A Tale of Two Studies
Everyday I seem to run across people who have a particular view of a certain health topic related to diet and nutrition. I find it amazing what people believe in. From having a certain blood type dictating what you can eat to requiring a specific amount of an exotic oil each day to maintain “health” to eating different groups of foods in a particular order, everyone seems to have their own theory as to how these things produce health and longevity.
Are these things really true though? Will swallowing two tablespoons of coconut oil daily or eating a meat-heavy diet if you have type O blood really produce better heart health, reverse diabetes, or prevent Alzheimer’s Disease?
I never ridicule or doubt anyone’s beliefs when it comes to these topics because everyone usually has a reason for believing what they believe. Instead, I ask them questions to try to understand why they believe what they believe. It’s amazing what I hear for their answers. Rarely does it involve a discussion of specific scientific studies. It’s almost always due to something like this – “I saw this video on Facebook where this person was talking about ____” or “My friend told me ever since she started consuming coconut oil everyday she feels better and her mind is clearer.”
While I don’t doubt that some of these things may be true, I would never want to base my health decisions on this so-called hearsay without solid scientific proof to back it up, which brings me to today’s topic – a tale of two studies.
Difference Between Two Major Types of Scientific Studies
The important factor in deciding whether a health claim made by someone is true or not true comes down to the scientific data. A good student of health will want to see studies to back up any specific health claim. An excellent student of health will understand what these studies mean when they read them.
Without getting too technical or in depth there are two major types of studies that help us understand whether or not something has an effect on our health. These include interventional studies (experimental) and observational studies (epidemiological).
Interventional studies are clinical studies in which study investigators employ a specific intervention (i.e. medication, procedure, diet, etc.) on a group of participants to see what kind of outcome it produces. These studies are very detailed and involve specifying exactly what intervention is to be done, and how it is to be done, to individuals participating in the study before the study begins. It also requires investigators to specify what outcomes they will be testing for and their methods of testing for these specified outcomes before beginning the study. Doing all these things helps to control different types of variables which could affect study outcomes. Interventional studies help us understand the cause and effect of a specific intervention on a specific outcome. Dr. Caldwell Esselstyn’s study using a whole foods, plant-based diet to halt and reverse heart disease is an example of an interventional study.
Observational studies are epidemiological studies. These studies do not involve a study investigator directly acting upon a study participant. Instead, there is an observation of the natural relationships between factors and outcomes. Observational studies help us establish a potential correlation between two items but do not prove direct cause and effect between them. An example of an observational study would be the famous Framingham Heart Study where researchers observed a select group of individuals over a certain amount of time to see how various lifestyle factors affected their risk of getting cardiovascular disease.
Observational studies are a great way to establish more interest in an area of study where an interventional study can then be used to measure direct cause and effect between two items. The Framingham Heart Study helped us understand that healthy eating was correlated with improved heart health, but Dr. Esselstyn’s study showed us exactly how a specific diet (whole foods, plant-based diet) could be used to treat and reverse a specific disease (i.e. heart disease).
Don’t Fall for Information Hype Regarding Diet and Health
Whenever someone tells you about a new exciting diet or miracle food don’t be too quick to jump on the bandwagon. Always do your due diligence to see if what they are saying is really true or not.
Maybe having a certain blood type does require a specific diet to be healthy, but is this based on observational data or a well-designed interventional study? Is drinking coconut oil daily something that leads to improved health outcomes for everyone based on controlled, interventional studies or did just one person experience better health based on their own observations? And what were the health outcomes in these situations¾less heart disease or no heart disease; better blood sugar control or a complete reversal of type 2 diabetes; less arthritic pain or the complete disappearance of rheumatoid arthritis confirmed by lab tests?
These are the types of questions you should ask yourself before implementing any type of change in dietary advice from other people (including your doctor or other healthcare professional). Remember, good students of health ask for proof of things they hear. Excellent students of health understand what this proof means and how to put it into context when it comes to the big picture.