No one imagines that soft drinks, whether sweetened with sugar or artificial sweeteners, are health food. But what about fruit juice? Most people do think that juice is healthful. A new study finds that sweet beverages of any sort contribute to a higher risk of diabetes (Diabetes Care, Oct. 2019).
The Evidence on Sweet Beverages and Diabetes:
The researchers analyzed data from more than 150,000 women in the Nurses’ Health studies and 34,000 in the Health Professionals Follow-Up Study. They had followed these individuals for decades, collecting information about diet and lifestyle every few years. They ultimately gathered and analyzed nearly three million person-years of data.
People who increased their consumption of sweet beverages, including fruit juice and artificially sweetened drinks, were more likely to be diagnosed with type 2 diabetes. Specifically, volunteers who reported an extra half-serving daily of sweet beverages over the last four years were 16 percent more likely to get a diabetes diagnosis in the next four-year period. Those who substituted coffee, tea or water for a serving of a sugary beverage actually reduced their diabetes risk modestly.
Other Problems with Soft Drinks:
Diabetes is not the only potential health hazard lurking for people who love sweet beverages. In previous studies, researchers have noted that individuals who consume the most sugar-sweetened drinks and fruit juice are more prone to cardiovascular disease. They are also more likely to have hypertension or gout. Another recent study found that soft drink consumers may die prematurely. Sugary drinks can also stress the kidneys.
Sweet Beverages and the Risk of Cancer:
People who consume sugary drinks may have a greater risk of developing cancer, according to a French study (BMJ, July 10, 2019). Soda pop is not the only culprit, though. Sweet beverages containing 100 percent fruit juice may also cause trouble.
The prospective cohort investigation called NutriNet-Santé included more than 100,000 middle-aged French adults. They completed a minimum of two validated dietary questionnaires during the roughly nine years of follow-up. All participants were healthy at the outset of the study.
Some People Got Cancer:
More than 2,000 volunteers reported a first diagnosis of cancer during the follow-up time frame, which averaged five years. Analyses show that those who consumed more sweet drinks, including 100 percent fruit juices, were more likely to be diagnosed with cancer. Specifically, an additional half cup daily increased the likelihood of any cancer by 18 percent and the chance of breast cancer by 22 percent.
There was no association between consumption of artificially sweetened drinks and cancer. However, the authors caution that too few of these French volunteers drank artificially sweetened beverages to draw strong conclusions.
The fact that fruit juices, which usually have a “health halo,” were as risky as soft drinks may be surprising. This is not the first time, however, that scientists have found problems with fruit juices. Earlier this year, a study published in JAMA Network Open demonstrated a link between fruit juice consumption and premature death.
Observational studies like this can’t establish cause and effect. However, an earlier study found a specific link between the consumption of soft drinks and the risk of pancreatic cancer.
Soda Pop and Pancreatic Cancer:
An epidemiological study in Singapore tracked more than 60,000 adults for 14 years (Cancer Epidemiology, Biomarkers & Prevention, February 2010). Those who drank at least two sodas a week raised their risk of developing pancreatic cancer by nearly 90 percent. Because pancreatic cancer is rare, however, there were only 140 cases during the entire study period. Consequently, the absolute risk, even for soda lovers, is still low. Nonetheless, we worry about the increased risk because pancreatic cancer is so often deadly.
The investigators hypothesized that the sugar in soda causes a rapid increase of insulin, which is produced by the pancreas. Insulin may act as a growth factor for cancer cells, and some scientists believe that sugar itself acts like fertilizer for the growth of tumors.
This was not the first time sugary drinks were linked to a higher risk of pancreatic cancer. Despite this, the findings were controversial. An industry group, the American Beverage Association, maintained that there were flaws in this epidemiological study. In this investigation, people who mostly drank fruit juice did not have a higher risk of pancreatic cancer.