Emu oil for osteoarthritic hand pain
Ray Power
B.Sc (Clin.Sc)
Abstract
Objectives
To
establish the effect of emu oil applied topically or ingested, on grip
strength, tenderness and pain on people with osteoarthritic hands.
Method
A double-blinded, placebo-controlled, repeated
measures design was used to compare the effects of emu oil against a placebo
(canola oil) when: (a) applied topically, (b) ingested, or (c) both applied
topically and ingested. Measures of grip strength and tender joint count were
undertaken at baseline and after 8 weeks of continued treatment. Visual analogue
scale measures of pain were recorded at baseline, and weekly, on the same day
and time each week, for 8 subsequent weeks.
Results
There were no significant changes in
grip strength or tender joint count, but the grip dynamometer was faulty, and
so the grip strength data were invalid. At the end of the study (week 8), pain
scores were statistically significantly lower in the emu oil users (mean of all
groups) compared with the placebo oil users. The treatment effect was medium to
large (p = .02, F = 2.68, h2 = .13).
From week 4 onwards the pain scores reported by emu oil users (all groups) progressively reduced whereas the placebo oil users’ pain scores fluctuated over time.
Conclusion
These results suggest that emu oil
may be useful in the management of pain in people with OA of the hands.
Clinically, practitioners are advised to forewarn clients that improvements
might not be observed for the first 3 weeks of treatment.
Introduction
As early as 1860, Bennett, a London
academic, reported that aborigines and early white settlers used emu oil to
heal wounds, reduce pain and relieve various muscular disorders(1).
Since that time there has been much anecdotal evidence claiming benefits from
treating with emu oil. One of these claims is that emu oil is effective in
reducing the symptoms of arthritis.
Previous Research
This study
compliments early Australian research (2,3,4), which established
the anti-inflammatory qualities of emu oil in rats.
Whitehouse (5)
reported that emu oil demonstrated “profound anti-arthritic potency, in
some respects, resembling some of the powerful immunosuppressant drugs. . . for
rheumatoid arthritis” (p. 3). Considering that it is 8 years since Whitehouse et
al. reported these findings it is disappointing that more progress has not been
made in examining the medicinal properties of emu oil. One of the
recommendations from the study (3) suggested that further
investigation into the anti-inflammatory activity of emu oil should be
undertaken and that these studies should include human clinical trials at the
earliest opportunity.
Osteoarthritis
Osteoarthritis (OA) is a disease characterised by
biochemical, physical and histological abnormalities of cartilage and is the
leading cause of pain and disability in the community (6).
Radiological evidence suggests that changes of OA are present in more than 50%
of people over 65 years of age and almost 100% in people over 85 years (7).
The presence of inflammation appears to depend on the rapidity and severity of
the osteoarthritis (8).
Systemic Drugs
Paracetamol
is usually the analgesic of first choice because of its relatively low cost and
safety. NSAIDs are usually only considered if paracetamol is inadequate because
of associated gastric ulcer complications. COX-2 inhibitors (eg celecoxib
(Celebrex®)) have similar efficacy to conventional NSAIDS with lower incidence
of ulcer complications (9). However the side effects of inhibiting
prostaglandins’ role in cartilage repair may be detrimental in osteoarthritis.
The side effect of bone depletion in corticosteroid usage and the lack of
evidence of florid acute inflammation in OA, means that most practitioners are
reluctant to prescribe corticosteroids for long-term treatment of
osteoarthritis.
Glucosamine
sulphate is a non-prescription drug that has been shown to have a 20-25%
reduction of pain in patients with mild to moderate primary knee
osteoarthritis. It may also slow radiological progression of the disease (10).
Because emu
oil has been shown to have equivalent anti-inflammatory efficacy to NSAIDs and
corticosteroids in rats (2), and because no adverse side effects
have been reported with emu oil use, it has the potential to be effective in
treating osteoarthritis in humans.
Emu Oil and Osteoarthritis Trials
There have
been only two minor studies concerning emu oil and its effect on osteoarthritis
in humans. Neither has been published in scientific or medical journals.
One is a
preliminary project by Leahey from the Arthritis Clinic in
The second
is an unpublished study by Ghosh and Whitehouse and showed a reduction in both pain and swelling in all volunteers
suffering from arthritis after 17 days of consecutive topical emu oil
applications. No control group was included in this trial.
Both of
these studies were small clinical trials over relatively short time spans, and
the details of methods used to measure results were not mentioned. The results
gave some encouragement for further more rigorous scientific research.
This research project was undertaken
to consider the potential benefits the anti-inflammatory qualities of emu oil
may have for osteoarthritis sufferers.
Materials and Method
The trial
was a double blinded, placebo controlled study as recommended by Chevallier (11)
and was a six group repeated measures design with 120 participants.
Participants
The 120 volunteers were aged
between 47 and 87 with a mean age of 62. They were
recruited by advertising in “Update”, the Arthritis Foundation of Victoria
periodical, “The Herald Sun” newspaper and “Magic FM” radio station.
The
participants were volunteers with hand osteoarthritis diagnosed by a medical
practitioner. Volunteers with rheumatic diseases or other hand pathologies were
excluded from the trial.
Most of the participants were taking
medication for their arthritis and remained on the medication for the duration
of the trial. No participants had used emu oil in the 12 months prior to the
trial.
101
participants (79 female, 22 male) completed the trial.
Trial
Emu Spirit staff randomly allocated
participants to one of six groups: -
1.
Emu oil (Emu Spirit® Oil
of Emu) applied topically (twice/day for < 30sec). (Emu oil analysis –
App.1)
2.
Placebo oil (Crisco®
canola oil) applied topically. (Canola oil analysis App.2)
3.
Emu oil ingested (5ml twice/day). (This oil has
Therapeutic Goods Administration (TGA) listing as an ingestible product. App.3)
4.
Placebo oil ingested
5. Emu oil applied topically and ingested
6.
Placebo oil applied topically and
ingested
Researchers and
participants were blinded to group allocation. The taste and scent of the oils
was disguised by the addition of edible lime oil. At the initial meeting all
participants were shown how to apply or ingest the oil twice per day (morning
and evening) and how to fill in the Visual Analogue Scale (VAS), by the student
investigator.
Measures-
Pain
Pain was
self-measured before the morning application, on days 1, 7, 14, 21, 28, 35, 42,
49 and 56 with a pain Visual Analogue Scale (VAS) (App 4). The VAS was chosen
over other self-reported measures of pain because it is easy to administer,
requires no special training, and was likely to be correctly used by
participants even in the absence of specific direction from the researchers.
The VAS has acceptable test-retest reliability (r = 0.87) for assessment of
pain, and is an instrument with good validity, excellent reliability, moderate
distribution-based responsiveness and good anchor based responsiveness compared
to multi-item questionnaires (12). Use of the VAS was explained to
participants at the initial meeting. Measuring at the same time each day, before
the morning application, avoided the influence of massage and any immediate
effect from the topically applied emu oil. It also accounts for the influence
of normal circadian rhythms on pain.
Tender Joint Count (TJC)
Fourteen
joints on each hand were squeezed firmly. Any pain elicited meant a positive
reading for that joint (13).
50 of the participants (Wed. Group 1) self
assessed their joints at the beginning and end of the trial under supervision
of the student investigator. The remaining 43 were assessed by student
volunteers trained by the student investigator. Results were recorded on a
diagram depicting two hands (App.5) by the placing of an “X” on the circle
representing the tender joint. Both of these methods of evaluation are
considered valid and adequate for research use (13).
Grip Strength.
Grip strength was assessed at the initial and final meetings. Two
students were instructed in use of a grip dynamometer and supervised
participants. Right and left hand grip strength were tested and recorded. Test-retest
results for grip dynamometers are excellent with ICC >0.91 in all instances.
Hand-held myometry is easily performed in patients of various ages and muscle
strengths, is a reliable measure of limb muscle strength, and can be used in
longitudinal studies and clinical trials (14).
Statistical
Analysis
All
pre-post data were analysed using descriptive statistics and univariate
ANCOVAs, in which the baseline scores for each variable were used as the
respective covariate measures. Pain data was further analysed using a time
plot, and a repeated measure ANCOVA, also with baseline scores as covariate.
Repeated measures increase the statistical power of the analysis, but complicate
the interpretation of results because of the interaction effect of the repeated
measures (15). Repeated measures results are included for the
analysis of trends over time.
Results
Missing
data
19 of the
120 participants did not complete the trial. Of those people who completed the
trial, 13 did not complete both Grip Strength measurements, 2 did not complete
all Pain Scale readings and 7 did not complete both Tender Joint Counts. For
those that completed the trial any missing data was replaced with mean data for
that group.
Tender Joint Count
There was no significant reduction in the
tender joint count in those participants using emu oil compared to those using
the placebo.
Grip Strength
Grip strength results were mixed and overall there
were no significant differences between the emu oil users and the placebo
groups. Groups B & C emu oil users (both groups were ingesting the oil)
showed improvement in both right and left grip strength compared to the placebo
users whilst in group A the placebo users showed more improvement. Group C emu
oil users showed a significant improvement in grip strength on both left and
right hands of approximately 20%. The grip dynamometer was found to be giving
sporadically low readings at the second initial meeting. This was addressed by
testing the dynamometer prior to each reading after the discovery of the fault.
The sporadically low readings from the faulty grip dynamometer may have
adversely affected results.
Pain
In the first three weeks of the trial there
were no significant differences between the groups and the mean VAS recording
for the emu oil and placebo oil users at the end of week 3 was 3.95.
After week 3 the readings for emu oil users
gradually reduced until the final mean reading in week 8 of 2.57. The placebo
users’ readings continued to fluctuate and the final mean reading was 3.42.
These readings were shown to be statistically significant in the pairwise
comparison test with a medium to large effect size (p = 0.02, F = 2.68, h2 = 0.13). The largest between
groups difference occurred between group A placebo and emu oil subgroups where
the final reading for the emu oil users was 2.07 and for the placebo group,
3.79.
Discussion
Of the
group A participants that applied the oil topically only, those using emu oil
had consistently lower pain scores than the placebo users. A similar result did
not occur with group C participants who applied the oil topically and also
ingested the oil. Whilst all groups of emu oil users had downward trends in pain
scale readings after week 3, groups A and B results were more significant than
group C when compared to placebo. It is difficult to explain why both topical
application and ingestion of emu oil had a more significant effect on reduction
of pain when used alone than in combination. This result was unexpected and not
consistent with anecdotal evidence that supports the use of emu oil both
topically (for faster relief) and ingested (for longer term relief).
There was
no significant difference in Tender Joint Count (TJC) readings between the emu
oil users and the placebo group. This finding was not unexpected as there was
no grading of tenderness but a simple affirmative or negative to any pain
elicited by the pressure applied. It is probable that emu oil is having an
effect on one of the symptoms of arthritis (pain) but not on the status of
arthritis.
In earlier trials, Whitehouse et al. (5) concluded that topical application (in rats) was more effective at reducing swelling than ingestion (though in this trial there was nothing to stop the rats from licking the topically applied oil). It was also shown that emu oil was more effective in rats when applied topically with a transdermal carrier, such as salicylate or eucalyptus oil to enhance skin permeation (4). In this human trial the authors used pure emu oil to rule out any effect from the transdermal carrier. The massage time was limited to less than 30 seconds so that the effect from the massage
was also limited. Topically applied emu oil treatment may be more successful if the oil was combined with a transdermal carrier and was massaged more thoroughly into the skin. This is more relevant when the oil is more viscous as is the case during cold weather.
40% of the
trial participants were taking NSAIDs (including COX-2 inhibitors). Vioxx®
has now been withdrawn from retail because of an apparent increased
cardiovascular risk. Recent research (CLASS trial) as reported by Fitzgerald (16)
suggests that celecoxib (Celebrex®) did not differ from the
traditional NSAIDs in its effect on the predefined gastrointestinal end points.
Neither has it been exonerated from increasing cardiovascular risk. The
non-specific NSAIDs cause gastric irritation in many patients. This combination
of factors means that for some patients, emu oil may be a welcome alternative
for treating pain associated with osteoarthritis.
Glucosamine
sulphate taken orally for 3 months at a dose of 1500mg per day has been shown
to be effective in reducing pain and slowing progression of mild to moderate
osteoarthritis. Topical application may also be effective in reducing pain from
the disease (9) OA sufferers may benefit from a combination of emu
oil and glucosamine sulphate either taken orally or applied topically. Further
research would be helpful to determine this.
In a 4 week
trial by McCarthy & McCarthy (17) a capsaicin cream produced a
40% reduction in arthritic pain when compared to a placebo. A preparation
combining emu oil and capsaicin may prove to be beneficial as a topical cream.
Pain was
the measurement that showed statistically significant positive results for emu
oil compared to the placebo. Because pain readings were still on a downward
trend for the emu oil users at the completion of the trial, it would have been
beneficial
to run a longer trial to ascertain
the longer term effect on pain reduction by the emu oil.
Since the
completion of the trial 5 participants have communicated with the student
researcher to comment on post-trial effects. All had been on the placebo during
the trial and had commenced using the emu oil post-trial. Each reported a
reduction in pain, one claiming complete relief. Another reported some relief
in hand pain but more substantial relief in pain from an osteoarthritic knee.
This is consistent with other anecdotal claims that prompted this research.
Whitehouse et al. (5) revealed a large variation in anti-inflammatory activity of different samples of emu oil. Some possible influences included genetic background, nutrition, bird age and the type of rendering process used. It would be prudent in future studies to have emu oil tested for efficacy prior to the trial. Research at Adelaide Royal Women’s and Children’s Hospital by Ferrante has been trying to develop a simple and effective method to identify the anti-inflammatory potency of the oil but as yet has not been successful. It would be helpful if eventually all retailed emu oil had a labelling system to identify anti-inflammatory potency.
It could
reasonably be argued that the positive effect that emu oil has on reducing pain
in hand osteoarthritis is due to its anti-inflammatory qualities. If this is
true then it is probable that emu oil is more effective on osteoarthritis
sufferers that have more extensive joint inflammation. Because other forms of
joint disease such as rheumatoid arthritis generally display more signs of
inflammation than osteoarthritis, it is probable that emu oil may be more
effective in reducing pain in these arthritides.
Clinical Relevance
Emu oil,
consistently ingested or topically applied may be effective in reducing pain in
osteoarthritis sufferers after 3 weeks. Topical applications of emu oil may be
a more effective treatment for osteoarthritis when combined with other products
such as glucosamine and capsaicin. Heating emu oil reduces its viscosity,
making it easier to ingest, particularly in cold weather when the oil thickens.
Emu oil is
an animal product and therefore likely to be unacceptable to vegetarians.
Acknowledgements
Thank you
to Emu Spirit® for supplying the emu oil used in the trial, for
allocating patients to groups, for paying the cost of advertising and for
assisting with administrative chores such as answering phones and sending out
information to participants.
Thank you
to Crisco® for supplying the canola oil used as a placebo.
References
1 Bennett G, Observations principally on the
animal and vegetable products of
2 Snowden J, O'Malley P. & Ellis T. Emu
oil. Its anti-inflammatory properties. Rural Ind R & D Corp 1999; RIRDC Research
Paper No 97
3 Whitehouse M, Turner A, Davis C. &
Roberts M. Emu oil(s): A source of non-toxic transdermal anti-inflammatory
agents in aboriginal medicine. Inflammopharmacology 1998; Ju:1-7.
4 Ghosh P. & Whitehouse M. Experimental
study to determine the anti-arthritic activity of a new emu oil formulation
(EEMP) Am Emu Ass News;1993.
5 Whitehouse M, Ghosh P. & Turner A. Concerning
emu oil and its potential anti-arthritic activity. 5th Qld Poultry
Symp. (Presentation); Jul 1996.
6 1995 National health survey.
7 Felson D, Zhang Y. An update on the
epidemiology of knee and hip osteoarthritis with a view to prevention. Arthritis
Rheum1998; 41:1343-1355.
8 Altman R. & Gray R. Inflammation in
osteoarthritis. Clin Rheum Dis 1985;11(2):353-65.
9 Grainger R. & Cicuttini F., Medical
management of osteoarthritis of the knee and hip joints. Med J Aust 2004;180:232-236.
10 Pavelka K, Gatterova J, Olejarova M. et al. Glucosamine
sulphate use delays progression of knee osteoarthritis. A three year randomised
placebo-controlled, double-blind study. Arch
Intern Med 2002;162:2113-2123.
11 Chevalier X, Mejjad O. & Babini S. Methodology
for the assessment of treatments in hand osteoarthritis. Osteoarthritis Cart
2000;8(Suppl.A):S70-72.
12 deBoer AG, van Lanschot JJ, Stalmeier JB,
PF, van Sandick JW, Hulscher de Haes JC, Sprangers MA Is a single-item visual
analogue scale as valid reliable and responsive as multi-item scales in
measuring quality of life? Qual Life Res 2004; 13(2):311-20
13 Houssien D, Stucki G. & Scott D. A
patient derived disease activity score can substitute for a physician-derived
disease activity score in clinical research. Rheumatology 1999;38:48-52.
14 Merlini L, Mazzone ES, Solari A, Morandi L. Reliability of hand-held dynamometry in spinal muscular atrophy. Muscle Nerve. 2002;26(1):64-70. 15 Huck SW, & McLean RA. Using the repeated measures ANOVA
to analyze the data from a pretest-posttest design: A potentiallyconfusing task. Psychol Bull 1975;82:511-518.
16 FitzGerald AF. Coxibs and cardiovascular
disease. N Eng J Med 2004; 351:1709-1711.
17 McCarthy GM & McCarthy
DJ. Effect of topical capsaicin in the
therapy of painful osteoarthritis of the hands. J Rheumatol 1992;19:604-7
Figure 1: Mean Visual Analogue Scale
(VAS) readings for emu oil and placebo oil users over 8 weeks.
Appendix 1
Food Laboratories (Aust.) Pty
Ltd
Sample:
Emu Oil
Batch No: ES031203
Tested On:
Report No: 283690
Moisture 0.1
%
Acid Value 0.5
Peroxide value 1.7 meq O2/kg
Refractive Index 1.4635
Weight per mL 0.910
g/mL
Saponification Value 195.6
Ester Value 195.1
Totox Value 9.1
Iodine Value 64.1
Fatty Acid Profile:
C12:0 0.1
%
C14:0 0.4
%
C16:0 24.0
%
C16:1 4.4
%
C18:0 10.3
%
C18:1 51.0
%
C18:2 9.2
%
C18:3 less
than 0.1 %
C20:0 0.2
%
C20:1 0.4
%
Microbiological
Analysis:
standard plate count per mL (72h at 30°C) less than 10
standard plate count per mL (5 days at 20°C) less than 10
Testing performed by chemist
G.M. Brown, B.App.Sc. M.R.A.C.I,
Appendix
2
Crisco® Canola oil specifications:
Quantity per 100 ml
Protein
0.0g
-saturated
8g
-trans 0.8g
-polyunsaturated 27.6
-monounsaturated. 55.6g
Cholesterol Nil
Carbohydrate 0.0g
Sugars 0.0g
Sodium 0mg
All specified values are
averages.
Appendix 3
Therapeutic Goods Administration
listing
Emu Spirit – Omega 369 Oil of Emu Capsules
ELF ID: 33057-23/08/2002-OE728-1
Item [27] Listing of Coded Indications
|
|
Code |
Description |
|
1 |
ARTH1 |
Temporary relief of pain on arthritis (or) temporary relief
of arthritic pain. [Warning S required] * |
|
2 |
ARTH2 |
May help reduce joint inflammation associated with
arthritis |
* Warning S: If symptoms persist, seek medical advice
Appendix 4
Visual Analogue Scale – to be completed on Friday mornings.
Please plot on the line the
amount of pain that you are experiencing in the hands now.
I________________________________________________I
No pain Worst possible pain
