“I’m not surprised. A lot of this policy comes from the USDA,” Lisa Gutekunst, MSEd, RD, CSR, CDN, Chair of the National Kidney Foundation (NKF) Council on Renal Nutrition, told FoodNavigator-USA. “That’s how trans fat got on to the label as well as potassium. It all had to do with the Dietary Guidelines. That’s where policy begins. They don’t have phosphorus on their radar now. Even though the science is out there and the FDA is aware of it, that’s not where policy is going to get changed.”
An essential mineral for cell structure and function, phosphorus is found naturally in foods such as dairy, meat, fish, eggs, nuts and legumes. Inorganic phosphates are commonly used to enhance flavor and preserve food and are as ubiquitous in our food supply as sodium, with common examples including flavored water, cola, deli meats and frozen chicken. The problem, Dr. Gutekunst says, is inorganic phosphorus may be absorbed even more readily than naturally occurring sources—a growing concern as Americans are reaching for more convenience foods than ever.
Though generally recognized as safe, phosphates’ safety as food additives has been called into question in recent years, with research linking elevated serum phosphate levels to higher mortality in people with chronic renal failure and increased risk of cardiovascular disease in healthy people. Even more recently, a study in the American Journal of Clinical Nutrition found that high phosphorus intake was associated with increased mortality in a nationally representative, healthy US population.
Baby steps: let’s get disclosure of phosphorus levels first
Currently, manufacturers are not required to report nutrient content of foods to the USDA. Additionally, disclosure of phosphorus content is not required by the FDA. NKF will continue to meet with the USDA and Institute of Medicine this fall to discuss the ensuring updates to the Dietary Guidelines, with an eye toward eventual policy change. (Read what RDs would like to see addressed in the 2015 Dietary Guidelines.)
“If we want phosphorus on food labels, I can call it out from a kidney perspective,” Dr. Gutekunst said. Indeed, roughly 24 million Americans have some form of kidney disease and many don’t know they have it—just 400,000 Americans are on dialysis.
But Dr. Gutekunst accepts that mandated phosphorus labeling will likely be a long, slow climb—indeed, it was a 20-year process to get trans fats on the label. Thus, NKF is hoping more manufacturers will voluntarily disclose phosphorus on pack.
“Even though a 12-ounce can of Diet Coke—which contains about 100 mg of phosphorus—could be considered a low-phosphorus food, we may get to a point where the education needs to come that says that’s coming from phosphoric acid, so it’s going to be absorbed more readily,” she said. “But baby steps! Let’s get phosphorus on food labels first. Then let’s look to the industry to find alternatives to give us what we want and we believe we need.”
Phosphorus in more foods than you’d think
The average consumer probably isn’t aware of how ubiquitous phosphorus has become in processed foods. A recent study in the Journal of Renal Nutrition found that nearly half (44%) of the best-selling grocery products contain phosphorus additives, based on a sample of product labels from 2,394 best-selling branded grocery items in northeast Ohio. The additives were especially common in prepared frozen foods (72%), dry food mixes (70%), packaged meat (65%), bread and baked goods (57%), soup (54%), and yogurt (51%) categories.
According to NHANES data, over one-third of Americans consume more than 1400 mg per day, roughly twice the daily recommended intake level of phosphorus, which isn’t likely to be reversed any time soon given our culture’s collective penchant for “fast” food.
“As we move along, our diets are changing with more convenience and fast foods. A lot of these types of foods that are making our lives easier, from self-rising bread dough to coffee creamers, have phosphate added, and consumers don’t even realize they’re getting exposed to that.”
Calcium fortification (AKA calcium trisphosphate) does more harm than good in children
This is particularly worrying among young kids, she added. “I look a lot at exposure to phosphate additives in young kids. It’s not just from colas anymore. Look at calcium-fortified juice, using calcium triphosphate. At these levels, it’s doing more harm than good. Even in some yogurts they’re boosting with calcium because yogurt is supposed to be a great source, but how is that affecting kids’ bone mass overall?”
While certain alternatives exist (such as lecithin or carigeenan for emulsifying), they’re more costly than phosphorus and would alter the production process considerably for manufacturers.
‘This is not an attack on the food industry’
“I want everybody to understand this isn’t attack against the food industry,” Dr. Gutekunst said. “Manufacturers are trying to meet our demands in this fast-paced world. And for a lot of consumers, that means grabbing a frozen dinner with the calories portioned out. They are trying to make a healthy, quick food choice without understanding that they’re being exposed to more phosphorus in the process. There may be other ways for manufacturers to bring us what we want without adding additional phosphorus.”
It’s easier for middle and upper class Americans who have more and more options (and the disposable income) available for organic and whole food than those in tougher economic situations.
“When we are making bad food choices, we need to make better bad food choices,” she said. “If I’m eating processed food, I should have the option of knowing the product doesn’t contain phosphorus anymore—even if I’m low income and that’s is the only thing available to me that I can feed my kids. They need to make responsible choices available to everybody.”