Farming, Fatherhood Hallmarks of Men Who Live to 100

Farming, Fatherhood Hallmarks of Men Who Live to 100
MONDAY, Nov. 19 (HealthDay News) -- A young, trim farmer with four ormore children: According to a new study, that's the ideal profile forAmerican men hoping to reach 100 years of age.
The research, based largely on data from World War I draft cards,suggests that keeping off excess weight in youth, farming and fathering alarge number of offspring all help men live past a century.
One finding in particular was unexpected, the researchers said.
"We were surprised that having more than three children is beneficialto longevity -- based on previous studies by other authors, and commonsense, quite the opposite could be expected," said study co-author LeonidGavrilov, who conducted the study with his wife, Natalia Gavrilova, bothof the University of Chicago's Center on Aging.
Gavrilov, a leader in longevity research, was to present the findingsMonday at the Gerontological Society of America annual meeting, in SanFrancisco.
The husband-and-wife team have long mined vital statistics and otherdata, looking for clues to why some people live into extreme old age.
Just last year, they reported one new finding: Babies born to womenunder 25 years of age were twice as likely to live to 100 years of agecompared to infants born to moms aged 25 or older.
The new research in men was spurred by the fact that a treasure troveof information about 20th-century American males has now been put online:World War I Draft Registration Cards.
From 1917 to 1918, almost all adult males aged 46 or under wererequired by law to fill out these cards, which asked them to detail anumber of physical and social attributes.
In their study, Gavrilov and Gavrilova first used Social Security datato locate 240 men born in 1887 who lived to be at least 100.
In 171 of those cases, the men's physical and social attributes at age30 were recorded on their WW I draft cards -- giving the researchers asnapshot of their lives at the time.
The Chicago team then compared that data against draft card informationfor a randomly selected group of American men who were also born in 1887but who did not reach 100.
Some surprising findings emerged. First of all, a man's chances ofreaching 100 rose along with the number of children he had produced by age30.
Compared to childless men of the same age, a 30-year-old man in 1917who had one to three children had a 61 percent increased chance of livingpast a century, the data showed. However, a man's chances for extremelongevity almost tripled if he had fathered four or more children by age30, the study found.
That's at odds with a prevailing theory in longevity research thatholds that "there is a trade-off between the number of children and[parental] longevity," noted Arnold Mitnitski, a longevity researcher andassociate professor of medicine, mathematics and statistics at DalhousieUniversity in Halifax, Canada.
He described the study as "very well-done, very clean."
Theoretically, a household full of young kids should deplete a family'sresources and undermine the longevity of parents, Mitnitski said. And yet,young dads with many children lived much longer than other men in thissample.
"This may be due to the support by the children when the person becomesolder," Gavrilov speculated. Alternatively, siring many children "could bean indicator of good general health and attractiveness on the marriagemarket, leading to earlier marriage and hence to more kids by age 30," hesaid.
In other words, the same robust health that boosted a man's marriageprospects and fertility might also promote long life, Gavrilovreasoned.
Another finding, replicated in prior studies, was that being a farmer(as listed on the Draft Card) more than doubled a man's odds of livinginto the triple digits.
"The most popular hypothesis [there] is that people in the past hadpoor sanitation in towns, and hence a high infection load early in life,"Gavrilov said. Farms were more isolated, and so farmers were less likelyto contract life-limiting illnesses, he reasoned.
Not unexpectedly, overweight -- what the researchers described as a"stout" physique -- reduced a man's likelihood for very long life. Infact, slender or medium-built men were twice as likely to reach thecentury mark compared to stout types.
But, "surprisingly, there is not much difference between the slenderand the medium body build, in terms of survival chance to 100," Gavrilovsaid. That runs counter to the results of animal studies that havesuggested that low-calorie diets, and resultant skinniness, boostslongevity.
Other characteristics -- including marital and immigration status at30 -- had little or no impact on longevity.
Finally, taller men were only marginally more likely to live to 100than their shorter peers, the team found. Experts have long linkedshorter adult height to the types of childhood infections that mightshorten lifespan, so this finding is also a bit of a puzzle, Gavrilovsaid.
"We need to make a larger study and take a closer look at the linksbetween adult height, childhood infection and longevity," he said.
He stressed that findings for women would no doubt be different, for avariety of reasons. "We need to find [similar] data for women to get theanswer," Gavrilov said.
More information
There's more on healthy aging at the U.S. National Institute on Aging.