Carbonated Soft Drinks Raise the Risk of Esophageal Cancer

[tmca]

I just saw this on Yahoo news:
Sodas Raise Cancer Risk, U.S. Study Finds

Washington (Reuters)- "Carbonated drinks may raise the risk of esophageal cancer, a usually fatal disease, researchers reported on Monday.

Several studies presented at a meeting of cancer and gastrointestinal experts in New Orleans showed that what people eat and drink could affect a range of cancers.

This research supports the widespread medical recommendations for healthy eating, "said Dr. Lee Kaplan of Massachusetts General Hospital and Harvard Medical School in Boston.

A team at Tata Memorial Hospital in India found a strong correlation between the rise in per capita consumption of carbonated soft drinks in the past 50 years and a documented increase in rates of esophageal cancer in the United States.

Team members studied U.S. Department of Agriculture data to find that per capita consumption of carbonated drinks rose by more than 450 percent, from 10.8 gallons on average in 1946 to 49.2 gallons in 2000.

And over the past 25 years, the incidence rates of esophageal cancer have risen by more than 570 percent in white American men. Esophageal cancer affected 13,900 U.S. men and women in 2003- more than 10,000 men-and killed almost all of them, according to the American Cancer Society.

The number of esophageal cancer cases clearly followed the rise in intake of carbonated soft drinks, the researchers found.

That could be coincidence, but they also found research that showed a possible biological basis for the effect. Carbonated soft drinks cause the stomach to distend, which in turn causes the gastric reflux associated with esophageal cancer."

The researchers found similar trends worldwide. Countries with per capita annual consumption of more than 20 gallons of fizzy soft drinks also had rising rates of esophageal cancer.

To add my own comments on this: I think it's pretty staggering ..On a good note, after being a supervisor (retail/grocery) for almost 15 years I can tell you that the sales and consumption of carbonated beverages has been on a steady decline for the last 2-3 years. Ironically, bottled water, consumption and sales, is rising faster than any other single serve or multi pack (non-alcoholic) beverage available today, atleast in the part of the country I live in..The vendors have told me many times that it is pretty much the same across the country. The new age beverages including bottled water, gatorades, juices, etc. are "slowly" but gradually replacing carbonated beverages....We can only hope that trend continues....Tessa

[daw]

Esophageal Adenocarcinoma Appears to Be Affected by Common Beverages

Karla Harby

May 18, 2004 (New Orleans) — Two common beverages have been found to be associated with either the inhibition or development of esophageal adenocarcinoma in two separate studies reported here during Digestive Disease Week.

Epigallocatechin gallate (EGCG), an extract of green tea, has been shown to inhibit cell proliferation in an esophageal adenocarcinoma cell line (BIC-1) in a dose-response fashion. In contrast, the dramatic rise in per capita carbonated soft drink consumption in the U.S. — from 10.8 gallons per year in 1946 to 53 gallons per year in 2000, an increase of 450% — has been found to be associated with a dramatic increase in the incidence of adenocarcinoma of the esophagus in white men living in the U.S.

In the first study, reported by Howard Y. Chang, MD, from the Veterans Affairs Boston Healthcare System in West Roxbury, Massachusetts, the BIC-1 cell line was treated with various concentrations of EGCG, the most abundant extract from the tea. This polyphenol was chosen because earlier studies found that it inhibits carcinogenesis in the gastrointestinal tract, and because the esophagus is presumed to be exposed to high levels of this compound when green tea is drunk, Dr. Chang told reporters. "It's a hot topic in lung, skin, and prostate cancers," he added.

The researchers treated cells with 0.1 to 100 µM of EGCG, which produced a dose-dependent inhibition of growth within 72 hours, with cell growth nearly stopped at doses greater than 20 µM. The chief effect of EGCG was enabling apoptotic cell death by increasing the activity of caspase 3 and cleaved PARP. Dr. Chang estimated that the most effective concentrations of EGCG represented in this study would be equivalent to at least two cups of green tea per day.

Lee Kaplan, MD, PhD, from Massachusetts General Hospital in Boston, who moderated an advance briefing for reporters, emphasized that these results are only in cell lines. "What we see in culture we don't always see in people, but the first step is to test it in a safe environment, as these researchers have done," he said.

In the second study, performed by Mohandas K. Mallath, MD, head of the Department of Digestive Diseases at Tata Memorial Hospital in Tata, India, data from the U.S. Department of Agriculture were searched for dietary changes over the past 50 years. Along with the 450% increase in carbonated soft drink consumption since 1946, Dr. Mallath found a highly significant correlation between the three-yearly incidence of adenocarcinoma (1974-2000) and the three-yearly increase in soft drink consumption 20 years previous (r = 0.99; 95% confidence interval, 0.92 - 1.0; P < .001).

The mechanism of action probably relates to acid exposure to the esophagus, Dr. Mallath said. Consuming 53 gallons of carbonated soft drinks per year would increase the esophagus' exposure to acid (pH < 4) by 32,100 minutes. He also noted that U.S. women drink much less soda than U.S. men, and they show correspondingly lower rates of esophageal adenocarcinoma. In countries where soft drink consumption is low (Eastern Europe and parts of Asia), there has been little increase in the incidence of esophageal adenocarcinoma over this time, he said.

"There is a reason to think biologically that this could be true," Dr. Kaplan commented. "Soft drink consumption is associated with obesity and with [gastroesophageal reflux disease]," which are associated with esophageal adenocarcinoma. "So there is a logic tree here." Dr. Mallath agreed, but he added that although essential, "These kinds of epidemiological studies are not a very good level of evidence."

Both studies were independently funded. The authors report no pertinent financial disclosures.

DDW 2004: Abstract 386, presented May 17, 2004; abstract W1354, presented May 19, 2004.

Reviewed by Gary D. Vogin, MD

Karla Harby is a freelance writer for Medscape.