Phosphorus Additives Might Have Unintended Effects

Phosphorous-based processed food additives have useful properties including bactericidal action, but might alter bone and mineral metabolism, according to human and animal studies.

The findings, Dr. Orlando M. Gutierrez told Reuters Health by email, “suggest that the high amount of phosphorous-based food additives in processed foods may have unintended consequences for cardiovascular and bone health. This should inform current efforts to determine the safety of phosphorous additives in the food supply.”

In a paper online for the Journal of Clinical Endocrinology & Metabolism, Dr. Gutierrez of the University of Alabama at Birmingham and colleagues note that dietary phosphorous consumption in the U.S. far exceeds recommendations for daily intake partly due to widespread use of phosphorous-based food additives.

To examine their potential impact, the team studied 10 volunteers, none of whom had kidney disease. For a week the participants were given additive-free food providing about 1,000 milligrams (mg) of phosphorous per day. This was immediately followed by a week of a diet containing identical food items but with additives, bringing the daily phosphorous content to almost 1,700 mg.

The additive enhanced diet prompted a significant 23 percent increase in circulating fibroblast growth factor 23 (FGF23). This was also true of concentrations of osteopontin (10 percent) and osteocalcin (11 percent). Mean sclerostin concentrations decreased significantly.

In studies of mice given high or low phosphorous diets for up to 15 weeks, the results were similar with significantly higher levels of osteopontin, FGF23, and osteocalcin and lower sclerostin levels. Bone mineral density was also significantly lower in the high- phosphorous group.

The researchers concede that the studies were small and relatively short “precluding us from being able to determine whether the observed changes were sustained over a longer period of exposure.”

These results, the researchers conclude “suggest that high phosphorous-additive intake may have adverse effects even in individuals with normal kidney function. Further, the diet-induced endocrine changes were correlated in a mouse model of dietary phosphorous-modulated bone loss providing a means to investigate the underlying mechanisms.”

Dr. Alexander Chang, Geisinger Health System, Danville, Penn., who has conducted research in the field, called the study “very interesting.”

“It highlights the need for the public to be aware of the presence of phosphorous in processed foods,” Dr. Chang told Reuters Health by email.