Disodium Guanylate vs Natural Flavors: which is worse?

What is Disodium Guanylate?

Disodium guanylate (E627) is the disodium salt of guanylic acid (GMP), a nucleotide naturally present in dried mushrooms, seaweed, and certain fish. It is used as a flavor enhancer with even greater synergy with glutamates than disodium inosinate. The combination of GMP and IMP (5'-ribonucleotides, E635) is one of the most potent umami enhancement systems available.

What is Natural Flavors?

Under FDA regulation (21 CFR 101.22), 'natural flavors' are flavoring substances derived from plant or animal sources including spices, fruits, vegetables, herbs, meats, seafood, dairy products, fermentation products, or edible yeast. The term is intentionally broad and does not require disclosure of the specific chemicals involved — a single 'natural flavor' entry on a label can represent a complex mixture of hundreds of compounds.

Documented risks

Disodium Guanylate: Considered safe at food use levels. As a purine nucleotide, it raises the same gout/hyperuricemia concerns as disodium inosinate. Commercial disodium guanylate is often derived from fish (sardines) or yeast, making it non-vegan and non-vegetarian in most commercial applications. People with gout should be aware of cumulative purine intake from these additives.

Natural Flavors: The term itself presents no specific health risk, but the lack of transparency is a significant concern for consumers with allergies, dietary restrictions, or sensitivities. 'Natural flavors' may contain allergens (such as shellfish, wheat, or soy derivatives), animal-derived ingredients (problematic for vegans), or added glutamates that some people wish to avoid. The Environmental Working Group (EWG) has noted that 'natural flavors' is the fourth most common ingredient on food labels, yet consumers have no right to know what specific compounds are included.