I love it when new research and shocking headlines come out about the foods and drinks we love how they are going to harm or kill us. I enjoy doing the research and finding out the basis of the claim and then sit back and watch the social media know-it-alls feed off the frenzy. I see people grasp onto the headline and try to “educate” us or show us their brilliance by citing the article written by some sedentary cat behind a desk (I’ll leave the overweight part out… He is just husky).
Most of the time…
More like 99% of the time the headlines really don’t fully reflect the study results.
People love standing on their soap-box without doing the necessary research.
I see it from normal everyday folks, professional athletes, CEOs and even Doctors get suckered.
We were just hit with a compelling study that claims diet soda causes stroke and dementia.
You can read the research here or just sit back and let me break it down for you.
First things first, before we dive into the study, we need to understand the difference between causation and correlation.
First off, the study under review is an observational study.
What does that mean little man?!?
Great question my friend.
An observational study is just that, an observation.
An observational study has no experimentation being done. There is no assigning a group to drink diet soda, and another group to drink only water; rather it involves an observation of lifestyle and possible health outcomes.
From these types of studies you can only find correlations. You cannot establish a cause and effect relationship. This is wicked important to understand and take into consideration when weighing these forms of research.
In this type of study there is a relatively high likelihood of unaccounted factors that will affect the outcome of the results.
Correlation studies can be strongly misleading. Throw misleading information on the inter-web and you have a circus waiting to happen.
Here are Two examples of correlative research:
Check out the graph below that shows a strong correlation between the number of swimming pool drownings and the number of Nicolas Cage movie appearances in a given year. Unfortunately the research “proves” that Mr. Cage has some splainin’ to do.
Mr. Cage has nothing to do with pool drownings, regardless of how bad some if his movies are. While this example is down right ridiculous, I contend that many correlative studies are almost as silly.
Let’s look at another study. This one is a little more serious and caused a stir that lasted for decades. This one is around 75-100 years old.
There was a strong line of research that ice cream consumption caused polio. The reason that this correlation was thought to be causal is simply that the polio virus spiked in the summer months. The reasons for the spike weren’t really understood but, researchers were determined to find a cause to hopefully curb the virus. They noticed that during the summer months ice cream sales spiked also so they concluded that ice cream was the cause of the polio virus. Due to this correlative research ice cream was villainized to try and stomp out the polio virus.
This seems ridiculous but we see it all the time today. People are trying to prove that some things are connected when in actuality there might not be any connection at all. Some of the time, as in the cases above, it turns out that there really isn’t the true research to prove causation. There are simply too many variables at play in most circumstances to prove causation from correlation.
Both of these studies prove the point that correlation research doesn’t give us all the information needed to prove causation. I use them both to stress the awareness needed to come to a sound conclusion.
Does any of this mean that we should automatically discount all observational studies?
There are a lot of things we can learn from observational research and there are many things we simply cant conduct experimental research on because of practicality and or ethics.
Observational studies are often used to generate an hypothesis which can be tested on further trials and studies.
It is important to note that observational studies cannot establish a cause and effect relationship.
Read that again!
Memorize it and NEVER forget it.
Observational studies are still a very important piece of the puzzle and should be examined in detail.
Enough of the foundation little man!
Onto the study!
What did the researchers find?
This study looked at the relationship between both sugar-sweetened and artificially-sweetened beverages and the incidence of strokes and dementia. The study focused on ~4,000 people from Massachusetts from 1991 until 2014 to see how many sugar-sweetened drinks and artificially-sweetened drinks each person drank, along with how many individuals were diagnosed with strokes or dementia.
This is actually a decent study and very intriguing.
There are many factors at play that were considered such as smoking, lack of physical activity, sleep quality and excessive caloric intake. These factors could also increase the risk of having a stroke or developing dementia and the researchers made some adjustments for these covariates.
The result of the study was pretty interesting:
people with a cumulative intake of more than one artificially-sweetened beverage per day were 2.96 times more likely to be at risk for an ischemic stroke and 2.89 times more likely to be at risk for developing dementia, compared to people who did not drink any sweetened beverages.
Those who drank sugar-sweetened beverages didn’t see an increased risk. With this information don’t be surprised if we see another push of the “surgery soda is more health than diet soda” hog wash.
In short, after following ~4,000 people over fourteen years, researchers found that people who consumed more than one artificially-sweetened beverage per day were around three times more likely to experience an ischemic stroke or dementia, while sugar-sweetened beverage drinkers didn’t have an increased risk.
These results are eye opening however, are the results as strong as they appear?
All observational studies have a number of limitations and as such it’s is important to point out that despite the researches attempts they simply cant adjust for all the possible covariates that might impact the outcomes as well as the consistency of exposure.
When considering this study we need to look at the possibilities of those who might regularly consume diet soda. On average these people might be a yo-yo dieter, have higher stress levels, possible sleep apnea, or have a host of other contributing behaviors that could, theoretically be tied to greater risk of disease.
In other words, there are more than likely bigger fish to fry than consuming a diet soda or two.
Another problem I found with the study is that there were some strange errors in the Food Frequency Questionnaires (FFQs) the researchers used. I noticed a number of variation errors in food reporting numbers that caused increased suspicion. I will save you from the p-value data so suffice to say the values the researchers deemed significant that were not within the acceptable significance range.
What’s that mean little man?!?
It shows me that there might be a little bias and the study was looking for a negative result. The study left a lot of wiggle room for determining false positives.
I’m cool with wiggle room, especially when exploring new territory and a certain level of freedom is needed. Researching uncharted territory is important however, the problem is that the data you collect isn’t always the most reliable.
This is exactly how this study should be taken. It is eyeopening enough to hopefully generate some interesting ideas for researchers to follow-up on.
For these reasons that we have clearly defined above, the results of this study should not be taken as heavily as the headlines would want us to believe.
We could throw all the rocks in the world at the Food Frequency Questionnaire as it is horribly inaccurate and not scientifically sound. However, most importantly, the study conducted multiple comparisons, which increases the likelihood of false positives and they were not statistically correct.
Again, this is an intriguing study to compel further scientifically sound research but, it is far from conclusive.
So, can we blame diet soda for strokes and dementia?
However, regardless of the studies limitations and inaccuracies eyes need to be opened. If you are consuming predominantly diet soda you may want to make some changes. QUICKLY!
This study also researched regular soda drinkers and didn’t draw the same conclusion.
So should you drink regular vs. diet because its “healthier” (we have all heard clowns pushing this one right?!?)?
Not so fast.
While no correlation was evident enough for note, we do know that sugary soda is STRONGLY linked to far more factors that would increase your chances for having a stroke (type 2 diabetes, high blood pressure etc.) and dementia (generally a poor diet etc.).
Artificial sweeteners however, are less clearly linked to chronic disease. They don’t appear to spike insulin (who funded that research?), metabolic derangements (the evidence of these studies is far more mixed than the headlines would have you believe) or altered glucose homeostasis, well, unless you’re a fruit fly.
There is some complex research on the human gut as well as the brain that artificial sweeteners may POTENTIALLY (We still don’t know definitively at this point) impact our gut microbiota as well as the sweet taste sensors of our brains.
There is a potential risk as with anything we do. If you’re consuming too much of something, anything, it is more than likely a bad thing.
So unfortunately, “diet soda causes strokes and dementia” is not accurate.
That being said, a lack of strong evidence does not close the chapter on this subject.
The research tells us that there is still a lot of information about artificial sweeteners that we don’t know.
Because of the vast amount of artificial sweeteners on the market it’s going to be a long time until we truly understand any of them well enough to make a definitive statement.
The researchers here weren’t clowns out to make a buck and prove something is “healthier” than another. The funding was government provided. This is important because too many of these types of studies are funded by an industry bias and as a result skewed.
This study is enough for us all to stop and evaluate our current condition and choices.
Take some time over the next few days and look closely at your nutritional intake and behaviors.
Watch for balance and regularities.
What are your main meals like? Do you regularly consume a balance of carbs, fats and proteins?
Are you unnecessarily eliminating food groups and consuming too much of another?
Do you have a diet soda IV drip?
Are you exercising regularly?
The cold reality is that for many of us soda is a terrific prozac.
It keeps me from blowing a gasket and chasing neighborhood kids with a stick however, it is not the bulk of my nutritional intake.
The key here is balance not deprivation.
Take a sharp look at your lifestyle and behaviors.
Hit me with questions and feel free to share what you find.
I love this stuff and would love taking a look at your information with you. Between the both of us I bet we can make a few tweaks and get you on the right track of long term success and balance.
Discover your balance.
Discover your healthy.
Discover your happy.
Discover your ELITE