STUDY: Lower cancer risk with dietary antioxidants

JOURNAL: Gastroenterology 2002;123:985-991.

AUTHORS: Dr. Mauro Serafini

ABSTRACT: The total dietary intake of antioxidants is inversely associated with the risk for developing cardia and distal gastric cancer, European researchers report.

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COMMENTARY: For the first time this shows that the total antioxidant capacity of the diet is inversely associated with the risk of developing gastric cancer.

In people exposed to abnormal bio-radical loads, such as smokers and Helicobacter pylori-infected individuals, the increased need for antioxidant equivalents seems even more important.

Dr. Serafini and colleagues collected data on 505 patients newly diagnosed with gastric adenocarcinomas and on 1116 controls to assess their dietary habits for the 20 years before the survey. To convert food frequency into antioxidant potential, Dr. Serafini's team used the total radical-trapping antioxidant potential of different plant foods.

"We believe that the total antioxidant capacity concept is a more complete measurement of the counteracting forces in the multi-factorial pathological process towards invasive gastric adenocarcinoma," Dr. Serafini explained. This approach may provide a new tool for investigating the relationship between dietary antioxidants and oxidative stress-induced cancer pathology, he said.

The researchers also accounted for cancer risk from exposure to higher oxidative stress, including smoking and Helicobacter pylori infection, according to their report.

They found that for both cardia and distal cancer the dietary intake of antioxidant equivalents reduced cancer risk (odds ratio 0.65 for the highest quartile of total antioxidant potential).

When Dr. Serafini's team adjusted the data for smoking, they found a more robust dose-response relationship of antioxidant potential to gastric cancer risk. People who never smoked and who had the highest antioxidant intake had the lowest cancer risk.

Among those who had H. pylori infection, the odds ratio for developing gastric cancer varied from 0.66 to 0.56 from the lowest to the highest antioxidant potential.