Why you can’t believe everything you read or hear in the media about nutrition and health
Misinformation, misunderstanding, misinterpretation and conspiracy theories abound about food, nutrition and health. You really need to maintain a critical eye to sort the wheat from the chaff. And it’s not just well-meaning friends, health food store employees, neighbours and websites you need to worry about. The media often get it wrong. Or they misconstrue a scientific study’s message because they love a catchy headline. Or they just published the press release. Or the editor gave the story to a news reporter not the health and science writer.
For example, if you see a headline that shouts out: ‘Study shows Amazon Jungle Juice will help you lose up to 50 pounds in 90 days’. Pause before you open your purse and fork out for a six-pack. Here’s why. In nutrition research terms a study which finds an association between eating a food or nutrient (say, Amazon Jungle Juice) and a health indicator (say, weight loss) in a particular group of people (say, Amazonian Indians) does not mean Amazon Jungle juice will help you lose weight. An epidemiological study like this (that’s a study of the relationship between diseases and contributing factors in populations) can’t prove cause and effect – it merely is saying, hello, here’s an association that’s worth more research. Epidemiological studies can have problems with the way they were carried out too (these are called methodological problems). For example:
- Was it a big enough population to properly power the study (i.e. were there enough people in it)?
- Was the Jungle Juice the only thing that was different in the group that lost weight?
- How was the intake of Amazonian Jungle Juice assessed within the population studied
- Did it rely on people’s memories of past consumption (memories fade)?
- Was a tool used with proven validity in this population (for example do Amazonian Indians think about food in the quantitative way that the researchers do)?
- Was the population’s level of physical activity properly factored in (this would also help weight loss)?
The gold standard intervention study is a double blind, placebo controlled trial in which both the subjects and researchers have no idea which group received what. This type of study also determines whether the intervention works statistically better than a placebo. And not just one of these studies but many to ensure the results are robust and repeatable. Alas, these issues are not considered by journalists working on the basis of one study, racing toward deadline.
I often receive feedback from readers urging me to read a book in order to educate myself about an alternative view. But books aren’t always trustworthy sources of information either. You don’t actually need qualifications to publish a book – anyone can do it if they have a marketable concept. I critically assess nutrition books very carefully. The best ones are usually (but not always) written by nutrition academics and registered dietitians who are experts on the topic and draw on scientifically sound research and evidence-based content. To help them get the message across in a clear and simple way, they may work in conjunction with experienced and qualified health writers.
In a world where we are bombarded with nutrition information how can you sort the wheat from the chaff? Here’s my 3-point checklist. Check out:
- The writer’s qualifications – top marks go to books, articles and websites written or co-written by nutrition experts
- Positive reviews by people who can form an educated opinion, such as registered/accredited dietitians, nutritionists or nutrition academics, and
- Does it overturn accepted nutrition wisdom? Strange or unusual ideas are often wrong and won’t provide any real and practical help for you.