Sugar kills?

I woke up this morning to a headline in Pulse news that read: Sugary Beverages Linked to 180,000 Deaths Worldwide.  Well, with a statement like that I had to read it.

This brought up one of my least favorite types of journalism: Science and Medical writing.

The problem is that journalists don’t really understand science or how studies are done.  They also look for attention grabbing headlines.

I have a Bachelor of Arts in Psychology because the University of Texas at Austin didn’t offer a Bachelor of Science at the time I got my degree.  I wanted to do experimental psychology.  One of the phrases I heard in every Psych class I took was: Correlation does not equal causation.  Just because two variables correlate (increase or decrease together) doesn’t mean that you can tell which one causes the other.

For example, mothers who listened to Mozart while pregnant had children who were several IQ points higher than those that didn’t.  So does that mean listening to Mozart will make your kid smarter?  Or, does that just mean that parents who listen to Mozart are smarter and thus pass on those genes for intelligence on to their kids?

The fact that journalists like to see causal links (as do most humans) leads to the conflicting headlines we used to get about butter being good for you, or bad for you, no, use margarine, no margarine is bad for you.  You get the point.

The problem isn’t that the studies were wrong.  The problem is that studies are there to gather evidence, not form ultimate conclusions.

The sugary beverage study is a good start, but is not the final word.

Now, after reading all that you may think I don’t believe that sugary beverages cause diabetes, obesity and other diseases.  I do.  I stopped drinking soda (aside from the occasional drink – no more than 16 oz per month or two) about a year or two ago.  I have acid re-flux and I just can’t drink sodas anymore.  The fact that my body essentially told me to stop drinking Dr. Pepper isn’t evidence that soda is bad.  There are people who drink soda till they’re 90.  It’s my biology and genetics that make it so I can’t drink that delicious Dr. Pepper anymore. Mmmmm, Dr. Pepper. Sorry.

Why do you want to hurt me, Dr. Pepper?

We know sugar is linked to diabetes, and that soda is linked to obesity.  I don’t doubt any of that.  My problem is that every article written treats this study as if it were a scientific law like the law of gravity.

The part about the article that irked me probably the most was this section:

In 2010 in the U.S., the researchers report that 25,000 deaths were linked to sugary beverages; these drinks were associated with 133,000 diabetes deaths, 44,000 heart disease deaths and 6,000 cancer deaths.

Read more: http://healthland.time.com/2013/03/20/sugary-beverages-linked-to-deaths-worldwide/#ixzz2OEcKkLPh

You see what the author did there?  25K deaths linked to sugary beverages.  The other numbers make it seem worse.  133K diabetes deaths, 44K heart disease, 6K cancer deaths.  Now the numbers linked to sugary beverages in the US seem a lot higher.  That’s 180K deaths right there!  But that’s worldwide.

How many diabetes deaths in the US? Heart disease?

According to the CDC in the U.S. deaths in 2010 (same year as the study used) for each of those diseases was:

  • Diabetes – 69,071
  • Heart Disease – 597,689
  • Cancer – 574,743

That totals 1,241,503 deaths of which 25K are linked (meaning sugary beverages were consumed in “excess” I’m guessing) giving you 2% (if I did my math right) of deaths linked to sugary beverages.  Or, if you wanted to spin it another way:  98% of these deaths had no link to sugary beverages. To put the numbers into bigger context in 2010, 2.4 million people died in the US. 38K by suicide.  Maybe mental health is something we should be concentrating on more than what people are drinking.

I don’t have a good ending for this so I just leave you with a comic from one of my favorite webcomics XKCD about this same subject, only more concise and wittier.

Click through for XKCD
This is what I think of most studies when I read them
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