The supplement industry is like the Wild West.
So, how can you differentiate between the genuinely health-beneficial and the, well, for lack of a better word, garbage?
One popular suggestion has been to look out for ‘clinically proven’ supplements: if something’s 'clinically proven' to work, that means it'll be effective for you, too, right? Because of science and everything? Not really.
In this article, learn why you should maintain a healthy level of skepticism toward ‘clinically proven’ supplements by understanding:
What a clinical study is (and what it can and cannot tell you)
How to evaluate a clinical study’s quality AND
Key factors to consider when interpreting a study’s results
A clinical study refers to research involving people. There are two main types of clinical studies:
1) Observational studies: Refer to studies where researchers observe the effect of a pre-selected characteristic without manipulation.
Example: Researchers took a random sample of adults and asked them about the dietary supplements they're currently taking. The data found that those who took turmeric had lower rates of cardiovascular disease than those who didn't.
2) Clinical trials (i.e., experimental studies): Refer to studies where researchers introduce an intervention and study the effect.
Example: Researchers took a group of adults, measured their blood lipids profile(baseline), and randomly divided them into two groups. They gave one group turmeric pills and the other placebo pills. After 12 weeks, they measured the participants' blood lipids profile to analyze turmeric's effects.
Answer: yes.
See, correlation does not equal causation. That means observational studies cannot prove a cause-and-effect relationship.
So, (back to our example) just because researchers found that those who took turmeric had lower rates of cardiovascular disease doesn’t mean that turmeric is necessarily the cause of improved heart health.
On the other hand, if an experimental study found that participants taking the turmeric pills reported a statistically significant improvement in blood lipids profile than those in the placebo group, it could prove that turmeric caused an improvement in heart health.
Why is it "could"? Why the uncertainty? Well, that's because, beyond the type of clinical study, other factors can also impact the reliability of a study’s results:
Study design (specific to experimental studies): A randomized controlled trial is the gold standard study design to ascertain an intervention's effect. Let's break down the components further, so you know what to look out for in any experimental study:
Randomized: Randomization (i.e., allocation sequence generation) ensures that the participants have an equal chance of being assigned to the intervention group of the control group. This reduces selection bias.
Placebo-controlled: The participants in the control group should receive a placebo that looks exactly like the intervention (with the only difference being the absence of active ingredients).
Blinding: Ideally, participants, investigators, and outcome assessors should be kept unaware of the treatment assignment throughout the study. This helps reduce performance bias and the "placebo effect" risk.
Funding source: Did the supplement company, which has enormous financial stakes in the evaluated supplement, fund the research? If so, you likely cannot trust the study's results.
Participants: How many participants are involved in the study? Generally, a study with more participants will have a higher "power" than one with fewer participants. Note: power indicates the chances that a study will detect an effect if that effect does exist. Also, what characteristics do those participants have? For example, if they're mostly above 60 years old, while you’re middle-aged, it’s unlikely that the findings apply to you.
Where it’s published: Legitimate scientific journals tend to publish studies that have been rigorously and objectively peer-reviewed—the gold standard for scientific research and publishing. An excellent way to spot ahigh-quality journal is to look for one with a high impact factor. This number primarily reflects how often other scientific studies have cited the average article from a given journal.
Bottom line? The next time you come across a ‘clinically proven’ supplement, be sure to ask yourself the following questions as you pore through its cited study:
Is it an observational or experimental study?
If it’s an experimental study, is it well-designed?
Who funded the study?
How many participants were there? What are their characteristics?
Which journal is the study published in?
Doing so maximizes the chances you'll steer clear of shady supplement companies—and walk away with a supplement that truly works for you.
