PHYTONUTRIENTS – why it makes sense to eat more colorful vegetables, but the Health Promotion Board's advice on this borders on the nonsensical

Let me explain…

Eating colourful vegetables and fruits has to do with phytochemicals, a Latin word that means "plant chemicals". To emphasise their nutritional value, such chemicals are nowadays more commonly called phytonutrients.

These are a group of plant substances – with names like flavonoids, isoflavonoids, lignans, carotenoids, phytosterols, etc – that scientists discovered and began to study only in recent decades.

Scientists still don't know a great deal about phytonutrients.

What they know so far is, firstly, that there are lots of them. Most of us know about beta-carotene. But do you know there are at least 600 other types of carotenes?

A typical vegetable may have over 10,000 different phytonutrients!

Secondly, phytonutrients protect us against many chronic diseases, such as heart disease, stroke and cancer. They are even claimed to reverse the process of aging.

Thirdly, most phytonutrients occur as pigments. Colourful fruits and vegetables are thus rich in phytonutrients.

Choosing by color

Great! But how do we translate this vital information into our daily lives?

This was where the HPB went off the mark. A recent newspaper report about its concept of "powerhouse foods" was illustrated with a chart of vegetables and fruits divided into different colour groups: white, green, yellow / orange, and red.

Within each group, the HPB advises us to choose the more colourful. Within the white group, for example, we are told to choose cabbage and cauliflower over potato, white radish and bean sprouts.

Such substitutions are meaningless and inappropriate. Each fruit or vegetable has its own value; its own use in cooking, and its own effect on the body. Which we choose depends on what our needs are.

Tempura

The Japanese, for example, eat tempura (which is deep fried in oil) with grated white radish, because white radish has cleansing properties and it removes fat from the body. The same effect cannot be achieved by eating tempura with grated cauliflower!

If you have just taken a few hundred dollars worth of Chinese tonic herbs, however, you wouldn't want to then eat white radish to "wash it all out". You need to understand what a food does to you, and not just go for colours.

The chart gets more ridiculous when we are told, within the yellow / orange group, to choose carrot over banana.

I once saw tennis star Michael Chang eat banana during the game. Many endurance athletes do the same because banana provides a quick energy boost. Is the HPB saying they should munch on carrot instead?

Richer colors mean more phytonutrients

The correct way of choosing is this – within the same plant species, choose the one with the deeper, darker, richer colour: dark green spinach over pale green spinach; deep orange pumpkin over light yellow pumpkin; rich red watermelon over washed-out watermelon…

Because vegetables and fruits with deeper, richer colors contain more phytonutrients!

There are people, myself included, who already select vegetables and fruits this way. We know – and not merely "believe" – all along that organic and other naturally grown foods have richer, more intense colours and hence, richer, more intense flavours as well as better nutrition.

The difference is sometimes subtle but usually discernible. In some cases, it is night-and-day, like dark green organic celery versus pale green chemical-grown celery.

Yet the HPB and all other health authorities have always refused to acknowledge the superiority of organic foods.

On its website, the HPB even had an article titled The Organic Foods Craze, which asserts that "organically grown products offer no nutritional advantages over non-organically grown products."

(Note: That article has apparently since been removed!)

Phytonutrients lacking in hydroponic vegetables

No. Those who choose organic foods are not crazy. Instead, the health authorities are colour blind!

They are similarly blind to the fact that hydroponic / aeroponic vegetable (grown in water / air with chemical nutrients), often appear anaemic. So they tell us that hydroponic / aeroponic vegetables are "no different" from the rest even though such statements are not backed by scientific research.

Very little research has actually been done on the nutritional content of hydroponic / aeroponic vegetables, or the long-term effects of eating them.

But now that we know about phytonutrients, it is obvious that hydroponic vegetables contain much lower levels of phytonutrients.

One feeble attempt was made some years back by local scientists who measured the level of about a dozen vitamins and minerals, such as vitamin A,vitamin C, potassium, etc. They ignored scores of other vitamins and minerals plus possibly 10,000 or more phytonutrients, and concluded that such vegetables were "equally nutritious".

I can tell you this – even if you perform a thorough scientific analysis of the chemical composition of man and monkey, you will reach the same conclusion that they are "equal".

But there is no need for analysis. One glance is all it takes to know than man is different from monkey.

Similarly, one glance is all it takes to know that organic, regular and hydroponic / aeroponic vegetables are very different. We can see, right away, the presence of phytonutrients.

With its latest piece of advice, the HPB has unwittingly contradicted itself and its fellow mainstream health authorities.

It is high time they review and retract their various assertions about organic, regular and hydroponic / aeroponic foods being all the same. It's time they see the (colourful) light!

A slightly different version of this article was published in TODAY
August 2004

Phytonutrients in vegetables and fruits