per cent of adults in the UK have sufficient levels of zinc in their diet.
"Why is Professor Ernst ignoring the extensive evidence base on the use of nutrition to prevent and relieve viral infections?
Also, when it is self-evident that supplies of vaccines and anti-viral drugs will be too little, too late, it is alarming that no global or national health authorities have broached the subject of how people can support their immune system through the use of diet and food supplements in the event of a pandemic," added Downing.
However, Dr. Ron Cutler from the School of Biosciences at the University of East London said that any supplement that boosted the body's immune system was bad news in relation to avian flu.
The H5N1 virus is said to stimulate the immune system, fill the lungs with blood and causes death.
The two main antiviral drugs targeted at bird flu, Tamiflu and Relenza, are said to have a window of operation of between six and 48 hours from the appearance of symptoms in humans.
The British government announced today a £33m pound contract to two pharmaceutical companies to produce 3.5bn doses of vaccine, and agreed a "sleeping contract" for a further 120m doses of the vaccine.