Sunday, July 10, 2011

Fizzy failures.

I am a Dr Pepper freak. Or at least, I used to be. In high school, I started each morning with a can of Dr Pepper. After my morning snack of Reese’s peanut butter cups, I would grab a quick lunch: a cup of pasta with red sauce and (of course) a Dr Pepper. If I still had any change left in my pocket at the end of the day, I would hit the vending machine once more after school.

In college, I upgraded to the plastic bottles. I wanted to recycle them, but I didn’t have easy access to a bin, so the empty bottles would pile up at home, at work, wherever I happened to be. When I first met my now-husband, he stopped by my work to say hi. I wasn’t around so he left me a note in which he pretended to be a building manager and scolded me for the myriad bottles and cans that “peppered” my workstation.

Over time, as I slowly but steadily gained weight, I started to wonder about all that Dr Pepper. I first zeroed in on the calories: 200 in every bottle I drank! A 20-oz bottle also has 68 grams of sugar. I didn’t really know how to interpret that number at the time. According to the Hershey's website, it’s just about the same as eating 7 peanut butter cups. SEVEN. For a while, I switched to Diet Dr Pepper. It didn’t taste as good, though, and I was bothered by all of the chemicals I knew must be in it to make it taste even remotely like Dr Pepper. Luckily, the whole chemical issue got me thinking… What is regular Dr Pepper besides chemicals? High fructose corn syrup is a highly processed substance, so how different is it really? And then I came to the fundamental issue: what is this stuff doing for me anyway?

Human beings have to eat or we die. Eating has a purpose. It nourishes us. It provides us with the absolutely necessary life-sustaining vitamins, minerals, and energy we need to function. In our culture, though, we have turned eating into a form of recreation. We eat something because it tastes good or because it’s convenient or cheap. We eat even when we aren’t hungry. And when we are hungry, we often satisfy that hunger with little regard for the quality of the calories we consume.

So what was all that Dr. Pepper doing for me? Well, at best it was doing nothing. Unfortunately, it is becoming increasingly clear that drinking soda day in and day out is anything but benign.

“Soft drinks and other sugar-sweetened beverages are the primary source of added sugars in Americans’ diets… Between 1970 and 2000, per-person daily consumption of caloric soft drinks increased 70%” [1]

In 2007, a study was published in which the authors reviewed the results of 88 previous studies on the health effects of soda consumption [2]. The first thing they determined was that people who drink soda do not eat less food. Unlike a snack, the extra calories in soda do not lessen a person’s urge to eat. I could never consume seven peanut butter cups in one sitting, partly because I’d be full after only two. I also know that peanut butter cups are candy – they are treats, meant to be enjoyed only now and then. I had no problem consuming just as much sugar in soda form, though, and never gave it much thought.

The same study found some evidence that drinking soda actually makes people consume more calories at mealtime than they otherwise would [2]. One reason for this may be that drinking soda conditions you to want sweet things, so you seek out sweeter (and generally higher calorie) foods throughout the day. The effect of soda consumption on overall calorie intake seems to be strongest amongst women.

The link between soda consumption and Type 2 diabetes was quite strong, according to the report: “In a study of 91,249 women followed for 8 years, those who consumed 1 or more servings of soft drink per day were twice as likely as those who consumed less than one serving per month to develop diabetes over the course of the study.” [2] Even when BMI and other factors were considered, this outcome persisted. Soda consumption was also linked to calcium deficiency and poor bone health although these were probably indirect effects; people who drink lots of soda tend to consume less milk or other dairy – the main sources of calcium in a typical Western diet.

Sugar is a huge downside of soda. Table sugar is sucrose – approximately equal parts glucose and fructose. High fructose corn syrup, which is the sweetener of choice in most sodas, is about 55% fructose. Either way, drinking soda delivers a lot of fructose. The liver is responsible for breaking it down, but it can only handle so much. The high levels we consume (mainly as HFCS in soft drinks and other processed products) can actually lead to a serious condition called non-alcoholic fatty liver disease [3]. It’s called “non-alcoholic” to distinguish this type of liver disease from cirrhosis caused by alcoholism. An important thing to note is that alcohol is just fermented fructose; your liver doesn’t see much difference between the two. So even if it won’t make you drunk, sugar can fry your liver just as effectively as booze.

If the sugar in soda is such a problem, is diet soda the solution? Unfortunately, it’s not looking that way. Although the exact biochemical and physiological processes are not well-understood, there is increasing evidence that even diet soda contributes to obesity and metabolic syndrome. In a long-term study by the UT Health Science Center, people who consumed diet soda increased their waist circumference by 70% more than participants who did not. Those who drank at least two diet sodas a day had 500% larger increase in waist circumference over non-drinkers. A different study - of 10,000 people over 9 years - found that those who consumed ONE can of diet soda per day were 34% more likely to develop metabolic disorder. Additional studies also linked diet soda consumption with higher rates of obesity and high cholesterol.

“On average, for each diet soft drink our participants drank per day, they were 65 percent more likely to become overweight during the next seven to eight years, and 41 percent more likely to become obese,” said Sharon Fowler, M.P.H., faculty associate in the division of clinical epidemiology in the Health Science Center’s department of medicine. (From the UT Health Science Center press release)

In the search to understand why diet soda would make people fat, researchers looked into the effects of aspartame on mice (read more here). It turns out that the mice experience an insulin response from consuming aspartame. It’s a big leap from mice to men, but perhaps our bodies recognize sweetness and respond – in part, by releasing insulin – even if the sweet taste is synthetic and calorie-free. Caramel color has also been linked to insulin response in some preliminary studies. Research into the effectiveness of sports drinks on athletic performance may offer some clues as well. Cyclists were given a swig of sport drink, and they either swallowed it or swished it in their mouths and spit it out. Participants in both groups saw a performance enhancement. Just having the drink in their mouths caused their bodies to respond. It is an intriguing result (read more about the study here and here). It seems the body may begin responding to artificially sweetened sodas, flavored water, or sports drinks as though it was about to get sugar even if the sugar never arrives.

Our bodies respond to sugar by releasing insulin. The more our bodies produce insulin, the more likely we are to become insulin resistant. The result is that our bodies do not release fat as easily as they are supposed to, and we ultimately get fatter. Type 2 diabetes is an serious form of insulin resistance.

The idea that regular consumption of sweets makes people crave them even more may also contribute to the correlation between diet soda and obesity. People drink diet soda, thereby avoiding the extra sugar and calories of regular soda, but it is made up elsewhere. A poor diet overall may also be a contributing factor. Every fast food restaurant has soda available; frequenting these places means you are eating unhealthy food and washing it down with soda. Even diet soda is not going to make up for the extra calories, added sugar, and fat in the food.

From an environmental standpoint, our high soda consumption is also worrying. It currently takes between 1.7 and 3.1 liters of water to produce 1 liter of Coke (depending on the location of the plant) [4]. Coke has actually received a lot of criticism for their practices in India and other parts of the world; their plants have drained local wells and contaminated groundwater. Only 1% of Earth’s water is both drinkable and accessible, and we are using quite a lot of it to make and bottle soda. And that doesn’t even include the water and fossil fuels required to grow the corn used in making high fructose corn syrup. (Of course, our surplus of cheap corn is the reason we have so much cheap sweetener for soda; if we all stopped drinking soda, some other use would be found for cheap corn.) It is crazy to think about just how many resources are now devoted to creating beverages that give us nothing we need and a lot of things we don’t want.

Our perception of soda as simply a water substitute is flawed and maybe even dangerous. Soda is dessert. It may be tasty, but it should not be consumed at every meal or probably even every day. Diet soda (and possibly other artificially sweetened drinks) can still contribute to the health problems associated with regular soda. And all of these drinks require precious resources that could be put to better use.

I am no longer known for my obsession with Dr Pepper. Now people send me links to articles about food or ask me for tips on running. There was a time when Dr Pepper brought me so much pleasure, but in the end, it is just a drink. There is a lot more to life than soda. And there may be more to life without soda.

[1] Johnson, R.K., et al. (2009) Dietary Sugars Intake and Cardiovascular Health: A Scientific Statement from the American Heart Association. Circulation, 120, p. 1011=1020.
[2] Vartanian, L.R., et al. (2007) Effects of Soft Drink Consumption on Nutrition and Health: A Systematic Review and Meta-Analysis. American Journal of Public Health, 94-4, p. 667-675.
[3] Ouyang, X., et al. (2008) Fructose consumption as a risk factor for non-alcoholic fatty liver disease. Journal of Hepatology, 48, p. 993-999.
[4] Greenbiz article on Coca-Cola's attempts to improve its water usage

1 comment:

  1. Oh man, I drank SO MUCH pop in high school. I really paid for it too... I got tons of cavities! Now I drink way less, but I still have the occasional diet coke as a treat because I love it so much, it tastes like a little bottle of heaven.