6

In a paper describing the effects of radiation on the human genome at peaks of solar cycles it is claimed:

Those born in peaks of solar cycles lived an average of 1.5 years (CL 1.3-1.7) less than those born in non-peak years. Males were more sensitive to this phenomenon than females.

I'm skeptical¹ of this claim, so I wonder if real evidences exist.

¹ The cosmic ray flux in the inner solar system is anticorrelated with the overall level of solar activity.

matt_black
  • 56,186
  • 16
  • 175
  • 373
Carlo Alterego
  • 3,963
  • 4
  • 29
  • 77
  • 1
    Original source: [The light of life: evidence that the sun modulates human lifespan](http://www.ncbi.nlm.nih.gov/pubmed/17951015) – Oliver_C Dec 02 '12 at 20:16
  • thank you @Oliver_C for having provided the original source. Now I have improved the question and, consequentially, I expect from you at least an answer, if not an upvote. Please, don't waste an opportunity. – Carlo Alterego Dec 02 '12 at 23:39
  • Are we talking sunspot cycles here? Is the correlation associated with the strength of the cycle? – matt_black Dec 03 '12 at 00:14
  • Yes @matt_black, here we are talking about solar cycles having a duration of about 11 years, but the cosmic ray flux in the inner solar system is anticorrelated with the overall level of solar activity. – Carlo Alterego Dec 03 '12 at 08:04
  • Another paper: [The effect of solar cycles on human lifespan in the 50 United states: variation in light affects the human genome](http://www.ncbi.nlm.nih.gov/pubmed/20452128) – Oliver_C Dec 03 '12 at 10:45
  • Great @Oliver_C. I was not aware of this paper, which, as it seems, clarifies some obscure aspects of first one. Now the claim is more solid and factual than before, so the question is pretty answerable. – Carlo Alterego Dec 03 '12 at 17:18

1 Answers1

3

Both the original paper and the subsequent one were published in Medical Hypothesis.

This is a journal that, by design, includes:

ideas which have a great deal of observational support and some hypotheses where experimental support is yet fragmentary [...] opening the field to radical hypotheses which would be rejected by most conventional journals.

It is an excellent source of novel ideas that may lead to experiments, but it is not a good place to find solid theories supported by substantial evidence.

In a way, it did its job, in that it inspired a more rigorous study of the evidence:

Here, the aim was to replicate the findings of those previous few studies that have suggested a reduced lifespan of individuals born during the years of high solar activity, measured as the sunspot numbers.

This author looked at a large amount of data - data from ten (mainly European) countries, over a period of over 160 years.

These data, however, provided no evidence that human life expectancy at birth was related to solar activity during gestation among the countries studied.

So, this was a nice idea, but was ultimately not correct.

Oddthinking
  • 140,378
  • 46
  • 548
  • 638
  • 1
    given the date range they got data from (1751-1915) I doubt they had quality data, also the Napoleonic wars, WWI and WWII seem like pretty significant confounding factors for a primarily European data set – Ryathal Dec 13 '12 at 13:43
  • [Here's the full article](http://users.utu.fi/sayrhe/Helle_Bioger.pdf) so you can see their source data - the Human Mortality Database and the NOAA web site. They reference an artcile suggested sun-spot activity is derived from radionuclide records. More recent data is complicated, as they point out, by the fact that people are still alive. – Oddthinking Dec 13 '12 at 14:37
  • There are many confounding factors (they mention: Sunspots may affect crops, that may affect maternal health). They would be very important to tease out if there was an effect to explain, but it appears there isn't one. (Let's not forget: The effect, if it existed, could actually be that sunspots make war more likely.) – Oddthinking Dec 13 '12 at 14:40
  • my main concern was the ability to get accurate ages at death for each/enough person(s) to calculate an accurate enough number to make a potentially small effect apparent. – Ryathal Dec 13 '12 at 15:02