It’s no wonder that we are uncertain whether we can trust nutritional science given the bombardment of information about what foods are healthy, and the ever-increasing and changing nutritional facts plastered online, in magazines and on bookshop shelves.
As a consequence, we seem to be immensely confused about what we should or shouldn’t eat. Who should we believe and what information shall we trust?
For some, trust is formed by believing in someone’s story. A story shared on how ‘insert proponents name’ discovered a healthy way of eating that enabled them to shed pounds and reverse a plethora of health conditions. These health proponents share their stories and passion for food and health through an ever-increasing myriad of health blogs and online programs. Their passion and enthusiasm may be admirable, but is often misguided or specific to their body and circumstance, and thus not widely applicable.
I confess, in the past, I was drawn in by such proponents. I am even guilty of having repeated their theories, advice or pseudoscience in cooking classes and presentations. At the time, I hadn’t investigated deeper into their claims, nor assessed them against scientific evidence or a thorough understanding of how the human body functions. Now years later, with a university qualification in nutrition, I have formed a more solid foundation to weed out fact from fiction. Unfortunately, the more I know, the more I know we don’t know about nutritional science.
Admitting to what we don’t know
Confused—you aren’t alone. The reason being is nutritional science is still very much in its infancy. Minerals that are vital compounds found in our food were only discovered in the early decades of the 1900s. Eggs were bad for us due to high cholesterol in the 1980s, until it was discovered that the cholesterol in food had no bearing on the cholesterol levels in the body.
We are continually learning about nutrition and the human body, and it is an ongoing process of scientific discovery and research.
Sensationalising what we do know
The tricky thing with nutritional science is that as consumers of this research we are living and breathing on the side-lines anticipating information that will enable us to live healthier and longer. Yet this is misguided hope. What is often released in popular media as ‘groundbreaking’ research is just one study in its infancy that has yet to be validated, and therefore is not yet collaborated by other researchers. This is ignored, and the information is often sensationalised for public consumption or becomes a cash cow for companies that want to make a buck out of our desire for perfect weight and health. Unfortunately, we often swallow what we are told if it’s backed by scientific research.
Yet as consumers of this research we are not told of scientific studies limitations or applicability to our own lives.
Despite my career in nutritional science being in its infancy, I have a strong background in science, having attained first-class honours in environmental science and undertaken postgraduate studies in scientific research. This has provided me with a solid understanding of the intricacies of scientific research.
So, let me share with you the basics of scientific investigations to enable you to be a more discretionary consumer of nutritional science. You may not have enjoyed science in school or understood its application, yet nutritional science is one field that affects us all. Let the science class begin!
Understanding scientific investigation
As a scientist, you devise a hypothesis that you wish to test. You establish a hypothesis through observation and detailed review and analysis of the scientific literature. Your hypothesis is essentially how you believe something works. Once you establish a hypothesis you then go about determining how to test it.
There are different experimental designs. Basic observational studies are where you can establish a correlation such as diabetes increases in prevalence in obese individuals. A correlation tells us how two things are related. Yet it doesn’t provide evidence of cause and effect. That is, does diabetes cause obesity or does obesity cause diabetes? Or is there some other factor such as sugar consumption or genetics that causes both obesity and diabetes, and thus drives this correlation? If we conclude that obesity causes diabetes based on a correlation we may be proven wrong in the future.
This is one of the first issues with sensationalising research, as health proponents and journalists may take the findings of a study and claim that obesity causes diabetes, and this then can become a widely held belief until proven otherwise. If you are at all nerdy like me you may now be asking, how do we prove cause and effect?
Correlative data provides a good foundation to develop a hypothesis. So, in the above example, a hypothesis we may want to test is whether obesity causes diabetes. Once a hypothesis is established scientists then go about designing a study that demonstrates cause and effect. For instance, inducing obesity in rats and seeing whether they develop diabetes, or injecting rats with a substance that makes them insulin resistant and seeing if they put on weight.
Life is more complicated than that found in a scientific lab or petri dish
A limitation of scientific research is confounding factors such as genetic predisposition or conditions, such as the environment or substance used to induce obesity in the rats. These factors may contribute to the findings or lack of findings in a scientific investigation.
For these reasons, to prove cause and effect as a scientist you need to limit the confounding factors. This means you need to isolate what you want to study and minimise other factors that may impact what it is you are studying.
So, say you want to know if coffee is good or bad for human health you would select a certain number of individuals to participate in your study. You would either control their diet or recruit such a large number of individuals that individual variability is unlikely to be a factor in the results. You would then randomly assign individuals to drink or not drink coffee. Another consideration in interpreting the results is who were selected for the study—healthy individuals, females or males, young adults or elderly people, individuals with health conditions or that are overweight.
Therefore, the results of a study may be published, the media grabs this and proclaims that coffee is good for us. Yet they don’t mention that the study demonstrated that coffee had a benefit in athletic performance in young men who compete at an Olympic level.
Popular media don’t care that the study doesn’t apply to a middle-aged housewife whose most strenuous exercise is running after her children. They want to provide sensational stories, often missing critical information that provides an indication of how applicable this is to the wider population. If you have ever read a scientific journal article you will have noticed language in the discussion and conclusion that are essentially caveats—this study indicates that coffee may improve athletic performance in young active men. Scientific studies are never definitive because science is never definitive—each scientific finding contributes to our understanding and further research. Yet, that doesn’t sound exciting as a news headline—and thus is ignored to sell a story.
Scientific research provides a probability of cause and effect, rather than an absolute definitive conclusion.
Accounting for the complexity of your lifestyle and relationship with food
Even if scientific research were definitive—even if we can say with absolute certainty that coffee is healthy or unhealthy—we don’t drink coffee in isolation to other nourishment.
Coffee, chocolate, wine, bread, pasta, carrots and apples form part of a whole diet. Our diet is as varied and diverse as we are. Prorating a food or drink as good or bad does not consider the dose taken in the average person, or more specifically your diet. Nor does this prorating account for other behaviours and consumption that may attenuate or compound the healthy or unhealthy effects.
These limitations are not only applicable to popular media but also government policies and health programs. Government policies and health programs are founded on the best science we have available at any given point in time. This is best practice. However, we need to remind ourselves that nutritional science will progress further, and the findings of any research is based on statistical probability and may not apply to you specifically. Therefore, rather than taking scientific findings as absolute truth, we need to stay open to other causes and cures to our health woes.
My intention in raising these limitations of scientific research is not to fault science, but to caution against taking half-baked truths and running with them. Often popular diets and diet proponents have some research to indicate the validity of their program or theories, but it is only indicative; and doesn’t account for the uniqueness of your body. We, therefore, should take guidelines with a grain of salt, and determine what holds true for ourselves or makes sense to us. Enjoying our diet is an important part of ensuring we are nourishing our bodies physically, mentally and emotionally.
Accounting for the pleasure of eating
We are not machines that we insert nutrition into without pleasure or emotions. It is relatively easy to determine the best fuel for a car to run optimally, but we humans not only require a myriad of vitamins and minerals, we desire pleasure from the food we ingest and have emotional associations with foods. Scientific research will be hard pushed to sway our love affair with chocolate or our social norms of raising a glass of bubbles in celebration.
Take scientific research with a grain of salt
My intention in writing this blog is not to advise you to turn your back on science, but to be more cautious of scientific findings, especially when they are relayed to us through news and popular media.
Understanding the limitations of nutritional research and how this research is sensationalised to generate fear or hope can assist in reducing how seriously you take this information—always with a grain of salt.
Scientific research and experts can provide guidance for what to put on your plate, yet the best measure of what is healthy or unhealthy for you is to use your body as a gauge. So, that you rely more so on your intuition and bodies signals in response to foods that are as close as nature intended