You'd hardly put the drinking of a can of soda or soft drink in the same league as taking heroin or cocaine, but startling new research suggests it's time we did. Sugar-sweetened drinks cause more deaths every year than illicit drugs and add billions of pounds and dollars to healthcare bills around the world through the diabetes, heart disease and cancers they are causing.
The drinks are killing about 180,000 adults every year around the world-although they are never cited as the cause-and their lethal effects are not recognized, nor are manufacturers forced to put warning labels on cans and bottles, say researchers from Harvard University, who are the first to estimate the death rates from soft drinks.1
Their major risk is causing and escalating diabetes, a disease responsible for 133,000 of the 183,000 deaths associated with the drinks. This is followed by 44,000 deaths from cardiovascular disease and 6,000 from some cancers.
In the US alone, around 25,000 people die every year from regularly drinking colas compared with 18,000 who are murdered across the country and the 24,000 who die after taking an illicit drug. Deaths associated with the drinks are similar to the numbers caused by prostate cancer, which kills around 28,000 Americans annually.
This grim picture may even be optimistic, the Harvard researchers warn. Their research concentrated on deaths from chronic disease among adults and the figures could be far worse if children and adolescents are included, as they probably drink more cola drinks than any other age group.
To get some idea of the real problem, take a closer look at Mexico, which has the highest death rate among adults from consuming colas; the drinks are responsible for 318 deaths per million adult deaths. Not surprisingly, its people also drink more soda drinks than anywhere else. Mexicans spend around $14.3 billion a year buying colas and sodas, and the average Mexican drinks 43 gallons of the stuff each year, which is roughly equivalent to 688 cans of the 330-mL standard cola cans; by comparison, the average American drinks around 31 gallons of soda a year, or 496 cans.
But not only does Mexico have the highest soda-related death rates in the world, it also has one of the highest rates of diabetes, second only to the US. Mexico's other great health challenge is the obesity levels among its children; it has the highest rate of childhood obesity in the world, with more than 28 per cent of children aged between five and nine who are obese, and this rises to 38 per cent in preteens and teenagers.
The association between sugary drinks, obesity and diabetes is hardly controversial, yet it points to the true extent of the problem, which the Harvard researchers were not able to uncover.
How much can you drink?
If the Harvard research is to be believed, it's a little like asking how much cocaine can you safely take. Researchers have been astonished by the speed that drinking colas and sodas changes our metabolism. Whether you drink two cans a week or one can a day, your metabolism will start changing within 30 days. You will start putting on weight and your insulin resistance will increase-and that's often a precursor of diabetes and heart disease.2
TWO CANS A DAY: Are you a Mexican? There are few guarantees in life, but this is one: drink two or more cans of soda or cola every day for years and you will live a short and painful life. Period.
ONE CAN A DAY: OK, you're improving your odds, but you're still almost doubling your risk of stroke, cancer and heart problems compared with someone who drinks nothing but water or natural fruit juices. If you're a man, you're also around 40 per cent more likely to develop an aggressive form of prostate cancer. The good news is that you can offset the worst effects of the drinks by eating a healthy diet. Do that and your odds reduce to 31 per cent.3
On that note, research among Japanese women found that those who drank one diet cola or soda a day increased their risk of stroke by 83 per cent, but it took 18 years for the risk to appear. So the relatively healthy Japanese diet may have been helping shift the balance-but why take the risk?4
ONE CAN EVERY FEW DAYS: Now we're into 'official healthy dietary guide' territory. The American Heart Association reckons it's safe for us to drink 450 calories of sugar-sweetened colas a week, and that equates to around two to three standard 330-mL cans every week. This 'sensible advice' flies in the face of research that suggests you are still gambling with your health. The trouble is that the drinks increase insulin levels whether you drink one or two cans a week or every day, and this opens the door to diabetes and heart disease.
ZERO HERO: If you have diabetes or cardiovascular disease-or you have the symptoms of prediabetes, such as being overweight-you should be avoiding all colas and sodas. Love yourself enough to just do it.
Are diet colas safer?
Don't kid yourself. Diet colas are usually sweetened with the artificial sweetener aspartame, and that's enjoyed similarly favourable press coverage as Bin Laden, Hitler and Vlad the Impaler rolled into one. Aspartame has been linked to every major chronic condition going, especially heart disease and cancer, and people have even marched on the White House to get it banned.
If you're not sure, let's take you to downtown Mooresville in North Carolina. There we meet Jan Jensen, whose home had been plagued by giant carpenter ants. They walked over standard issue ant poison, and they ate the most lethal kind just for fun. At her wit's end, Jan remembered reading that aspartame was first developed as an ant poison before someone had the bright idea to put it in our diet drinks. She bought two packets of aspartame and sprinkled the contents in the corners of her bathroom. Guess what? The ants disappeared.
"It works better than the most deadly poisons I have tried," said a delirious Jan. "Any time those ants show up again, I simply dump another packet in a corner, and they will be gone for a year or so again." Jan recommends that anyone who follows her lead to handle the aspartame with care. Always wear gloves and have a thorough wash afterwards if you come into direct contact with aspartame. Of course, never swallow it (sorry, we forgot, you do swallow it, don't you?).5
Are sports drinks safer?
Sorry, it's another no. Energy and sports drinks can increase your blood pressure and disturb your heart's natural rhythm (arrhythmia). It's all to do with the 'QT interval': that's a measure of your heartbeat as seen on electrocardiography, and the longer the QT interval, the more dangerous it is. A slightly prolonged interval means the heart is beating in an irregular pattern, and an even longer one indicates a heart attack.
Heart specialists who have monitored people after drinking one to three cans found that almost everyone's QT interval was extended by 10 msec (milliseconds); at 30 msec they call the ambulance. But even at 10 msec, specialists become concerned because even that kind of heart rate irregularity can be life-threatening. That's not all. The drinks also make blood pressure rise, sometimes by as much as 3.5 points. People who don't usually drink caffeine could also be more affected as they aren't so accustomed to the effects of the drinks' contents.
People who already have raised blood pressure or suffer from an irregular heat beat should avoid these drinks.6
The drinks have already caught the eye of some health regulators. The German Federal Institute for Risk Assessment lists heart arrhythmia, seizures, kidney failure and death as possible effects of energy drinks. The Institute points out that 17 cases of poisoning and two deaths were reported to Ireland's National Poisons Information Centre over a six-year period after people had an energy drink. The reported effects included confusion, tachycardia (accelerated heart rate) and seizures.
Still not sure?
If the threat of heart disease, cancer or diabetes doesn't phase you, colas and sodas have a few other effects that weren't identified by the Harvard researchers.
Paralysis The drinks can send potassium levels in the blood crashing, and this can cause serious muscle problems and paralysis. The effect is immediate. The good news is that you have to drink a lot of the stuff before you become paralyzed; the people who were suffering from this were drinking around two litres of cola a day (that's around six cans, or a super-Mexican), and the paralysis went away when they stopped.7
Pregnancy complications Drink five or more cans of cola a week while you're pregnant and you run the risk of developing a form of diabetes known as 'gestational diabetes' (GDM). Babies born to GDM mothers are more likely to be obese, glucose-intolerant and suffer from early-onset diabetes.8
Osteoarthritis If you already suffer from osteoporosis, don't drink colas or sodas-they speed up the crippling effects of the disease. Cartilage in the knee joint breaks down quicker in people who drink around one cola drink a day.9
1. Presentation at the American Heart Association's Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism 2013 Scientific Sessions, March 19, New Orleans, Louisiana.
2. Eur J Nutr, 2012; doi: 10.1007/s00394-012-0401-x.
3. Am J Clin Nutr, 2012; 96: 1409-18
4. Am J Clin Nutr, 2012; 96: 1390-7.
5. Idaho Observer, 1 July 2006
6. Presentation at the American Heart Association's Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism 2013 Scientific Sessions, March 21, New Orleans, Louisiana.
7. Int J Clin Pract, 2009; 63: 900-2
8. Diabetes Care, 2009; 32: 2236-41.
9. Presentation at the American College of Rheumatology Annual Meeting, November 11, 2012, Washington, DC.