And if you get a regular eight hours of unbroken good quality sleep a night; always eat a well balanced diet supplying all the nutrients your body needs; find your employment or business life both personally and financially rewarding; and take regular time out for relaxing breaks and vacations, those experts are probably right.

But if you're like most of us, your life's a long way from this ideal. Likely you find that our culture's obsession with work and 24/7 activity all militate against your getting anywhere close to the amount of quality sleep and nutrition you need.

Now, this isn't going to make you ill right away. It may be years before you notice any specific physical symptoms. But you may well already be aware of a vague feeling that you somehow lack the energy to enjoy all that you want out of life. Physicians see this kind of pre-clinical malaise so often that they simply label it "TATT" ("Tired All The Time"). Not that doctors aren't sympathetic; but the problem is that short of recommending a major and completely impractical overhaul of your entire lifestyle there's really very little they can do for you.

You see, conventional Western medicine is primarily geared to producing a specific "magic bullet" treatment for each specific ailment with which it is presented. And to be fair, it does this extremely effectively for many previously dangerous or even fatal illnesses. But it's much less good at providing what you need to prevent you from becoming ill in the first place.

That's to say a powerful tonic and stimulant for every system in your body which will not only protect you against disease, but optimise every aspect of your physical and mental performance. Luckily, substances which contain this power do exist and are known as adaptogens, a term coined in Russia in 1947 to describe compounds found to help normalise the body's functions and increase its resistance to all kinds of stress. One in particular, eleuthero herb extract (also known as Siberian Ginseng) has been extensively studied by Soviet and Russian scientists since the early 1960s.

And the power of this remarkable plant has been known in China for at least 2,000 years, where it is still widely used in keeping with the general emphasis of Chinese medicine on prevention rather than cure.

In Russia, eleuthero was approved for human use as early as 1962 and many subsequent scientific studies have examined its effect upon thousands of individuals of all ages.

These studies have shown a significant improvement in individuals' adaptogenic response to all kinds of stresses, including heat, cold, excessive noise and vibration, physical exhaustion, viruses, bacteria and pollution. In fact, so many and diverse have been the positive effects that you could almost say that eleuthero improves adaptation to the stresses of life itself. Not surprisingly, therefore, the herb quickly became, and remains, extremely popular with the Russian public.

Eleuthero is also a traditional Chinese folk remedy for bronchitis, all kinds of heart and circulatory problems, rheumatism and male infertility to name but a few. And more recent Russian studies have confirmed its potential benefits in tackling cardiac disease, disorders of the circulatory system, blood pressure problems, diabetes and even cancer. Now it's important to stress that eleuthero is not claimed as a cure for these conditions, but that the herb extract performs the essential function of the adaptogen - stimulating the body's natural healing processes to restore it to normal function.

But eleuthero is not just for those who are already drifting towards illness. It's also used extensively by individuals whose occupations subject their bodies and minds to levels of stress that those of us living "normal" lives can only imagine. Cosmonauts, deep-sea divers, soldiers, explorers, mountain rescue teams and elite athletes are just a few of the groups of such people who have experienced the benefits.

So the great twin benefits of eleuthero are that it seems to help the drive towards optimal mental and physical performance; while also giving mind and body the best possible chance of resisting the stresses that are systematically breaking down the health of so many millions in the affluent Western world.