There have been many studies into the effect of food phosphates on the human body. All have demonstrated that industrial food phosphates are not toxic. They are assimilated in the same manner as the phosphates which occur naturally in foodstuffs.
The quantities of food phosphates added to foodstuffs are tiny. Depending on the application, the authorized maximum ranges from 0.07% to 4%. On average, the proportions used by industry are 0.35% in meat, 2.5% in processed cheeses, 0.4% in cakes and 0.05% in colas.
The vast majority of phosphates occur naturally in high-protein foods such as meat, eggs, fish and cereals.
Total phosphate intake therefore depends less on what has been added industrially than on the type of foods eaten. Contrary to a widespread belief, phosphates are no more toxic than other regularly consumed products such as vinegar, bicarbonate of soda or table salt.
Of course, high doses administered in laboratories can have a negative impact on health, such as temporary nausea in humans or kidney malfunction (observed in rats injected with extreme doses).
The European Food Safety Authority (EFSA) concluded in 2005 that excessive phosphorus intake does not negatively affect humans unless they are suffering from severe kidney trouble.
In the United States and Canada, the health authorities have set the maximum daily phosphorus intake at 3,000-5,000 mg per day, depending on body mass. In 2003, the average national daily intake was 1,260 mg per day.
