Updated 06 October 2015

Why soda is bad for you

Love your fizzy drink? Think again. A growing body of research suggests a link between sugary soda consumption and diabetes, hypertension, liver disease and some types of cancer.


According to the American Heart Association soft drinks and other sugar-sweetened beverages are the primary source of added sugars in Americans’ diet.

This comes as little surprise, considering that researchers at the University of California, Berkeley, have found that the average serving size of soda in the US has skyrocketed since the 1950s from a modest 185ml to between 340ml and 500ml.

What’s more, each 500ml soda contains almost 17 teaspoons of sugar. The result: “Sodas and other sugary drinks are a major cause of the alarming increase in both obesity and diabetes in the past 20 years,” says Barry Popkin, who holds a doctorate in nutrition and is a professor at the University of North Carolina at Chapel Hill.

But obesity and diabetes aren’t the only health hazards. A growing body of research suggests a link between sugary soda consumption and high blood pressure, liver disease, gout and some types of cancer as well. Some recent findings show just how bad soda is for your health:

  • A child’s risk for obesity increases an average of 60% with every additional serving consumed per day of sugar-sweetened beverages, including sugary soda, according to a study conducted at the Harvard School of Public Health.
  • Harvard studies have also shown that women who drink the most sugar-sweetened beverages have a 35% higher risk of coronary heart disease than those who drink the fewest.
  • Researchers at the University of British Columbia and the Harvard Medical School have discovered that men who consume two or more servings of sugary soda per day have an 85% higher risk of developing gout compared with those who consume less than one serving per month.
  • People who drink two or more sweetened soft drinks a week have an 87% higher risk of developing pancreatic cancer compared to those who drank fewer, according to a study analysing data from the Singapore Chinese Health Study published in the journal Cancer Epidemiology, Biomarkers & Prevention.

Is high-fructose corn syrup to blame?

Some experts have pointed an accusing finger at high-fructose corn syrup, the concentrated sweetener used in almost all soda. Made of 55% fructose (the sugar found in fruit) and 45% glucose (the simplest form of sugar), high-fructose corn syrup is said to be especially bad for health, promoting obesity and high blood pressure more than other sweeteners.

Indeed, researchers at Princeton University found that high-fructose corn syrup is responsible for increasing triglyceride levels in the blood, a risk factor for cardiovascular disease. But most health experts say overdoing it on any source of sugar is a bad idea.

How much soda is too much?

According to the 2005 US Dietary Guidelines for Americans, a healthy, balanced diet has no room for added sugars from any source, including soda. That means those 500ml drinks we’re chugging at the movies are just extra kilojoules. And you know where those go.

So what’s a health-conscious, soda-loving person to do?

  • Drink beverage blends made with 100% fruit juice and sparkling water.
  • Try spritzers that contain nothing more than sparkling water and natural flavours.

Remember, research continues to prove that soda is bad for your health, but you can never go wrong with water.

(Written by registered dietician Denise Webb)

Read more:

Slideshow: 10 foods with hidden sugar
Sugary drinks increase diabetes
Kilojoule bomb in your beverages


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