Disease prevention

7 March 2001

Published in The Age

For a millennium, fearful epidemics desolated Western humanity like a procession of angry gods. Generations went to their graves believing the mass infections were divine vengeance for communal sin. Even a century ago, infectious disease caused one in four Australian deaths.

That medical science could, in the twentieth century, check this old cosmic enemy was a watershed in history - and a watershed in our psychology. It was hardly surprising, thereafter, that we embraced the “treatment and cure” paradigm of health with some devotion.

Until, perhaps, the last twenty years, the maintenance of health through right living played a subdued counterpoint to this dominant theme. Disease-prevention had been behind sanitation and vaccination - but it was only in the 1970s that the concept finally made inroads onto the sacred space of lifestyle.

The cause was the second great epidemic of the past century: the rise of chronic illness. The generations spared by plague, smallpox and cholera were (and are) now being struck down, in numbers worthy of any medieval pestilence, by circulatory and lung disease, depression, dementia, diabetes, asthma, arthritis and cancer.

In part, this is because we’re now living long enough to contract chronic illnesses, which typically don’t affect people before middle age. More immediately, the cause is modern lifestyle.

Of course lifestyle has always had a close relationship with illness - but equally with health. The ancient Chinese and early Islamic philosophies developed a strong focus on bodily vitality. Classical Indian medicine is Ayurveda: “the science of longevity”.

Western Medicine is sometimes seen as the laggard. But Dr Rebecca Flemming, an expert on ancient medicine at King’s College, London, disputes this:

“The positive pursuit of health by living well - in terms of balancing the famous five of exercise, food, drink, sleep and sexual activity - was very much part and parcel of Hippocratic medicine.”

Hippocrates of Cos (fifth century BC) was the “father of Western Medicine”.

Hippocrates also taught that psychic health is pre-requisite to the health of the body. Indeed the “mind-body continuum” was part of all classical systems - from east and west. Like the concept of prevention itself, it only waned with the rise of medical science.

The first great advance in the prevention of illness came with the invention of sanitation, which is generally credited to the Romans. A bit before the time of Christ, they pioneered hygienic urban design, sewers and aqueducts, thus inaugurating the science of public health.

But it was a more tenuous start than popular history suggests. Dr Flemming says: “While individual Romans, especially of the elite, may have been cleaner than their medieval counterparts, and there was a sewer system in ancient Rome, there is little evidence of concern for public health or hygiene as such, and I'm sure that living conditions for the urban poor were as nasty and filthy as those of later ages.”

And certainly the Roman innovations didn’t endure: by the Middle Ages public health was non-existent, and preventive medicine was pretty much reduced to pest control. (Even this was hit and miss; in 1488 the High Vicar of Autun was constrained to excommunicate all weevils.)

Though Edward Jenner invented vaccination in 1796, the science was slow to develop, and even in the London of the 1800s multitudes died from typhoid, cholera and influenza. Nearly one in three children didn’t make it past five.

By century’s end, mass calamity had inspired inoculation programs, and public health and pure food acts. Because of them, the agonies which had claimed millions began to abate.

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Having staved off obliteration, the West was able to start exploring new ideas.

In the first half of the twentieth century, “Natural Hygiene” movements sprang up in Europe and the US. Their common emphasis was on “strengthening the constitution” - through such things as walking, fasting, spas, vitamins and “mono-diets” of fruit.

Though marginal, these movements re-seeded in the public imagination the idea of maintaining vitality to ward off ill health. In the 1970s, when chronic disease statistics were going from bad to worse, and optimism about pharmaceuticals was on the wane, many of these “fringe” practices were finally launched upon the mainstream.

Today in the United States, the holistic arts attract more clients than medicos.

The bottom line of this new movement was prevention. Prevention, indeed, was the name of a magazine launched by JI Rodale, who did much to make the idea popular.

The success of the new movements might be gauged, in a rough rule of thumb, by the ages of death of their founders - many of whom billed themselves “longevity experts”.

1950s health guru Paul Bragg died of head injuries incurred whilst surfboarding, at the age of 92, according to devotees. (Though it was actually 81.) Dr Norman Walker ("To become younger, keep the colon clean!") lived - according to one follower or another - to 109, 113, 116, 118 or even 119. (But actually to 99.)

But even these health gurus are the exceptions to the rule.

Dr Paavo Airola (How to Keep Slim, Healthy and Young With Juice Fasting) expired at 64 (stroke); Natural Hygiene eminence TC Fry went at 70 (pulmonary embolism); George Ohsawa, inventor of Macrobiotics - “the way of long life” - at 73 (lung cancer); and best-selling diet author Adelle Davis at 70 (cancer).

The founder of the jogging movement, Jim Fixx, dropped dead from a heart attack at 52, whilst jogging. The American author Dr Stuart Berger, who advocated vitamins, minerals and exercise, died of a cocaine-induced heart attack at 40.

Finally, JI Rodale himself - after announcing on US television that he would live to 100 - died of a heart attack in his chair. He was 72 - three years under the average age of mortality for males.

All this underlined that, whilst the idea of prevention might have been a good one, little science had yet been applied to making it work.

To everyone’s surprise, the initial moves came from the heart of the enemy camp. Drug scientists turned their attention to diet. Doctors began investigating vitamins and exercise.

In 1993, the prestigious New England Journal of Medicine published two large studies demonstrating that “the use of large doses of vitamin E supplements is associated with a significantly decreased risk of coronary heart disease”.

Antioxidant vitamins - an holistic mainstay - had entered the medical mainstream.

Subsequent studies have shown that certain antioxidants can (among other things) reduce the incidence of neural tube defects in newborns, retard atherosclerosis in men, and reduce bone loss in older people.

Of course not all the results are so favorable. One study, for instance, showed that beta carotene supplements do not protect against bladder cancer in smokers, and may even increase cancer risk.

Dr Stephen Barrett, founder of the Quackwatch website - and a critic of holistic medicine - summarises: “The key question is whether supplementation with antioxidants has been proven to do more good than harm. The answer is no.”

But editorialists for major medical journals have been more optmistic. Whilst medical science has not issued a carte blanche for vitamin therapy, the approach is now drawing increasing support from the profession which resisted it for decades.

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Over the last decade or two, the concept of prevention took root across a wide range of endeavours.

Companies, public bureaucracies and armies invested serious money in occupational health and safety. Lead was removed from petrol, and asbestos from buildings. Governments spent millions to persuade us not to contract HIV, smoke cigarettes or fall off ladders. And medical education went through some big changes.

Associate Professor Susan Elliott, who oversees the development of Melbourne University’s Medicine curriculum, says the course now has a strong preventive focus.

“The study of nutrition is now integrated throughout the entire course - from year one to year six - and students study it in relation to the causes of a disease, and also its management.

“One of the first clinical problems students tackle is skin malignancy. They also learn about tobacco-related illness, and risk-taking behaviour. All of this is prevention. There’s been a seachange in thinking in the last ten years: we’re steadily going from a ‘treatment’ model to a preventive one for many diseases.”

Michael Abramson - Associate Professor of Epidemiology and Preventive Medicine at the Monash University Medical School -  believes that “the medical schools are not doing a terrific job” in the area of prevention.

“Monash actually dropped the preventive medicine subject in the fourth year of its medical course a few years ago. However we are currently engaged in developing a new five-year medical curriculum” which he thinks will include more about prevention and lifestyle diseases, and will be more evidence-based.

Thanks to an episode of Oprah last October, Preventive Medicine is now widely associated with high-tech tests like the full-body CT scan - which enables examination of the internal organs and skeleton, and the detection of anything from cancer to osteoporosis. (One of Oprah’s guests had a CT scan which revealed a kidney cancer, and saved her life.)

Dr Michael Parkinson, of the American Board of Preventive Medicine, has reservations about the cost-effectiveness of these “pre-emptive” scans, stating: “Technology typically outpaces the ability to understand its appropriate use”.

Medicare and most private Australian funds don’t cover pre-emptive scans. (Though the funds often provide rewards for preventive health behaviour, such as MBF’s “healthy lifestyle bonus”.)

But Professor Brian McAvoy from the Royal Australian College of GPs explains that “‘preventive medicine’ or ‘health promotion’ - whether it be a diagnostic test, counselling about smoking or alcohol or diet - is covered by Medicare where the circumstances warrant it. For example, a middle-aged man with a family history of heart disease would most certainly be covered by Medicare for blood pressure and cholesterol testing.”

More in the Australian medical mainstream are the unspectacular measures which have led to a reduction in heart disease deaths over the last 30 years. Monash Professor Michael Abramson states that “a decline in smoking, less consumption of meat and animal fats leading to lower blood cholesterol levels, and better control of high blood pressure, have contributed about half the reduction.”

The holistic sector also has its high-tech tools. Flavour of the month is Live Blood Microscopy (LBM) - where a blood sample is put under a microscope, and the image projected onto a monitor. Both patient and practitioner can then view the action.

LBM offers information about health which - it is claimed - is not available through “regular” blood tests.

“With older samples the cells don’t move,” says Patti Dyne of SAFE, a Gold Coast LBM laboratory. “To give one example, looking at a live red blood cell wall may lead you to prescribe some essential fatty acids for the person’s diet.”

Holistic therapists claim that LBM can provide a “reading” of, say, poor blood oxygenation (common to athletes), long before disease symptoms appear.

Ray Lowenthal, Clinical Professor at the University of Tasmania, isn’t buying that:

“There is no scientific validity for the claims made by 'holistic' practitioners that they can detect illness or determine treatments by observing the motion of blood cells... Watching one's blood cells move under a microscope may be interesting and impressive, but it is not helpful in medical diagnosis or treatment. Scientific medicine demands evidence before it will accept claims...”

Where therapies are concerned, too, not everything holistic has good science behind it - though some have achieved dramatic success. The American journal Pediatrics has published a double-blind study in which homeopathic remedies successfully treated diarrhoea in Nicaraguan children.

Diarrhoea is the foremost killer of children in many developing nations; and homeopathy is often used preventively. So it’s possible that, if trial evidence continues to mount, homeopathy’s safe, cheap remedies may play a public health role in future years.

[2013 note: The evidence on homeopathy has since gone the other way, unfortunately.]

This is particularly so because “pharmaceutical” vaccinations have recently drawn fire from some quarters, including the US House Committee on Government Reform, which is concerned about growing reports of disastrous side-effects. Meryl Dorey, President of the Australian Vaccination Network states:

“A careful look at government statistics will show that the introduction of vaccines had absolutely no effect upon deaths from [infectious] illnesses which, in most cases had declined by 90 percent and more before the advent of vaccines...

“For instance, prior to the introduction of the measles vaccine in 1970, the death rate from measles had declined by 90 percent in this country... Scarlet Fever killed as many people as did diphtheria - and it declined at the same rate as diphtheria before the introduction of antibiotics, and despite the fact that there has never been a vaccination to prevent it.

“Yes, infectious diseases have had a sharp decline this century, but better hygiene and nutrition have been the reason, not  vaccines.”

The view of the majority - which is diametrically opposite - is outlined by Monash University’s Professor Michael Abramson:

“One of the great success stories of preventive medicine has been childhood immunisation. In Australia, children no longer die from preventable diseases such as diphtheria, tetanus, polio and measles.

“However,” Professor Abramson acknowledges, “over a quarter of Australian children will develop asthma, a dramatic increase over the last generation. It has been suggested that a little bit of infection is necessary for the immune system to mature and prevent the development of allergies. So far we have not found a safe way to prevent allergic diseases such as asthma.”


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Whilst holistic therapies have influenced science from the outside, the rise of evolutionary thinking over the past 20 years has made science more “holistic” (i.e less reductionist) from the inside. This emerging evolutionary context for human wellbeing is gradually outlining the life that the “whole person” might be “designed” for. This, in turn, is driving much of the global seachange toward prevention.

The new field of “Evolutionary Diet and Exercise” is at the cutting edge of the new thinking - bringing together archaeologists, biologists, nutritionists, exercise physiologists, geneticists, botanists and others, in a worldwide multi-disciplinary endeavour.

The aim of these researchers is to reconstruct human diet and physical activity patterns from the hundreds of thousands of years before the agricultural revolution of about 10,000 years ago.

Because there has been only .02 percent change in the human genome in the last 40,000 years, these researchers believe we are still largely adapted to the modes of eating and moving of that paleolithic era.

Paleolithic people ate lots of animal protein, and moderate amounts of carbohydrate from tubers, leaves and wild fruits. They ate virtually no dairy, grains, yeast, salt, oils or legumes.

For those wanting to emulate this lifeway, there are some important caveats. Palaeolithic meat was game meat, replete with “good” fats, and very low in the “bad” fats of lot-fed animals. And paleolithic fruits were far less sugary and more fibrous than selectively bred modern fruits.

Loren Cordain, Professor of Health and Exercise Science at Colorado State University, says “studies of modern day [unWesternised] hunter-gatherers, our best surrogates for Stone Age people, show them to be almost completely free of the signs and symptoms of chronic disease - diabetes, hypertension, high cholesterol, obesity, certain cancers and other illnesses - that currently afflict 50-75 percent of all people in Western nations.

“By emulating the dietary and exercise patterns of our Stone Age ancestors, the risk of developing many of these chronic diseases can be significantly reduced.”

Professor Arthur De Vany - a Chaos theoretician, mathematician and exercise buff from the University of California at Irvine - believes the human body is “non-linear and dynamic”. Exercise, he says, should mix chaos and order - structure and novelty - as it did in paleolithic times.

“Intermittent exercise, mixing intensities over all scales, reduces stress hormones that compromise immune function, and kill brain cells. This form of exercise builds the muscle mass that provides the reserve of protein on which your immune system relies, when it has to produce killer cells in large numbers to mount an attack.”

Archaeologist William Rathje, Professor Emeritus of Anthropology, University of Arizona, and a Research Professor at Stanford University, believes that insufficient paleolithic human skeletons have been unearthed to support the “paleo” view.

“My opinion is still that there is no evidence that paleolithic peoples were healthier than we are today. Consider, for example, the work on parasites. In the arid south-west of the US, the analyses of preserved human faeces have found a plethora of debilitating organisms in virtually every sample.”

When Dr Rathje quizzed his peers as to whether paleolithic people lived healthier (though shorter) lives than we do:

“Several of my colleagues said, ‘Of course!’ That is because the chronic debilitating diseases that plague our society don't usually kick-in until later in life - after the 30s... Try comparing the health profiles of those paleolithic people against people today up to age 35!”
 
Jennie Brand-Miller, Associate Professor in Human Nutrition at Sydney University, feels we would “definitely” do well to be guided by “paleo” principles in our diets and activity patterns. She believes “we need to take on board the broad principles of the average hunter-gatherer diet and lifestyle - nutrient distribution, energy expenditure - not the extremes, and apply them to what we eat and do thesedays.”

Moreover the recent field of Darwinian Medicine has taught us that some illness serves an evolutionary purpose. Chaos Theory’s idea that “irregularity” is a building block of life is leading to dramatic rethinking of systems such as the heart and brain.

And the birth of psycho-neuro-immunology is revealing, at last, the precise feedback mechanisms between behavioural, immunologic and nervous functions - between emotional states and physical health: thus bringing the mind-body continuum of all hunter-gatherer, classical and medieval healing systems into the mainstream of modern science.

But in the field of preventive medicine, for sheer drama nothing rivals the potential which - only in the last month or two - the Human Genome Project has unleashed. Apart from anything else, the Project has spawned the startling innovation of “predictive medicine”.

Adelaide University Professor Grant Sutherland - former President of the Human Genome Organisation - led the Australian contribution to the sequencing of the human genome. He believes the recent publication of the sequence will lead to the prevention of disease and disability in two ways.

Firstly, “Genes for the remaining 3,000 rare genetic diseases will be identified, and this will lead to prevention of these diseases by a combination of prenatal diagnosis, treatment by conventional means as the disease biochemistry and physiology becomes known, and in some cases gene therapy.”

“Susceptibility genes” for about 200 more common diseases will also eventually be identified.” (These include asthma, diabetes, arthritis, depression, heart disease, cancer, epilepsy, hypertension and schizophrenia.)

“The identification of such genes will then allow environmental factors which are also involved in the cause of these diseases to be identified.

“Once this has occurred, and it will happen progressively over the next 50 or so years, it will open the way to predictive medicine. This is the prediction of future disease likelihood based upon genetic testing results... This will eventually allow appropriate strategies to avoid or delay the onset of disease.”

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Fad diets, anti-fat crusades, single-nutrient supplements, a repetitive exercise routine - in short a narrow frame of reference - are entirely out of keeping with the symphonic complexities of the lifestyle for which our genes have equipped us.

As we’ve seen, the old axiom that “prevention is better than cure” is ballooning into a new understanding of health - rooted in prevention - which is also “symphonic”.

For the only time since the first pre-human put together what’s known as the “Stone Age toolkit”, our species comprehends the requirements our evolutionary past impose on us. Additionally, we have access to an “Information Age toolkit” which can reveal our health status in tables, charts and living colour, and which is prescribing preventive action with growing accuracy.

In the province of public health, family planning agencies and women’s education are having a significant downward effect on world population growth: perhaps the greatest “preventive medicine” triumph of all. UN projections now tell us that our population may plateau at 9.4 billion by 2050, then decline - perhaps even below present levels.

This owes much to pro-active human intervention. The human genome evolved through vast climatic, geographical and cultural changes. Thus our genetic “instructions” - which we thought in our more pessimistic moments were scripting our reality - have in fact conferred on us a surprising adaptability.

It would be churlish not to mobilise this adaptability - and the knowledge revolution it has spawned - to prevent not only the calamity of over-population, but individual lives filled with the expense, limitation and misery of chronic illness.

As the ancient Greeks sang to Hygieia, goddess of health: “Without you, no-one is happy.”