A diet with a high glycemic index was associated with an increased risk of developing lung cancer in non-Hispanic whites, according to recent research.
To clarify the associations between GI, GL and lung cancer risk, the researchers surveyed 1,905 MD Anderson patients newly diagnosed with lung cancer and 2,413 healthy individuals recruited from Kelsey-Seybold clinics. Participants self-reported past dietary habits and health histories. Dietary GI and GL was determined using published food GI values, and subjects were divided into five equal groups, based on their GI and GL values.
“We observed a 49 percent increased risk of lung cancer among subjects with the highest daily GI compared to those with the lowest daily GI,” said Xifeng Wu, MD, PhD. “The associations were more pronounced among subjects who were never smokers, diagnosed with squamous cell carcinoma or had less than 12 years of education.”
Interestingly, GL had no significant associations with lung cancer risk. “This suggests that it is the average quality, instead of quantity, of carbohydrates consumed that may modulate lung cancer risk,” said Wu.
When investigating never smokers in the study, the researchers found that those in the highest GI group were more than twice as likely to develop lung cancer as those in the lowest group. Among smokers, the risk was only elevated by 31 percent between the two groups. The relatively mild effects of a risk factor such as GI are more evident in the absence of the dominant risk factor, explained Wu.
The researchers also noted stronger associations in those diagnosed with SCC and those with lower educational levels. Participants in the highest GI group were 92 percent more likely to develop the SCC subtype compared to the lowest GI group, possibly due to the influence of elevated IGFs on SCC development.