Glycemic Index, But Not Glycemic Load or Carb Intake, May Increase Bladder Cancer Risk

An analysis showed that glycemic index – but not glycemic load or total carbohydrate intake – significantly increased the risk of developing bladder cancer.

Higher glycemic index was associated with an increased risk of developing bladder cancer, though there was no correlation between disease development and glycemic load or carbohydrate intake, according to a recently published analysis that pooled data from a dozen studies.

“Studies on glycemic index or glycemic load and bladder cancer risk have been mixed with null and positive associations,” the authors wrote.

Glycemic index is a score ranging from 0 to 100 that is based on how quickly it causes blood sugar to rise. High glycemic index scores (70 or above) indicate that a food will make someone’s blood sugar rise very quickly, compared to moderate (56-69) or low (55 and below) scores.

“Foods with high glycemic index are rapidly digested and lead to a rapid peak in blood glucose and the secretion of insulin,” the researchers wrote. “Hyperinsulinemia can increase the bioactivity of insulin-like growth factor 1, which may potentially mediate the association between glycemic index and bladder cancer risk.”

An analysis of the dose of daily glycemic index disease risk found that there was a 1.02% increase in bladder cancer risk for every 10 units of glycemic index consumed.

While glycemic index was significantly associated with an increase in bladder cancer, glycemic load – which measures both the potential for the food’s carbohydrate to raise blood sugar levels and the quantity of carbohydrate in the food – was not, nor was total carbohydrate intake.

The researchers did mention that there were limitations to their study. Namely, people who have a diet that has a high daily glycemic index, carbohydrate intake or glycemic load may also tend to have unhealthy behaviors such as poor diet, lack of physical activity, excess intake of energy, diabetes and obesity, which could skew the correlation found between glycemic index and bladder cancer. Not to mention, much of the data was derived from food frequency questionnaires, which may not be accurate.

“Furthermore, large prospective studies that account for other relevant factors, such as body weight, diabetes, physical activity and intake of total energy, are needed,” the researchers wrote.

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