People coping with cancer often look to natural therapies to complement conventional medical treatments. But how do we know what can really help and what may cause us harm?
In his book, Complementary Therapies for Cancer, Professor Shaun Holt sets out why we should make these important health choices based on good medical research, not anecdotes.
Holt holds honours degrees in pharmacy and medicine and is a New Zealand-based doctor, researcher, author, commentator, speaker and adviser. He has been the principal investigator in more than 50 clinical trials.
Cancer patients' symptoms can include stress, anxiety, pain, nausea, fatigue and depression and many ask their doctors to recommend something to help ease the problems.
Holt says he was sceptical about natural therapies before he began researching his first book, Natural Remedies That Really Work. After it was published in 2008, he was inundated with questions about therapies for cancer.
Holt spent two years researching Complementary Therapies for Cancer, assessing papers from medical journals. He found that when he looked into natural therapies, hidden among the nonsense were useful evidence-based treatments.
"By that, I mean supported by good research. The book is not based on my opinions but is an interpretation of what medical literature says."
Holt emphasises that natural therapies cannot cure cancer and are useful only in complementing conventional treatment.
Most of the book is divided into two chapters, "What Works" and "What Doesn't Work".
Holt classifies therapies into:
* Alternative medical systems
* Manipulative and body-based systems
* Mind-body interventions
* Biologically based therapies, and
* Energy therapies.
He uses stars to rate therapies that work, and crosses for those that don't. Therapies such as massage and yoga get three stars, so are highly recommended. Two stars means a remedy is worth considering.
On the other hand, three crosses means a therapy should definitely be avoided. One of these is colonic irrigation, which Holt says has no scientific evidence of any health benefits but can cause infection and even death.
Many studies have been done on the benefits of yoga for women with breast cancer. It has been found to improve many aspects of quality of life and general health, including social functioning, sleep and fatigue.
Holt says he wrote the book for patients in his usual chatty style, but it's become a textbook for GPs and oncologists.
In his latest book, Depression - Natural Remedies That Really Work, he makes the case that natural remedies are better than antidepressants, which he says is a big call but is based on scientific research.
* Shaun Holt's books are available from major booksellers and through his website.