Coconut oil is natural and can be wonderful for the skin, but claiming benefits that it is “antibacterial” is simply not true. I see everyone from sunbathers in their 20’s to young mothers in their 30’s slathering it everywhere as a skin-healing antibacterial agent that can do no wrong, but that is not the truth.

Where the Rumor Comes From

There are three places the rumor coconut oil is an antibacterial comes from:

First, there are studies that show lauric acid may have antibacterial activity, particularly against P. acnes, the bacterial species responsible for acne. However, these studies use purified lauric acid, not the 50% lauric acid, other fatty acids, and trace organic materials coconut oil is derived from.
In addition, the studies I have found using lauric acid as an antibacterial agent don’t subject all of the skin’s microflora to lauric acid, just to P. acnes, which is means these studies are NOT concluding lauric acid is antibacterial towards ALL species of bacteria commonly found in the skin. In fact, lauric acid is known to have antibacterial effects, but is NOT included on the FDA monograph as an antibacterial chemical, simply because it doesn’t work against the full range of organisms that are tested for this designation.

Second, coconut oil has low water activity, which some people interpret to mean that bacteria can’t grow because there isn’t much water. But in fact, this is not true. “Low water activity” is not the same thing as “low water content.”

Instead, “low water activity” refers to the amount of unbound water in a substance, and the fact water activity is low doesn’t make coconut oil any more antibacterial than, say, biscuits, a food we all know grows bacteria and fungal mold, and which also has a low water content (http://drinc.ucdavis.edu/dairychem4_new.htm).

How much water content is in coconuts depends on the drying and heating process. Coconut derived from well-dried copra will have less moisture than that from less dried copra or from fresh coconuts (virgin coconut oil).

Similarly, the oil subjected to heat will have less moisture than that which was not exposed to heat.

The third and final reason for this rumor is that there is a widespread belief on the internet coconut oil contains antimicrobial and anti-fungal agents like monocaprin and monolaurin when acted upon by certain enzymes. But this has not been verified by any peer-reviewed research using sound methods — and certainly never verified when you are out using coconut oil on your skin!

Why Coconut Oil Grows Bacteria

Coconut oil grows bacteria because it is full of things bacteria like to feed on. It includes the lipids lauric acid, capric acid and caprylic acid, all of which have some antibacterial activity on their own, but do NOT cover the entire range of microorganisms they might be susceptible to encountering on a regular basis. In addition, after regular use, all of that bacteria and moisture on your hands gets into the jar, resulting in a prime place for bacterial growth.

How to Know if Your Coconut Oil Has Turned

Dark spots at the top or bottom of your container are the clear telltale signs your coconut oil has grown bacteria or fungi. Sometimes it will also smell different. If this is the case, throw it away immediately.

Since coconut oil is NOT an antibacterial agent effective against a wide range of susceptible microorganisms, and usually does not contain preservatives, repeatedly reaching into the jar with wet or bacteria-laden hands can cause bacteria or fungi to grow in your jar.

Why Use Coconut Oil at All?

Coconut oil is an emollient that’s gentle enough to use in baby formulas on infants’ thinner, more delicate skin (Indian Pediatrics). In fact, one study found it in 44.4% of products for newborns (Journal of Allergy and Clinical Immunology).

One study found that virgin coconut oil could be used for its properties against P. acnes to treat acne (Dermatitis). It can also help to heal burn wounds, though the researchers did not uncover why exactly, hypothesizing that it is because coconut has anti-inflammatory and antiseptic properties (Indian Journal of Pharmacology).

And while hydration, antioxidants and healing power might be great uses for coconut oil, FORGET USING COCONUT OIL AS A SUNSCREEN. It is true coconut does have some UV protection — blocking about 20% of UV rays, but who wants to let 80% of UV rays through when an SPF 50 sunscreen only lets 2% of rays through?! (Pharmacognosy Reviews).

Bottom Line

Coconut oil is a proven hydrator, antioxidant, and skin soother in skin care, but it has NEVER been shown to have antibacterial activity against the FULL range of microorganisms your skin or your jar of coconut oil will encounter.

As a result, without any preservatives, your jar of coconut oil MAY become infested with bacteria or fungi over time, which you may notice as brown spots on the top of your jar (from contact with moisture/bacteria-laden fingers) or the bottom of your jar (from moisture seeping down the sides of your product and through small cracks within the product).

I personally do like it for hydration and healing dry skin patches — but I buy mine in small quantities, wash and dry my hands thoroughly before each use, use a Q-Tip, and am religious about storing mine in a cool, dark place.

Got questions or something to say about coconut oil? Let me know in comments!