Fruit for Thought

ARE "chemicals" in food products bad for our health?

This term is often associated with artificial and harmful substances. But food is, really, nothing but an assortment of edible chemicals.

Do you like mangoes? To many, this most popular of fruits has unequalled fragrance and taste.

There is a scientific explanation: mangoes probably contain more chemicals than any other fruit. This natural blend of a large array of complex chemicals - a "chemical cocktail" - gives mangoes their unique taste and fragrance.

If an ingredient label were to be put on.a potato taken directly from the soil, the list will easily contain 150 different chemical compounds. Just the oil of an orange contains more than 40 different chemicals.

We can safely say that, without any exception, the chemicals isolated from food grown on a farm or orchard far exceed those on the ineredient label of processed food.

One could argue that when we say chemicals, we mean those that are artificially made in the laboratory. Like the familiar vitamin C.

A Delicate Balance

GIVEN its well-established value in disease prevention and general health protection, vitamin C is probably the most commonly consumed dietary supplement.

Vitamin C is plentiful in citrus fruits such as lemons and oranges, but almost none of the vitamin C tablets we buy in bottles, or those added to sweets and fruit juices, contain ascorbic acid (the scientific name for vitamin C) isolated from these natural sources.

The synthetic stuff is biochemically produced. Is there any difference between "natural" and "synthetic" ascorbic acid ?

Pure ascorbic acid synthesised in the lab is absolutely identical in all its chemical, physical and biological properties, to pure ascorbic acid from natural sources. In fact, the "natural" vitamin is costlier.

What about synthetic chemicals like Saccharin, that do not occur naturally in food ? Are they bad ?

Saccharin, the classic sugar substitute, was discovered in 1879. It is truly a synthetic compound, cooked up in reaction flasks, with zero nutritive or food value.

It provides neither energy nor any body-building materials. Saccharin is intensely sweet. more than 300 times that of table sugar. This led to its commercial use in sugar-free food for sufferers of diabetes in the earlv 1900s. The demand for diet soft drinks in the 1960s brought saccharin into much wider use.

With widespread consumption, questions were raised about its safety. Laboratory studies soon showed that saccharin is a weak carcinogen that produces bladder cancer in mice. But subsequent human studies proved negative.

The proposed ban on this substance bv the United States' Food and Drug Administration (FDA) in 1977 therefore did not go through. To many, weight gain is a scarier prospect than a remote risk of cancer!

Chemicals in food also bring to mind "culprits" such as preservatives. Food preservation slows down the process of spoilage by bacteria and micro-organisms.

A widely used preservative, sodium nitrite, protects processed meat effectively against botulinum toxin, one of the world's deadliest natural poisons. A teaspoon of a particular strain called botulinum toxin A can wipe out almost a quarter of the world's population.

However, the use of sodium nitrite is not without controversy. There is sufficient evidence to suggest that sodium nitrite, once digested, can react with metabolic products of proteins to form a class of powerful carcinogens known as nitrosamines.

Removing sodium nitrite from meats might reduce the risk of cancer, but it could increase the risk of botulinum poisoning. Each is a risk of uncertain magnitude.

When ready access to fresh food is a problem, such as in impoverished parts of the world, or in areas hit by natural disasters, processed food products - preservatives and all - provide basic nutrition and even a chance at a balanced diet.

For privileged Singaporeans who have access to abundant fresh produce and who take refrigeration for granted, the consumption of processed food is simply a lifestyle choice.

How about pesticides which end up on our fruits and vegetables? We certainly did not choose to have them. Since they are lethal enough to kill insects, the majority of them are poisonous to humans. Fortunately, we have a far higher level of tolerance to pesticides.

Again, the risks in the use of pesticides balance the risks of serious hazards caused by crop-destroying insects. Early pesticides were mostly compounds containing poisons such as arsenic, lead and mercury.

Nurture over Nature

THANKFULLY, much progress has been made in insect control. New pesticides such as parathion are very toxic and effective against insects, yet they decompose very quickly in water to form relatively harmless substances.

We can, of course, choose to go "organic". Pesticide-free organic produce are gaining popularity but they come with high price tags, costing as much as six times more than non-organically grown ones.

The big question is: Are they worth their price? I am sure you have nagging doubts when you pay $10 for a pack of eight small biscuits which taste, at best, as good as your regular $2.50 packs.

So, what can we conclude? Let me share this: It is estimated that for every 1g of synthetic pesticide that we eat as unwanted residue, 10kg of natural pesticides enter our bodies as natural toxins of natural food!

Ordinary fruit and vegetables that we accept as safe food do contain naturally occurring chemicals that may pose potential health hazards. For example, nutmeg contains myristicin, which can cause hallucinations and liver damage.

Safety aside, we have certainly benefited from what we learnt from nature. Lycopene, the brilliant red compound that gives tomatoes their red color, is a good antioxidant that may be effective as a defence against cancer. This is a typical example of the growing market of nutritional pharmaceuticals - "nutriceuticals" - that can be mass-produced in the laboratory.

When these chemicals added to processed food or paste, their absorption into our body can be even better than in their natural form. Tomato skin is hence not the best source of lycopene.

So what is safe? Truth be told, very few chemical substances, both natural and artificial, can be considered completely free of hazards.

Losing your appetite? The good news is, for all the food products found in farms, orchards, supermarkets and shops, our normal levels of consumption lie far below anything that may cause any acute iilness. Moderation and a balanced diet are the key.

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Editor, GoodFood.SG.