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Study: Astronauts Who Reach Deep Space 'Far More Likely To Die From Heart Disease' (independent.co.uk)
An anonymous reader quotes a report from The Independent: Astronauts who venture into deep space appear to be much more likely to die from heart disease, according to a new study. In another sign that leaving planet Earth is fraught with danger and a potential blow to hopes of establishing a colony on Mars, researchers discovered deep space radiation appears to damage the body's cardiovascular system. They reported that three out of the seven dead Apollo astronauts died as a result of a cardiovascular disease, such as a heart attack or stroke. Although the numbers are small, that rate of 43 percent is four to five times higher than found among astronauts who flew in low Earth orbit or who did not actually go into space, according to a paper in the journal Scientific Reports. In an attempt to test whether the higher numbers of cardiovascular deaths were simply a statistical blip or a genuine sign of the effect of traveling into deep space, the scientists exposed mice to the same type of radiation that the astronauts would have experienced. After six months, which is the equivalent of 20 human years, the mice showed damage to arteries that is known to lead to the development of cardiovascular disease in humans.
FTFA:
We do however know a lot about the effects of terrestrial radiation on human heath... a long-term side effect of radiation therapy to the chest area can be a increased risk of heart disease... apparently. :-/
"I bless every day that I continue to live, for every day is pure profit."
A sample size of seven is too small to draw any conclusions. The radiation hypothesis makes sense, though.
I agree that the sample size of 7 is rot, the 95% confidence interval around a binomial with 3/7 is 10%-82%, in other words: "we don't have a clue". /. summary actually link to the source, so here it is:
However, neither TFA nor the
Michael D. Delp, Jacqueline M. Charvat, Charles L. Limoli, Ruth K. Globus & Payal Ghosh, Apollo Lunar Astronauts Show Higher Cardiovascular Disease Mortality: Possible Deep Space Radiation Effects on the Vascular Endothelium, Nature Scientific Reports (open ac
Interestingly, they do claim statistical significance on the 7 astronaut "study", but I don't have time atm to have a better look...
I agree that the sample size of 7 is rot, the 95% confidence interval around a binomial with 3/7 is 10%-82%
Wrong test. The article says that "that rate of 43 percent is four to five times higher than found among astronauts who flew in low Earth orbit or who did not actually go into space". So the background rate is between 1/4 and 1/5 of 43% ... let's guess 10%. Out of 7 astronauts in deep space, we would then expect 0.7 deaths from heart disease. From a binomial distribution, the probability of getting 3 or more is 2.6%.
So, for the hypothesis that astronauts who went to deep space have an elevated risk of heart disease compared to those who did not, we can say that it is supported, with 97.4% confidence. Still not great - it's an a posteriori hypothesis, and we don't know how wide a hypothesis space we're testing - but certainly better than you've suggested.
You have to die of something. Neil Armstrong died aged 82, Buzz Aldrin is 86, and Michael Collins is 85. So all the three Apollo astronauts lived longer than the average male life expectancy for the USA, which wikipedia tells me is 76.9 years. In fact they all managed better than the average male life expectancy of the top country in the world; Japan which has one of 80.5 years.
So while you might be at some elevated risk of dying from heart disease if you go into deep space, and the sample size is way to small to actually draw that conclusion.
Looking at Apollo 8 through 11 so that's 12 astronauts into deep space they have *ALL* lived into their eighties with only one dying (Neil Armstrong), who also lived into his eighties.
I can't be bothered to click through on the rest of the Apollo missions, but the only Apollo astronaut I am aware of not reaching their eighties is Ronald Evans from Apollo 17. Basically the Apollo astronauts looks to be living *VERY* full lives if you ask me.
Just pointing out that life expectancy at age 40, which is when these astronauts flew, is 79.9 years.
No mod points today, so just reinforcing your statement.
The life expectancy figures cited by grandparent are based on a starting age of "zero". A lot of kids don't make it to age five, many due to car accidents. Once you've made it to age five, the "average life expectancy" of the remaining pool has gone up quite a bit.
As you move up the population pool age brackets, you have already lost the people who were going to bring down the average. To state otherwise brings you to the situation where you're introduced to an 85 year old man and say to him "you should have been dead five years ago!" In the case of astronauts, you're also dealing with a bunch of guys who are in relatively good shape - you've already weeded out the morbidly obese, drug addiction, etc.
The IRS actually has tons of tables in the XLS format for figuring this sort of thing out. They're used primarily in figuring out distribution of retirement benefits over time, but have other uses.