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Fast food chains are in the hot seat yet again for using questionable ingredients in their products. This time, it’s something most people would consider to be healthy: grilled chicken breasts.

I’m one of the instigators. I was contacted by the producers of “CBC Marketplace,” an investigative consumer TV program, to examine the nutrition and ingredients in fast food chicken breasts.

Along with sodium, that common nutrition and health scapegoat, there was a group of ingredients I flagged that the producers had never heard of before: phosphate additives. And they’re in so much more than fast food chicken.

Mark my words, phosphate additives will be the trans fats of the future; at one time prevalent throughout our food supply, and eventually banned due to overwhelming evidence of their negative impact on human health.

What are phosphate additives?

Phosphorus is a mineral that’s naturally found in milk products, nuts, eggs and poultry. We need phosphorus in our diets for bone health and other key functions, such as making protein and helping our body store energy.

In the form of phosphate compounds, phosphorus can also be added to food and beverages. These additives help baked goods rise, they act as emulsifiers in processed cheese and canned soup, they add flavor to cola and color to frozen french fries. They also can be added to meat, poultry and seafood to help the protein bind more water, making it juicier after freezing and reheating.

Olga Naidenko, an Environmental Working Group senior science adviser, is concerned that the prevalence of phosphorus additives in all types of packaged foods has led to the average American consuming more phosphorus than is recommended.

Add to this the fact that while only 40 to 60 percent of phosphorus naturally found in foods is absorbed by the body, 90 percent of phosphate additives are thought to be absorbed, according to a study by the National Center for Biotechnology Information.

It seems possible that we could be getting too much phosphorus. So what’s the risk of overdoing it on this mineral?

Health concerns linked to phosphate additives

According to Megan McSeveney, press officer for the U.S. Food and Drug Administration, every type of phosphate additive is “considered by the FDA to be safe for its intended use in food.”

But not all experts agree.

According to the Environmental Working Group, the impact of phosphate additives on our health is of moderate concern,” since much of the research is based on associations rather than cause-and-effect relationships.

For some phosphate experts, the link to health risks is enough of a reason to limit the use of these additives. Registered dietitian Lisa Gutekunst is part of a research group investigating the impact of phosphate additives on our health.

As Gutekunst puts it, “On my gravestone it will probably say, ‘Phosphates are bad for you.’ I’m one of many people who are in the camp that these phosphate additives aren’t good for the general public . . . not just those with kidney problems.”

If you take a look at the scientific literature, the links between ingesting too much phosphorus and negative health outcomes are difficult to ignore.

Associations between higher phosphorus intake or higher phosphate concentrations in the blood and higher mortality are found not only in people with chronic kidney disease (who need to limit their intake of phosphorus), but also in the general population.

High-normal levels of phosphate in the blood are linked to a higher risk of cardiovascular disease, calcium deposits and hardening of the arteries in the heart, even in healthy young men.

In the Framingham Offspring Study, high-normal phosphate blood levels were found to be a predictor of heart attacks.

Emerging research has also linked higher intakes of phosphorus to a negative impact on bone health.

Phosphate additives: How much is too much?

Our intake of phosphate additives in fast food and processed foods has more than doubled since the 1990s, from less than 500 mg a day to 1,000 mg a day. This is just from phosphate additives and doesn’t include foods that naturally contain phosphorus, yet it’s still higher than the recommended amount of phosphorus adults should get each day — 700 mg, according to the Institute of Medicine. The institute has also determined a safe upper limit for phosphorus and phosphate intake of 4,000 mg a day for healthy adults.

So we have an idea of how much phosphorus we need and how much is too much. The problem? We have no idea how much total phosphorus we’re consuming.

Phosphorus is not a required nutrient in the nutrition facts table on food and drink labels. That’s why companies aren’t analyzing the amounts of phosphate in their food and beverages.

Even the USDA food composition database is missing information about phosphate amounts in foods. This database is often used for research purposes and by dietitians to analyze people’s diets. You could be hitting or exceeding the safe upper limit for phosphorus and not even know it.

McSeveney states that in 2014, “the FDA found that phosphorus intakes are generally adequate and not of public health significance for the general U.S. population.”

But does getting enough necessarily mean we’re not getting too much?

The links between high intake of phosphates or high phosphorus levels in the blood are linked to a higher risk of health problems and early death, but we need more research to know whether there is a cause-and-effect relationship. Gutekunst asks, “What are these phosphate additives adding to the diet nutritionally? Nothing. Therefore, recommending that people limit their exposure to them may have a benefit.”

Tips to limit phosphate additives in your diet

While phosphorus amounts aren’t typically provided in the nutrition facts label, phosphate additives are listed in the Ingredients List.

Gutekunst recommends you take the time to look for any word that contains “phos-” in the ingredients list on everything from yogurt and cereal to iced tea. Phosphate additives go by many different names, but seeing “phos” is a sure sign there are some in that product. “Look for an alternative product that doesn’t use those additives,” she advises.

Another tip from Gutekunst: Look for a nutrition label on your meat, poultry or fish. If the sodium content is more than 120 mg for a 4-ounce portion, you know it’s been enhanced with something — potentially a phosphate salt.

When it comes to avoiding phosphate additives and eating well in general, I have to agree with advice from Naidenko and the Environmental Working Group. “The best solution is to prepare your own fresh foods and avoid processed, packaged foods as much as possible.”

Does your favorite food or drink company use phosphate additives? Write to them and ask for a change. There are other ingredients that can be used instead that aren’t linked to health problems.

Christy Brissette is a dietitian, foodie and president of 80TwentyNutrition.com. Follow her on Twitter @80twentyrule.