Public health's blindspot

While life expectancy is increasing marginally, countries everywhere are doing badly in their efforts to reduce cancer, heart disease and many of the commonest, chronic illnesses.

Public health, the government sponsored variety, loves to broadcast standardized health messages. It also loves standard, population-wide interventions like vaccination and iodine added to table salt.

What public health does poorly is to understand the huge differences in makeup between you, me and the next person.

Dubbed biochemical individuality, the large variations across the population occur in far more than height, weight and eye color. They include our internal anatomy, functioning of organs and glands, and blood chemistry.

The shape and size of our stomachs can vary to an extraordinary extent, even across healthy people. The way that blood vessels branch and connect can be very different between individuals.

Levels of enzymes and hormones in our bodies range greatly; some people can be quite healthy with levels way outside those labeled as normal in the blood test results your doctor sees.

There is large variation in our requirement for nutrients. This was discovered many decades ago with vitamin C-some people needing very little and others requiring thousands of milligrams daily for good health. Likewise for other nutrients.

When health officials provide mass advice to the public they revert to speaking to a mythical, average person. This is fine when discouraging smoking, a universally harmful practice. There are dangers though when it comes to other health behaviors.

Public health pamphlets and posters across some decades have advised people on how to eat. They mostly tell us to eat less fat and less calories.

The advice on fat may be good for certain people, but what of the person who already eats very low fat due to their taste, fussiness or other reasons? If they heed the broadcast advice and reduce further, they risk nutritional deficiency. Some fats and oils are important for health.

We know that many young women, already underweight, respond to the advice on calories by starving themselves further.

Problems arise because the written advice, or spoken advice in TV campaigns, cannot select who will listen. It cannot be tailored to each listener; if it can be taken the wrong way it will be.

Health campaigns don't stop at information, some actually do things to people. A minority of countries including USA and Australia add fluoride compounds to community water supplies. Intended to strengthen children's teeth against decay, the program does not take individuals into account.

Many people don't need fluoride; their teeth are fine. Some people have much higher sensitivity to thetoxic effects of fluoride than others. This makes a bad mix with the large variation in how much water people consume through drinking and cooking.

When the high-sensitivity person happens to be working outdoors in 35 degrees or more heat, drinking ten liters across their working day, they suffer. The public is rarely informed of the possible danger of too much fluoride; indeed doctors mostly overlook it.

I have known people who took years to discover the cause for their fluoride-related fatigue, joint pains and headaches. The simple solution-stop using fluoridated tap water-is unfortunately an expensive one.

While fluoridation is a crude sledgehammer, iodine addition to table salt has been a better program. The balance of evidence shows that it does good and it has the advantage of allowing for an easy opt-out by those who discover that their iodine intake from other sources is already high.

Even salt iodization though was questioned by the W.H.O in a 2014 review. It stated that the programs may be 'inadvertently causing harm' and better research data is needed.

I was once asked by a politician whether I was pro or anti vaccination. It is an odd question-a meaningful response would have to take into account the particular vaccine, the age of adult or child concerned, any special health problems for that patient and the latest data on the safety and effectiveness of that vaccine.

People often align themselves one hundred per cent for or against health programs; if they are a 'true believer' then context and exceptions can go out the window. Officials love to look like they are doing good for large numbers of people with a simple law or action. Our biology, though, will not conform to that thinking.

The appeal of mass, shotgun approaches to public health is their simplicity and relatively low cost-water fluoridation for example. But if they don't work well and harm people, we must do something different, something more targeted. This may mean that we cease telling everybody how to eat, think and behave. Efforts have to go to directing people to providers and programs that offer individualized health promotion.

It may or may not cost more, but we must do it. Diabetes, unhealthy body weight, cancer, heart disease, mental disorders and even tooth decay are costing our society dearly in dollars, lost productivity and misery. Our advanced knowledge of biology, psychology and sociology is not matched, but should be, by equally sophisticated public health initiatives.