CAPRYLIC ACID

BACKGROUND

Ingredient Type: Constituent

Also Known As: Octanoic acid

Octanoic acid, better known as caprylic acid, is an eight-carbon saturated fatty acid that is found naturally in the milk of various mammals as well as a minor constituent of coconut oil and palm kernel oil (1). Commercially, caprylic acid is used in the production of esters, which are then used in the manufacturer of dyes as well as in perfumery. One of the attractive qualities of caprylic acid is that it acts as an anti-microbial. This quality has made it very popular commercially as a component for sanitization in food handling establishments, healthcare facilities, schools/colleges, animal care/veterinary facilities, office buildings, recreational facilities, livestock premises, and hotels/motels. Similarly, this quality is applied as an algaecide, bactericide, fungicide, and herbicide in nurseries, greenhouses, garden centers, and interiorscapes (2).

TRADITIONAL USES

The historical use of caprylic acid, aside from its commercial use, was to help treat Candida albicans infections. The treatment was first introduced in the 1940s & 1950s when preliminary results from test-tube research and animal studies revealed caprylic acid’s anti-microbial properties (2,3,4,5,6).

WHAT DOES SCIENCE TELL US?

Caprylic Acid Possibly Helps Reduce Inflammation:

It is commonly known that medium-chain triglycerides (MCT) are administered to patients with gastrointestinal disorders such as Crohn’s disease (CD) or short-bowel disorder. Little is currently known as to the mechanism behind the effects of MCT on intestinal inflammation. This study was conducted to examine whether caprylic acid and MCT suppress IL-8 secretion by differentiated inflammatory Caco-2 cells. Upon completion of the study, it was noted that caprylic acid and MCT suppressed IL-8 secretion by the Caco-2 cells at a transcriptional level when pre-cultured together for a duration of 24-hours. Another assay conducted to determine other associated mechanisms was the dual-luciferase assay, which revealed that the caprylic acid inhibited the activation of the IL-8 promoter. In this study, it was recognized that inhibition of IL-8 did not necessarily require the marked suppression of transcription factors and that the mechanism between caprylic acid and other MCTs may have inhibitive inflammatory responses that differ in origin and mechanism (9).

A recent study was conducted to evaluate the similarities among fatty acid compositions of common vegetable oils sold in the Brazilian market and whether or not they would be good candidates in support of wound healing. Twenty-one types of vegetable oils were utilized in this study, all purchased from Brazilian markets. The results noted that the oils had similar fatty acid compositions to the reference product (caprylic acid, 18.8%; capric acid, 17.4%; oleic acid, 27.5%; and linoleic acid, 28.1%). Except for linoleic acid, all the oils had a detection of these fatty acids along with myristic acid. Oleic acid was present in andiroba, avocado, canola, copaiba, olive, pequi, and pracaxi oils while being predominant in olive oil. Linoleic acid was present in corn, cottonseed, grapeseed, passionfruit, and sunflower oils. This constituent, along with the current scientific understanding of medium-chain fatty acids being natural anti-microbial, notes that it is likely the balanced composition of the fatty acids in these plant oils that make them potentially effective alternatives for treating wounds (13).

Caprylic Acid Possibly Supports Cardiovascular Health:

In previous studies, it was found that medium-chain triglycerides could ameliorate atherosclerosis. The research team working on this study hypothesized that caprylic acid (C8:0) would be able to suppress inflammation via TLR4/NK-kB signaling and further promote the amelioration of atherosclerosis in apoE-deficient (-/-) mice. In the study, 50 6-week old male ApoE (-/-) mice were randomly allocated into fiver diet groups: a high-fat diet (HFD) with or without 2% caprylic acid (C8:0), capric acid (C10:0), stearic acid (C18:0), or linolenic acid (C18:3). RAW246.7 cells were then treated with caprylic acid, docosahexaenoic acid, palmitic acid, and lipopolysaccharides with or without TLR4 knock-down. The measured markers in this study were: serum lipid profiles, inflammatory biomolecules, and mRNA and protein expression levels. Atherosclerotic lesions that occurred in the aorta and aortic sinuses were evaluated and quantified. The results of their study indicated that C8:0 reduced body fat, improved lipid profiles, suppressed inflammatory cytokine production, downregulated aortic mRNA expression, and alleviated atherosclerosis in ApoE (-/-) mice. It was concluded from the results that C8:0 (caprylic acid) functions via TLR4/NF-kB signaling, thus improving the health of the mice through suppressing inflammation and ameliorating atherosclerosis; potentially leading to an alternative nutrient against chronic inflammatory diseases such as atherosclerosis and associated morbidities (15).

Caprylic Acid Might have Anti-Microbial Properties:

The objective of this study was to assess the effectiveness of caprylic acid and its monoglyceride, monocaprylin, on the inactivation of some of the more common mastitis pathogens (Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Staphylococcus aures, and Escherichia coli. In this study, milk samples containing either 50 mM or 100 mM of caprylic acid, and 25 mM or 50 mM monocaprylin were inoculated separately with a 3-isolate mixture of each of the five pathogens and incubated at 39°C. Populations of bacteria were grown, isolated, and measured at various time intervals (0 min., 1 min., 6h, 12h, and 24h post-incubation). From the results, it was noted that both caprylic acid and monocaprylin significantly suppressed all five strains of bacteria. Interestingly, it was noted that of the five strains of bacteria, E. coli was the most tolerant to both treatments. Further study is necessary to evaluate better the mechanisms as well as the potential for use as an alternative to antibiotics for the treatment of bovine mastitis (8).

In a different study, the use of caprylate for the inactivation of lipid-enveloped viruses in biologically active proteins was evaluated. The viruses tested in this study were: herpes simplex I, vesicular stomatitis virus, vaccinia virus, and Sindbis virus. The procedures used a dissociation reaction with varying concentrations of an ionized form of caprylate; a specific form of non-ionized caprylate was maintained over a wide pH range. The observed results revealed that virus-solution, which came in contact with the caprylate, responded with rapid virus inactivation. From this study, it was noted that in certain conditions, except for coagulation factor AHF, virus activity was inhibited by various concentrations of ionized caprylate (10).

Another similar study assessed the susceptibility of inactivation of Candida albicans to certain fatty acids and their 1-monoglycerides. Following treatment with capric acid, a similar medium-chain fatty acid, the results showed that it caused the fastest and most effective inhibition of all three strains of C. albicans. Following the treatment, the C. albicans was noted to have disorganized and shrunken cytoplasm due to a disrupted or disintegrated plasma membrane. Lauric acid, on the other hand, a 12-carbon saturated fatty acid, was the most active at lower concentrations following a longer incubation time. From this study, it was concluded that capric acid, lauric acid as well as others have the ability to not only inhibit the growth of C. albicans but to kill it all together (11).

A study assessed common intractable medical conditions that are often associated with or secondary to coexisting, mixed infections of Candida albicans (CA), Helicobacter pylori (HP), or Cytomegalovirus (CMV) with or without additional bacterial species, viral infections, increased Asbestos, with or without Hg deposits. Mixed infections are very common in or around the urinary tract, as well as the oral cavity. In this study, treatments were either conventional medications, alternative supplements, or a combination of both. It was found that the best treatment was to give a combination of an optimal dose of caprylic acid orally in the form of “CaprilyCare” or “CaprylicAcid” with a capsule of Omega-3 Fish Oil as an anti-viral agent, Amoxicillin, Substance Z & a Cilantro tablet. This particular dose of Caprylic acid was said to increase normal cell telomere (NCT) to a desirable range of 750 ng, while Diflucan only increased the cell telomere to 25 ng. It was concluded that the use of caprylic acid is far more effective and less expensive than Diflucan while also having the potential application(s) for anti-cancer, anti-aging, anti-Alzheimer’s disease, anti-Autism, anti-microbial, and supportive of the general circulatory system (12).

A study was conducted to see if improved fungicidal effects of naturally derived antifungals against C. albicans within short periods was possible utilizing a synergistic effect of combining, caprylic acid (CA), carvacrol (CAR), and thymol (THM) for 1 – 10 minutes. Results were noted as follows: Flow cytometry results showed exposure to CA along damaged the fungal membranes (15.7-36.5%) while also damaging the efflux pumps (15.4-31.3%). Treatment with CAR/THM slightly affected the cell membranes (1.8-6.9%) but damaged efflux pumps (14.4-29.6%) of the fungal cells. However, when the treatments were combined, CA/CAR/THM significantly disrupted the membrane (>83.1%) and the efflux pumps (>95.0%). The synergistic effect is said to be led by membrane damage from CA, further allowing CAR/THM to degrade the membrane along with the efflux pumps cumulatively. Successful synergism of CA + CAR/THM showed significant destruction of the C. albicans fungal cells within minutes at room/body temperature. It should be considered as a possible alternative treatment to synthetic antifungals for C. Albicans (14).

SAFETY

Caprylic acid has become more popular as of late because of the keto, paleo, and intermittent fasting diets. Although popular, it has limited human studies on conditions not involving a microbial nature. As far as safety is concerned, oral consumption in nutritionally-supplemental doses is considered safe. If an individual is consuming caprylic acid as part of a ketogenic diet or another diet high in medium-chain triglycerides (MCTs), it is advised to consult your healthcare provider best to ensure proper delivery and doses that are supportive yet healthy for your current state and health.

For those individuals with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, it is likely unsafe to consume caprylic acid, being that it is considered a medium-chain triglyceride and may increase one’s risk of coma or other associated side-effects related to the inability to break down the fatty acids properly. Similarly, those with liver disease or other associated conditions(s) involving the liver, are recommended to consult their healthcare provider before consuming caprylic acid. As the liver is the primary organ dealing with the breakdown of fatty acids, if this system is compromised, caprylic acids may begin to build up in the blood, causing serious, if not life-threatening side-effects (2).

Interactions:

Caprylic acid may have interactions with certain conditions, especially associated with hepatic, cardiovascular, and inflammatory conditions. Please consult your healthcare provider if you are with or think you may be with the following conditions associated with the following medications before supplementing with caprylic acid (2).

• There may potentially be interactions with medications taken for high blood pressure (antihypertensives). Consumption of caprylic acid may cause a decrease in one’s blood pressure naturally. This can be a risk of concern for those currently taking the following medications: captopril, enalapril, losartan, valsartan, diltiazem, amlodipine, hydrochlorothiazide, furosemide amongst others. A drastic drop in blood pressure may be experienced in those not properly monitoring their levels if combined with caprylic acid.
• Interactions may also occur in those currently taking or planning on taking nonsteroidal anti-inflammatory (NSAIDs) medications. The mechanism for how NSAIDs work is by whether they are bound to the common plasma protein, albumin. When bound to albumin, the NSAIDs are inactive. However, when they are not bound to the albumin, they are considered in their active state. Caprylic acid also mechanistically binds to albumin, thus creating a competitor for albumin adherence. When combined, caprylic acid may displace NSAIDs that normally would bind to albumin, leading to a higher amount of active NSAIDs available in the blood, leading to increased effects of the NSAIDs (ibuprofen, indomethacin, naproxen, piroxicam, aspirin, amongst others).
• Lastly, concerns revolve around caprylic acid and blood-thinning agents, specifically warfarin (coumadin). Similar to NSAIDs, warfarin binds to the serum protein, albumin. When bound to albumin, warfarin is considered inactive. As warfarin is released from the albumin, it becomes active. When taking caprylic acid with warfarin, the warfarin may be displaced by the binding of caprylic acid to albumin, potentially increasing the effects of warfarin, which may lead to higher risks of bruising and bleeding.

Side-Effects:

Due to the lack of research, little is known about the long-term use of supplementation with caprylic acid. Currently, the only known side-effects related to supplementation and consumption of caprylic acid are related to either excessive consumption or use with hepatobiliary related conditions or inflammation. Some of the more common side-effects are nausea, constipation, diarrhea, heartburn, acid reflux/indigestion, bloating, vomiting, gastrointestinal pain, and hypocalcemia.

A study in 2009 was initially conducted to determine if an oral ketogenic compound, A-1202, could help improve cognitive function in subjects with Alzheimer’s disease (AD), through supplementally induced ketosis. Some of the test subjects were noted to experience bouts of diarrhea due to the administered supplement with caprylic acid during the study (7).

REFERENCES

1. Beare-Rogers J, Dieffenbacher A, Holm JV. Lexicon of Lipid Nutrition (IUPAC Technical Report). Pure and Applied Chemistry. 2001;73(4): 685-744.
2. Caprylic Acid. Rx List. https://www.rxlist.com/caprylic_acid/supplements.htm. Accessed 8 June 2020.
3. Nair MK, Joy J, Vasudevan P, et al. Antibacterial Effect of Caprylic Acid and Monocaprylin on Major Bacterial Mastitis Pathogens. J Dairy Sci. 2005;88(10): 3488-3495.
4. Liu S, Ruan W, Li J, et al. Biological Control of Phytopathogenic Fungi by Fatty Acids. Mycopathologia. 2008;166(2): 93-102.
5. Keeney EL. Sodium Caprylate: A New and Effective Treatment of Moniliasis of the Skin and Mucous Membrane. Bull Johns Hopkins Hosp. 1946;78(1): 333-339.
6. Neuhauser I, Gustus EL. Successful Treatment of Intestinal Moniliasis with Fatty Acid Resin Complex. Arch Intern Med. 1954;93(1): 53-60. doi:10.1001/archinte.1954.00240250063005.
7. Henderson ST, Vogel JL, Barr LJ, Garvin F, Jones JJ, Costantini LC. Study of the Ketogenic Agent AC-1202 in Mild to Moderate Alzheimer’s Disease: A Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial. Nutr Metab (Lond). 2009;6: 31.
8. Nair MK, Joy J, Vasudevan P, Hinckley L, Hoagland TA, Venkitanarayanan KS. Antibacterial Effect of Caprylic Acid and Monocaprylin on Major Bacterial Mastitis Pathogens.  J Dairy Sci. 2005;88(10): 3488-3495.
9. Hoshimoto A, Suzuki Y, Katsuno T, Nakajima H, Saito Y. Caprylic Acid and Medium-Chain Triglycerides Inhibit IL-8 Gene Transcription in Caco-2 Cells: Comparison with the Potent Histone Deacetylase Inhibitor Trichostatin A. Br J Pharmacol. 2002;136(2): 280-286.
10. Lundblad JL, Seng RL. Inactivation of Lipid-Enveloped Viruses in Proteins by Caprylate. Vox Sang. 1991;60(2): 75-81. doi: 10.1111/j.1423-0410.1991.tb00878.x.
11. Bergsson G, Arnfinnsson J, Steingrimsson O, Thormar H. In Vitro Killing of Candida albicans by Fatty Acids and Monoglycerides. Antimicrob Agents Chemother. 2001;45(11): 3209-3212. DOI: 10.1128/AAC.45.11.3209-3212.2001.
12. Omura Y, O’Young B, Jones M, Pallos A, Duvvi H, Shimotsuura Y. Caprylic Aid in the Effective Treatment of Intractable Medical Problems of Frequent Urination, Incontinence, Chronic Upper Respiratory Infection, Root Canalled Tooth Infection, ALS, etc., Caused by Asbestos & Mixed Infections of Candida albicans, Helicobacter pylori, & cytomegalovirus With or Without other Microorganisms & Mercury. Acupuct Electrother Res. 2011;36(1-2): 19-64. doi:10.3727/036012911803860886.
13. Alves AQ, da Silva VA Jr., Goes AJS, et al. The Fatty Acid Composition of Vegetable Oils and Their Potential Use in Wound Care. Adv Skin Wound Care. 2019;32(8): 1-8. doi: 10.1097/01.ASW.0000557832.86268.64.
14. Bae YS, Rhee MS. Short-Term Antifungal Treatments of Caprylic Acid with Carvacrol or Thymol Induced Synergistic 6-Log Reduction of Pathogenic Candida albicans by Cell Membrane Disruption and Efflux Pump Inhibition. Cell Physiol Biochem. 2019;53(2): 285-300.
15. Zhang X, Xue C, Xu Q, Zhang Y, Li H, Li F, Liu Y, Guo C. Caprylic Acid Suppresses Inflammation via TLR4/NF-kB Signaling and Improves Atherosclerosis in ApoE-Deficient Mice. Nutr Metab (Lond). 2019;16: 40.