Why was the Mad Hatter in Alice in Wonderland mad?

Probably a victim of mercury poisoning because felt hatters used mercury to polish their top hats. You and your dentist could also be at risk, as mercury is one of the most toxic poisons known to man.

Mercury vapour is continuously released from amalgam fillings which are a mixture of several metals, mercury comprising the largest part. The amount of released vapour increases when chewing, especially hot or acidic foods.

Once in your mouth, it becomes methyl mercury which is 100 times more toxic than plain, elemental mercury.

If you constantly ingest mercury, expose your skin to it or inhale mercury vapour, you have a higher risk of immune, digestive, hormonal and cardio- vascular disorders, damage to liver and kidneys, dermatitis, neurological and mental deterioration.

Research even shows that mercury from dental amalgam fillings increases antibiotic resistance in bacteria.

Methyl mercury also crosses the placental barrier,so the British Dental Association very thoughtfully advises pregnant women not to have treatment on any mercury containing fillings. Fair enough, but what about the rest of us?

Mercury can remain in body tissues for years, even once the source has been removed. It is especially toxic to brain and nerve tissue. Diagnosis is elusive, as not everyone reacts in the same way.

To identify metal poisoning, a variety of tests are available to nutritionists, such as liver detoxification profiles and hair mineral analysis which provide information on the presence and levels of toxic minerals.

Besides amalgams, other sources of mercury include skin lightening creams, contaminated fish, fungicides, insecticides, paper products and photographic supplies.

Foods that help to detoxify mercury include garlic, onions and protein high in sulphur-containing amino acids. Fibre-rich foods such as unprocessed organic grains, fruits and vegetables promote excretion of toxic metals. Fruits with their cores (apples, pears) contain pectin which latches on to the metals and escorts them out of the body.

Alfalfa and organic vegetable juices also help to displace them. Nutrients are essential for a mercury detox: Selenium and vitamin E work together in neutralising the effects of mercury.Other useful nutrients are vitamins A, C and the bioflavonoids, B vitamins, lecithin, N-Acetyl-Cysteine and the herb silymarin.

Only humans, in their wisdom, put toxic metals into their mouths. The question is whether the health of a tooth matters more than the health of a person.

Safe, affordable replacement dental materials are needed.

To coincide with publication of his book Menace in the Mouth, leading dentist and amalgam critic Dr Jack Levenson is hosting an evening seminar in London. For tickets, or his book called What Doctors Don't Tell You on 020 8944 9555.