When the headline “Chocolate Prevents Brain Disease” popped up on my phone screen the other day, you could have seen me jumping for joy. All of my dreams had come true. But then, just as quickly, another headline popped up along the lines of “Butter is Death.”
How do we reconcile the constant bombardment of health headlines telling us something is good for us one day and terrible the next?
Let’s take a depressing headline: “Eight-year Study Finds Heavy French Fry Eaters Have 'Double' the Chance of Death.” Well, considering last night I had a big glass of red wine with an even bigger basket of perfectly golden French fries, I’m in trouble. And yes, the research study from the American Journal of Clinical Nutrition did say that eating French fries doubles your risk of death.
Here’s the trick to keep in mind when reading the health headlines -- it’s something called relative risk.
The risk of death for a 60-year-old man (sorry, guys) is 1 percent, meaning that if 100 men age 60 line up, one will die in the next year simply because of his age.
Now, if all 100 of those men eat fried potatoes at least three times per week (the amount the study denoted a risk) for their whole lives, then yes, their risk of death doubles. But what is one doubled? It's two.
So instead of one of those 100 men dying over the course of the year, two of them will. And those guys get to eat fried potatoes three times a week or more for their entire lives. I think I’ll be OK ordering my fries and wine tonight.
Plus, like me, could those men have been enjoying a glass of wine or pint of beer with their fried potatoes? Could something else have actually been the culprit?
My point is the next time you see an increase or decrease in risk associated with a certain food or drink, the first question you should ask is: an increase or decrease from what original risk?
The same concept applies to bacon. From “Eating Bacon Can Kill You…” to “Yes, Bacon is Really Killing Us” those hot dogs at the ballpark aren’t looking quite as tasty this season.
Again, total hogwash (don’t mind the pun).
Eating 50 grams of processed meat (a bit more than one hot dog) every single day for your entire life will increase your risk of bowel cancer by about 20 percent. But, as with the French fries, an increase from what original risk?
If you line up 100 people, about five will get bowel cancer at some point in their lives regardless of bacon because there's a 5 percent risk of bowel cancer in the general population. If all 100 people eat one hot dog per day for their entire lives, it will increase the risk by 20 percent.
What is 20 percent of five? It's one. So one extra person will get bowel cancer because of the bacon, meaning that instead of five out of 100 people getting bowel cancer, six people will.
Basically, if the risk of getting some disease is one in a billion, and you double your risk of getting that disease (increase by 100 percent), your chance of getting that disease is still only two in a billion.
So stop getting fooled by the scary health headlines and know how to break down the numbers.