Tea tree oil is touted
as having anti- fungal properties.
So what happens when it’s put to the test
against a variety of fungal infections?
Watch the video to find out.
"Does Tea Tree Oil Work for Dandruff, Athlete’s Foot and Nail Fungus?"
Our entire understanding of the cause of dandruff
shifted with this landmark article published in 1984.
Instead of relying on secondary sources, reviews, editorials, opinion pieces,
he looked at the primary literature, the original studies,
and was amazed to find out how overwhelming was the evidence
of the true cause, and how it had been ignored,
because it was so well buried under the mountain of error,
since some expert in the 1800s put forth some bogus theory.
We now know that dandruff is triggered by a fungus
that lives and feeds on the human scalp,
the two major implications being: first, how alarming it is that some bogus theory
can remain in the medical literature unchallenged for a century
despite evidence to the contrary;
and second, hey, if it's a fungus, what about trying tea tree oil,
which contains components that have anti-fungal activity
against a range of fungi.
That was based on studies like this, though,
where tea tree oil in a Petri dish can fight off pathogenic skin fungi.
But you don't know if it works for dandruff until you put it to the test.
A hundred and twenty-six men and women randomized to daily use
of a 5% tea tree oil shampoo or placebo for a month.
The placebo worked a little bit,
decreasing dandruff severity by about 10%,
but the tea tree oil shampoo worked better, about a 40% drop.
Looks like more than 40% from the graph,
but that's because they misleadingly started the Y-axis at negative 60.
This is a classic deception featured in chapter 5 of the 1954 classic,
"How to Lie with Statistics."
The graph should really look like this, which makes the effect less impressive,
but it was still statistically significant.
Only one patient in the tea tree oil group actually achieved a complete response,
though one in the placebo group did as well.
Thus, it seems that tea tree oil shampoo would require ongoing application
for control of dandruff.
Speaking of fungus, what about tea tree oil in the treatment of athlete's foot?
That may actually be our most common fungal skin infection,
affecting up to 1 in 10.
So, about a hundred patients randomized into one of three groups:
a 10% tea tree oil cream, tinactin, an antifungal drug, or a placebo cream.
A month later, the fungus was wiped out in 85% of the drug group,
but only about a quarter of the placebo and tea tree oil groups.
This is somewhat surprising, since tea tree oil can kill off the fungus
in a Petri dish, but apparently not on toes.
That reminds me of some of the oral health data on tea tree oil.
It can wipe out some oral pathogens in a Petri dish,
but have people swish a tea tree oil solution around in their mouth,
and here's the dental plaque buildup after 4 days of no brushing,
swishing with a placebo.
Here's swishing with a medicated chlorhexidine mouthwash,
which keeps the plaque a bit at bay.
But the tea tree oil mouth rinse? No effect.
So, if tea tree oil doesn't influence the amount of plaque,
presumably it wouldn't help with gingivitis,
the gum inflammation that's caused by plaque buildup.
But, no, here's the twist.
True, no reduction in plaque with a 2.5% tea tree oil gel.
Yet significant reduction in gingivitis scores.
Since decreased gum inflammation occurred without a decrease in plaque,
it appeared to just be helping more from an anti-inflammatory
rather than antimicrobial mechanism.
Might the same thing be happening here?
Yeah, from a mycological cure standpoint—a fungus cure standpoint—
tea tree oil didn't really do any better than placebo.
But though the drug wiped out the fungus in 85% of cases,
in some of those cases, the patients actually didn't notice an improvement
in symptoms, or they actually felt worse after the drug,
probably a reflection of tinactin's irritant side effects.
If instead of mycological cure, you looked at symptom improvement,
tea tree oil works as well as the drug.
So, this may be the basis for the popular use of tea tree oil
in the treatment of athlete's foot,
but people should realize that it's just symptomatic relief,
and they're not necessarily eliminating the underlying cause.
Of course, maybe they didn't use a strong enough concentration.
And indeed, if you go with not a 10% cream, but up to 25 or 50%,
you can get mycological cure rates above that of placebo,
but still not as good as the drug.
And at those high concentrations, some of the patients applying tea tree oil
developed moderate to severe dermatitis—they broke out in a rash.
But, hey, if you have a patient
that doesn't want to use the medicated creams,
then a 25% tea tree oil application has a decent chance
of knocking it out without being too risky.
But the standard over-the-counter antifungal creams may work better.
Onychomycosis is a fungal infection of our nails,
usually toenails, but sometimes fingernails,
characterized by nail discoloration, deformity, detachment, thickening,
crumbling, ridging.
Here’s an example of what it can look like.
Reported prevalence is estimated
to be about 1 in 25 people,
though it’s more common in older individuals:
1 in 5 over 60,
and like half of 70-year-olds.
Unfortunately, it’s really hard to treat,
because the fungus can hide
deep inside the nail,
protected from the blood supply on one side
or anything you want to put on
topically on the other.
So, recurrence after treatment
is common due to residual fungus,
even if you are able to beat it back.
Many of the oral systemic treatments can be toxic,
and many topical applications
require long treatment courses,
which may limit patient compliance,
especially in patients who want
to use nail polish or
something to cover it up.
So, given all the problems
with a lot of prescription anti-fungals,
there has been renewed interest
in natural remedies.
Well, if tea tree oil can affect
athlete’s foot and dandruff fungus,
what about nail fungus?
Well, there was this study
of a combination of the antifungal drug
in Lotrimin cream with tea tree oil
that seemed pretty effective—
compared to nothing.
But, what about compared to each other?
Well, there was one head-to-head study
comparing tea tree oil with a
common antifungal drug,
a double-blind, randomized controlled trial:
twice-daily application of either
the drug or pure tea tree oil
on the nail for 6 months.
Debridement was performed every few months,
where some of the fungal mass
is debulked, scraped, ground off.
And, after 6 months, the drug only
wiped the fungus out completely
in about 1 in 10 cases,
but looked better, with partial
or full resolution of the appearance,
in the majority of patients either
from the doctor’s assessment or the patient’s.
And, the tea tree oil did just as well.
The two preparations were comparable
in efficacy of cure, clinical assessment,
and subjective improvement—
even their cost was comparable.
So, for patients desiring a “natural” treatment for
athlete’s foot or nail fungus,
topical tea tree oil is a reasonable
alternative to prescription or
over-the-counter anti-fungals.
Speaking of natural treatments,
how about a truly natural treatment.
One potential reason for the poor
long-term benefits of any therapy
for nail fungus is that it may be
only treating a manifestation
of underlying disease,
such as generalized immune suppression
or peripheral micro- or macrovascular disease.
Maybe fungal nail infections are just
a manifestation of poor peripheral
blood circulation that would normally
allow your body’s natural defenses
to keep the fungus from
taking root in the first place.
Evidently, there was a non-English
language study of 400 patients
that looked at the “relationship
between blood circulation of the skin
and the development of fungus disease”—
that was the title—and
“found a greater than 50% reduction
in blood flow in patients with
[athlete’s foot and nail fungus]…
compared with patients without these disorders.”
So, if fungal nail infections are
just a symptom of an underlying process,
then treatment aimed at eradication
of a pathogen may be unrealistic.
No wonder it just grows right back.
A more appropriate goal, then,
may be to just give up and live with it.
But wait!
If it’s a circulation problem,
why not try to instead improve the circulation.
We’ve known since the 1950s
that you can effectively switch
peripheral artery circulation on
and off like a light switch
within days by switching people
between a low fat plant-based diet
and the more conventional diet
that contributed to the problem
in the first place.