In the study, lung cancer-model mice were studied for four weeks and were randomly assigned to receive a diet of either 0.5 or 1.0 percent phosphate, a range roughly equivalent to modern human diets. At the end of the four-week period, the lung tissue was analyzed to determine the effects of the inorganic phosphates on tumors.
"Our results clearly demonstrated that the diet higher in inorganic phosphates caused an increase in the size of the tumors and stimulated growth of the tumors," Dr. Cho said.
Dr. Cho noted that while a moderate level of phosphate plays an essential role in living organisms, the rapidly increasing use of phosphates as a food additive has resulted in significantly higher levels in average daily diets. Phosphates are added to many food products to increase water retention and improve food texture.
"In the 1990s, phosphorous-containing food additives contributed an estimated 470 mg per day to the average daily adult diet," he said. "However, phosphates are currently being added much more frequently to a large number of processed foods, including meats, cheeses, beverages, and bakery products. As a result, depending on individual food choices, phosphorous intake could be increased by as much as 1000 mg per day."
"Although the 0.5 percent was defined as close to 'normal,' the average diet today is actually closer to the one percent diet and may actually exceed it," Dr. Cho noted. "Therefore, the 0.5 percent intake level is actually a reduced phosphate diet by today's scale."
Dr. Cho said future studies will help refine what constitutes a "safe" level of dietary inorganic phosphate, with recommendations that will be easily achievable in the average population.
| Contact: Keey Savoie ksavoie@thoracic.org 212-315-8620 American Thoracic Society Source:Eurekalert |