Health Effects of Food Additives

Today, we look at the health effects of food additives. And, in our first story, NutritionFacts’ Senior Research Scientist, Dr. Kristine Dennis asks, “Do the reactions ascribed to monosodium glutamate (MSG) represent a menace, myth, or marvel?”

Reducing sodium intake by 30% could save the lives of more than 40 million people. And guess what can reduce sodium intake by more than 30% in standard recipes? Substituting traditional salt with monosodium glutamate, commonly known as MSG. But what about “Chinese Restaurant Syndrome,” reported in a 1968 letter to the New England Journal of Medicine, characterized by numbness on the back of the neck, general weakness, and palpitation? One of the proposed causes was MSG, a common seasoning often used in Chinese cooking. Since then, MSG has been blamed for causing numerous adverse reactions, including asthma, headache, and neuropsychiatric disorders. But is this so-called monosodium glutamate “allergy” a menace or a myth?

You don’t know until you put it to the test––or in this case, many tests. In a multicenter, double-blind, placebo-controlled, multiple-challenge trial of MSG, 130 self-reported MSG-reactive volunteers first consumed beverages containing 5g of MSG or a placebo, and those who reported two or more of 10 different symptoms, such as flushing or headache, were then re-challenged in a dose-response study. Of the 19 people who consistently responded to 5g of MSG mixed in a drink, once MSG was given in a capsule (therefore ensuring people couldn’t actually taste the MSG, which they could when it was mixed in a drink), only two people had reactions. The researchers noted that large doses of MSG without food may result in more symptoms, but no persistent or serious effects were observed. For context, estimated MSG intakes in the UK are about 0.58 g/day and in Asian countries, such as China, Korea, and Vietnam, where it is a more commonly used seasoning, it ranges from 0.33 g/day to 3.8 g/day, which is generally much less than the massive 5g or greater single doses provided in the challenge trials. Yet only two out of 130 people who claimed to be sensitive to MSG had any more symptoms than when they just took a placebo.

Given the controversy, consensus meetings with scientific experts convened in 1997 and again in 2007, and concluded that MSG was harmless and no dietary intake limits needed to be set. But in 2017, the European Food Safety Authority reevaluated the safety of glutamate as a food additive and decided to set a limit of 30mg per kilogram of body weight per day, which is exceeded by most people every day. This limit was based off a rat study from 1979, with the European Food Safety Authority (EFSA) citing potential neurodevelopmental toxicity concerns. But even the author of the original study says they failed to convincingly show such an effect.

And given MSG’s salt-reducing benefits, might it be a-okay as a much-needed tool to reduce sodium in foods? Now, MSG still has sodium; it’s monosodium glutamate, after all, with about one-third the sodium of typical table salt. So, a better salt substitute would be potassium salt––potassium chloride, which has the potential to save even more lives.

Did you know the consumption of phosphorus preservatives in junk food and injected into meat may damage blood vessels, accelerate the aging process, and contribute to osteoporosis?

In my video, Treating Kidney Failure through Diet, I profiled research suggesting that the use of plant-based diets may be helpful for patients with kidney failure, because “control of dietary phosphorus intake is the lynchpin in the successful control” of a leading cause of disease and death in kidney failure patients: too much phosphorous in the blood.

But now, we’re beginning to realize that absorbing too much phosphorus isn’t good for anyone. Having high levels in our blood “has…been found to be an independent predictor of [heart attacks] and mortality in the general population”—increasing the risk of not only kidney failure, but heart failure, heart attacks, coronary death, and overall death. Higher phosphate levels associated with a significantly shorter lifespan.

Dietary intake of phosphate is an important matter not just for persons with kidney disease, but for everybody. It’s thought to cause damage to blood vessels and accelerate the aging process—even potentially hurting our bones, contributing to osteoporosis by disrupting hormonal regulation.

The estimated average requirement of phosphorus is less than 600 a day, but the estimated average intake is nearly twice that in the United States. How do we stay away from the stuff? If you look at nutrient tables, it looks like many plant foods have as much phosphorus as many animal foods. So, why are plant-based diets so effective in treating kidney failure patients? Because most of the phosphorus in plant foods is found in the form of phytic acid, which we don’t digest. So, the bioavailability of plant phosphates is usually less than 50%. See, only a third to a half of plant phosphorus may be absorbable, whereas most animal products are all up around 75%.

So, when you adjust for how much actually gets into our system, you see plant foods are better. It’s like the absorption of heme and non-heme iron; our body can protect itself from absorbing too much plant-based iron, but can’t stop excess blood-based, or heme iron from animals, slipping through the intestinal wall.

The worst kind of phosphorus, absorbed nearly 100%, are phosphate additives added, for example, to cola drinks. Why would they do that? Otherwise, cola drinks would be black. Without the added phosphate, there would be so many glycotoxins produced that the beverage would turn “pitch-black. Thus, cola drinks owe their brown color to phosphate.”

“Phosphate additives play an especially important role in the meat industry, where [they’re] used as preservatives” for the same reason: “to enhance a meat product’s color.” Just like the dairy industry adds aluminum to cheese, meat and poultry is “enhanced” by injecting it with phosphates. If you look at meat industry trade journals, and can get past all the macabre ads for head-dropping robots for the kill floor, and foot chopper-offers, you’ll see all these ads for injection machines. Why? Because of increased profitability. Enhanced meats have better color and “less purge.”

“Purge is a term used to describe the liquid that [seeps from flesh] as it ages. Many consumers find this unattractive,” and so the industry views it as a win-win. When you inject chicken with phosphates, “[t]he consumer benefits through the perception of enhanced quality, and, the processor benefits from increased” yield—because they just pumped it up with water, and they sell it by the pound. The problem is that it can boost phosphorus levels in meat nearly 70%—a real and “insidious” danger for kidney patients. But, now we know it’s a danger for all.