According to a new study, increased use of preservatives containing phosphates may lead to high blood pressure.
The increased intake of phosphates — used in the preservation of meat, making cheese spreadable, preventing coffee clumping and as an additive in may foodstuffs — can lead to increase in the blood pressure and pulse rate in healthy young adults. The findings of this new study have appeared in the Journal of the American Society of Nephrology.
Although natural foods also contain phosphates, but modern eating habits mean that we are increasing our intake of them. Increased consumption of processed foodstuffs has significantly increased phosphate intake in recent years, which now often exceeds the daily intake of 700 mg recommended in the US.
Reto Krapf, professor, Department of Medicine, University of Basel, Basel, Switzerland, and colleagues conducted the study to determine the impact of high dietary and serum phosphate in humans with the normal renal function on cardiovascular morbidity and mortality.
“Higher serum 25(OH) vitamin D levels are associated with better cardiovascular outcomes, but vitamin D increases intestinal phosphate absorption,” write the authors.
As a high phosphate level can lead, for example, to deposits in blood vessels, a low-phosphate diet has long been recommended for people with chronic kidney problems.
However, an increase in dietary phosphate also increases the likelihood of developing or even dying from arteriosclerosis or a cardiovascular disease in healthy people. This has been shown by epidemiological studies that examine the connection between potential risk factors and certain diseases.
For the first time, the research team has now verified this statistical connection in a qualitative study with 20 healthy test subjects.
For the study, half of the participants received an additional dose of sodium phosphate in tablet form alongside their normal diet over 11 weeks. This increased the phosphate content in their blood to an above-average level, albeit one that is widespread in the population.
The second group took a phosphate binder that inhibits the substance’s intake in the body. They also received salt as sodium chloride to equal the first group’s sodium intake.
After six weeks, the doctors examined the effects of the different diets on various cardiovascular indicators such as blood pressure and pulse. A comparison of the two groups showed that the increased phosphate intake significantly increased the systolic and diastolic blood pressure of healthy young adults – by 4.1 and 3.2 mmHg, respectively. At the same time, pulse rate increased by an average of four beats per minute.
- Compared with the low-phosphate diet group, the high-phosphate diet group had a significant increase in mean±SEM fasting plasma phosphate concentration; 24-hour systolic and diastolic BP (SBP and DBP); mean 24-hour pulse rate (PR); and urinary metanephrine and normetanephrine excretion.
- Vitamin D had no effect on any of these parameters.
- Neither high- nor low-phosphate diet nor vitamin D affected endothelial function or arterial elasticity.
“Our results demonstrate that increased phosphate intake (controlled for sodium) significantly increases SBP, DBP, and PR in humans with normal renal function, in part, by increasing sympathoadrenergic activity. These conclusions are important for public health and should be further examined in larger studies in various population groups,” concluded the authors.
For more information log on to 10.1681/ASN.2017121254