A bowl of cereal and a vitamin B tablet could be excellent protection from heart disease if clinical trials successfully implicate a rogue amino acid dubbed as the "new cholesterol".

There are currently over 200,000 people involved in 15 clinical trials dedicated to investigating the acid. They are receiving folic acid and vitamin B supplements which lower the level of the molecule in the blood stream and are being monitored to see if these are effective in reducing heart disease.

It is potentially a very inexpensive and widely available therapy

Aleksander Rajkovic

The molecule in question is called homocysteine and enters the bloodstream as a by-product when the digestive system converts animal protein into energy.

Professor Rene Malinow, from the Oregon Regional Primate Research Center, told the AAAS annual meeting: "Within five years, it may be proven that 0.2 to 5.0 milligrams of folic acid per day can prevent heart attacks and strokes in patients with elevated homocysteine levels."

If the link is successfully shown, it is estimated that up to 50,000 heart attack deaths a year could be prevented by folic acid treatment in the US alone.

Sensitive tests

Folic acid is commonly added to breakfast cereals and is taken by pregnant women to help prevent spina bifida. It is an essential biochemical for the body to synthesise DNA.

New and sensitive tests for measuring levels of homocysteine in the blood have allowed researchers to establish associations between high levels and strokes, kidney failure and the pregnancy disorders, pre-eclampsia and eclampsia.

Professor Donald Jacobsen, from the Cleveland Clinic Foundation, believes the latest commercial tests for homocysteine could mean patients would be tested for the molecule as often as they are for cholesterol.

And Professor Aleksander Rajkovic, at the Baylor College of Medicine, said: "More attention and effort is needed in these areas - it is potentially a very inexpensive and widely available therapy".

Although the presence of homocysteine in the blood stream has been known about for decades, the number of research papers published doubled in the second half of the 1990s.

The burgeoning research includes a trial taking place in Scotland, which has both the highest levels of homocysteine and the highest rate of heart attack deaths in the UK - 17,000 deaths a year.