It doesn’t matter where the sugar in your drink comes from; sugar is sugar, and a new study published in The BMJ (British Medical Journal) found a significant relationship between drinking lots of sugary liquid and increased cancer risk. Researchers say part of the problem is that too much sugar can lead to weight gain, which is an established cancer risk factor. (It won’t surprise you to learn, though, that doctors are quick to say that you shouldn’t eliminate fruit juice from your diet altogether after reading about this study. Moderation is naturally still important.)
“Sugary Drink” Means 100% Fruit Juices, Too
Read MoreIt's important to remember that the study only addressed the association between people who drank sugary drinks and people who got cancer. It didn't go far enough to say that the sugary drinks were actually the reason these people got cancer. Much more research is needed to draw that conclusion.
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That being said, the study was really large (over 100,000 people enrolled) and decently long (about nine years), which helps rule out sheer coincidence between people who got cancer and their sugary drink consumption habits.
Sugar is SugarEven When it Comes From Fruit
The team of French researchers leading the study, who were from NurtiNet-Sante, collected 24-hour dietary records from the thousands of people, who ranged in age, but were 42-years-old, on average.
During the study, over 2,000 of these people were diagnosed with cancer for the first time, and almost 700 of them were specifically diagnosed with breast cancer.
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Looking at those people diagnosed with cancer alongside the dietary records, the researchers found that drinking as little as 100mL of a sugary beverage per day was associated with an 18 percent increased risk of overall cancer and a 22 percent increased risk of breast cancer. For context, 100mL is really small (its less than half of an average soda can's worth).
Apart from breast cancer, the study couldn’t break the overall cancer risk down into other types of cancer, because the numbers were too low to be sure.
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Here's where things get interesting: when the researchers split up the types of drinks, they found that regularly drinking 100% fruit juice was no different than other types of fruit juices. When it came to cancer risk, it was the amount of sugar in the drinksnot where that sugar came fromthat was associated with cancer, and in that regard, the 100 percent fruit juices weren't that different from the other sugary drinks (the fruit juices had an average sugar level of 10.3 g/100mL, and the other group had an average of 10.9 g/100mL).
So What About Diet Drinks?
The researchers did not find that artificially sweetened (diet) beverages were associated with cancer risk. This goes against the "artificial sweeteners cause cancer" idea.
According to the authors of the study, though, people shouldn't take this part of the results too seriously, because few people in the study regularly drank artificially sweetened drinks anyway. But in the wake of the study, Catherine Collins, a dietician in the UK's National Health Service (who wasn't directly involved in the research), still said she thought the lack of cancer risk from diet drinks was the "take-home message" of the study.
"For too long the nutri-myth of sweeteners being a health risk has remained in popular culture," Collins told the UK’s Science Media Centre. "All current sweeteners in use have been through rigorous safety testing before being acceptable for human use. This study shows no impact of artificially sweetened drinks with cancer risk, adding to the body of knowledge from laboratory work to human studies confirming this."
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Ok, So Sugar Seems to Be the Villain. Why?
Again, because this study was observational, it wasn't able to conclude a reason for the association. All it did was take note of people who drank sugary drinks and got cancer.
"We cannot make a causal inference," the senior author of the study, Dr. Mathilde Touvier of the French National Institute of Health and Medical Research (Inserm), told the New York Times. "But we took into account many demographic and lifestyle factors, and the association was still significant."
Although they couldn't deduce a cause, the study's authors did say it's possible that sugary drinks might promote "visceral fat deposits"meaning fat around the internal organswhich could possibly promote tumor formation.
SurvivorNet previously asked Krista Maruschak, a registered dietician at the Cleveland Clinic Cancer Center, to explain the link between sugar and cancer, and she told us that sugar itself doesn't cause cancerbut in excess, it can cause obesity, which is a big risk factor for cancer.
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And Dr. Stephen Freedland, Director of the Center for Integrated Research in Cancer and Lifestyle at the Cedars-Sinai Medical Center, who has studied the link between obesity and prostate cancer in-depth, told SurvivorNet, "I've talked to a lot of dieticians, and amazingly, there are just two things I can get [them] to agree on: trans-fats are bad and simple sugars are not good." These "simple sugars" are the type found in sugary beverages (yes, including fruit juices.)
Moderation is Key: You Don't Need Fruit Juices Out of Your Diet Altogether
Dr. Touvier told The Guardian that people shouldn't worry about the occasional sugary drink; this study was all about people who drank the stuff every day.
"The recommendation from several public health agencies is to consume less than one drink per day," Dr. Touvier said. "If you consume from time to time, a sugary drink it won't be a problem, but if you drink at least one glass a day it can raise the risk of several diseases."
Fruit juices, it's also important to note, aren't the same as fruit alone, health-wise. Fruits have natural sugars, and you need a lot of fruit to make a little juiceso proportionately, per serving, fruit juices have much more sugar than the fruits they came from.
Additionally, when you turn a fruit into juice, you get rid of a lot of the healthy fibers.
So if you're craving orange juice or apple juice, you're better off grabbing an orange or an apple than the juice versioneven if it's labeled as "100% fruit."
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