Are sugar-sweetened soft drinks bad for you?
How do sugar-sweetened soft drinks compare to other drinks like diet soft drinks or low fat milk or water?
Besides the increased risk of dental decay just how bad are sugar-sweetened soft drinks?
Despite all the criticism about soft drinks, there have been few clinical trials lasting more than a few weeks that compare sugar-sweetened soft drinks to other beverages.
A recent study from Denmark is very informative.
This study randomly assigned 47 adult men and women to one of four groups and followed them over 6 months. Those groups were assigned to drink 1 liter (equal to just under three 12 ounce cans or about a quart) of one of the following beverages daily:
· regular Coca Cola or
· diet Coca Cola or
· water or
· reduced fat milk
The low fat milk provided about the same calories as the regular Coca Cola: about 450 calories. The diet soda provided only 15 calories per day and, of course, no calories came from the water.
In Europe, Regular Coca Cola is sweetened with half glucose and half fructose. Unlike the U.S., Europe does not use high fructose corn syrup in their regular sodas. The diet Coca Cola used the sweetener aspartame.
Now you might think that a quart of soda is a lot, but in the U.S, over a third of those aged 18-34 years of age drink soft drinks several times a day. Drinking three 12 ounce cans daily would be just like these people did in this study.
And these participants were not at a healthy weight to start.
They had an average body mass index (BMI) of 31.
A BMI of 25 but less than 30 is considered overweight.
A BMI of 30 and above is considered obese.
Their body fat was evaluated by magnetic resonance imaging (MRI) and magnetic resonance spectroscopy.
And blood lipids (cholesterol and triglycerides) and blood pressure were carefully measured. Other measurements such as blood glucose and insulin were taken.
So what did the researchers find at the end of this 6 month trial?
Those drinking the regular sugar-sweetened soda had:
- much more fat (130-200% more) in their liver and their muscles as compared to the other group
- 32% higher blood triglycerides and 11% higher blood cholesterol as compared to the other groups
The systolic blood pressure appeared to be lower in the milk and diet soda groups as compared to the regular sugar-sweetened soda.
Diet soda, otherwise, had effects similar to water. This is consistent with a recent post.
There was no significant difference in weight in the four groups as compared to the baseline weight over the 6 months. That means that the groups drinking the diet soda and water must have taken in more calories from other sources, like food. And the groups drinking the caloric beverages, milk and regular soda, must have taken in less calories from other sources, like real food.
You may know that fat in your liver and muscle is not good.
Although this study had fairly few participants it was 6 months long and was well designed. Further work needs to be done to confirm and extend these findings.
In the meantime, I think this study provides more evidence to conclude:
- not all calories are the same
- sugar sweetened drinks are nasty
- it's best not to drink your calories