Jane McCredie: Elixir to ignominy

WHEN I worked on a consumer health magazine some years ago, we used to raise an eyebrow at the conflicting health claims that came across our desks.

This week’s miracle exercise regimen for building core strength could be next week’s certain path to injury. Today’s super food might turn up on tomorrow’s list of top 10 foods to avoid, and vice versa.

It could be entertaining to watch the trajectory from elixir to ignominy, and sometimes back again, but the shifting messages perhaps had more serious implications.

US journalism academic Dr Rebekah Nagler has spent some time looking at apparently contradictory health messages delivered by the media and how these may affect health behaviours.

A recent study looked at the possible impact of contradictory messages about nutrition.

The paper focused on four particular nutrition topics that have been particularly prone to conflicting media stories — red wine and other alcohol; fish; coffee; and vitamins or other nutritional supplements.

How is the average consumer supposed to make sense of, for example, two news stories with one linking red wine consumption to improved cardiovascular health, and the other to increased breast cancer risk?

Or the myriad claims about contemporary society’s favourite drug, coffee, which apparently delays dementia, kills you, makes you live longer, increases cancer risk, reduces cancer risk, and so on. (For an analysis of some of the wilder media stories making claims about coffee, see this article on HealthNewsReview.org.)

Dr Nagler’s analysis of survey results from 631 Americans found 72% of respondents reported medium- or high-level exposure to contradictory information across the four selected topics.

Perhaps unsurprisingly, those who were most exposed to contradictory messages also reported greater confusion about nutrition in general.

“Exposure to conflicting information on the health benefits and risks of, for example, wine, fish, and coffee consumption was associated with confusion about what foods are best to eat and the belief that nutrition scientists keep changing their minds”, Dr Nagler writes.

Confusion, in turn, was associated with higher levels of “nutrition backlash”, she writes, possibly leading people “to doubt nutrition and health recommendations more generally — including those that are not surrounded by conflict and controversy [such as] fruit/vegetable consumption, exercise”.

This could undermine public health interventions such as healthy eating campaigns, she suggests.

The implications may be even broader. Conflicting messages about cancer screening come to mind, or the possible conflict between skin cancer prevention messages and research into the health benefits of vitamin D.

The real problem here is not the research, but the lack of scientific literacy in some sections of the media and in the general population.

If “Coffee kills” or “Coffee saves lives” stories reveal anything, it’s that there’s precious little understanding of the difference between association and causation among some media reporters.

Compounding the problem is our desire for clear messages, for the eradication of uncertainty, which makes us vulnerable to these kinds of over-simplified claims.

Red wine could help to promote cardiovascular health and, at the same time, increase breast cancer risk.

Things don’t have to be all good or all bad, and the nature of scientific evidence is that it changes over time as new information comes to hand.

Given that uncertainty will always be with us, the most sensible health message of all is probably that old axiom, “all things in moderation”.
 

Jane McCredie is a Sydney-based science and medicine writer.