Researchers have discovered why phosphate rich foods can increase blood pressure and promote vascular calcifications.
When the level of FGF23 is raised, as through a high phosphate diet, calcium and sodium accumulate, putting strain on the cardiovascular system. Phosphate rich foods include processed cheese, Parmesan, cola, baking powder and most processed foods.
Phosphates are widely used in the food industry as preservatives and pH stabilizers. When large quantities of phosphates are consumed, production of the FGF23 hormone is stimulated, which has a negative effect on the cardiovascular system.
Reinhold Erben, the head of the Unit of Physiology, Pathophysiology and Biophysics at the Vetmeduni Vienna, warns that "our phosphate consumption is relevant for our state of health."
The researchers showed that FGF23 has a so called sodium conserving effect, meaning it controls the reabsorption of filtered sodium in the kidneys. Mice lacking FGF23 excrete higher amounts of sodium in their urine, resulting in low blood pressure. Animals with high FGF23 levels show high levels of sodium in their blood, and in turn, high blood pressure.
A raised level of FGF23 puts increased strain on the heart. Reinhold Erben explains that, "In patients with chronic renal disease, both the phosphate levels and the levels of FGF23 are chronically high. This often leads to cardiovascular disease.
A second study, published by Erben's group in mid-January in EMBO, showed that FGF23 also controls calcium levels. As with sodium, the calcium is filtered in the kidneys and reabsorbed back into the body. If this reabsorption does not take place, the body loses calcium.
Too much FGF23 leads to increased take up of calcium by the kidneys, and results in vascular calcification.
The study has been published on the journal, EMBO Molecular Medicine.