The study, published in the Journal of Alternative and Complementary Medicine, presented a systematic review of existing research on whole-system naturopathic medicine with multiple modalities (or clinical techniques).
Australian naturopaths use nutritional medicine, herbal medicine and tactile therapies as their modalities, while the World Naturopathic Federation has identified seven core modalities: clinical nutrition and diet modification/counselling; applied nutrition (use of dietary supplements, traditional medicines, and natural health care products), herbal medicine, lifestyle counselling, hydrotherapy, homeopathy, and physical modalities (including yoga, naturopathic manipulation, and muscle release techniques).
The published study comes at an important time for Aussie naturopaths, after the government cancelled private health insurance rebates for their services.
Over the course of a year, the researchers, led by adjunct professor Stephen P Myers, assessed academic papers on human studies that evaluated the effectiveness of naturopathic medicine.
They subsequently identified 33 studies involving 9,859 participants — 11 of the studies had been conducted in the US, four in Canada, six in Germany, seven in India, three in Australia, and one each in the UK and Japan.
They then wrote that the studies "predominantly showed evidence for the efficacy of naturopathic medicine for the conditions and settings in which they were based".
"To date, research in whole-system, multi-modality naturopathic medicine shows that it is effective for treating cardiovascular disease, musculoskeletal pain, type 2 diabetes, polycystic ovary syndrome (PCOS), depression, anxiety, and a range of complex chronic conditions."
When it came to naturopathic medicine's impact on cardiovascular disease, the researchers found that naturopathic treatment led to a 'clinically significant benefit' for the treatment of hypertension, reduction in metabolic syndrome parameters, and improved post-surgery cardiac outcomes.
They also reported that treatment of type 2 diabetes patients with naturopathic medicine resulted in significantly lower levels of HbA1c (glycated haemoglobin).
Furthermore, naturopathic treatment was said to have "decreased pain scores to a degree comparable to or better than standard care or other active treatment controls" in patients with musculoskeletal pain, and also reduced the severity of anxiety and depression in participants.
At the same time, two of the Indian studies showed "significant positive results for 'intensive inpatient naturopathic treatment' of asthma in lung function parameters".
However, the researchers also acknowledged several limitations of their study — one of these was that the range of study types, assessed outcomes, treatment settings and modalities used meant there was no specific analysis of the effectiveness of naturopathic treatment conducted.
The researchers noted that the global naturopathic research landscape contained a small but growing body of practice-based, whole-system, multi-modality research, adding that the generally positive results across world regions for similar conditions likely reflected the global consistency in applying the "core concepts of naturopathic practice, utilising the common set of naturopathic modalities".
However, they also wrote that there was a "distinct lack" of pragmatic trials assessing the complex intervention of such naturopathic care.
They also highlighted the need for pragmatic, real-world trials that would compare complex naturopathic treatment to usual care, in order to build a high-quality evidence base on the effectiveness of whole-system, multi-modality naturopathic practice.
Myers told NutraIngredients-Asia: "This study clearly shows that research on whole-system naturopathic medicine is effective on a broad range of chronic conditions. This type of research assesses naturopathic medicine as a health discipline and gathers data about what happens in clinical practice.
"While the study did not assess individual treatments or specific supplements, it is important to note that evidence on the effectiveness of specific dietary supplements and herbal medicines is also evidence that supports the practice of naturopathic medicine.
"These supplements are part of the 'tools of the trade' of naturopathic clinicians, and form the second pillar of evidence for the effectiveness of the discipline."
Unsure about insurance
Myers had strong words for the Australia Department of Health, which recommended the removal of health insurance rebates for naturopathic medicine and other natural therapies.
He said this decision was based on a "very limited review" conducted by the National Health and Medical Research Council (NHMRC), which found no evidence to support any need for naturopathy.
"Our study was undertaken to do what the NHMRC should have done. They limited their review to systematic reviews, which are studies that summate research in a given field. Not finding these reviews led them to draw an erroneous conclusion that there was no evidence supporting a range of natural therapies.
"The NHMRC should have looked at individual studies and drawn their conclusions from the primary sources. Conventional medicine professionals would consider assessing its effectiveness in such a limited method to be ludicrous, and it should also be considered ludicrous for assessing naturopathic medicine."
He added that since his team had demonstrated the error of the NHMRC's conclusion, the Australian government had "no grounds on which to restrict health insurance rebates" for naturopathic medicine.
"It's highly possible that the conclusion drawn by the NHMRC about many of the other natural therapies that will be excluded (from health insurance rebates) from April 1 is also erroneous," he added.