I bet you’ve already heard some alarming news about the dangerous eggs that cause cancer or how broccoli lowers the risk of cardiovascular disease and improves lifespan, or how sugar causes this and flour cases that. These articles usually start with the magic mantra “Recent studies show…”.
There’s probably nothing emptier than such claim yet people use it as a failsafe when it comes to a discussion where they suddenly lack arguments to protect their opinions.
It’s always important to realize that studies are nothing more than some kind of trial, where a certain hypothesis is tested by experiment and can be either confirmed or not confirmed. There’s one problem, though. These studies are usually quite costly and somebody must pay for them. Scientists aren’t very wealthy to conduct such studies and cover the expenses on their own yet somebody has to pay the bill in the end.
As Dr. Mercola warns, most of the studies regarding the effects of some substance are usually conducted by companies with a vested interest in the result. This makes perfect sense. These days, people don’t usually take for granted some claim of self-proclaimed guru, that something is healthy, so the game changed, these days, those gurus use a different mantra “Recent studies show…”
When you encounter such a claim, always ask two questions:
- Where can I read the study? Send me the link, please
- Who did the study, who was the lead scientist, who paid for the study?
More often than not, you’ll never get answers. People using this mantra actually don’t know about any specific study or they didn’t read it or they didn’t consider the possible conflict of interest. They just want to sound educated, they probably heard somewhere about some study, but they actually never read it.
Why? Because reading studies is actually pretty hard and extremely time-consuming. Dr. Peter Attia has a whole series of articles on his blog about how to “Study the Studies” (https://peterattiamd.com/ns001/) where he addresses all the flaws. Make sure to check it out and next time somebody tries to lecture you with “Recent studies show…”, you’ll know what to do 🙂
Another important aspect is a particular type of scientific study. Let’s take a look at the pyramid of evidence:
As you can see, the weakest evidence is provided by case studies, clinical experience, and animal studies conducted on rodents like mice and rats. Above them are observational studies that can only show the correlation, but can not prove causality. In other words, if one phenomenon correlates with another phenomenon, it says nothing about the cause and effect. As you might know, Ancel Keys found a correlation between fat consumption and the risk of coronary heart disease and wrongly claimed there is a strong causality.
Unfortunately, such correlation has the same effect as the claim that new movie with Nicolas Cage causes more drowning in the garden pools or that firefighters cause the fire because they are always present where the fire is.
The only type of study that can prove causality are randomized controlled clinical trials, their meta-analysis, and systematic reviews.