Lysine is an essential amino acid playing a vital role in numerous bodily functions, from protein synthesis to immune support. While total lysine content in foods is often measured, a significant portion can become less available during food processing due to heat and pressure. This altered form is known as “reactive lysine,” and understanding its digestibility is crucial for maximizing the nutritional benefits of Lysine Foods.
A recent study investigated the difference between total and reactive lysine digestibility in common cooked and processed foods. Researchers analyzed several foods, including cooked black beans, toasted wheat bread, and processed wheat bran, noting a discrepancy between total lysine and reactive lysine levels. To understand how the human body utilizes these different forms of lysine, they conducted a study with adult ileostomates. Ileostomates allow for direct collection of digesta at the end of the small intestine, providing accurate data on nutrient absorption.
The findings revealed that true ileal digestible reactive lysine was significantly lower than true ileal digestible total lysine in the processed foods tested. Specifically, reactive lysine digestibility was reduced by 89% in cooked black beans, 55% in toasted wheat bread, and 85% in processed wheat bran compared to total lysine. This highlights that while a food might appear to be a good source of lysine based on total lysine measurements, the actual amount of lysine the body can absorb and utilize, the reactive lysine, can be considerably less, especially after cooking or processing.
This research underscores the importance of considering reactive lysine when evaluating the nutritional value of foods, particularly those that undergo heat treatment or processing. Focusing solely on total lysine content may overestimate the actual lysine available to the body. Choosing minimally processed lysine foods and diverse protein sources can help ensure adequate intake of digestible and reactive lysine for optimal health. Further research is needed to broaden our understanding of reactive lysine in various food processing methods and dietary contexts.
