Peptides: The Next Breakthrough in Bioactive Nutritionals?

Taking a closer look at the health and beauty value of peptides.

By Gregory Stephens, RD

Although peptide drugs have been on the market for decades, it wasn’t until the late 1990s that pharmaceutical and nutraceutical companies began to seriously work on the de­velopment of a new generation of peptide-based products. Peptides provide numerous functional and health benefits. In fact, they play an important role in many areas for consumers today, including: cardiovascular health, obesity, diabetes, gastrointestinal health, sport’s nutrition, cognitive health, inflammation, immunity, stress reduction and outer cosmetic beauty.

Bioactive peptides are specific protein fragments that have a positive impact on body functions or conditions that may ultimately influence health. Splitting proteins into small fragments allow for better absorption and faster uptake by the body, as well as increased solubility in liquids. Upon oral administration, bioactive peptides may affect the major body systems—namely, the cardiovascular, digestive, immune and nervous systems. The beneficial health effects may be classified as antimicrobial, antioxidative, antithrombotic, antihypertensive, and antimicrobial or immunomodulatory1, 2.

Evolutionary Path for Functional Peptides

Peptides have come a long way through the decades. Figure 1 lays out where they’ve been and where they’re headed.
1 & 2: For many centuries there’s been a deep-rooted belief that foods and food components have health-giving and curative properties. In the 20th century, however, reliance shifted to drugs and other medical therapies to treat and prevent disease.
3: The 1970s witnessed a reawakening in interest in the healthful effects of food and specific food components, as research findings began to identify the structure-function relationships between naturally occurring chemicals in foods and the human body3.
4: The functional foods concept grew out of a maturation of ideas stemming from the health food movement. The growth in functional foods was precipitated by a number of factors, including increasing life expectancy, rising healthcare costs, advances in food and ingredient technologies, a more informed public, and increased credibility of functional foods. All of this simultaneously gave rise to and was enhanced by governmental regulation.
5: The completion of the human genome project in 2003 was a major factor responsible for the growth of functional peptides and other bioactive ingredients. The human genome project provided data facilitating the growth of nutrigenomics. Nutrigenomics, the science of how bioactive dietary components affect gene expression, genes, proteins and me­tabolites, is expected to fuel the growth of the nutritional supplement and functional food industries as they move forward4.

In addition to the emerging field of nutrigenomics and the appetite of aging baby boomers for methods to forestall the effects of aging and to prolong health and well-being, other factors supporting the opportunities for functional peptides include:

• Scientific study results specifically demonstrating the benefits of bioactive compounds;
• Scientific study results elucidating mechanisms of action of bioactive compounds;
• Advances in food science and food technology that allow identification, isolation and purification of bioactive compounds; and
• Advances in production and manufacturing technology that allow nutritional application and production of marketable bioactive ingredients and foods.


These various advances have o­pened up several doors for peptides. Figure 2 shows the increase in the number of food, beverage and other consumer packaged goods containing “peptides” launched globally since 2001. The increase in launches since 2006 is quite significant.

Differentiating Between Peptides and Proteins

All proteins are peptides—chains of amino acids linked by peptide bonds. Amino acids are the smallest structural unit of proteins. A dipeptide, the smallest possible peptide, is a two amino acid chain; tripeptides contain three amino acids; peptides are generally considered to contain 10 amino acids or less; polypeptides contain chains of 10 to 30 amino acids.

Functional Peptides and Their Future

Functional peptides have the potential to provide numerous benefits beyond the nutritional benefits of providing fuel and substrates for metabolism, growth and preventing nutritional deficiency. So far, only a few have been clearly identified. Some of the benefits include: anti-inflammatory, anti-microbial, anti-hypertension and immunomodulation.

Functional peptides have been ap­plied in the following areas. With re­gard to disease prevention, peptides have been applied to cancer, cardiovascular disease/dysfunction, diabetes and gastrointestinal disease/ dysfunction. From a well-being, performance and maintenance standpoint, peptides have been applied to cognition, gastrointestinal healthcare, skin health and cosmetics, sports/ athletic performance and weight management. Currently there are numerous peptides commercially available to the nutraceuticals market. A few of their (proposed) mechanisms of action are listed in Table 1 (page 22). Although far from an inclusive listing, this reference provides a glimpse into the ingredients and how they function.

The factors described in Table 1 are favorable for the commercial success for functional peptides. But there are also barriers. Some of these include:

• Rigorously designed research supporting safety, efficacy and marketing claims will be demanded;
• Premium pricing will be necessary for profitability; and
• Stay away from products that are unsafe, not efficacious, poor tasting, inconvenient or perceived as poor value.


As an ingredient, proteins possess many functional properties that affect the processing, packaging and quality of the final product. Proteins can impact gelation (the process of solidification on cooling), viscosity, foaming, film-formation, water control, emulsification and taste 5. These attributes vary according to the type and composition of the protein and each has considerable potential to benefit or sabotage new product development.

Food scientists developing new products from specifications based on medical and nutritional science often face considerable challenges. While they do understand the characteristics and performance of individual protein sources, protein systems containing combinations of proteins, peptides and/or amino acids are frequently unpredictable. And, once a small batch is perfected, these “fragile” solutions may be difficult to scale up to commercial batch sizes.

Peptides can have significant im­pact on flavor and other sensory aspects of the final product. Some amino acids can impart a bitter taste, whereas others such as glutamic acid actually enhance flavor. The taste that is perceived in the final products largely depends on the types and amounts of amino acids and peptides they contain.

Although some peptide manufacturing processes have reached commercial scale, a large number of processes are still too complex and expensive to be commercially viable. The recent development in proteomics may provide useful information to formulate new tools that could specifically bind bioactive peptides in a single step.

In an industry seeking sustainable products, essential fatty acids, prebiotics and probiotics are recent examples of ingredients gaining widespread acceptance with mainstream consumers. Take a closer look at peptides as an emerging class of efficacious bioactive nutraceutical ingredients that have the flexibility to address a variety of consumer health and beauty needs.NW


References
1. FitzGerald, R. J. and Meisel, H. (2000). Milk protein derived inhibitors of angiotensin-I-converting enzyme. British Journal of Nutrition 84:S33–S37.
2. Korhonen, H. and Pihlanto, A. (2001). Food-derived bioactive peptides—opportunities for designing future foods. Current Pharmaceutical Design 9:1297–1308.
3. Labuza T. Foreword in Goldberg I (ed) Functional Foods, Designer Foods, Pharmafoods, Nutraceuticals. 1994. London: Kluwer Academic Publishers. pp. xi-xiii.
4. Debusk RM, Fogarty CP, Ordovas JM, Kornman KS. Nutritional genomics in practice: Where do we begin? J Am Dietet Assoc 2005;105:589-598.
5. Miraglio AM. Design elements. Proteins power up. August 2003. http://www.foodproductdesign.com/archive/2003/0803DE.html. Accessed Nov 16,2007.