Around 70% of people who suffer from food related illnesses would feel better if they simply eliminated certain foods from their diet, according to nutritional scientists.

There has been a huge increase in people suffering from food related illnesses in recent years.

Medical experts believe some foods are linked to, or at least exacerbate, problems such as stomach pains, migraines, eczema, or breathing problems like asthma.

The York Nutritional Laboratory study concentrates on a type of food allergy commonly known as food intolerance.

It differs from what some experts call "classical allergies" because the body doesn't react immediately.

That makes food intolerance particularly difficult to detect - yet one in three adults in the UK suffer from it.

Researchers at the laboratory are developing new tests which will make diagnosing the condition far easier.

The traditional method involves pricking the skin with small samples of food substances, and looking for a reaction. Which? magazine has questioned their benefit.

The new tests involve simple blood tests instead.

Food changes helped

The scientists found that of those who significantly altered their eating habits, 76% said they felt better in less than 60 days, while 60% of those who made moderate changes to what they ate reported a "useful improvement" to their well-being.

Even people who had suffered chronic illnesses for up to 20 years reported improvements within months.

Seven out of 10 patients reported a distinct relief from their symptoms - many of which had troubled them for at least 12 years.

Diet might trigger asthma

Some doctors are demanding more money should be spent on tests to try to detect food intolerance rather than allowing GPs to treat the symptoms with antibiotics, painkillers and anti-inflammatory ointments.

They claim that drugs cost money, are largely short-term solutions and may even damage people's health in the long-term.

But they warn that for people to benefit from a change in diet, they must only alter their eating habits under strict medical supervision.

Discovering what foods people are intolerant to often takes time.

It usually has to be done by a process of elimination, with certain foods being reintroduced to the diet over a period of months when no adverse reaction occurs.

Wheat: potential problem for allergy sufferers

The most problematic food for people with an intolerance is cow's milk and dairy products. This affects 55% of people who are sensitive to what they eat.

Other problem foods include wheat, yeast, and eggs and soya.

Some claim children are being brought up in environments which are so hygienic that they are not being exposed to as many infections.

This has increased their tendency to be allergic to apparently innocuous substances such as pollen, peanuts and pets.

One in 200 children now suffer from a peanut allergy - reactions to these can range from mild allergic symptoms to anaphylactic shock, which can kill.