Antioxidant vitamins include vitamin E, beta-carotene, and vitamin C. They are often recommended and widely used for preventing major cardiovascular outcomes. However, the effect of antioxidant vitamins on cardiovascular events remains unclear. There is plenty of evidence but the trouble is that it is not always of high quality and confusingly contradictory. Consequently, it is possible to cherry-pick the studies you prefer in order to come up with the answer you like. That this approach is counter-productive should be obvious to every reader of this blog. Only a rigorous systematic review can provide an answer that is as reliable as possible with the data available to date. Chinese researchers have just published such an assessment.
They searched PubMed, EmBase, the Cochrane Central Register of Controlled Trials, and the proceedings of major conferences for relevant investigations. To be eligible, studies had to be randomized, placebo-controlled trials reporting on the effects of antioxidant vitamins on cardiovascular outcomes. The primary outcome measures were major cardiovascular events, myocardial infarction, stroke, cardiac death, total death, and any adverse events.
The searches identified 293 articles of which 15 RCTs reporting data on 188209 participants met the inclusion criteria. In total, these studies reported 12749 major cardiovascular events, 6699 myocardial infarction, 3749 strokes, 14122 total death, and 5980 cardiac deaths. Overall, antioxidant vitamin supplementation, as compared to placebo, had no effect on major cardiovascular events (RR, 1.00; 95% CI, 0.96-1.03), myocardial infarction (RR, 0.98; 95% CI, 0.92-1.04), stroke (RR, 0.99; 95% CI, 0.93-1.05), total death (RR, 1.03; 95% CI, 0.98-1.07), cardiac death (RR, 1.02; 95% CI, 0.97-1.07), revascularization (RR, 1.00; 95% CI, 0.95-1.05), total CHD (RR, 0.96; 95% CI, 0.87-1.05), angina (RR, 0.98; 95% CI, 0.90-1.07), and congestive heart failure (RR, 1.07; 95% CI, 0.96 to 1.19).
The authors’ conclusion from these data could not be clearer: Antioxidant vitamin supplementation has no effect on the incidence of major cardiovascular events, myocardial infarction, stroke, total death, and cardiac death.
Few subjects in the realm of nutrition have attracted as much research during recent years as did antioxidants, and it is hard to think of a disease for which they are not recommended by this expert or another. Cardiovascular disease used to be the flag ship in this fleet of conditions; not so long ago, even the conventional medical wisdom sympathized with the notion that the regular supplementation of our diet with antioxidant vitamins might reduce the risk of cardiovascular disease and mortality.
Today, the pendulum has swung back, and it now seems to be mostly the alternative scene that still swears by antioxidants for that purpose. Nobody doubts that antioxidants have important biological functions, but this excellent meta-analysis quite clearly and fairly convincingly shows that buying antioxidant supplements is a waste of money. It does not promote cardiovascular health, it merely generates very expensive urine.
One of the best-selling supplements in the UK as well as several other countries is evening primrose oil (EPO). It is available via all sorts of outlets (even respectable pharmacies – or is that supposedly respectable?), and is being promoted for a wide range of conditions, including eczema. The NIH website is optimistic about its efficacy: “Evening primrose oil may have modest benefits for eczema.” Our brand-new Cochrane review was aimed at critically assessing the effects of oral EPO or borage oil (BO) on the symptoms of atopic eczema, and it casts considerable doubt on this somewhat uncritical view.
Here is what we did: We searched six databases as well as online trials registers and checked the bibliographies of included studies for further references to relevant trials. We corresponded with trial investigators and pharmaceutical companies to identify unpublished and ongoing trials. We also performed a separate search for adverse effects. All RCTs investigating oral intake of EPO or BO for eczema were included.
Two experts independently applied eligibility criteria, assessed risk of bias, and extracted data. We pooled dichotomous outcomes using risk ratios (RR), and continuous outcomes using the mean difference (MD). Where possible, we pooled study results using random-effects meta-analysis and tested statistical heterogeneity.
And here is what we found: 27 studies with a total of 1596 participants met our inclusion criteria: 19 studies tested EPO, and 8 studies assessed BO. A meta-analysis of results from 7 studies showed that EPO failed to improve global eczema symptoms as reported by participants and doctors. Treatment with BO also failed to improve global eczema symptoms. 67% of the studies had a low risk of bias for random sequence generation; 44%, for allocation concealment; 59%, for blinding; and 37%, for other biases.
Our conclusions were clear: Oral borage oil and evening primrose oil lack effect on eczema; improvement was similar to respective placebos used in trials. Oral BO and EPO are not effective treatments for eczema.
The very wide-spread notion that EPO is effective for eczema and a range of other conditions was originally promoted by the researcher turned entrepreneur, D F Horrobin, who claimed that several human diseases, including eczema, were due to a lack of fatty acid precursors and could thus be effectively treated with EPO. In the 1980s, Horrobin began to sell EPO supplements without having conclusively demonstrated their safety and efficacy; this led to confiscations and felony indictments in the US. As chief executive of Scotia Pharmaceuticals, Horrobin obtained licences for several EPO-preparations which later were withdrawn for lack of efficacy. Charges of mismanagement and fraud led to Horrobin being ousted as CEO by the board of the company. Later, Horrobin published a positive meta-analysis of EPO for eczema where he excluded the negative results of the largest published trial, but included results of 7 of his own unpublished studies. When scientists asked to examine the data, Horrobin’s legal team convinced the journal to refuse the request.
The evidence for EPO is negative not just for eczema. To the best of my knowledge, there is not a single disease or symptom for which it demonstrably works. Our own review of the data concluded ” EPO has not been established as an effective treatment for any condition”
Our new Cochrane review might help to put this long saga to rest. In my view, it is a fascinating tale of a scientist being blinded by creed and ambition. The results of such errors can be dramatic. Horrobin misled all of us: patients, health care professionals, scientists, regulators, decision makers, businessmen. This caused unnecessary expense and set back research efforts in a multitude of areas. I find the tale also fascinating from other perspectives; for instance, it begs the question why so many ‘respectable’ manufacturers and retailers are still allowed to make money on EPO. Is it not time to debunk the EPO-myth and say it as clearly as possible: EPO helps only those who financially profit from misleading the public?
I think I must have mentioned this once or twice before: I am constantly on the look-out for new evidence which shows or suggests that some form of alternative medicine works. Today, it seems, I have been lucky.
In this randomised, double-blind, placebo-controlled clinical trial, 200 patients suffering from chronic obstructive pulmonary disease (COPD) were randomly allocated to receive oral therapy with 3 × 30 drops/day of an extract of Pelargonium sidoides (EPs 7630) or placebo. Both treatments were administered in addition to standardised COPD- therapies, and the treatment period lasted 24 weeks. The primary endpoint of this study was the time to the next exacerbation of COPD. Secondary endpoints were the number of such exacerbations, consumption of antibiotics, quality of life, patient satisfaction, inability to work, and the tolerability of the treatment.
The results show that the median time to exacerbation was significantly prolonged with the herbal treatment compared to placebo (57 versus 43 days). The superiority of EPs 7630 over placebo was also confirmed in secondary endpoints, e.g., fewer exacerbations, less patients with antibiotic use, improved quality of life, higher patient satisfaction, and less days of inability to work. The incidence of minor gastrointestinal adverse events was higher in the EPs 7630 group.
The authors of the study conclude that “the results demonstrate a statistically significant and clinically relevant superiority of add-on therapy with EPs 7630 over placebo and a good long-term tolerability in the treatment of moderate to severe COPD. EPs 7630 prolonged time to exacerbations and reduced exacerbation frequency and antibiotic use.”
Chronic obstructive pulmonary disease, is a progressive and serious condition linked to smoking which makes breathing increasingly difficult. The symptoms of COPD typically include a productive cough, wheezing, shortness of breath and chest tightness. Long-term exposure to other lung irritants—such as air pollution, chemical fumes, or dust may contribute to COPD. The condition is a major cause of disability, and currently it is the third leading cause of death, which means that millions of people suffer from COPD.
There is no cure for COPD; the damage to the airways and lungs is not reversible. Various symptomatic treatments exist, for instance, antibiotics, bronchio-dilators, steroids and physiotherapy. Lifestyle changes can further improve the situation, help patients to stay more active, and slow the progress of the disease.
It is clear that COPD is a very serious condition, that the burden of suffering for individual patients can be immense, that therapeutic options are limited and often associated with adverse-effects. In this situation, any new effective and safe therapy would be more than welcome. Pelargonium has previously shown promise in the treatment of asthma, acute bronchitis as well as other respiratory infections. It seems generally safe but is not totally devoid of adverse-effects.
This new study gives hope to COPD-sufferers as it suggests that Pelargonium sidoides might alleviate their symptoms. The trial seems rigorous but the benefit is not huge and the treatment is not a cure of COPD. Moreover, I should point out that any new finding of this nature requires independent confirmations. I do think that the trial is an important step in the right direction, yet I feel that it is too early for issuing general recommendations.
The developed world is in the middle of a major obesity epidemic. It is predicted to cause millions of premature deaths and billions of dollars, money that would be badly needed elsewhere. The well-known method of eating less and moving more is most efficacious but sadly not very effective, that is to say people do not easily adopt and adhere to it. This is why many experts are searching for a treatment that works and is acceptable to all or at least most patients.
Entrepreneurs of alternative medicine have long jumped on this band waggon. They have learnt that the regulations are lax or non-existent, that consumers are keen to believe anything they tell them and that the opportunities to make a fast buck are thus enormous. Today, they are offering an endless array of treatments which are cleverly marketed, for instance via the Internet.
Since many years, my research team are involved in a programme of assessing the alternative slimming aids mostly through systematic reviews and occasionally also through conducting our own clinical trials. Our published analyses include the following treatments:
Supplements containing conjugated linoleic acid
There are, of course, many more but, for most, no evidence exist at all. The treatments listed above have all been submitted to clinical trials. The results show invariably that the outcomes were not convincingly positive: either there were too few data, or there were too many flaws in the studies, or the weight reduction achieved was too small to be clinically relevant.
Our latest systematic review is a good example; its aim was to evaluate the evidence from randomized controlled trials (RCTs) involving the use of the African Bush Mango, Irvingia gabonensis, for body weight reduction in obese and overweight individuals. Three RCTs were identified, and all had major methodological flaws. All RCTs reported statistically significant reductions in body weight and waist circumference favoring I. gabonensis over placebo. They also suggested positive effects of I. gabonensis on blood lipids. Adverse events included headache and insomnia. Despite these apparently positive findings, our conclusions had to be cautious: “Due to the paucity and poor reporting quality of the RCTs, the effect of I. gabonensis on body weight and related parameters are unproven. Therefore, I. gabonensis cannot be recommended as a weight loss aid. Future research in this area should be more rigorous and better reported.”
People who want to loose weight are often extremely desperate and ready to try anything. They are thus easy victims of the irresponsible promises that are being made on the Internet and elsewhere. Despite the overwhelmingly evidence to the contrary, consumers are led to believe that alternative slimming aids are effective. What is more, they are also misled to assume they are risks-free. This latter assumption is false too: apart from the harm done to the patient’s bank account, many alternative slimming aids are associated with side-effects which, in some cases, are serious and can even include death.
The conclusion from all this is short and simple: alternative slimming aids are bogus.
In my very first post on this blog, I proudly pronounced that this would not become one of those places where quack-busters have field-day. However, I am aware that, so far, I have not posted many complimentary things about alternative medicine. My ‘excuse’ might be that there are virtually millions of sites where this area is uncritically promoted and very few where an insider dares to express a critical view. In the interest of balance, I thus focus of critical assessments.
Yet I intend, of course, report positive news when I think it is relevant and sound. So, today I shall discuss a new trial which is impressively sound and generates some positive results:
French rheumatologists conducted a prospective, randomised, double blind, parallel group, placebo controlled trial of avocado-soybean-unsaponifiables (ASU). This dietary supplement has complex pharmacological activities and has been used since years for osteoarthritis (OA) and other conditions. The clinical evidence has, so far, been encouraging, albeit not entirely convincing. My own review arrived at the conclusion that “the majority of rigorous trial data available to date suggest that ASU is effective for the symptomatic treatment of OA and more research seems warranted. However, the only real long-term trial yielded a largely negative result”.
For the new trial, patients with symptomatic hip OA and a minimum joint space width (JSW) of the target hip between 1 and 4 mm were randomly assigned to three years of 300 mg/day ASU-E or placebo. The primary outcome was JSW change at year 3, measured radiographically at the narrowest point.
A total of 399 patients were randomised. Their mean baseline JSW was 2.8 mm. There was no significant difference on mean JSW loss, but there was 20% less progressors in the ASU than in the placebo group (40% vs 50%, respectively). No difference was observed in terms of clinical outcomes. Safety was excellent.
The authors concluded that 3 year treatment with ASU reduces the speed of JSW narrowing, indicating a potential structure modifying effect in hip OA. They cautioned that their results require independent confirmation and that the clinical relevance of their findings require further assessment.
I like this study, and here are just a few reasons why:
It reports a massive research effort; I think anyone who has ever attempted a 3-year RCT might agree with this view.
It is rigorous; all the major sources of bias are excluded as far as humanly possible.
It is well-reported; all the essential details are there and anyone who has the skills and funds would be able to attempt an independent replication.
The authors are cautious in their interpretation of the results.
The trial tackles an important clinical problem; OA is common and any treatment that helps without causing significant harm would be more than welcome.
It yielded findings which are positive or at least promising; contrary to what some people seem to believe, I do like good news as much as anyone else.
I WISH THERE WERE MORE ALT MED STUDIES/RESEARCHERS OF THIS CALIBER!
I don’t suppose that many readers of this blog believe all things natural to be entirely safe, but the general public seems to be hard-wired victims of this myth: Mother Nature is benign, and herbal remedies must be harmless!
There are, of course, several reasons why supposedly “natural” herbal treatments can be unsafe. Plants extracts can be toxic, they might interact with prescribed drugs or they can be contaminated or adulterated.
The latter two terms describe similar but not identical phenomena: contamination means the accidental addition of substances which should not be present in an herbal remedy; and adulteration signifies the deliberate addition of ingredients. If the substances in question are not pharmacologically inert, their presence in herbal remedies can cause adverse effects.
Both contamination and adulteration break laws and regulations; both are therefore illegal. Sadly, this does not mean that such things do not happen.
We have recently published an overview of the existing knowledge in this area. For this purpose, we summarised the evidence from 26 previously published reviews. Our findings were interesting but far from reassuring: the most commonly found contaminants were dust, pollen, insects, rodents, parasites, microbes, fungi, mould, pesticides, and heavy metals. The adulterants invariably were prescription drugs such as steroids, anti-diabetic medications etc.
These substances were implicated in a wide range of serious adverse effects in the unfortunate patients who took the remedies in question: agranulocytosis, meningitis, multi-organ failure, stroke, arsenic poisoning, mercury poisoning, lead poisoning, caner, encephalopathy, hepato-renal syndrome, kidney damage, rhabdomyolosis, metabolic acidosis, renal failure, liver failure, cerebral oedema, coma, and intra-cerebral bleeding. Several patients did not survive.
To avoid such disasters, consumers need to know which types of herbal remedies are most frequently implicated; our review showed that these were foremost Chinese and Indian remedies. While herbal medicines from the US or Europe ought to comply with certain rules and regulations regarding their quality and safety, Chinese and Indian herbal mixtures frequently enter our countries illegally or are bought from dubious sources, for instance, over the Internet. It is this type of herbal remedy that we should be concerned about.
We have to ask whether the risks outweigh the proven benefits of Chinese or Indian herbal mixtures. The short answer to this question is NO. There is very little compelling evidence to suggest that these treatments are efficacious. In the absence of proven benefit, even small or rare risks weigh heavily.
If the risk-benefit profile for any medical intervention fails to be positive, there can only be one reasonable conclusion regarding the use of this therapy – and that is: DON’T DO IT!