Randomised Controlled Trials (RCTs) are considered the best method for testing the effect of drugs and are widely used in medicine. However, it is not always possible to use RCTs in nutrition as there are many considerations to take into account. For example, it would be unethical to feed people with foods or compounds that are suspected to have negative effects on health (e.g. processed meat). Another issue is that people eat many different types of foods daily and separating the effect of a single food from all the others eaten within an overall diet is quite complex. Moreover, people follow different lifestyles and have different behaviours related to food. Therefore establishing a cause-effect between the consumption of a certain food and health outcomes is challenging.
To overcome these problems, scientists look at evidence from observational studies. In these types of studies, people are asked to provide information about their diet through a questionnaire and are followed-up over many years. However, there are problems with this type of research too. People may not accurately remember what they ate when asked, and this can affect the results.
Also, conflicts of interest can influence research findings. For example, when studies are funded by the food industry, the results may favour their interests. Personal beliefs and biases can also influence how researchers interpret the results, leading to conclusions that may not be reliable.
It’s important to understand that nutrition is more complex than just focusing on individual nutrients or foods.. The way foods are combined and consumed matters too. This can create confusion and doubts when trying to understand nutrition research.
Overall, making clear and definite statements in nutrition science is difficult because of these challenges and limitations. It’s important to carefully evaluate the research data and consider different factors before drawing conclusions.
Sources
- PAN Nederland. ‘PAN Nederland -’. Accessed 26 May 2023. https://www.pan-nl.org/voedingswetenschap-kritisch-beschouwd/.
