Enhanced Protection With Lactoferrin

Milk, the first food for mammals, is rich in nutrients and compounds so newborns can mature and survive. Many milk proteins provide not only the building blocks for growth, but also for protection against pathogens and diseases. Lactoferrin (LF), one of the many multifunctional proteins in milk, is also found in saliva, tears, seminal fluids, mucins and the secondary granules of neutrophils.

LF, a bioactive glycoprotein of the transferrin family, consists of a single polypeptide chain with a molecular weight of 75,000 to 80,000 Daltons. Capable of binding two ferric ions with two bicarbonate ions, it enhances the absorption of iron by transporting and releasing it at specific receptors in the intestines. Differences exist in LF among species. For example, cow’s milk has more saturated, but less overall, LF than human milk. LF is the main whey protein in human milk.

In a 2001 GRAS notice, DMV International, Delhi, NY, estimated that persons who consume milk and milk-derived ingredients ingested 84 mg of bovine lactoferrin (bLF) per person per day at the 90th percentile consumption level. Most commercial bLF is isolated and purified from whey.

First line of defenseFor years, health authorities have been preaching that breast milk is best for babies because colostrum and mature breast milk contain immunological factors important in infants’ defense against pathogens. Research has identified LF as a major factor in this defense system, partly due to its iron-binding capacity. Numerous studies have demonstrated LF’s antimicrobial and antiviral properties. Additionally, it acts as a prebiotic, as it stimulates the growth of beneficial intestinal organisms, such as Bifidobacteria, and therefore, helps develop infants’ gut microflora.

The presence of LF in tissues at various sites of entry (e.g., mouth, eyes, gastrointestinal tract) points to its role as part of the front line in the defense system against invading pathogens. Its antimicrobial effectiveness primarily stems from its iron-binding capacity. As LF scavenges for iron, it deprives microorganisms of this essential nutrient and acts as a bacteriostat. However, it also directly damages the microbial membranes and becomes a bacteriocide. Lactoferricin, a product of LF digestion in the stomach, is considered responsible for this action.

A multitude of organisms appear to be susceptible to LF — bacteria (Haemophilus influenzae, which causes otitis media in children, E. coli, Helicobacter pylori, Salmonella enteritidis, Klebsiella pneumoniae, Campylobacter jejuni, and Listeria monocytogenes), viruses (cytomegalovirus, influenza, rotavirus, HIV, herpes simplex types 1 and 2, and hepatitis C) and fungi (Candida and Tinea pedis). Studies suggest that its antiviral property results from its ability to compete for cell-receptor sites and to block entry into the cell.

Strengthening the defensesLF exhibits many other characteristics that help with the body’s defenses against chronic diseases. As it binds iron, it protects against damaging free radicals and oxidative processes that may contribute to the aging process and many chronic diseases. LF also stimulates the immune system, modulates immune functions, such as the production of cytokines, and acts as an anti-inflammatory agent.

In animal studies, ingestion of bLF has inhibited colon, lung, esophagus, tongue and bladder cancer by blocking and suppressing cell proliferation. Other studies show a role for chemoprevention of cancer through effective treatment of initiating infections. A preliminary clinical trial demonstrated a possible role for bLF in the treatment of chronic active hepatitis C, which is associated with cirrhosis and liver cancer. Additionally, bLF and recombinant human LF (rhLF) were effective in treating H. pylori gastric infections in animals, with some evidence that rhLF in combination with low-dose antibiotics may have enhanced therapeutic qualities. H. pylori infections can lead to ulcers and stomach cancer.

Food and beverage applications In August 2001, DMV International received a “no objection” letter from the FDA for bLF as a GRAS ingredient for use in sports and functional foods at a level of 100 mg per product serving, provided the label clearly states the source. Since it is allergenic for some people with milk allergies, FDA renamed bLF to “milk-derived lactoferrin.” Europe and a number of Asian countries have also approved its use.

The presence of LF enhances iron bioavailability due to its high affinity and ability to transport iron. Thus, using LF in conjunction with iron supplements and fortified foods offers the potential to increase absorption with lower doses of iron while also minimizing side effects. In infant formulas, adding bLF will achieve the same immunologic and iron bioavailability as human milk.

Loren Ward, Ph.D., manager of whey research at Glanbia Nutritionals, Inc. Twin Falls, ID, says: “In Asia, lactoferrin is found in more mainstream products, such as yogurt, infant formula and nutritional drinks. In the U.S. you are more likely to find lactoferrin in the form of tablets or capsules. In general, the Asian markets are more aware of nutraceutical food components such as lactoferrin.” He points out the existence of more than 3,000 research articles on LF.

A number of other possibilities exist for LF use in sports-nutrition supplements and other nutritional drinks and foods, as well as cosmetics and pharmaceutical applications. One of the more innovative uses for LF is to use its activated form as an antimicrobial spray on beef to prevent contamination during processing and inhibit bacterial growth after packaging. Clearly, LF is a multifunctional ingredient that can contribute to health on many fronts.

Angela M. Miraglio ([email protected]) is a registered dietitian and Fellow of the American Dietetic Association from Des Plaines, IL. Her firm, AMM Food & Nutrition Consulting, provides communications and technical support to food and beverage companies and associations.

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