Hereditary fructose intolerance

MYTH Eating less salt will reduce your blood pressure.

FACT A 30-year-old study shows that a low-salt diet may be linked to an increase in cardiovascular failure (those with the lowest salt intake had the highest death rate).

Other studies have shown that: (a) in a significant proportion of people (20 per cent), blood pressure will rise, sometimes alarmingly, if salt levels are reduced; (b) that when salt intake was cut by half for 12 weeks, there were insignificant reductions in blood pressure, while (c) the 1997 Intersalt study, the largest ever carried out, showed no correlation between salt intake and blood pressure.

MYTH We should exercise as much as possible.

FACT Excessive exercise can cause more harm than good. There are good reasons to take regular aerobic exercise (such as half an hour of brisk walking each day), along with movement and stretching exercises, a few times a week. But pushing the body too hard results all too frequently in injury.

MYTH Sugar causes coronary heart disease, diabetes, hypertension, gout, tooth decay and obesity.

FACT It only really contributes to tooth decay. Only in the case of hereditary fructose intolerance and other rare genetic disorders is sugar a specific health risk.

MYTH Breast cancer screening saves thousands of lives.

FACT Sadly, screening is unlikely to catch fatal cancers, and even in the best centres for every

woman who has cancer detected, another will have a false alarm.

MYTH Our food is full of harmful pesticides.

FACT Illness due to pesticide residues is rare and mostly confined to countries without regulatory systems.

MYTH Pollutants in the air are harmful to health.

FACT The air is cleaner and healthier than it has been for at least 100 years and it is unlikely that healthy people are much affected by the daily fluctuations in levels of air pollution. We shouldn't be complacent, but it is encouraging.

MYTH Alcohol is a health risk.

FACT Moderate alcohol intake increases longevity. Life Assurance companies have known for generations that moderate alcohol use is associated with longevity, actually reducing deaths from coronary heart disease (just how this works isn't yet understood).

MYTH Passive smoking causes lung cancer.

FACT Statistically improbable and biologically implausible. A World Health Organisation mega-study into the link was never published as it found "no association between lung cancer risk and exposure to environmental tobacco smoke".

MYTH E numbers are harmful and undesirable.

FACT Most are perfectly safe, and their use is well-controlled.

The modern food-supply chain could not exist without food additives. Some groups of people are allergic or intolerant to some additives but the E number system allows us to make informed choices.

MYTH Drink two litres of water every day.

FACT Most of that two litres is already supplied in the food we eat.

The World Health Organisation reasonably suggested that the human body needs two litres of water a day. A normal mixed diet supplies one litre of that in food (fruit and fish, for example, are 80-90 per cent water), while a few cups of tea, fruit juice and a bowl of soup will supply the rest.

MYTH A high cholesterol intake causes heart disease.

FACT Cholesterol levels are not affected by cholesterol intake (usually associated with fried foods, dairy products and meat) and, in any case, there is no evidence to suggest that cholesterol and heart disease are linked.

MYTH Hormone Replacement Therapy is risky.

FACT There is no evidence to suggest there is any significant health risk from HRT; indeed, there are a number of welldocumented health benefits including reduction in hot flushes, insomnia and depression.

MYTH Obesity is caused by eating "the wrong kinds of food".

FACT The most likely causes of obesity are hormonal and genetic. It is hard to become clinically obese by voluntarily eating excessively.

Recently discovered hormones which control appetite centres in the brain are key to why some people continue to eat when they ought to feel full, but more study is needed on these to establish their full role. Genetics is an important element: identical twins brought up separately end up looking and weighing the same, whereas non- identical ones don't.

MYTH A salad is better for you than a Big Mac.

FACT Many pre-packed salads have more calories than a Big Mac.

A Big Mac contains protein, carbohydrates and fats which, if presented in other forms, many might consider healthy. Equally, a supermarket salad containing pasta, chicken, mayonnaise and tomato has no advantage over a hamburger in that it also offers wheatbased refined carbohydrates, protein, and animal fats, with an equivalent calorie intake, but it is perceived as a healthier option (any fresh vegetables will add vitamins).

. Extracted by Alice Hart-Davis from Panic Nation, edited by Stanley Feldman and Vincent Marks (John Blake Publishing, Pounds 9.99) to be published 20 June.

(c)2005. Associated Newspapers Ltd.. Provided by ProQuest Information and Learning Company. All rights Reserved.