Last week we looked at certain built-in bias that favors drugs being tested. I have previously discussed how studies and/or their news reports can be slanted to discredit natural health products (#112 A Sabotaged Cancer Study, #176 Nutrition in the News). In August 2012 (#177 Preventing Fractures) I reported on a critique of the 2012 USPSTF meta-analysis study which concluded that calcium and vitamin D supplementation at RDA levels provided no benefit and were best avoided due to slightly increased risk of kidney stones. Among the noted flaws were the low dosage of vitamin D; the poorly-absorbed form of calcium used; and missing cofactors for bone formation including magnesium, vitamin K2, and various trace minerals. A similar study with similar conclusions was recently re-analyzed leading to a completely different conclusion.
The Women’s Health Initiative (WHI), a large controlled study of more than 36,000 post-menopausal women over 7 years, examined the effects of supplementation with 1000mg calcium and 400iu vitamin D on bone density and fractures. The original analysis, published in the New England J. of Medicine in 2006, concluded that the supplementation provided no significant reduction in hip fractures and only a small improvement in bone density.
A recent re-analysis of the WHI data by Dr. Ross Prentice and colleagues from the Fred Hutchinson Research Center in Seattle, published in Osteoporosis International 24(2) in February 2013, came up with a different conclusion. The authors found that the original analysis didn’t account for women who were taking supplements prior to the study and for women who quit partway through. After adjusting for these data, the researchers found significant reductions of fracture risk: 29% and 38%. They concluded “…long-term use of calcium and vitamin D appears to confer a reduction that may be substantial in the risk of hip fracture among postmenopausal women”. Just imagine the benefits they might have found had they used optimum supplementation levels and included all the co-factors!
For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.
February 25, 2013
February 19, 2013
204 Scientifically Proven? [19 February 2013]
Last week I wrote about red palm oil and how the health food and supplement industry too often over-exaggerates the benefits of their products based on questionable evidence. Unfortunately the pharmaceutical industry exhibits a similar, but potentially more serious, bias. Dr. Ben Goldacre in a February 1, 2013, New York Times op-ed describes medical research publication bias as “…a cancer at the core of evidence-based medicine.” Basically this means that “scientifically proven” is no guarantee that drugs (or supplements) are safe and effective.
Goldacre, a British physician and epidemiologist, describes the different ways in which this bias occurs, in his 2012 book Bad Pharma: How Drug Companies Mislead Doctors and Harm Patients.
• trial manipulation - trials are often purposefully designed, and the data manipulated, to favor positive results.
• funding - studies funded by industry are far more likely to be favorable than are independent studies.
• publishing - favorable studies are approximately twice as likely to be published as negative ones, and retractions of fraudulent studies often go unpublished.
• withholding data - unfavorable results are frequently withheld from government regulators who have the task of approving drugs. For example data from 8 of the10 clinical trials on the influenza drug Tamiflu, which governments have spent billions stockpiling, have never been released despite years of requests.
The problem with this situation is that regulators and physicians are making decisions which affect your health (and possibly your life) based on incomplete or misleading information. To remedy this, Goldacre is calling for more transparency – all human trials, past and present, of all current treatments be published and available for review. He gives the example of 100,000 deaths from anti-arrhythmia drugs which might have been prevented had a single study of a similar drug, which was never brought to market, been published.
Sources and further reading:
• Salon article
• Scientific American article
• Wikipedia article on "Bad Pharma" book
• Mercola article
• sign petition for all human trials to be published
For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.
Goldacre, a British physician and epidemiologist, describes the different ways in which this bias occurs, in his 2012 book Bad Pharma: How Drug Companies Mislead Doctors and Harm Patients.
• trial manipulation - trials are often purposefully designed, and the data manipulated, to favor positive results.
• funding - studies funded by industry are far more likely to be favorable than are independent studies.
• publishing - favorable studies are approximately twice as likely to be published as negative ones, and retractions of fraudulent studies often go unpublished.
• withholding data - unfavorable results are frequently withheld from government regulators who have the task of approving drugs. For example data from 8 of the10 clinical trials on the influenza drug Tamiflu, which governments have spent billions stockpiling, have never been released despite years of requests.
The problem with this situation is that regulators and physicians are making decisions which affect your health (and possibly your life) based on incomplete or misleading information. To remedy this, Goldacre is calling for more transparency – all human trials, past and present, of all current treatments be published and available for review. He gives the example of 100,000 deaths from anti-arrhythmia drugs which might have been prevented had a single study of a similar drug, which was never brought to market, been published.
Sources and further reading:
• Salon article
• Scientific American article
• Wikipedia article on "Bad Pharma" book
• Mercola article
• sign petition for all human trials to be published
For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.
February 11, 2013
203 Red Palm Oil – A Miracle Cure? [11 February 2013]
The latest “miracle health product of the week” from TV personality Dr. Oz is red palm oil. Red palm oil (RPO) is a less refined version of the palm oil commonly used in industrial food production. It is derived from the fruit of the oil palm (palm kernel oil is from the kernel) and is grown in West Africa and Indonesia. RPO is about half saturated fat (44% palmitic acid) and half unsaturated (39% oleic acid) which makes it a soft solid at room temperature. The red color comes from a high content of carotenes including beta-carotene (think carrots) and lycopene (tomatoes). RPO is also a good source of tocopherols and tototrienols (forms of vitamin E I’ve written about previously). Next to coconut oil it is a good source of medium chain fatty acids (MCTs) which I have also written about. It has a distinct bitter flavor.
Now here are some of the claims Dr. Oz made for red palm oil on his show:
• protects against dementia & Alzheimer’s
• reduces bad cholesterol & atherosclerosis
• reduces belly fat
There is little or no evidence to support these claims. The scientific studies he casually refers to were either in-vitro or animal studies; there have been few human trials. For example a 2007 South African study found that red palm oil “significantly decreased p38-MAPK phosphorylation in rat hearts subjected to a high-cholesterol diet” [Wikipedia]. Another from Hungary in 2011 showed that red palm oil reduced heart damage in heart attacks in rats fed a high cholesterol diet. These are encouraging but still a long way from proving a health benefit to humans. A human trial by researchers in Denmark published in 2011 found that RPO actually raised LDL and total cholesterol compared to olive oil.
So you can try it if you want, but don’t expect a miracle. Oh, and if you do, make sure the oil doesn’t come from a Malaysian or Indonesian plantation carved (clearcut and burned) from dwindling orangutan forest habitat where 90% of the world’s palm oil originates.
For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.
Now here are some of the claims Dr. Oz made for red palm oil on his show:
• protects against dementia & Alzheimer’s
• reduces bad cholesterol & atherosclerosis
• reduces belly fat
There is little or no evidence to support these claims. The scientific studies he casually refers to were either in-vitro or animal studies; there have been few human trials. For example a 2007 South African study found that red palm oil “significantly decreased p38-MAPK phosphorylation in rat hearts subjected to a high-cholesterol diet” [Wikipedia]. Another from Hungary in 2011 showed that red palm oil reduced heart damage in heart attacks in rats fed a high cholesterol diet. These are encouraging but still a long way from proving a health benefit to humans. A human trial by researchers in Denmark published in 2011 found that RPO actually raised LDL and total cholesterol compared to olive oil.
So you can try it if you want, but don’t expect a miracle. Oh, and if you do, make sure the oil doesn’t come from a Malaysian or Indonesian plantation carved (clearcut and burned) from dwindling orangutan forest habitat where 90% of the world’s palm oil originates.
For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.
February 4, 2013
202 Obesity & Food Cravings [4 February 2013]
A recent study shows that the brains of overweight people react differently to the sight of food than those of their normal weight friends.
Researchers from the University of Southern California Keck School of Medicine used functional MRI to observe brain activity in 5 obese and 7 normal weight adults at different blood sugar levels. The subjects were shown pictures of high calorie foods, low calorie foods, and non-food items at different glucose levels and asked to rate their hunger and desire for the food.
As would be expected, both obese and normal weight subjects reported more hunger and desire for high calorie foods at hypoglycemic (low blood sugar) than at euglycemic (normal blood sugar) levels. Correspondingly, while hypoglycemic, both groups showed higher brain activity in the hypothalamus and limbic brain (which initiates cravings for food to replenish blood sugar). When the blood sugar levels were returned to normal, the normal weight group had higher activity in the prefrontal cortex (which controls rational decision making), and the desire for food fell. This didn’t happen in the obese group – the activity remained high in the hypothalamus and hind brain and the cravings for food was not alleviated. This explains why it is harder for obese individuals to eat appropriately to lose or even maintain weight, something their normal weight friends often fail to comprehend.
Here is what I think this study means to someone who is overweight:
• there is a physiological explanation for your cravings – it’s not just a character weakness;
• eat more frequent small meals to keep your blood sugar levels even and to reduce cravings and subsequent overeating;
• avoid visual cues of food between meals (hide the cookie jar);
• once you have lost your excess fat weight it will be easier to keep it off.
Source: “Circulating glucose levels modulate neural control of desire for high caloric foods in humans”, J Clin Invest 121(10), October 2011.
For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.
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