Hydrolyzed proteins nothing to fear
DEAR DR. BLONZ >>
Along with the tuna itself, some canned tuna contains “vegetable broth with hydrolyzed soy protein and hydrolyzed casein.” Are these ingredients unhealthy? Does a can of tuna that lists these ingredients contain MSG, which should be avoided?
— S.I., New York City
DEAR S.I. >> Proteins are made up of amino acid building blocks arranged in long chains. In the last stage of being produced, these chains get twisted into three-dimensional shapes to fit their functions. Aside from the protein in tuna, products such as the one you describe also contain soy protein (from soybeans) and casein (the primary protein in milk).
A protein described as “hydrolyzed” indicates it has been broken apart into fragments of one or more amino acids. Outside the body, this gets done using enzymes or chemicals. In addition to being chewed, swallowed and treated in the stomach, proteins undergo a similar process with our digestive enzymes to break them into amino acids to facilitate their absorption. Water molecules are used in this breakdown, half on each side of the formerly linked amino acids.
Hydrolyzed proteins are used as ingredients to enhance flavors; nothing weird here. The vegetable broth is also there to enhance flavor. These ingredients are not unhealthful: They represent a blend of amino acids used to achieve a consistent flavor that manufacturers often seek. Such additives, however, could represent an unnecessary risk for the small number of people who react to monosodium glutamate, or MSG.
There has been a lot of controversy regarding MSG — some of which may be undeserved. The nonessential amino acid glutamate is most prevalent in intact dietary proteins, where it’s part of a chain in a three-dimensional structure. On its own, however, glutamate is a key molecule in cellular metabolism. As the additive MSG — glutamate with a sodium molecule attached — it can affect flavors. Up to 2% of individuals may have shortterm reactions to MSG. Symptoms are typically mild and don’t require treatment — but there can be exceptions. Blind testing, in which your reactions to foods are assessed without you knowing whether MSG is present, can help determine your risk. For individuals found to be sensitive, the only way to prevent a reaction is to avoid foods containing MSG.
Despite concerns raised by early reports and viral proclamations, decades of research have failed to affirm that MSG ingestion must be a concern for all. As an FYI, the May 2017 issue of Food Science & Nutrition reported that the intake of glutamate from the use of MSG as a food additive is much lower than the estimated intake from glutamate naturally present in foods. (Read more on the MSG controversy at b.link/cqrp4m.)