For this blog, I am constantly on the lookout for ‘positive news’ about alternative medicine. Admittedly, I rarely find any.
All the more delighted I was when I found this new study aimed to analyse the association between dietary long-chain n-3 polyunsaturated fatty acids (PUFAs) and incidence of rheumatoid arthritis (RA) in middle-aged and older women.
Data on diet were collected in 1987 and 1997 via a self-administered food-frequency questionnaire (FFQ). The risk of RA associated with dietary long-chain n-3 PUFAs and fish intake was estimated using Cox proportional hazard regression models, adjusted for age, cigarette smoking, alcohol intake, use of aspirin and energy intake.
The results show that, among 32 232 women born 1914–1948, 205 RA cases were identified during a mean follow-up of 7.5 years. An intake of dietary long-chain n-3 PUFAs (FFQ1997) of more than 0.21 g/day (lowest quintile) was associated with a 35% decreased risk of developing RA compared with a lower intake. Long-term intake consistently higher than 0.21 g/day (according to both FFQ1987 and FFQ1997) was associated with a 52% decreased risk. Consistent long-term consumption (FFQ1987 and FFQ1997) of fish ≥1 serving per week compared with<1 was associated with a 29% decrease in risk.
The authors concluded that this prospective study of women supports the hypothesis that dietary intake of long-chain n-3 PUFAs may play a role in aetiology of RA.
These are interesting findings which originate from a good investigation and which are interpreted with the necessary caution. As all epidemiological data, this study is open to a number of confounding factors, and it is therefore impossible to make firm causal inferences. The results thus do not led themselves to clinical recommendation, but they are an indication that more definitive research is warranted, all the more so since we have plausible mechanisms to explain the observed findings.
A most encouraging development for alternative medicine, one could conclude. But is this really true? Most experts would be surprised, I think, to find that PUFA-consumption should fall under the umbrella of alternative medicine. Remember: What do we call alternative medicine that works? It is called MEDICINE!
Linus Carl Pauling (1901 – 1994), the American scientist, peace activist, author, and educator who won two Nobel prizes, was one of the most influential chemists in history and ranks among the most important scientists of the 20th century. Linus Pauling’s work on vitamin C, however, generated considerable controversy. Pauling wrote many papers and a popular book, Cancer and Vitamin C. Vitamin C, we know today, protects cells from oxidative DNA damage and might thereby block carcinogenesis. Pauling popularised the regular intake of vitamin C; eventually he published two studies of end-stage cancer patients; their results apparently showed that vitamin C quadrupled survival times. A re-evaluation, however, found that the vitamin C groups were less sick on entry to the study. Later clinical trials concluded that there was no benefit to high-dose vitamin C. Since then, the established opinion is that the best evidence does not support a role for high dose vitamin C in the treatment of cancer. Despite all this, high dose IV vitamin C is in unexpectedly wide use by CAM practitioners.
Yesterday, new evidence has been published in the highly respected journal ‘Nature’; does it vindicate Pauling and his followers?
Chinese oncologists conducted a meta-analysis to assess the association between vitamin C intake and the risk to acquire lung cancer. Pertinent studies were identified by a searches of several electronic databases through December of 2013. Random-effect model was used to combine the data for analysis. Publication bias was estimated using Begg’s funnel plot and Egger’s regression asymmetry test.
Eighteen articles reporting 21 studies involving 8938 lung cancer cases were included in this meta-analysis. Pooled results suggested that highest vitamin C intake level versus lowest level was significantly associated with the risk of lung cancer. The effect was largest in investigations from the United States and in prospective studies. A linear dose-response relationship was found, with the risk of lung cancer decreasing by 7% for every 100 mg/day increase in the intake of vitamin C . No publication bias was found.
The authors conclude that their analysis suggested that the higher intake of vitamin C might have a protective effect against lung cancer, especially in the United States, although this conclusion needs to be confirmed.
Does this finding vindicate Pauling’s theory? Not really.
Even though the above-quoted conclusions seem to suggest a causal link, we are, in fact, far from having established one. The meta-analysis pooled mainly epidemiological data from various studies. Such investigations are doubtlessly valuable but they are fraught with uncertainties and cannot prove causality. For instance, there could be dozens of factors that have confounded these data in such a way that they produce a misleading result. The simplest explanation of the meta-analytic results might be that people who have a very high vitamin C intake tend to have generally healthier life-styles than those who take less vitamin C. When conducting a meta-analysis, one does, of course, try to account for such factors; but in many cases the necessary information to do that is not available, and therefore uncertainty persists.
In other words, the authors were certainly correct when stating that their findings needed to be confirmed. Pauling’s theory cannot be vindicated by such reports – in fact, the authors do not even mention Pauling with one word.
Tai Chi has been suggested to have many health benefits. Might it even prolong life? There are many enthusiasts who claim just that, but is there any evidence?
This study is a retrospective cross-sectional investigation to compare the rejuvenating and anti-ageing effects among a Tai Chi group (TCC) and a brisk walking group (BW) and a no exercise habit group (NEH) of volunteers. Thirty-two participants were separated into three groups: the TCC group (practicing TC for more than 1 year), the BW group (practicing BW for more than 1 year), and the NEH group. The CD34+ cell counts in peripheral blood of the participants was determined, and the Kruskal‐Wallis test was used to evaluate and compare the antiaging effects of the three groups. The results show that the participants in the TCC group (N = 10) outperformed the NEH group (N = 12) with respect to the number of CD34+ progenitor cells. No significant difference was found between the TCC group and the BW group. The authors of this study conclude that TCC practice sustained for more than 1 year may be an intervention against aging as effective as BW in terms of its benefits on the improvement of CD34+ number.
I was alerted to this new paper by several rather sensational headlines in the daily press which stated that Tai chi (TC) had anti-aging effects. So I searched for the press release about the article where I found the following quotes:
“It is possible that Tai Chi may prompt vasodilation and increase blood flow,” said Lin. “Considering that BW may require a larger space or more equipment, Tai Chi seems to be an easier and more convenient choice of anti-aging exercise.” “This study provides the first step into providing scientific evidence for the possible health benefits of Tai Chi.” said Dr. Paul R. Sanberg, distinguished professor at the Center of Excellence for Aging and Brain Repair, Morsani College of Medicine, University of South Florida, Tampa, FL. “Further study of how Tai Chi can elicit benefit in different populations and on different parameters of aging are necessary to determine its full impact.”
Personally, I find both the press release and the original conclusions of the authors quite amazing. If anyone wanted to write a textbook on how not to do such things, he/she could use them as excellent examples.
Seen with just a tinge of critical thinking the paper reports a flimsy case-control study comparing three obviously self-selected groups of people who had chosen to follow different exercise regimen for several months. In all likelihood they also differed in terms of life-style, nutrition, sleeping pattern, alcohol intake, smoking habits and a million other things. These rather tiny groups were then compared according to a surrogate measure for ageing and some differences were identified.
To conclude from this, or even to imply, that TC has anti-ageing effects is as far-fetched as claiming the tooth fairy has money problems.
This story could be just funny or trivial or boring – however, I think, it is also a bit worrying. It shows, I fear, how uncritical researchers in conjunction with some naïve press officer are able to induce silly journalists and headline-writers to mislead the public.
After a traumatic brain injury (TBI) the risk of stroke is significantly increased. Taiwanese researchers conducted a study to find out whether acupuncture can help to protect TBI patients from stroke. They used Taiwan’s National Health Insurance Research Database to conduct a retrospective cohort study of 7409 TBI patients receiving acupuncture treatment and 29,636 propensity-score-matched TBI patients without acupuncture treatment as controls. Both TBI cohorts were followed for up to two years and adjusted for immortal time to measure the incidence and adjusted hazard ratios (HRs) of new-onset stroke.
TBI patients with acupuncture treatment (4.9 per 1000 person-years) had a lower incidence of stroke compared with those without acupuncture treatment (7.5 per 1000 person-years), with a HR of 0.59 (95% CI = 0.50-0.69) after adjustment for sociodemographics, coexisting medical conditions and medications. The association between acupuncture treatment and stroke risk was investigated by sex and age group (20-44, 45-64, and ≥65 years). The probability curve with log-rank test showed that TBI patients receiving acupuncture treatment had a lower probability of stroke than those without acupuncture treatment during the follow-up period (p<0.0001).
The authors conclude that patients with TBI receiving acupuncture treatment show decreased risk of stroke compared with those without acupuncture treatment. However, this study was limited by lack of information regarding lifestyles, biochemical profiles, TBI severity, and acupuncture points used in treatments.
I want to congratulate the authors for adding the last sentence to their conclusions. There is no plausible mechanism that I can think of by which acupuncture might bring about the observed effect. This does not mean that an effect does not exist; it means, however, that it is wise to be cautious and to not jump to conclusions which later need to be revised. The simplest interpretation, by far, of the observed phenomenon is that those patients opting to have acupuncture were, on average, less ill and therefore had a lower risk of stroke.
Having said that, the findings are, I think, intriguing enough to conduct further investigations – provided they are rigorous and eliminate the confounders that prevented this study from arriving at more definitive conclusions.
The news that the use of Traditional Chinese Medicine (TCM) positively affects cancer survival might come as a surprise to many readers of this blog; but this is exactly what recent research has suggested. As it was published in one of the leading cancer journals, we should be able to trust the findings – or shouldn’t we?
The authors of this new study used the Taiwan National Health Insurance Research Database to conduct a retrospective population-based cohort study of patients with advanced breast cancer between 2001 and 2010. The patients were separated into TCM users and non-users, and the association between the use of TCM and patient survival was determined.
A total of 729 patients with advanced breast cancer receiving taxanes were included. Their mean age was 52.0 years; 115 patients were TCM users (15.8%) and 614 patients were TCM non-users. The mean follow-up was 2.8 years, with 277 deaths reported to occur during the 10-year period. Multivariate analysis demonstrated that, compared with non-users, the use of TCM was associated with a significantly decreased risk of all-cause mortality (adjusted hazards ratio [HR], 0.55 [95% confidence interval, 0.33-0.90] for TCM use of 30-180 days; adjusted HR, 0.46 [95% confidence interval, 0.27-0.78] for TCM use of > 180 days). Among the frequently used TCMs, those found to be most effective (lowest HRs) in reducing mortality were Bai Hua She She Cao, Ban Zhi Lian, and Huang Qi.
The authors of this paper are initially quite cautious and use adequate terminology when they write that TCM-use was associated with increased survival. But then they seem to get carried away by their enthusiasm and even name the TCM drugs which they thought were most effective in prolonging cancer survival. It is obvious that such causal extrapolations are well out of line with the evidence they produced (oh, how I wished that journal editors would finally wake up to such misleading language!) .
Of course, it is possible that some TCM drugs are effective cancer cures – but the data presented here certainly do NOT demonstrate anything like such an effect. And before such a far-reaching claim is being made, much more and much better research would be necessary.
The thing is, there are many alternative and plausible explanations for the observed phenomenon. For instance, it is conceivable that users and non-users of TCM in this study differed in many ways other than their medication, e.g. severity of cancer, adherence to conventional therapies, life-style, etc. And even if the researchers have used clever statistical methods to control for some of these variables, residual confounding can never be ruled out in such case-control studies.
Correlation is not causation, they say. Neglect of this elementary axiom makes for very poor science – in fact, it produces dangerous pseudoscience which could, like in the present case, lead a cancer patient straight up the garden path towards a premature death.
Research is essential for progress, and research in alternative medicine is important for advancing alternative medicine, one would assume. But why then do I often feel that research in this area hinders progress? One of the reasons is, in my view, the continuous drip, drip, drip of misleading conclusions usually drawn from weak studies. I could provide thousands of examples; here is one recently published article chosen at random which seems as good as any other to make the point.
Researchers from the Department of Internal and Integrative Medicine, Faculty of Medicine, University of Duisburg-Essen, Germany set out to investigate associations of regular yoga practice with quality of life and mental health in patients with chronic diseases. Using a case-control study design, 186 patients with chronic diseases who had elected to regularly practice yoga were selected and compared to controls who had chosen to not regularly practice yoga. Patients were matched individually on gender, main diagnosis, education, and age. Patients’ quality of life, mental health, life satisfaction, and health satisfaction were also assessed. The analyses show that patients who regularly practiced yoga had a significantly better general health status, a higher physical functioning, and physical component score on the SF-36 than those who did not.
The authors concluded that practicing yoga under naturalistic conditions seems to be associated with increased physical health but not mental health in chronically diseased patients.
Why do I find these conclusions misleading?
In alternative medicine, we have an irritating abundance of such correlative research. By definition, it does not allow us to make inferences about causation. Most (but by no means all) authors are therefore laudably careful when choosing their terminology. Certainly, the present article does not claim that regular yoga practice has caused increased physical health; it rightly speaks of “associations“. And surely, there is nothing wrong with that – or is there?
Perhaps, I will be accused of nit-picking, but I think the results are presented in a slightly misleading way, and the conclusions are not much better.
Why do the authors claim that patients who regularly practiced yoga had a significantly better general health status, a higher physical functioning, and physical component score on the SF-36 than those who did not than those who did not? I know that the statement is strictly speaking correct, but why do they not write that “patients who had a significantly better general health status, a higher physical functioning, and physical component score on the SF-36 were more likely to practice yoga regularly”? After all, this too is correct! And why does the conclusion not state that better physical health seems to be associated with a greater likelihood of practicing yoga?
The possibility that the association is the other way round deserves serious consideration, in my view. Is it not logical to assume that, if someone is relatively fit and healthy, he/she is more likely to take up yoga (or table-tennis, sky-diving, pole dancing, etc.)?
It’s perhaps not a hugely important point, so I will not dwell on it – but, as the alternative medicine literature is full with such subtly misleading statements, I don’t find it entirely irrelevant either.
Ignaz von Peczely (1826-1911), a Hungarian physician, got the idea for iridology (or iris-diagnosis) more than a century ago, after seeing streaks in the iris of a man he was treating for a broken leg, and similar phenomena the iris of an owl whose leg von Peczely had broken many years before. He subsequently became convinced that his method was able to distinguish between healthy organs and those that are overactive, inflamed, or distressed. Iridology became internationally known when US chiropractors began adopting this method in their clinical practice. In the United States, most insurance programs do not cover iridology but, in some European countries, they often do. In Germany, for instance, 80% of the Heilpraktiker (non-medically qualified health practitioners) practice iridology.
Iridologists claim to be able to diagnose the health status of an individual, medical conditions or predispositions to disease through abnormalities of pigmentation in the iris. The popularity of iridology renders it necessary to ask whether this method is valid.
The aim of my systematically review from 1999 was to critically evaluate all available, reliable tests of iridology as a diagnostic tool. Four case control studies were included; these are investigations where iridologists are asked to tell by looking at the iris of individuals whether that person does or does not have a certain condition. The majority of these studies suggested that iridology is not a valid diagnostic method. Back then, I concluded that “the validity of iridology as a diagnostic tool is not supported by scientific evaluations. Patients and therapists should be discouraged from using this method.”
Since the publication of my article, several further studies have emerged:
One German team conducted a study investigating the applicability of iridology as a screening method for colorectal cancer. Digital color slides were obtained from both eyes of 29 patients with histologically diagnosed colorectal cancer and from 29 age- and gender-matched healthy control subjects. The slides were presented in random order to acknowledged iridologists without knowledge of the number of patients in the two categories. The iridologists correctly detected 51.7% and 53.4%, respectively, of the patients’ slides; therefore, the likelihood was statistically no better than chance. Sensitivity was, respectively, 58.6% and 55.2%, and specificity was 44.8% and 51.7%. The authors’ conclusion was blunt: “Iridology had no validity as a diagnostic tool for detecting colorectal cancer in this study.”
A study from South Africa aimed to determine the efficacy of iridology in the identification of moderate to profound sensorineural hearing loss in adolescents. A controlled trial was conducted with an iridologist, blind to the actual hearing status of participants, analysing the irises of participants with and without hearing loss. Fifty hearing impaired and fifty normal hearing subjects, between the ages of 15 and 19 years, controlled for gender, participated in the study. An experienced iridologist analysed the randomised set of participants’ irises. A 70% correct identification of hearing status was obtained with a false negative rate of 41% compared to a 19% false positive rate. The respective sensitivity and specificity rates therefore were 59% and 81%. The authors of this investigation concluded that “iridological analysis of hearing status indicated a statistically significant relationship to actual hearing status (P < 0.05). Although statistically significant sensitivity and specificity rates for identifying hearing loss by iridology were not comparable to those of traditional audiological screening procedures.”
A further German study investigated the value of iridology as a diagnostic tool in detecting some common cancers. One hundred ten subjects were enrolled; 68 subjects had histologically proven cancers of the breast, ovary, uterus, prostate, or colorectum, and 42 were cancer-free controls. All subjects were examined by an experienced practitioner of iridology, who was unaware of their medical details. He was allowed to suggest up to five diagnoses for each subject and his results were then compared with each subject’s medical diagnosis to determine the accuracy of iridology in detecting malignancy. Iridology identified the correct diagnosis in only 3 cases (sensitivity, 0.04). The authors concluded that “iridology was of no value in diagnosing the cancers investigated in this study.”
Based on these results it is impossible, I think, to claim that iridology is a valid or useful diagnostic tool. As there is no anatomical or physiological basis for its assumptions, iridology is not biologically plausible. Furthermore, the available clinical evidence does not support its validity as a diagnostic tool. In other words, iridology is bogus. This statement is in sharp contract to the information consumers receive about the method on uncounted websites, books, articles, etc. One website picked at random provides the following information:
The iris reveals changing conditions of every part and organ of the body. Every organ and part of the body is represented in the iris in a well defined area. In addition, through various marks, signs, and discoloration in the iris, nature reveals inherited weaknesses and strengths.
By means of this art / science, an iridologist (one who studies the coloration and fiber structure of the eye) can tell an individual his/her inherited and acquired tendencies towards health and disease, his current condition in general, and the state of every organ in particular.
Iridology cannot detect a specific disease, but, can tell an individual if they have over or under activity in specific areas of the body. For example, an under-active pancreas might indicate a diabetic condition.
Another source claims:
The underlying platform of iridology is that that eyes act as a ‘window’ to a person’s health & well being. This ‘window’ enables the practitioner to see whether areas or organs within the body are healthy, inflamed or ‘over active’. It also enables them to assess a person’s past/ possible future health problems & consider if the patient has a susceptibility to certain diseases. It is important to understand that iridology is simply a method of diagnosis & analysis.
You may well think that none of this really matters. Who cares whether iridology is bogus or not! I would argue that it does matter. Bogus methods cost money that could be better spent elsewhere. More importantly, false positive and false negative diagnoses generated by bogus diagnostic methods can put lives at risk.
But there is a more general and perhaps more crucial point here: alternative medicine is an area where people far too easily get away with ignoring the published evidence and scientific consensus. In the last two decades, I have seen many alternative modalities getting scientifically dis-proven; not in a single such instance can I remember that the corresponding alternative practitioners and their professional organisations took any notice of this fact, and not once did I notice that their practice had changed.
If research is systematically ignored, it becomes a useless appendix. More importantly, progress is then stifled to the detriment of all our best interests.