It might be no surprise that sugar in sweetened coolers helps to mask the taste of alcohol and make it more appealing to novice consumers, including young people.
Based on the first study to look at the role of high-fructose corn syrup – the main ingredient in most coolers – a University of Guelph professor suggests that these sweetened beverages can actually promote harmful alcohol consumption.
The results should prompt caution particularly among university-age drinkers and their parents about the potential of coolers to encourage consumption of other alcoholic beverages, said psychology professor Francesco Leri.
“The more sweetened drinks that an adolescent drinks, the more likely they are to drink alcohol that is not sweetened,” said Leri, who conducted the study with master’s student Samantha Ayoub and psychology professor Linda Parker
As with earlier studies of how sweetened alcoholic beverages affect adolescent drinking behaviour, he said, this study suggests that these beverages act as “a gateway – a way to get introduced and then like alcohol itself.”
Other researchers have found that sweeteners such as sucrose and glucose encourage rats to drink more alcohol.
Published recently in the journal Alcohol, the U of G study is the first to look at the effects of high-fructose corn syrup (HFCS), which makes up about one-quarter of the volume of many sweetened alcoholic beverages.
Using rats able to self-administer liquids, the researchers tested consumption of different proportions of alcohol mixed with 25-per-cent HFCS.
Adding the corn syrup increased rats’ intake and the palatability of the beverage. Palatability was measured by observing behaviours such as rats licking their snouts. Rats given alcohol normally show facial signs of disgust.
“Most rats don’t voluntarily drink alcohol by itself. The moment we added HFCS, there was a huge increase in consumption,” said Leri.
Beverages containing 10 percent alcohol and 25 percent corn syrup encouraged some rats to drink an amount equivalent to an average adult human consuming 4.5 beers in 30 minutes.
Although the researchers didn’t measure blood alcohol levels, consuming that much alcohol would cause blood alcohol levels in people to spike to “binge drinking” amounts.
Mixing alcohol with saccharin (a non-caloric sweetener) also prompted more consumption but less than with HFCS.
In earlier studies, Leri looked at the effects of HFCS on the brain. This time, he wanted to see how sweeteners might affect consumption of other addictive drugs such as alcohol.
He said someone drinking sweetened coolers can grow accustomed to the taste of alcohol, even if they initially dislike the latter on its own.
“Most people that don’t like the taste of alcohol in a drink will drink sweetened coolers. We think they get an introduction to alcohol via sweeteners.”
Leri said beverage manufacturers might be persuaded to use more natural sweeteners such as regular cane sugar or to refrain from marketing their products to younger consumers.
He encourages parents to discuss coolers with young people.
“Because it’s sweet and tastes like pop doesn’t make it any safer than a straight can of beer or glass of wine. Alcohol is alcohol no matter what.
Because alcohol is sweet, there’s a danger of over-drinking. It’s important to monitor the amount taken, especially when it’s mixed with other substances. It’s just another drug of addiction, that’s all it is.”
The consumption of sugary drinks has increased worldwide in the last decades; according to the Global Burden of Disease,1 their “summary exposure value” (taking into account the extent of exposure by risk level and the severity of that risk’s contribution to disease burden) increased by more than 40% from 1990 to 2016.
The impact of sugary drinks on cardiometabolic health is well studied:2 they are associated with an increased risk of weight gain, being overweight, or obesity;34 a greater incidence of type 2 diabetes (independently of adiposity);5 a higher risk of hypertension;6 and with cardiometabolic death.7
In 2010, Singh and colleagues estimated that among all worldwide yearly deaths from diabetes and cardiovascular diseases, about 178 000 were attributable to sugary drink consumption.8
Sugary drink consumption was one of the behavioural risk factors that contributed the most to the increase in global attributable deaths and disability adjusted life years (DALYs) between 1990 and 2016.1
Artificially sweetened beverages were initially envisioned as a healthier alternative, however, they are associated with a higher incidence of hypertension,9 obesity,10 and type 2 diabetes.5
Besides, some artificial sweeteners were suggested to increase glucose intolerance by altering the gut microbiota.11
In contrast, the association between sugary drinks and the risk of cancer has been less investigated. However, this potential relation raises increasing concerns owing to its mechanistic plausibility.
Indeed, sugary drinks are convincingly associated with the risk of obesity,34 which in turn, is recognised as a strong risk factor for many cancers.12
Apart from the obesity and adiposity pathways, mechanisms underlying a link between sugary drinks and cancer might involve insulin resistance caused by their high glycaemic index or glycaemic load, which have been related to breast cancer,1314 hepatocellular cancer,15 and diabetes related carcinomas.16
The chemical compounds in sugary drinks, such as 4-methylimidazole in drinks containing caramel colourings (defined as possibly carcinogenic to humans by the International Agency for Research on Cancer, IARC),1718 pesticides in fruit juices,1920 or artificial sweeteners such as aspartame might play a role in carcinogenesis.21
However, epidemiological literature on sugary drinks and the risk of cancer is still limited and there was not enough evidence to support a link in the recent report by the World Cancer Research Fund/American Institute for Cancer Research.12 Very few prospective studies have been conducted on the association between sugary drinks and individual cancer site.
Two prospective cohorts published contrasting results regarding breast cancer: one suggesting an increased risk in post-menopausal women (Melbourne Collaborative Cohort Study, 946 cases),22 and the other observing no association (Framingham Offspring cohort, 124 cases).23
Increased risks were also suggested for adiposity related and obesity related cancers in recent surveys,22 23 as well as for pancreas,24 gallbladder, 25 and endometrial cancers,26 although some other studies observed null results.12 27 28 29
Thus, literature concerning sugary drinks and the risk of cancer is inconsistent and needs further explorations. Furthermore, sugary drinks and artificially sweetened beverages were rarely analysed separately in previous studies.
Thus, the aim of this study is to investigate the relations between the consumptions of sugary drinks and artificially sweetened beverages and the risk of first cancer in a large prospective cohort with detailed and up to date dietary intake assessment.
University of Guelph