Coconuts as a Functional Food in the Prevention and Treatment of AIDS

Abstract
Coconuts play a unique role in the diets of mankind because they are the source of important physiologically functional components. These physiologically functional components are found in the fat part of whole coconut, in the fat part of desiccated coconut, and in the extracted coconut oil. Lauric acid, the major fatty acid from the fat of the coconut, has long been recognized for the unique properties that it lends to nonfood uses in the soaps and cosmetics industry. More recently, lauric acid has been recognized for its unique properties in food use, which are related to its antiviral, antibacterial, and antiprotozoal functions. Now, capric acid, another of coconut's fatty acids has been added to the list of coconut's antimicrobial components. These fatty acids are found in the largest amounts only in traditional lauric fats, especially from coconut. Also, recently published research has shown that natural coconut fat in the diet leads to a normalization of body lipids, protects against alcohol damage to the liver, and improves the immune system's anti-inflammatory response.

Clearly, there has been increasing recognition of the health-supporting functions of the fatty acids found in coconut. Recent reports from the US Food and Drug Administration (FDA) about required labeling of the trans fatty acids will put coconut oil in a more competitive position and may help return to its use by the baking and snack food industry where it has continued to be recognized for its functionality. Now it can be recognized for another kind of functionality: the improvement of the health of mankind.

Introduction
Mr. Chairman and members of the Asian Pacific Coconut Community (APCC), I would like to thank you for inviting me to once again speak to this gathering of delegates on the occasion of your 36th session as you celebrate the 30th anniversary of APCC.

When I addressed the 32nd COCOTECH meeting in Cochin, India, I covered two areas of interest to the coconut community. In the first part, I reviewed the major health challenge facing coconut oil at that time, which was based on a supposed negative role played by saturated fat in heart disease. I hope that my talk was able to dispel any acceptance of that notion. In the second part of my talk, I suggested that there were some new positive health benefits from coconut that should be recognized. These benefits stemmed from coconut's use as a food with major functional properties for antimicrobial and anti-cancer effects.

In my presentation today, I will bring you up to date about the new recognition of functional foods as important components in the diet. Additionally, I would like to briefly review the state of the anti-saturated fat situation and bring you up to date on some of the research that compares the beneficial effects of saturated fats with those of omega-6 polyunsaturates, as well as the beneficial effects of the saturated fats relative to the detrimental effects of the partially hydrogenated fats and the trans fatty acids. In particular, I will review some of the surprising beneficial effects of the special saturates found in coconut oil as they compare with those of the unsaturates found in some of the other food oils. Components of coconut oil are increasingly being shown to be beneficial. Increasingly, lauric acid, and even capric acid, have been the subject of favorable scientific reports on health parameters.

Functional Properties of Lauric Fats as Antimicrobials
Earlier this year, at a special conference entitled, Functional Foods For Health Promotion: Physiologic Considerations (Renaissance Washington Hotel, Washington, DC; Saturday, April 17, 1999), which was sponsored by the International Life Sciences Institute, Technical Committee on Food Components for Health Promotion, the term "functional foods" was defined as "a functional food provides a health benefit over and beyond the basic nutrients."

This is exactly what coconut and its edible products, such as desiccated coconut and coconut oil, do. As a functional food, coconut has fatty acids that provide both energy (nutrients) and raw material for antimicrobial fatty acids and monoglycerides (functional components) when eaten. Desiccated coconut is about 69% coconut fat, as is creamed coconut. Full coconut milk is approximately 24% fat.

Approximately 50% of the fatty acids in coconut fat are lauric acid. Lauric acid is a medium chain fatty acid, which has the additional beneficial function of being formed into monolaurin in the human or animal body. Monolaurin is the antiviral, antibacterial, and antiprotozoal monoglyceride used by the human or animal to destroy lipid-coated viruses such as HIV, herpes, cytomegalovirus, influenza, various pathogenic bacteria, including listeria monocytogenes and helicobacter pylori, and protozoa such as giardia lamblia. Some studies have also shown some antimicrobial effects of the free lauric acid.

Also, approximately six to seven percent of the fatty acids in coconut fat are capric acid. Capric acid is another medium-chain fatty acid that has a similar beneficial function when it is formed into monocaprin in the human or animal body. Monocaprin has also been shown to have antiviral effects against HIV and is being tested for antiviral effects against herpes simplex and antibacterial effects against chlamydia and other sexually transmitted bacteria.

The food industry, of course, has long been aware that the functional properties of the lauric oils, and especially coconut oil, are unsurpassed by other available commercial oils. Unfortunately, in the US, both during the late 1930s and again during the 1980s and 1990s, the commercial interests of the US domestic fats and oils industry were successful in driving down usage of coconut oil. As a result, in the US and in other countries where the influence from the US is strong, the manufacturer has lost the benefit of the lauric oils in its food products. As we will see from the data I will present in this talk, it is the consumer who has lost the many health benefits that can result from regular consumption of coconut products.

The antiviral, antibacterial, and antiprotozoal properties of lauric acid and monolaurin have been recognized by a small number of researchers for nearly four decades: this knowledge has resulted in more than 20 research papers and several US patents, and this past year it resulted in a comprehensive book chapter which reviewed the important aspects of lauric oils as antimicrobial agents.1 In the past, the larger group of clinicians and food and nutrition scientists has been unaware of the potential benefits of consuming foods containing coconut and coconut oil, but this is now starting to change.

Kabara2 and others have reported that certain fatty acids (FAs) (e.g., medium-chain saturates) and their derivatives (e.g., monoglycerides (MGs)) can have adverse effects on various microorganisms: those microorganisms that are inactivated include bacteria, yeast, fungi, and enveloped viruses. Additionally, it is reported that the antimicrobial effects of the FAs and MGs are additive, and total concentration is critical for inactivating viruses.3 The properties that determine the anti-infective action of lipids are related to their structure: e.g., monoglycerides, free fatty acids. The monoglycerides are active; diglycerides and triglycerides are inactive. Of the saturated fatty acids, lauric acid has greater antiviral activity than either caprylic acid (C-8), capric acid (C-10), or myristic acid (C-14). In general, it is reported that the fatty acids and monoglycerides produce their killing/inactivating effect by lysing the plasma membrane lipid bilayer. The antiviral action attributed to monolaurin is that of solubilizing the lipids and phospholipids in the envelope of the virus, causing the disintegration of the virus envelope. However, there is evidence from recent studies that one antimicrobial effect in bacteria is related to monolaurin's interference with signal transduction,4 and another antimicrobial effect in viruses is due to lauric acid's interference with virus assembly and viral maturation.5

Recognition of the antiviral aspects of the antimicrobial activity of the monoglyceride of lauric acid (monolaurin) has been reported since 1966. Some of the early work by Hierholzer and Kabara6 that showed virucidal effects of monolaurin on enveloped RNA and DNA viruses was done in conjunction with the Centers for Disease Control (CDC) of the US Public Health Service. These studies were done with selected virus prototypes or recognized representative strains of enveloped human viruses. The envelope of these viruses is a lipid membrane, and the presence of a lipid membrane on viruses makes them especially vulnerable to lauric acid and its derivative monolaurin.

The medium-chain saturated fatty acids and their derivatives act by disrupting the lipid membranes of the viruses.7,8 Research has shown that enveloped viruses are inactivated in both human and bovine milk by added fatty acids and monoglycerides,9 and also by endogenous fatty acids and monoglycerides of the appropriate length.3,7-11 Some of the viruses inactivated by these lipids, in addition to HIV, are the measles virus, herpes simplex virus-1 (HSV-1), vesicular stomatitis virus (VSV), visna virus, and cytomegalovirus (CMV). Many of the pathogenic organisms reported to be inactivated by these antimicrobial lipids are those known to be responsible for opportunistic infections in HIV-positive individuals. For example, concurrent infection with cytomegalovirus is recognized as a serious complication for HIV+ individuals.12 Thus, it would appear to be important to investigate the practical aspects and the potential benefit of an adjunct nutritional support regimen for HIV-infected individuals that will utilize those dietary fats that are sources of known antiviral, antimicrobial, and antiprotozoal monoglycerides, and fatty acids such as monolaurin and its precursor lauric acid. Until now, no one in the mainstream nutrition community seems to have recognized the added potential of antimicrobial lipids in the treatment of HIV-infected or AIDS patients. These antimicrobial fatty acids and their derivatives are essentially nontoxic to man; they are produced in vivo by humans when they ingest those commonly available foods that contain adequate levels of medium-chain fatty acids such as lauric acid. According to the published research, lauric acid is one of the best "inactivating" fatty acids, and its monoglyceride is even more effective than the fatty acid alone.2,13-15

The lipid-coated (envelope) viruses are dependent on host lipids for their lipid constituents. The variability of fatty acids in the foods of individuals as well as the variability from de novo synthesis accounts for the variability of fatty acids in the virus envelope and also explains the variability of glycoprotein expression, a variability that makes vaccine development more difficult. Monolaurin does not appear to have an adverse effect on desirable gut bacteria, but rather on only potentially pathogenic microorganisms. For example, Isaacs et al.7,9 reported no inactivation of the common Escherichia coli or Salmonella enteritidis by monolaurin, but major inactivation of Hemophilus influenzae, Staphylococcus epidermidis and Group B gram-positive streptococcus.

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The potentially pathogenic bacteria inactivated by monolaurin include Listeria monocytogenes, Staphylococcus aureus, Streptococcus agalactiae, Groups A, F, & G streptococci, gram-positive organisms, and some gram-negative organisms if pretreated with a chelator.2,3,7-11,16-18

Decreased growth of Staphylococcus aureus and decreased production of toxic shock syndrome toxin-1 was shown with 150 mg monolaurin per liter.19 Monolaurin was 5000 times more inhibitory against Listeria monocytogenes than ethanol.20 Helicobacter pylori is rapidly inactivated by medium-chain monoglycerides and lauric acid, and there appears to be very little development of resistance of the organism to the bactericidal effects21 of these natural antimicrobials. A number of fungi, yeast, and protozoa are inactivated or killed by lauric acid or monolaurin. The fungi include several species of ringworm.7,9 The yeast reported is Candida albicans.7,9 The protozoan parasite Giardia lamblia is killed by free fatty acids and monoglycerides from hydrolyzed human milk.7,9,22-24 Numerous other protozoa were studied with similar findings; these findings have not yet been published.25

Research continues in measuring the effect of the monoglyceride derivative of capric acid monocaprin as well as the effects of lauric acid. Chlamydia trachomatis is inactivated by lauric acid, capric acid, and monocaprin,26 and hydrogels containing monocaprin are potent in vitro inactivators of sexually transmitted viruses such as HSV-2 and HIV-1 and bacteria such as Neisseria gonorrhoeae.

About Dr. Mary Enig
Dr. Mary G. Enig has had approximately 30 years of research and training in biochemistry, pharmacology, and nutrition of fatty acids including food fats and oils chemistry. A recognized expert in the antimicrobial properties of fatty acids, Dr. Enig was also one of the original researchers who brought the dangers of trans fatty acids to the attention of the FDA. She initiated the first comprehensive analysis of trans fatty acid components of the fat content of over 200 foods. This extended our knowledge of foods commonly consumed by Americans. This research considered how the trans fatty acids from foods affected the liver's mixed function oxidase enzyme system that metabolizes drugs and environmental pollutants in the body. An important finding of this study was that laboratory animals fed experimental diets containing trans fatty acids have altered activity of this enzyme system. Dr. Enig also developed dietary support regimens using lauric oils as physiologically functional foods to provide antimicrobial fatty acids to individuals with compromised immune systems, e.g., AIDS/HIV+. This research protocol was used successfully by the San Lazaro hospital group in the Philippines in 1999 under the charge of Dr. Eric Tayag. As a result of this protocol development, Dr. Enig was asked to contribute a chapter on "Lauric Oils as Antimicrobial Agents: Theory of Effect, Scientific Rationale, and Dietary Application as Adjunct Nutritional Support for HIV-Infected Individuals" in Nutrients and Foods in AIDS. She is also author of Know Your Fats: The Complete Primer for Understanding the Nutrition of Fats, Oils, and Cholesterol.
Mary G. Enig, PhD, FACN