Where does nutrition misinformation come from?

One of my passions is to help raise awareness about the nutrition misinformation out there.

So where does this misinformation come from?

Well unfortunately, too many people cite nutrition “science” without checking the funding, the authors’ bias and the study type.

Funding

The Funding section of a study is the most important section to look out for. This is where you will see first signs of any potential bias.

In addition, many journals are influenced by funding and are therefore selective in what they publish. A recent study[1] reveals funding from the food industry influences such journals, meaning a large amount of the nutrition “science” cannot be trusted.

Further author bias

We should check the authors’ conflicts of interest (there is usually a section in the study specifying this), their previous stance, and whether they are cherrypicking the data to fit their agenda. See my post re Ancel Keys and his cholesterol hypothesis.

Study type

Most nutrition studies are epidemiological (observational). An example of such a study is to send out a questionnaire to a group of heart disease patients and ask them what they ate in the last 12 months. Another might be to follow a group of people for several years, collect data about what they eat and then record what disease they end up with or what age they end up dying.

Such studies can only show correlation, not causation, and are not intended to be taken as the basis for dietary guidelines. They are meant to identify an association, and then researchers are supposed to do a high quality study like a randomised controlled clinical trial.

Sadly, most of the nutrition guidelines are based on epidemiology studies, and it is also these studies that make the headlines, eg “Red meat increases death, cancer and heart risk”. In this case, variables have not been considered. For example, data on nonsmokers who eat their meat with other whole real foods are lumped together with data on smokers who eat theirs with junk food!

Without a clinical trial, saying red meat causes these diseases is like saying margarine causes divorce. Yes, there is a correlation between margarine and divorce,[2] but we would be foolish to draw the conclusion that margarine causes divorce!

Misinformation ends up on food packaging too, eg low fat foods high in sugar being labelled as “heart healthy”.

Please don’t take nutrition advice from news headlines & food packaging!

References

1. Sacks G, Riesenberg D, Mialon M, Dean S, Cameron AJ (2020) The characteristics and extent of food industry involvement in peer-reviewed research articles from 10 leading nutrition-related journals in 2018. PLOS ONE. 2020;15(12): e0243144.
2. Spurious Media LLC. Spurious correlations. https://tylervigen.com/spurious-correlations.