Nutrition Facts with Dr. Greger

Health Effects of Food Additives

December 18, 2025

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  • Double-blind, placebo-controlled trials suggest that adverse reactions commonly attributed to MSG (monosodium glutamate) are largely a myth, with only 2 out of 130 self-reported sensitive individuals reacting when MSG was administered in a capsule (taste-masked). 
  • Phosphate additives, commonly found in cola drinks and injected into meat, are highly absorbable (nearly 100%) and pose a significant danger by contributing to high blood phosphorus levels, which is an independent predictor of heart attacks, mortality, and accelerated aging. 
  • While MSG contains sodium and could potentially reduce overall sodium intake, potassium chloride (potassium salt) is suggested as a better salt substitute with greater potential for saving lives. 

Segments

Introduction and MSG Inquiry
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(00:00:00)
  • Key Takeaway: The episode of Nutrition Facts with Dr. Greger addresses the health effects of food additives, starting with MSG.
  • Summary: The podcast opens by framing the importance of understanding what we consume. Dr. Michael Greger introduces the topic: the health effects of food additives. The first story focuses on whether reactions attributed to monosodium glutamate (MSG) are a menace, myth, or marvel.
MSG Sodium Reduction Potential
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(00:00:38)
  • Key Takeaway: Substituting traditional salt with MSG can reduce sodium intake by over 30% in standard recipes, potentially saving millions of lives.
  • Summary: Reducing sodium intake by 30% could save over 40 million lives. MSG substitution offers a pathway to achieve this sodium reduction. MSG contains about one-third the sodium of typical table salt.
Testing MSG Sensitivity
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(00:00:56)
  • Key Takeaway: Rigorous, multi-center, double-blind, placebo-controlled challenge trials found that only 2 out of 130 self-reported MSG-sensitive volunteers consistently reacted when MSG was taste-masked in a capsule.
  • Summary: The segment addresses ‘Chinese restaurant syndrome’ linked to MSG since 1968. A major trial challenged 130 volunteers with 5 grams of MSG; when MSG was given in a capsule (taste-masked), only two people reacted consistently. Estimated daily MSG intakes in Asian countries are generally much lower than the 5-gram challenge dose.
MSG Safety Consensus and EFSA Limit
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(00:02:59)
  • Key Takeaway: Scientific consensus meetings in 1997 and 2007 concluded MSG was harmless, but the European Food Safety Authority (EFSA) set a limit in 2017 based on a 1979 rat study concerning neurodevelopmental toxicity.
  • Summary: Expert consensus meetings concluded MSG was harmless and required no dietary limits. However, the EFSA set a limit of 30 mg/kg body weight/day in 2017. This EFSA limit is exceeded by most people daily and is based on a study whose author claims failed to convincingly show neurodevelopmental toxicity.
Phosphorus Additives Danger
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(00:04:12)
  • Key Takeaway: Consumption of phosphorus preservatives in junk food and injected into meat may damage blood vessels, accelerate aging, and contribute to osteoporosis.
  • Summary: High blood phosphate levels are an independent predictor of heart attacks and mortality in the general population, increasing risks for heart failure and overall death. Absorbing too much phosphorus is harmful to everyone, not just kidney failure patients. Phosphate additives are thought to damage blood vessels and disrupt hormonal regulation affecting bone health.
Phosphorus Bioavailability Differences
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(00:05:51)
  • Key Takeaway: Plant-based phosphorus is largely indigestible phytic acid with less than 50% bioavailability, whereas animal product phosphorus is absorbed at around 75%.
  • Summary: Plant foods are better for kidney patients because most phosphorus is in phytic acid, which is poorly digested. Plant phosphate bioavailability is typically less than 50%, compared to nearly 75% absorption from most animal products. This difference explains why plant-based diets aid kidney failure patients despite similar nutrient tables.
Phosphate Additives in Food Coloring
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(00:06:51)
  • Key Takeaway: Phosphate additives are used in cola drinks to prevent them from turning pitch black due to glycotoxin production and are used in meat to enhance color and reduce unattractive liquid purge.
  • Summary: Phosphate additives are nearly 100% absorbed and are the worst kind of phosphorus source. In cola drinks, phosphate is responsible for maintaining the brown color by preventing the beverage from turning black. In the meat industry, phosphates are injected to enhance color and increase yield by retaining water, which is sold by the pound.
Meat Phosphates and Yield
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(00:08:27)
  • Key Takeaway: Injecting meat with phosphates increases processor profitability by boosting yield through added water, but this can increase phosphorus levels in the meat by nearly 70%.
  • Summary: The practice of injecting meat with phosphates is driven by increased profitability and consumer perception of quality. Enhanced meats retain water, which is sold to the consumer. This injection process can boost phosphorus levels in meat by nearly 70%, posing an insidious danger to kidney patients and the general population.
Closing Information and Resources
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(00:08:47)
  • Key Takeaway: All proceeds from Dr. Greger’s books benefit charity, and NutritionFacts.org is a free, non-commercial, science-based non-profit resource.
  • Summary: Listeners can find episode descriptions, sources, and notes at nutritionfacts.org/audio. Information on his books is available at nutritionfacts.org/books, with all proceeds going to charity. The website is a free, non-profit public service without ads or corporate sponsorships.