Vitamin C May Protect Against Ulcer-causing Bacteria, Study Finds

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Source:

 

University Of California - San Francisco

 

Date:

 

2003-08-01

 

Vitamin C May Protect Against Ulcer-causing Bacteria, Study Finds

 

A study led by researchers at the San Francisco VA Medical Center (SFVAMC)

has found that the lower the level of vitamin C in the blood the more likely

a person will become infected by Helicobacter pylori, the bacteria that can

cause peptic ulcers and stomach cancer.

 

" This is the largest study to look at the relationship between vitamin C

levels and infection by H. pylori, " said Joel A. Simon, MD, MPH, SFVAMC

staff physician and UCSF associate professor of medicine and epidemiology

and biostatistics.

 

The study was published in the August 1 issue of the Journal of the American

College of Nutrition. Simon and his collaborators utilized data and blood

samples collected from a random sample of nearly 7,000 American adults by

the National Center for Health Statistics and the U.S. Centers for Disease

Control and Prevention during NHANES III, the Third National Health and

Nutrition Examination Survey, conducted between 1988 and 1994.

 

From the available data, researchers cannot determine whether or not vitamin

C might prevent initial infection by H. pylori, which often happens during

childhood, Simon said. Neither do the data shed light on the mechanism for

the association between vitamin C and bacterial infection they observe. " We

cannot be certain if the infection lowers blood levels of vitamin C or if

higher blood levels protect against infection. However, some studies using

animal models suggest that adequate vitamin C intake may reduce infection

with these bacteria, " Simon said.

 

Even if it is infection itself that lowers blood levels of vitamin C, Simon

said, it would still be prudent for people who test positive for H. pylori

infection to increase their intake of vitamin C. " The bottom line is that

higher levels of vitamin C may have the potential to prevent peptic ulcers

and stomach cancer, " he said.

 

In 1982, scientists discovered that H. pylori was responsible for causing

peptic ulcers--painful sores in the lining of the stomach or the duodenum,

the upper portion of the small intestine. (One in 10 Americans develops an

ulcer at some time in their lives.)

 

More recently, researchers discovered that H. pylori is also associated with

stomach cancer, a particularly deadly form of cancer.

 

For the current analysis, researchers used data collected during the first

phase of NHANES III, which was conducted from October 1988 through October

of 1991. The survey included participants between 2 months and 90 years of

age. Researchers tested stored blood samples for H. pylori infection.

 

Samples of nearly one-third (32 percent) of the 6,746 participants tested

positive for antibodies to H. pylori, indicating that their immune systems

had previously mounted an attack against the bacteria. More than half of

those who tested positive showed evidence of infection by the particularly

toxic strain of the bacteria.

 

In addition to testing for H. pylori infection, the researchers analyzed

vitamin C, or ascorbic acid, levels in the blood of these participants.

After accounting for age, ethnicity, weight and other factors, they found

that white participants with the highest blood levels of vitamin C had a 25

percent lower prevalence of infection.

 

Testing is now widely available for H. pylori infection and is often

performed when stomach or duodenal ulcers are suspected or have been

diagnosed. Simon encourages those who test positive--as well as all

Americans--to increase their consumption of vitamin C-rich foods because

they may help prevent infection with H. pylori or mitigate the effects of

infection with the bacteria. " Current public health recommendations for

Americans are to eat five or more servings of fresh fruits and vegetables a

day to help prevent heart disease, cancer and other chronic diseases and

recent data suggest that we're not doing very well in achieving that goal. "

 

Additional authors include statistician Esther S. Hudes, PhD, MPH, of the

UCSF Department of Epidemiology and Biostatistics and Guillermo I.

Perez-Perez, DSc, of the New York University School of Medicine.

 

This research was supported by a donation from Roche Vitamins, Inc. and a

grant from the National Heart, Lung, and Blood Institute.

 

None of the researchers involved in this study have financial interests in

Roche Vitamins, Inc. or in Roche pharmaceuticals.