We hear so many conflicting health reports, particularly those related to the heart-healthy diets. We are told consuming too much sugar and other high-glycemic index sweeteners will raise your blood sugar, lead to weight gain, metabolic syndrome, and ultimately diabetes, a major risk factor for heart disease. All the studies seem to agree, eliminate much of the sugar and you will be healthier.

Like many, I bit the bullet and made a major dietary change by switching to diet soft-drinks made with anything but sugar and its ubiquitous cheap and sugary replacement high-fructose corn syrup (which many believe to be even worse than sugar). You name it — aspartame, sucralose, acesulfame K, stevia, rebiana, erythritol, etc. — I tried them all. I must admit, it was difficult at first. Despite the claims of soft-drink manufacturers, their sugar-free replacements did not taste just like their original sugared products and there always seemed to be a strange aftertaste. But, over time, my tastes and preference changed. Today, I cannot stand the syrupy, over-sweet taste of sugar in anything. I thought to myself, “Hey, I did it – I made a healthy change I can stick with!”

But now, doubts have started creeping in. A number of studies have been published suggesting that substituting diet soft drinks for their sugared counterparts is no healthier. Others have even gone on to accuse artificial sweeteners of causing all sorts of ills perhaps even worse than the increased risk of heart disease. I was angry, confused, and depressed. Had all that time and discipline to make the switch to diet soft drinks been in vain? So I did what I always do — used statistics and good science to try and make sense of the conflicting messages.

The potential hazard

"People who had diet soda every day experienced a 61 percent higher risk of vascular events than those who reported drinking no soda," according to study’s lead investigator. Wow, 61 percent, that is amazingly large number, one that should grab everyone’s attention. It certainly got mine!

I carefully examined the numbers and they were compelling. The study tracked more than 2,500 people for close to 10 years. Talk about taking the wind out of my sails. What now — I can’t even drink a diet soda? What’s next?! But, a closer examination of the study’s findings was revealing.

Guilt by association

It seems there was one problem with the study. There was nothing there that said diet soft drinks caused heart disease. All they could prove was an association between diet drinks and vascular events (stroke, heart attack, etc.). I recently posted a follow-up analysis on HeartConnect that looked at these studies and the association between diet soft drinks and heart disease. It turns out things are much more complicated that they seem.

In a nutshell, the confounding factor has to do with diet patterns. It seems quite possible — perhaps even probable, in my estimation — that people who drink diet beverages do not eat as healthy as their counterparts who drink coffee, tea, or, better yet, water.

Go to any fast-food restaurant and you are likely to see dozens of patrons ordering double cheeseburgers and large fries then washing it all down with — drumroll please — a diet cola in the false belief that drinking 20 ounces of sugar-free soda magically transforms their terribly unhealthy lunch into a healthy one. I can understand how this happens. We all are looking for ways to be healthier. We learn that eliminating sugar is healthy so we become accustomed to drinking sugar-free beverages. But, thinking we have struck some sort of healthy balance, we never eliminate all the other heart-hazardous foods we consume along with the soda.

It should be no surprise then when researchers find little difference in the heart health of people who drink soda whether it is a sugar-free soda or not. It may not necessarily be the soda that causes the problem. It may be all the other junk we tend to eat when we drink a soda of any kind! I wonder what would happen if they studied people who drank water with their super-sized burgers and fries. Would they conclude that water is hazardous to your health?

Here is my favorite analogy regarding the difference between whether one thing causes another or is simply associated with it. Suppose that every time a plane flies over your house, your dog barks. You notice that every time your dog barks at a plane, it never lands in your backyard. While you can definitely say that your barking dog is associated with the fact that no plane has ever landed in your backyard, you would never think to imply that your barking dog caused planes to keep flying past your house without landing.

To Drink or Not to Drink: What is the answer?

The takeaway point here is the same as barking dogs and planes landing in your backyard. What we can say for certain is that drinking diet soda is associated with increased heart disease risks. Is it the soda itself that causes the increased risk or perhaps something else associated with drinking soda? New evidence suggests, at least to me, that it is the latter.

Do I still drink diet soda? Yes, but much less these days. The best answer, as always, is to talk to your doctor. My doc counsels that it is true that too much sugar is certainly bad for you, but who knows about all those other sweeteners. However, we also know your body was made to drink water. Drink lots of it!