Cognitive gamble

sleep deprived
Worn-out, Iditarod champ Lance Mackey in Nome after the winning his fourth and last Iditarod in 2010/James Brooks, Wikimedia Commons

New research is suggesting that seriously competing in the Iditarod Trail Sled Dog Race could be bad for your brain.

A study by scientists from universities in Missouri, Georgia, Iowa and Massachusetts has linked sleep deprivation to brain changes associated with Alzheimer’s disease.

Sleep deprivation is the 1,000-mile Iditarod’s biggest challenge for human competitors. Asked about the health consequences of this on Tuesday, the lead researcher on the study, Dr. David Holtzman at the Washington University School of Medicine in St. Louis, emailed this response:

“Speculating about this, I would think it could be potentially increasing risk for health later in life but I would think its more likely to be a risk if people do this after the age of 40.”

A tired Mitch Seavey from Sterling was 57 when he became the oldest of Iditarod champions in 2017. Among those helping round out the top-20 that year were Aliy Zirkle, 49; Paul Gebhardt, 60; four-time champ Jeff King, 63; Michelle Phillips, 50; Hans Gatt, 58; Ralph Johannsen, 56; John Baker, 55; and Linwood Fiedler, 65.

Most of them have been involved in long-distance races in which they’ve gone sleepless for decades.

Holtzman cautioned there is no definitive answer to the question of sleep-deprivation and Alzheimer’s, and there have been other studies suggesting a highly active lifestyle offers some protection against the disease.

“Physical activity seems to help your brain not only by keeping the blood flowing but also by increasing chemicals that protect the brain,” writes Dr. Jonathan Graff-Radford at the Mayo Clinic. “Physical activity also tends to counter some of the natural reduction in brain connections that occurs with aging.”

Into the unknown

Brain science is a steadily evolving field of research. It is only recent years, for instance, that scientists recognized the association between repeated concussions and chronic traumatic encephalopathy or CTE as it is more often called.

CTE has been linked to memory loss, difficulty controlling impulsive or erratic behavior, impaired judgment, behavioral disturbances and depression, difficulty with balance, and the gradual onset of dementia. 

The disease came to the fore after medical examiner Dr. Bennet Omalu found signs of it in the brain of the late Mike Webster, a center for the Pittsburgh Steelers with a long history of concussions.  Webster had three years earlier filed a disability claim with the National Football League Retirement Board claiming football caused his dementia.

“By the time Webster entered the Hall of Fame in July 1997, he had become a recluse, in agony from herniated discs and hand injuries, impoverished and angry at his fate,” Meryl Gordon wrote in Reader’s Digest in 2003. “…His two sons, who lived with him at different times, saw a more tortured side. Colin remembers that his father was shaking so much from his condition that his desperate solution was to buy a police Taser gun. ‘He’d zap himself to calm his nerves. He’d do it 10 or 20 times to relax.'”

The NFL at first fought Omalu’s claims that football was implicated in Webster’s slide into a personal hell, but has since accepted the danger of concussions and established protocols for making sure players are examined after any collision that shows any sign of brain trauma.

The issue is complicated in that some of those who suffer multiple concussions appear immune to CTE in the way the smoker who smokes a pack a day only to die at a ripe old age is immune to lung cancer.

An exhaustive, peer-reviewed examination of all available concussion studies reported in the Journal of Athletic Training in 2017 concluded that “no prospective, longitudinal studies have shown the long-term risks of cognitive decline, neuropsychiatric disorder, or neurodegenerative disease
associated with repetitive sports-related concussion in contact sports. Furthermore, evidence from human studies of the neurologic and neuropsychological effects of repetitive impacts not associated with diagnosed concussion is currently quite limited.”

But the study recognized that concussions, like sleep deprivation, are generally not good for the body. Sleep deprivation has been previously linked to heart disease, heart attack, heart failure, irregular heartbeat, high-blood pressure, stroke and diabetes, and it has long been known for increasing accidents rates.

Researchers studying sleep last year, according to Science magazine, “found that (automobile) drivers who reported fewer than four hours of sleep had 15.1 times the odds of responsibility for car crashes, compared with drivers who slept for the recommended seven to nine hours in the preceding 24-hour period….drivers who reported six, five, and four hours of sleep in the past 24 hours had 1.3, 1.9 and 2.9 times the odds of responsibility for a crash.”

Tough-man history

The Iditarod has never paid much attention to the health of its human athletes. The race puts a strong focus on protecting the health of the dogs, but injured mushers have regularly been allowed to continue along the trail.

Competitors themselves scoff at the need for even one doctor along the trail, though there are multiple veterinarians at every checkpoint.

Toughness and the ability to do without sleep have always been considered Iditarod virtues. Whether mushers pay a price for that in later years has never been studied.

Little is known definitively about the causes of Alzheimer’s, either. But if it has anything to do with sleep deprivation, Iditarod mushers would appear prime candidates.

“Most mushers receive less than two hours of sleep each day and display signs of severe sleep deprivation by the end of the race,” the scientific journal Cell reported in 2012.

The article was the journal’s effort to ” ‘pop the hood’ of a sled team to examine its engine and on-board diagnostics. We explore the genetics and biochemistry of the dogs’ extreme endurance and learn what happens in the central nervous system when sleep deprivation sets in.”

Most of the story was about the dogs. Sleep-deprivation entered only at the end with a reference to “cat napping” as an aid to surviving long periods without sleep.

“Some race experts speculate that the ability to function under severe sleep deprivation is what separates the Iditarod champions from the middle of the pack. It would be quite interesting to see whether such differences in performance also correlate with less neuronal “catnapping” in the neocortex of the mushers,” the report said.

Whether cat napping would help fend of Alzheimer’s is unclear.

Holtzman and his associates studied both humans and mice looking for chemical changes associated with sleep deprivation. What they found were increases in the protein tau and the amyloid protein. Both have been associated with buildups of plaques thought to play a role in  Alzheimer’s.

“Amyloid is important in initiating disease, but the actual damage in the brain is probably due to the accumulation of tau,” Holtzman told the website MedPage Today . “Normally tau protein is inside cells but there is more and more evidence suggesting that its spread to different parts of the brain is responsible for the progression of Alzheimer’s disease.”

Real world

Burt Bomhoff, a now retired 82-year-old musher still sharp as a tack, said he found the study “very interesting.”

In an email, he joked that people have “to be insane to get started” in Iditarod to begin with, but having pleaded guilty to insanity he added that he never experienced any symptoms of long-term problems related to sleep deprivation.

Then again, Bomhoff never won the Iditarod. His best finish was 12th in 1984, although there were a number of years in which other mushers thought he had the dogs to contend. The rap on Bomhoff was that he was a “sleeper,” a musher who just couldn’t conquer the sleep-deprivation demands necessary to win.

That aside, Bomhoff said he never noticed much in the way of cognitive decline in the other old mushers he knew and knows, and the professional engineer in him looks for it.

“I still occasionally take an IQ test to see what’s going on,” he confessed, “and work all the puzzles in the news every day for the mental exercise. My IQ is basically what it always was. Don’t know if that’s any measure.”

Maybe, he added, he was just genetically blessed. Three genes have been linked to early on-set Alzheimer’s and one gene has now been linked to a greater chance of suffering late-onset Alzheimer’s, according to the National Institute on Aging.

The connections between genes and environmental influences, such as sleep deprivation, are unclear. Bomhoff said he is convinced “genetics play a role.

“My father lived to be 102 as did his sister. They were still publishing his weekly column in a number of Iowa newspapers when he was 100. He was a Lutheran minister and the columns were faith oriented, lots of Bible stuff that required research.

“Don’t know if that was any measure either. He was a scholar who studied five languages – English, German, Greek, Hebrew and Latin. When he died, some of those references were still in his library.

“The geezers I knew well during Iditarod were close friends like Joe (Redington) and Norman (Vaughan). Both seemed very sharp.”

Both men are long gone. Vaughan, who was already old when he ran his first Iditarod, never really dealt with sleep deprivation. An Alaska legend, he only finished four of the 13 races he started, and his fastest took 21 days and two hours; there was plenty of time to rest.

Redington, one of the founders of the race, was for years a contender. He finished fifth in the 1988 Iditarod at the age of 71. He was a man who slept little and often sitting up. He died of cancer in 1999. He was mentally sharp until the very end, but then almost everyone who met Redington considered him unique.


19 replies »

  1. Driverless dog sledding done by remote joysticks. Onboard drones you can launch to see ahead on the trail. Mushers wait at the checkpoints to take care of dogs. What do you think:]

  2. Someone should do a sleep dep study on those 1970s Bering Sea Crabbers. Prob’ly a lot of fried brains. Back in those wide open, lightly regulated times with few closures it was a wild, snooze-you-loose contest where those who could run non-stop stood to make a fortune. Many crews depended on cocaine along with intense disdain for, and relentless shaming of any fellow deckhand who couldn’t hack the sleep dep. I knew those who went without ANY sleep for days while they jammed the holds and racked up $100K crew shares.

    • Rod, you are right, damn those boys could get by on little sleep. But, to use cocaine to crab for days, rack-up $100k in spoils, blow $100k up nose, little sleep, repeat. Now, that is one study I am pretty sure they have plenty on. Ha

    • This is just hearsay but back in Spring, 85 a friend who crewed in Bristol Bay told me that “the only thing that could get you out of bed was a line of coke.” May have been some good shares back then but certainly not anywhere near $100k. They may have been sleep-deprived, tho.

      • Bill, I held a Bristol Bay permit during those 80s glory years. Bay salmon money was good, alright, but never near what Bering crabbers made.

    • Rod,
      That didnt stop in the ‘70’s nor was it confined to king crab.It was par for the course through the ‘80’s to early ‘90’s.I finally got on a civilized boat in ‘92 or ‘93.Relatively easy 18 hr days.
      Longest i ever stayed up was 56 hrs for a 4 day Chatham Straights opening,there was no blow on that boat.
      In the ‘80’s the longline fleet regularly had 24-36 hr days,partially to grind out trips.But also to pump up landings for the coming “qualifying” yrs for IFQ.

  3. Good treatment of Iditarod sleep dep, Craig. On the first Iditarod, which took me 30 days to finish 17th, although progress was slow with lots of snowshoeing ahead breaking trail, and the minimally athletic dogs needing a lot of rest, I had to stay awake sewing booties by hand for the next day’s run, so didn’t get much sleep. My brother Alan carefully documented his sleep during his top ten run a few years later at 2.2 hours per day. Systems were not as slick and mushers not as organized in those 20 day races as today. Our modern mushers only have to endure for a couple of 3-4 day stretches with a fair sleep catcher-upper in the middle for those very organized competitors who are able to manage their 24s to include some downtime amidst “maintaining the machinery.”

    Commenting on probable demise of the Iditarod, for the sake of the dogs pray it never happens. Joe’s primary inspiration for Iditarod’s creation was to save the working sled dog. In the succeeding 50 years, it’s been only the Iditarod and its spinoffs that have restored and preserved the “trotting sled dog.” Should the race go, the trotting dog goes down with them.

    Iditarod’s orginal Rule #1 stated, “The Iditarod Trail Sled Dog Race shall start the first Saturday in March regardless of weather of trail conditions. Should warming continue, that SHALL means the race just moves north. I suppose all the way to the Pole if need be. As we have seen in recent years, the race does not even have to run over the Iditarod Trail to be labeled the Iditarod Trail Sled Dog Race. On years it has run down the Yukon it did not run over one inch of the historic Iditarod Trail proper.

  4. Craig, very interesting article. I am curious why the powers-to-be haven’t looked to the very in-depth research and studies from the military on physical activity, sleep deprivation, and resulting brain function? The NFL is a waste. SPECOPS and I.E.D/ T.B.I in Afghanistan and Iraq would be more aligned with the strains and relation of the Iditarod and possible onset of Alzheimers. There is mountains of data compiled on these very questions and issues.

  5. Climate Alarmists . -5 in Missouri jan 24 . Windchill-30 . North Dakota today many places break record ranging-30 -40 not counting wind chill . Chicago windchill hits-60 . Hasn’t been this cold since before 1900 . Cycles ? Variables? Wait -OCA claims world to end in 12 years without fix ! Star of socialist politics. Let’s trust her and al gore the champion hypocrite who lives in electricity guzzling mansion. When was last time his fat cheeks used a bicycle to hold down carbon and toxic fumes ? Hillary bill ,pelosi, waters, fauxohontas , sanders and all the democrats could use some time on a bicycle – money where mouth is ? What a bunch of bought and paid for lying baby aborting hypocrites. Does any of them live in an earthen house to reduce fossil fuel dependence? Earthen houses stay warm in winter cool in summer. I Bet you not one politician lives in one . Hypocrites ! Scam pushers . Open our eyes folks ! A year ago I was as blind as anyone . These politicians are pushing a bought and paid for America destroying agenda. To be fair to pure socialism- socialism is a good concept at its base though inherent with dysfunctional flaws . The problem is these political pushers are not real ! They are fakes ! Flying around in private or military jets ! Any real socialist doesn’t do these things and lives an extremely basic frugal lifestyle. Wake up you are being duped . John the Baptist lived frugal . The sky for a roof honey and roots for food . No carbon emissions. Does any of these democrat climate alarmists live in a house powered solely by solar or wind / alternative energy? Do any of these climate alarmists use bicycles , foot , or public transportation? If not then they are hypocrites. How about msm left wing media moguls? Do they ? Open your eyes folks . Quit accepting hypocrisy from so called virtue signaling left wingers . Let’s vote for people who put money where their mouth is and aren’t looking to creepily stick their hands into neighbors pockets with wealth redistribution huge taxes . That’s called theft folks . Are you going to vote for that . As Americans we should be free to help those we choose when we choose . Stand on our own feet when we can and Be willing to give shirt , donations or life as we choose . Appears to me there is some underlying push by some entity to weaken Americans morals and self sufficiency using a divide and conquer teqnique under the guise of social progress. Be a skeptic if so called leaders are not living their words. Ok now a token to article . Sleep deprivation. Very interesting. Have to look into . I prefer to stay sleep stuffed : )

  6. Well, as it is above freezing and raining in Willow…I wonder how this race with work out this year?
    The Willow 300 sled dog race just cancelled due to poor trail conditions (i.e. open water on rivers and streams).
    This is after the Knik 100 and 200 were also forced to cancel events this winter due to a lack of frozen trails.
    As I look at the aging “chronics” that found this doglot lifestyle appealing, I can only think that with an “AARP” group of mushers, a lack of solid leadership at the ITC level and global warming effecting Alaska that the long distance mushing events under corporate sponsorship are soon to resemble old salmon runs of years ago.

    • Thanks Opinion, just remember their explanation is hot is actually cold and cold is actually hot.
      Steve, you have been told time and time again why it is raining in Willow but, you do not want to hear it – el Nino. This is a dact.

      • I guess “el nino” is also the one who is ripping the shoreline at Trump’s Ireland golf resort?
        I get it…
        El nino must also be the one causing the Greenland ice shelf to melt?

      • You see Steve, last year our Climate Hucksters told us a run of warm weather proved the planet is warming, which means we all have to give up our freedoms to a centralized government in order to save the planet. BUT… a run of frigid weather this year also proves the planet is warming and we all have to give up our freedoms to a centralized government in order to save the planet.

        So no matter what happens, no matter how cold or warm or temperate it is, everything proves Global Warming is fer real.

        Hey, remember when the Climate Grifters told us Global Warming would make hurricanes worse?

        Remember how, when that scientific prediction was humiliated in the face of record low hurricane activity, these same Climate Grifters told us this lack of hurricane activity proved Global Warming was really fer real?

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