Isotretinoin and suicide: Epidemiological study shows no association

London, Ontario, Canada — Suicidal behavior among patients taking isotretinoin represents an uncommon, idiosyncratic phenomenon, according to the author of a recent study of nationally representative patient data spanning a decade.

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As much as this study disappoints me, it would be disingenuous for me to omit it from this blog, and as much as one has to sigh at the possibility of countless hours of research going up in smoke, it is of course helpful if it redirects our energies elsewhere (if it is indeed true).

To summarize the press release, which is unfortunately a bit lacking in details, Dr David Gems from UCL and his colleagues studied the action of ‘key genes’ involved in removing superoxide in C. elegans (nematode worms). They (presumably) upregulated these genes to enhance the worms’ innate anti-oxidative capacities. They found that the lifespans of the worms were ‘relatively unaffected’ by the change.

Which led Dr Gems to say:

One of the hallmarks of ageing is the accumulation of molecular damage, but what causes this damage? It’s clear that if superoxide is involved, it only plays a small part in the story. Oxidative damage is clearly not a universal, major driver of the ageing process. Other factors, such as chemical reactions involving sugars in our body, clearly play a role. A healthy, balanced diet is very important for reducing the risk of developing many diseases associated with old age, such as cancer, diabetes and osteoporosis, but there is no clear evidence that dietary antioxidants can slow or prevent ageing. There is even less evidence to support the claims of most anti-ageing products.”

In the absence of the actual study, I can’t really comment on the science, except to say that I hope they checked their results properly. However, I guess I’ve never heard of a substance that extends lifespan as a result of its anti-oxidant capacity alone. Indeed, if supplementing with anti-oxidants did extend lifespan, one would assume a daily vitamin C would do the trick (it doesn’t). Does this mean there’s no point in trying to quench free-radicals? Well, as Dr Gems says, they’re good for reducing the risks of age-related pathologies, just not the main one – death.

From my limited information, it appears that this study stands in opposition to the recently-reported ‘Universal Theory of Aging‘, which suggests aging is a result of the re-deployment of sirtuins away from DNA regulation to sites of oxidative damage. So, I’m of the opinion that the book is not yet closed on the Free-Radical theory of Aging, and it’s just another case of over-excited scientists jumping the gun.

After all, there is always this study: Extension of murine life span by overexpression of catalase targeted to mitochondria., which one would consider to be more important given that it used a higher organism (mice). I guess the debate will continue to rage for some time yet.

To me, acupuncture is one of those things that I do try to believe in (although, one shouldn’t have to ‘believe’ when it comes to science!). I know the mechanisms by which it is supposed to work border on the metaphysical, but it seems to have somewhat more credence among sane(ish) individuals than other, completely ridiculous, complementary medicines (homeopathy).

Now, in a blow to acupuncture’s credibility, the European Society for Human Reproduction and Embryology looked at real and placebo acupuncture given on the day of embryo transfer in 370 patients.

The researchers found that the overall pregnancy rate (defined by a positive urinary pregnancy test) for placebo acupuncture was 55.1%, versus 43.8% for the real acupuncture.

You might wonder what ‘placebo acupuncture’ is, as you’d expect that one could tell if they were having a needle inserted into them or not. In fact, they used dummy needles that work in a similar way to those retracting-blade knives that are used in school plays, and they would either insert the real needle or create the appearance of inserting a needle at the same acupuncture points.

The problem that springs to mind is that the pressure exerted by the fake needle might have been such that it created a similar effect to the real needle – after all, proponents of these techniques often claim that pressure alone (acupressure) is sufficient.

In fact, it was noted that:

measurements for the receptivity of the uterus and the levels of patient stress changed significantly for both the real and control groups after the women had received the real or placebo acupuncture.

It’s all very strange indeed, and it would have been good to have controls who received neither real nor placebo acupuncture. However, this would eliminate the possibility of discriminating a placebo effect from the real thing.

So, there may be hope yet for this unusual and reasonably interesting branch of alternative medicine.

Adapted from materials provided by Eurekalert.

The researchers evaluated breast cancer incidence in 36,282 post-menopausal women who were randomly assigned to take 1,000 mg of calcium plus 400IU of vitamin D daily or a placebo.

It turned out that the incidence of breast cancer was comparable between the two cohorts, with 528 and 546 cases, respectively.

They then thought it fit to conclude that “The main findings do not support a causal relationship between calcium and vitamin D supplement use and reduced breast cancer incidence”.

Observe this quote (from Wikipedia):

The 2005 Dietary Guidelines for Americans recommend that older adults, people with dark skin, and those exposed to insufficient ultraviolet radiation (i.e., sunlight) consume extra vitamin D from vitamin D-fortified foods and/or supplements.

Individuals in these high-risk groups should consume 25 micrograms (1000 IU) of vitamin D daily to maintain adequate blood concentrations of 25-hydroxyvitamin D, the biomarker for vitamin D status.

The Canadian Pediatric Society recommends 2,000 IU daily for pregnant and breastfeeding women.

This is to say that it remains possible that the women in the supplementation cohort were not even receiving minimum adequate levels of vitamin D, depending on their diets and exposure to sunlight.

Vitamin D is produced in the skin when exposed ultraviolet light. The amount of vitamin D the skin can produce in this manner can exceed 10,000 IU per day.

The 400 IU vitamin D supplementation would have been vastly outweighed by any number of lifestyle decisions, and could probably be considered ‘noise’ in the overall scheme of things.

I’m confident that this extremely lazy and irresponsible study can be safely ignored.

Adapted from materials provided by Eurekalert.