Exceptional longevity and potential determinants of successful ageing in a cohort of 39 Labrador retrievers: results of a prospective longitudinal study

[drewab]

This is a fun paper to read, especially for anyone who has a medium-to-large breed dog including Labrador retrievers, which I happen to have. I know that Dean has commented on a few studies involving Labrador retrievers on this forum before, though I didn't see this one offhand. 

 

Some highlights of the study include:

• A study involving 39 Labrador's, 11 (28%) of which reached at least 15.6 years of age or greater (which the researchers refer to as 'exceptional')
• Of note the typical Lifespan of a Labrador is 12 years of age
• These 'exceptional' long-lived dogs accumulated fat slower, though still had similar declines in lean tissue (they measured this with DEXA scans)
• There are mixed results about the impact of neutering on health/longevity in general
• Long-lived dogs have a delayed onset of disease (this sounds just like long-lived humans and the compression of morbidity usually experienced)
• The living conditions for the dogs in this study were fairly well controlled for and sounded pretty good for animals in captivity
• The dogs were fed twice a day and using a fairly normal commercial chow (which is to say that it wasn't particularly healthy IMO)
• Female dogs were 10x as likely to reach the 'exceptional' age (again, this sounds similar to humans)
• Interestingly, 90% of the dogs in this study met or surpassed average life expectancy for the breed
  • Perhaps this suggests that even basic medical care goes a very long way in supporting longevity... at least if you are a cute and cuddly Labrador in captivity getting regular check ups and being closely monitored. 
• To quote directly - "Somewhat paradoxically, the dogs in the Long lifespan group of the current study lost weight between the ages of 9 and 13 years whilst the Exceptional lifespan dogs maintained or slightly gained weight during this time period." This makes me thing of centenarians who need enough mass to protect against frailty without being obese. 
• There were still 5 Labradors alive at the end of the study that were all 16-17 years old! 
  • The researchers state - "There are many factors that may have contributed to the ability of these dogs to exceed a typical lifespan and reach exceptional longevity. These include genetics, husbandry, preventative healthcare, socialisation, housing and environmental enrichment."
• Cancer was the most likely to kill all ages of dogs and was most prevalent in the 'expected' survival group
  • " In the current study, cancer was the cause of euthanasia in 54 % of the dogs that lived to an Expected age, 27 % in the Long group and 33 % in the Exceptional group."

The Kaplan-Meier survival plot can be seen below. 

And because who can resist a cute Lab, here's my own who I hope to have live a long and healthy life! He is about 16 months in this photo from a while back. 

Even for a non-dog owner the paper could be an enjoyable read!

 

 

[IgorF]

Hm,

their data for those exceptionally long-lived fits very good into a strangely underestimated allometric angle of view that is thorouthly described in a book (Human Body Size and the Laws of Scaling: Physiological, Performance, Growth, Longevity and Ecological Ramifications. Edited by Thomas Samaras; contributions by, Andrzej Bartke and, C. David Rollo.) by one of the proponent of this angle Thomas T. Samaras (he claims that he analyzed approx. 5000 of different data sources and just has no way to mention all of them in the book refs for obvious reasons).

The conclusion in the book as a kind of redline in it (imho) - do not grow big at all, no matter if it is adipose hyperaccumulation or culturally-imposed desire for higher stature (but low height due to malnutrition or other unhealthy reasons is not desired offcourse).

Do not grow fast - those who experience acceleration ("catch up growth")  have more health troubles. This was suddenly unexpectedly (for me) echoed in the fact described in a nice book about trees "The Heartbeat of Trees.." by Peter Wohlleben - the longevity championing amongs trees seems also requires to grow slowly.

The same is for sex - allometric data for the dogs mentioned shows the same sex dimorphism for males/females and this describes the longevity chances for them the same way as for humans - females do have less body frames, lower igf1 and so on.

Actually the interesting thing about blue zones is that their inhabitants were almost all low-framed, that is itself lowers the unwanted load of igf1, ldl risks, ros-related stress and so on and so on.

And the most exciting thing for me is that all this stuff was already known for a long time but the last two decades it completely murked out, left in rather scientific books and papers and is not visible due to a huge amount of misleading "explanations", probably forced by "eat more" of a "good stuff <forced variable>" promoters and newer media frenzy powered by the tools available now.

Br,

Igor

[mccoy]

What I know is that Sardinians sure have been, in all the Italian regions, the citizens with the lower average stature. I don't know though about the average stature in the Ogliastra province. 

[IgorF]

It is a bit tricky to quot the book due to its restricted availability online (it seems possible to buy it via google store but not in my location, so I bought a used paper one and searching for direct quotes on scanned one avaible at google %))

https://books.google.com/books?id=PCU0RwDI6c4C&pg=PA90&lpg=PA90&dq="compared+to+americans,+when+okinawans+suffer+heart+attacks"&source=bl&ots=sCULWlG8Vj&sig=ACfU3U3JANqac5XkSnX1j7TMPH1-oyLl4A&hl=en&sa=X&ved=2ahUKEwiwyrrBlpeGAxXKXvEDHQb8AQ4Q6AF6BAgPEAM

Elderly Okinawan men and women are also short and have the smallest physique of all Japanese. Compared to the taller population on the mainland, death rates from stroke and heart disease are over 40% lower. The annual death rate per 100,000 people from CHI) is 18for Okinawans vs 102 for Sweden and 100 for the US. Stroke mortality is lower than that ofSweden, Italy and Greece but 25% higher than for the US. However, Willcox et al.(2004)found the elderly Okinawans had exceptionally young arteries and low blood homocysteineand cholesterol levels in comparison to Westerners.The heights of the elderly (75 to < 100 years) average 158.5 cm for males and 144.8 cmfor females (Chan et al., 1997). However, centenarians are substantially shorter and average148.3 cm for males and 138.6 cm for females. Compared to Americans, when Okinawanssuffer heart attacks, they are more than twice as likely to survive. However, recent healthtrends are not good due to changes in diet, lifestyle and body size, and younger Okinawansare seeing substantial increases in heart disease.

(the paper mentioned in the text is Dietary, anthropometric, hematological and biochemical assessment of the nutritional status of centenarians and elderly people in Okinawa, Japan. DOI:10.1080/07315724.1997.10718679 "scihubbable")

Actually the whole book chapter is interesting, with much more data from different studies of different things, sometimes with peculiar graphs like:

 

Edited Saturday at 12:30 PM by IgorF

[IgorF]

And another interesting quot from the book, not related to dogs but to the topic of body size and longevity:

 

Quote

Polednak (1979) conducted a study on the longevity of Harvard college athletes based on
body size. Using only natural deaths, he collected height and weight data on major and minor
athletes and nonathletes for three decades: 1860-69, 1870-1879 and 1880-89. Major athletes
were defined as those who received one Or more awards in major varsity sports. Minor
athletes were those who played in major sports without winning a letter or who participated in
minor sports. Polednak found the shorter and lighter .minor athletes lived longer than the
larger major athletes. Differences in average age at death were small (O. I to 2 years) as were
height differences ( < I cm). Analysis Of his data indicated that the taller athletes had a
decrease in longevity of 0.59 y/cm, somewhat higher than other study findings in this section.
A similar pattern was observed for weight between the two types Of athletes. In addition,
nonathletes who were shorter and lighter than the major and minor athletes, had longer
average life times compared to major athletes for the period 1860-69. Polednak also reported
that earlier studies have shown greater longevity for former sportsmen. However, four
subsequent cohort studies found a 1 to 2 years longer average age at death from natural causes
for nonathletes vs former athletes.

this was about things not so murked out by very aggressive tactic adopted (and further developed) after tobacco war by "food" industry now to promote novadays body ideal, so sheds some light on data about excercising at athletes grade but in the age when there was no modern chemistry tricks and excercising was more focused on "to be" rather than "to look like", how unhealthy it could be now is an interesting question.