AN APPLE A DAY KEEPS THE DOCTOR AWAY! TRUTH OR FICTION?

The assertion that an apple a day keeps the doctor away, as well as other health claims are addressed by Prof. Dr. Martijn B. Katan, professor of Nutrition, Free University of Amsterdam, in his book: So What is Healthy? Myths and Facts about Nutrition. (Published in January 2008. ISBN 978 90 351 3133 0. See also: www.mkatan.nl)

Professor Katan is a world-renowned scientific researcher with a particular interest in the health claims of the food industry. In this little book he explains in lay-man’s terms what is and is not scientifically proven about nutrition and health.

He begins by saying that very little has been scientifically proven; western nutritional science is in its infancy.

He describes the chaos in the field of scientific nutritional research. How tentative scientific research results are published prematurely though there is a gap of at least 10 to 20 years to prove whether wine and chocolate, for example, are really healthy. The food industry and the media are unable to wait that long, and to get positive messages out into the public domain as quickly as possible, the food industry runs ‘public relations agencies’ set up specifically to feed favourably comments on new research results to scientific publications. These premature articles are then lifted from the scientific publications by newspapers, radio and TV, to be laid before the general public which is always eager for news about nutrition and health. This leads to the circulation and entrenchment of myths about nutrition and health. These myths are based on tentative research results, many of which have been retracted decades later.

So, is it so bad to miss your apple a day? According to professor Katan, it is not, as long as you do not systematically replace the apple with a fruit cake, a slice of apple tart or another handy snack. Professor Katan is of the opinion that the most important advantage of fruit is that you take it instead of junk food. Fruit, therefore, is especially important for what it does not contain. When compared to a chocolate bar, sweets or fruit biscuits, an apple is an innocent snack with relatively few calories.

However, you do want to take more than one apple a day. Apples contain sugar and acids. Eating apples, or other fruits, several times a day undermines your teeth. All fruits contain sugar.

Myth: Fruit protects against overweight and obesity

Fruits are largely sugar. This sugar is identical to sugar from sugar beets or sugar cane. Half of the sugar in orange juice – be it freshly squeezed or from a pack – is the same sucrose that you get from your sugar bowl. The other half is fructose and glucose, i.e. pre-digested sucrose. These fructose and glucose give the same amount of calories as ordinary sugar and they are equally bad for the teeth. In terms of your health, the sugar from a glass of coca cola is the same as the sugar from a glass of fruit juice, fruit yoghurt or concentrated fruit lemonade. (Note that TCM equals ‘overweight’ and ‘obesity’ with Stomach Heat and Spleen Damp. Sugars form ‘Damp’.)

Myth: Fruit is rich in vitamins

Apples, grapes and pears contain very few vitamins. One apple contains the same amount of vitamin C as one cooked potato or a slice of fried liver. The same applies to grapes and pairs. As for the fibre content, one apple gives about 2 grams of fibre, but one slice of wholemeal bread is better for constipation than one apple.

Unlike apples, pairs and grapes, fruits such as raspberries, berries, oranges and bananas contain more nutrients. Bananas are rich in vitamin B6, potassium, folic acid (vitamin B11) and fibre. Oranges are rich in fibres, folic acid and potassium. And citrus fruit, oranges, mandarin oranges and grapefruit are rich in vitamin C.

Myth: Fruit juices are good for you

Oranges and vegetables are the most important source of vitamin C in our diet. However, professor Katan shares one very clear message with TCM, namely that “too much of anything healthy becomes unhealthy”. Fruit juices contain the equivalent of several fruits in one glass. If we stop taking fruit juices, and confine ourselves to some citrus fruit, vegetables and potatoes, professor Katan contends that we get more than enough vitamin C (70 milligram per day), plus the necessary fruit fibres. Drinking less fruit juices, therefore, does not lead to a lack of vitamin C. On the contrary, fruit juices represent an overdose of fruit.

Professor Katan adds that fruit does not contain vitamin D, B12 and iodine, three important nutrients that tend to be in short supply in our time.

Myth: Fruit protects against cancer and heart disease

It was once said that fruit prevented cancer and heart disease, but this link has been refuted. At this moment, scientists think that there is no link between fruit and cancer, except perhaps in mouth- and throat cancer. These, however, are primarily caused by smoking and alcohol.

Nor is there any definitive proof that fruit consumption prevents against heart problems and vascular disease. The most important dietary anti-oxidant is vitamin E. Thorough scientific research has shown that vitamin E does not prevent heart attacks or cancers.

Myth: Fruit protect against infectious disease

There is no scientific proof either that healthy eating protects against infectious disease. There is proof that certain vitamins and minerals minimise the chance of infections and their complications in undernourished children in poor parts of the world. These include vitamin A and zinc. People in the west do not lack vitamin A, which is found in liver, fish liver oil, red palm oil, butter, egg yolk, cheese, coloured vegetables, red peppers (sweet, mild peppers), carrots and radishes. To prevent a deficiency in this vitamin, there is an indication that small children should avoid a strict vegetarian diet. Zinc is found in oysters, fish, meat, sausages, egg yolk, yeast, grains, vegetables, mushrooms, nuts, fruit, cheese, milk, tea, and coffee. But research shows that zinc does not protect against the infectious diseases of the west, namely the cold.

Myth: Fruit strengthens the immune system

Fruit does not really strengthen our immune system. It contains no zinc and no vitamin A. Citrus fruits such as oranges and lemons contain vitamin C, but this does not help against the cold. Nor does vitamin E protect against bronchial infections.

Myth: Fruit protects against the open back syndrome in the unborn

Fruit contains folic acid (B11).* This makes fruit an important part of the diet for young women. If there is enough folic acid at the moment of conception, there is a reduced risk of the open back syndrome. However, if you want to be certain that you prevent it, you need to ingest, not 30 micrograms of folic acid – as you would if you take your daily portion of fruit, but 400 microgram. You get this in tablet form.

* Note that folic acid (meaning ‘leaf’) is also found in leafy vegetables, lentils, rice, wheat, organ meat, yeast, eggs, bread and potatoes.

In short:

Fruit is a good snack or desert because it is a whole food that contains fibres, potassium, some vitamins and, compared with cakes, puddings, and snacks, few calories.

You need not panic if you miss your daily portion of fruit, provided you do not replace it with fruit juice, fruit drinks, fruit biscuits, fruit cakes, etc. since these give too many calories.

Do not think that you can rely exclusively on fruit to stay healthy. Too much of a healthy food becomes unhealthy. Several helpings of fruit during the day also undermine your teeth. Moreover, fruits lack some important vitamins.

References
Smith-Warner, S.A. ‘Intake of fruits and vegetables and risk of breast cancer: a pooled analysis of cohort studies’.
Van Gils, C.H. ‘Consumption of Vegetables and Fruits and Risk of Breast Cancer’.
World Cancer Research Fund. Food, Nutrition, Physical Activity and the Prevention of Cancer: A Global Perspective. 2007 (www.wcrf.org)
Eur J Clin Nutr. 2000: ‘an extensive literature has pointed out that anorexic patients, even though severely malnourished, are relatively free from infectious diseases’.
Carpenter, K.J. ‘Nutrition and immune function: a 1992 report’.
Glasziou, P.P. ‘Vitamin A supplementation in infectious diseases: a meta-analysis’. BMJ. 1993.
Fisher Walker, C. ‘Zinc and the risk for infectious disease’. Annu Rev Nutr. 2004
Graat, J.M. ‘Effect of daily vitamin E and multivitamin-mineral supplementation on acute respiratory tract infections in elderly persons: a randomized controlled trial. JAMA 2002.

HEALTH FORUM - You can discuss this topic further on our new Alternative Health Forum.

Author Details: Leni Hurley