Tags: rh blood group and hearing loss
This Transfusion: Parachutes and death from gravitational challenge | Hawthorn and heart disease | Blood group A and ovarian hyperstimulation syndrome | Rh blood group and hearing loss | Epigenetics, diet and super oxide dismutase (SOD)
Welcome to The Weekly Transfusion, 1.5 for the week of April 13, 2009.
Insufficient evidence for parachute use to prevent death and major trauma related to gravitational challenge
As with many interventions intended to prevent ill health, the effectiveness of parachutes has not been subjected to rigorous evaluation by using randomised controlled trials. Advocates of evidence based medicine have criticised the adoption of interventions evaluated by using only observational data. We think that everyone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute.
Evidence based medicine is the buzz-phrase of the moment, the idea being that you scour the medical literature on a particular association,for example using the herb Hawthorn to treat chronic heart failure. You set the selection criteria, such as the type of study (placebo controlled, etc.) and the amalgamate the data. Evidence Basis has some very important advantages, namely that it gives the most accurate current assessment of a treatment or strategy since you are pooling all the available data.
One problem with evidence based medicine is the simple reality that evidence and benefit are not always the same thing. As shown by this slightly tongue in cheek study, there is still an insufficient evidence basis to conclude that parachutes are effective in preventing major trauma related to gravitational challenge. The researchers failed to find suitable studies showing the effects of using a parachute during free fall, despite setting logical criteria (death or major trauma, defined as an injury severity score > 15) and scouring he available literature.
Setting artificial standards can also impeded the workings of common sense: Edward Murphy put it best in his classic The Logic of Medicine: 'Only a fool would require a double-blind study to see if it was raining outside.'
Lack of evidence is not evidence of lack.
Evidence based medicine has potential to revolutionize day to day health care. However I think an even bigger revolution lurks under the surface: The reinterpretation and reorganization of medical facts derived under the older 'disease-care paradigm' by evolving paradigms that better fit new real-world circumstances.
A common argument against the need for heterodoxy in medicine is that 'when facts are proven, they stop being alternative.' This may well be true, but it neglects that facts themselves are forever open to reevaluation, deconstruction and recycling. Much of my work with the ABO polymorphisms was the simple reappraisal and restructuring of the conventional biomedical literature on the subject --but done with an eye to its ulterior benefits in naturopathic circumstances. Had they not been subjected to the 'naturopathic lens' these facts may well still be floating in their own splendid isolation.
Hawthorn extract for treating chronic heart failure
For the physiologic outcome of maximal workload, treatment with hawthorn extract was more beneficial than placebo... Exercise tolerance were significantly increased by hawthorn extract... The pressure-heart rate product, an index of cardiac oxygen consumption, also showed a beneficial decrease with hawthorn treatment... Symptoms such as shortness of breath and fatigue improved significantly with hawthorn treatment as compared with placebo...These results suggest that there is a significant benefit in symptom control and physiologic outcomes from hawthorn extract as an adjunctive treatment for chronic heart failure.
I first wrote about Hawthorn (Crataegus spp.) in my book Eat Right For Your Type over thirteen years ago, making specific reference to its benefit for blood group A individuals with cardiovascular problems. In general the plant has a good track record, especially, if used in quite low doses for extended periods of time. The herb seems to allow cardiac patients to derive extra benefit from exercise (link), has some very nice effects on the artery lining (link) and has been shown to lower blood pressure in patients taking diabetic medication. (link)
Hawthorn was shown to be well tolerated and safe. However, it should not be used as a substitute medication in circumstances of active heart disease or concurrently with other cardiac medicines unless under the supervision of a physician trained in its use. In one study, it actually seemed that the hawthorn group had a worse outcome than the placebo group. (link) Hawthorn also does produce occasional side-effects, though they appear uncommon and rather mild.(link) Perhaps this is the darker side of the biochemical individuality revolution; it's no longer acceptable to claim that all natural products are safe in every person. Anything that can add to the personalization of herbal recommendations can only help to increase their safety profile.
Blood type A women get more complications from fertility treatment
Ovarian hyperstimulation syndrome is a potentially life-threatening complication during controlled ovarian stimulation for fertility treatment. Since no association of this condition with ABO blood groups was known, we compared ABO antigens with severity and onset of symptoms in a case-control study...The odds ratio for patients undergoing controlled ovarian stimulation with blood group A versus O to develop the early-onset form of this condition was 2.171 (p-value 0.002). Blood group A may be associated with early-onset ovarian hyper-stimulation syndrome in Caucasians...This possible association may be considered for an individualized hormone dosing in controlled ovarian stimulation.
Ovarian hyperstimulation syndrome (OHSS) is a complication from some forms of fertility medication. Most cases are mild, but a small proportion is severe. Symptoms can range from a more mild form that includes abdominal bloating and feeling of fullness, nausea, diarrhea, and slight weight gain to a more severe form that includes and fullness/bloating above the waist, shortness of breath, urination significantly darker or cessation of urination altogether, calf and chest pains, marked abdominal bloating or distention, and lower abdominal pains. This study looked at 127 Caucasian patients hospitalized because of ovarian hyperstimulation syndrome after receiving in vitro fertilization, in the period from January 2000 to February 2007 and found that blood group A was markedly more frequent and blood group O less frequent in patients with ovarian hyperstimulation syndrome.
Other studies have found a slightly greater incidence of ovarian cancer in women who are blood group A (link) and blood group antigens (as mucins or 'blood group substances') are known to be richly deposited on ovarian tissue. (link) Hopefully fertility specialists will consider individualizing hormonal treatment by blood group when working with fertility patients.
Four patients developed thrombosis (clots) in the jugular or subclavian vein, none of whom had blood group O; this correlates with earlier studies linking blood groups other that type O with an increased risk of thrombosis (link) at some of this clotting may in fact be due to enhanced sensitivity to estrogen, at least in women who are not blood group O.(link)
What was that? Being Rh positive may increase your risk of hearing loss
Noise-induced hearing loss (NIHL) is one of the most common occupational problems and is one of the main causes of deafness. Many factors cause NIHL. Individual susceptibility is one of them. Rhesus (Rh) antigens and ABO blood groups can be factors in determining individual susceptibility. In conclusion, we suggest that the people with Rh-positive blood group are more prone to develop NIHL.
The researchers looked at factory workers who had been exposed to a noise level more than 85 dB for 8 hours a day for a period of over 15 years. Two hundred and nineteen (55.4%) of Rh-positive workers and seventeen (39.5%) of Rh-negative workers have noise-induced hearing loss, and the difference between the two groups was statistically significant (P < 0.05). There was no link between hearing loss and ABO blood type.
If you are a rabid reader of this blog, you'd immediately notice that these results are just ever-so-slightly statistically significant (and not be much of a discovery) since given enough noise, virtually anyone will develop hearing loss. However we could speculate that something in being Rh positive influences the structure of the ear anatomy to make these people more likely to get hearing damage. Or on the other hand, what is it about being Rh negative that makes these people less likely to get hearing loss?
An earlier study with infants and adults also showed a higher incidence of hearing loss in Rh positive people, with a slightly better level of significance (0.01) if the mother was Rh negative blood type (which might support the idea that the problem would then be seen in the incompatible Rh-positive children). Another maternal influence via blood group!
Diet influences epigenetic regulation of super oxide dismutase (SOD) gene
The impact of nutrition on the epigenetic machinery has increasingly attracted interest. The aim of the present study was to demonstrate the effects of various diets on methylation and gene expression. The antioxidative enzyme mitochondrial superoxide dismutase (MnSOD) was chosen as the model system because epigenetic regulation has been previously shown in cell lines for this gene. A 3-fold increase in the expression of the MnSOD gene was associated with decreased CpG methylation of the analyzed promoter region in the vegetarian group compared with the age-matched omnivores group. These results indicate that diet affects the epigenetic regulation of human MnSOD.
The super oxide dismutases are a class of enzymes that catalyze the conversion of free radical superoxide molecules into oxygen and hydrogen peroxide. They are an important antioxidant defense in nearly all cells exposed to oxygen. SODs 'outcompete' healthy tissue for the damaging free radical molecules. They protect the cell in a way reminiscent of a common scene in the the old Laurel and Hardy movies where two soldiers in a trench hoist a helmet on a stick above their heads and then retrieve it having been shot full of bullet holes. Although SOD supplements are a common item on health food store shelves, oral SOD products are completely destroyed in the gut, so methods to increase the native (endogenous) production in our own cells would be optimal.
Epigenetics is best explained as the 'non-genomic' or 'post-genomic' control of gene expression, mechanisms such as DNA methylation, or histone acetylation, which act a 'volume controls' on the ability of the cell to read the section of DNA that contains that gene. In the case of this study, the vegetarian group has less methylation on the CpG section of promoter region of the SOD gene.
In English, what they are saying is that diet removed some of the restrictions (methyl groups) on the part of the gene that activates it (the promoter region). Removing methyl groups usually takes the brakes off a gene, especially when they are in the gene's cystine-rich 'front.'
Exciting stuff. Now we'll need to see exactly which specific foods have the maximum epigenetic effects on SOD.
Until next week.
Note to readers: By mistake I had uploaded an earlier, non-spell-checked version of this entry on Monday. I beg your indulgence on this matter. Although I am a reasonably good speller, if truth be told I am a terrible typist.