Probably because the study was badly done. The difference in their results between 50-65 and 65+ is almost impossibly large and other studies done have never found those kinds of differences.
I once took a class in business school on medical pricing and the instructor said that if you look at a graph of life expectancy that a large percentage of the population dies in the 50-60 age range, but statistically people who live past the age of 60 or 65 (I can't remember the exact figure) will be likely to live to be over 75. In other words, once you make it past a certain age you are sort of screened out as somebody who is high-risk to die of certain ailments like heart disease or cancer.
So if we take that to be generally accurate, then these findings make sense because I would wager that if you studied any diet or habit thought to be unhealthy, more people would die off between 50-65 than after 65.
This also explains why averages don't make sense with regard to any conversation about life expectancy since the averages really need to be observed in bands.
That has the dank stench of an urban legend. According to the CDC, death rates increase monotonically with age once you pass early childhood, and begin to increase dramatically at about age 65:
I dunno the instructor was a surgeon and faculty member at the University of Michigan medical school. Not saying that makes him correct but I wouldn't be too quick to dispute him either.
Besides, death rates increasing monotonically is not at odds with what I am saying. Once a person reaches age 65, their odds of reaching age 85 are higher than the average person at the age of 50. Many serious medical problems onset between the ages of 50-65. With each passing year, people who are susceptible to hereditary illnesses, for example, will die. This leaves people less likely to succumb to those illnesses. Yes, within the smaller group mortality rates will be higher than the previous overall group because more medical complications occur as you age.
In short what I am saying is that even though overall death rates increase, the odds of each person in those groups of living to the age of 85, goes up after the age of 65.
You seem to be changing what you're saying. You previously said:
> more people would die off between 50-65 than after 65
And that is clearly untrue.
Yes, someone who's 65 is more likely to live to 85 than someone who's 50. That's extremely obvious once you know that 1) people occasionally die and 2) people don't come back to life after they die. The closer you are to an age, the more likely you are to reach that age.
I'm getting confused as to what sort of point you're trying to make. You originally seemed to be saying that there's a spike in mortality around ages 50-60. Now you seem to be saying... well, I can't figure it out.
Yes, someone who's 65 is more likely to live to 85 than someone who's 50. That's extremely obvious once you know that 1) people occasionally die and 2) people don't come back to life after they die. The closer you are to an age, the more likely you are to reach that age.
What you're doing here is grossly oversimplifying the statistical significance of that fact. You seem to think that all people, regardless of race, genetic profile, income, etc. have equal chance of dying the older they get. This is simply untrue.
For example, people between the ages of 50-65 have a higher likelihood of dying from cancer before the age of 85 than somebody who is age 66. This isn't simply because the 66 year old has already made it to 66 so is 1/3 of the way ahead of a 55 year old, which is what you seem to be suggesting.
The fact is that certain diseases, statistically, have a higher incidence in that 50-65 age band and once you are out of it, your odds of succumbing to those diseases are lower. Sure, the 66 year old could get a clean bill of health and then walk in front of a bus, but the odds are they aren't going to die of cancer. That isn't insignificant. Obviously the longer you live the greater the odds something will happen that will end your life, but looking at life expectancy in a black box and ignoring the causes of death is misinformed.
The rate of death from cancer goes up with age. There's no age where it decreases.
Perhaps there are certain diseases that have a higher incidence in the 50-65 group than in the 65+ group. Cancer, at least taken as a whole, is not it though.
If you're going to continue this, please give me some numbers before calling me "misinformed" because I'm actually checking your claims.
If there's a confounding variable, it's likely that it is affected by retirement. For instance, a high protein intake in someone who's fifty might signify junk-food lunches, whereas the same thing in a retired person might be a sign of a more affluent lifestyle in general.
I suspect that there are confounding variables at work.
Also, given that they only chose one day on which to sample, it could be something as kooky as Catholics eating fish on a Friday and being regularly exposed to aromatic hydrocarbons from incense. The possibilities are virtually endless.
Also isn't it possible teenagers and young adults could need way more protein than the middle aged?