In the 1980s, we took our health scares seriously.

When Edwina Currie claimed British eggs were infected by salmonella, the country took note, and by the time the warning proved a little overblown, sales had plummeted.

Since then, pretty much everything we eat has at one time or another been declared off-limits and in the deluge of contradictory advice, we seemed to have switched off.

According to Dr Peter Marsh, co-director of the Social Issues Research Centre, our exposure to high doses of health scares has resulted in a kind of "warning fatigue".

"The problem is that we have been bombarded with a whole series of scare stories, and in a lot of cases we then seem to witness U-turns quite quickly," he says.

"People do not know who to believe or how to react, and there is a danger that when there is a real risk, it will not be heard above all this noise."

Alcohol

Warnings about excessive binge drinking abound, but many have drawn comfort from claims that wine, particularly red, may reduce the risk of heart disease.

The reality is that in 1997 the World Health Organisation calculated the reduced risk of coronary disease was only found among those who drank one glass every other day.

The Institute of Alcohol Studies has also found that alcohol causes 10 per cent of all ill health and premature death in Europe.

Drinkers may point to a new "wonder"' drug mimicking resveratrol, a compound found in the skin of red grapes, which is now in development. It may eventually hold back the ageing process, help prevent cancer, Alzheimer's and heart disease, but to get similar benefits, a drinker would have to drink around 1,000 bottles of wine.

Water

Until recently, drinking two litres (eight glasses) of water a day was standard advice, but a recent report disputed the supposed health benefits and others have warned of the risk of water overdose, or hyponatremia, which occurs when water consumption dilutes vital salt and mineral levels in the body.

According to kidney specialist Professor David Oliveira, we should be drinking a minimum of one litre a day.

"That figure's calculated on the basis that, daily, we lose about 100ml of water breathing out, 500ml sweating and another 500ml in urine," he says.

While it's sensible to drink up to two litres a day, he says that food, especially fruit and vegetables, can provide around 20 per cent of our water intake.

Exercise

While being unfit carries a similar risk of heart disease to smoking 20 cigarettes a day, the latest research on exercise is optimistic.

You do not need impractical levels of exercise to be healthy, according to Paul Clayton, chair of the forum on Food and Health at the Royal Society of Medicine.

He points out that moderate exercise three times a week for 20 minutes a time raises the heart rate by 30 per cent, makes you sweat and raise your breathing level. That's enough to begin to lower cholesterol, blood pressure and improve muscle tone.

Salt

Excessive salt intake has been blamed for an estimated 14,000 premature deaths a year.

The Food Standards Agency found that adults are eating an average 8.6g of salt a day – 44 per cent more than the recommended daily level, but cutting out salt altogether also comes with risks.

Some sodium is needed for the body to function properly, especially in summer. It helps to regulate fluid balance and is needed for nerves and muscles, including those in the heart, to work.

However, cutting down on bread, the single biggest source of salt in the nation's diet, can help bring daily intakes within recommended levels.

Meat

It has been found that eating 1.8oz of processed meat a day – the equivalent of one sausage or three rashers of bacon – raises the likelihood of bowel cancer by 20 per cent.

The disease kills 16,000 people a year, and according to Professor Martin Wiseman, medical and scientific adviser of the World Cancer Research fund, the safest amount to eat is none at all.