by When the cold and dark winter sets in, some of us envy animals that can hibernate. This long deep rest is an example of how nature develops intelligent solutions to difficult problems. In this case, how to survive for a long time, cold and dark without much food and water.
But winter has closer ties to human history than you might expect.
An article in a 1900 copy of the British Medical Journal describes a strange human quirk called “.locket” was common among farmers in Pskov, Russia. In this area, food was so scarce during the winter that the problem was solved by sleeping through the dark part of the year.
Once a day people woke up to eat a piece of bread and drink a glass of water. After the simple meal, they went back to bed and family members took turns keeping the fire alive. You will also find descriptions in Greenlandic Inuit stories of a long hibernation-like sleep during the long dark winter months. In parts of Greenland it is dark from November to the end of January.
There is a 2020 study that suggests that humans’ ancient ancestors, known as hominins, may have been able to hibernate 400,000 years ago. Bones found in a cave in Spain show seasonal disruption of growth, suggesting that one of their predecessors may have used the same strategy as cave bears to survive the long winters.
Animals and hibernation
Hibernation is deeper and more complex than usual, including dramatic changes in metabolism. This long period of rest combines several conditions related to longevity, reduced calorie intake, low body temperature and lowered metabolism.
Hibernating animals tend to live longer compared to other species of the same size. Recent studies using epigenetic clocks, which map activity within genes over time, suggest that hibernation delays aging in marmots and bats. So wintering may hold important clues on how to slow down aging processes.
There are different types of aging – chronological and biological age.
Chronological age is simply how many revolutions the earth has made around the sun since we were born.
It is not time itself that ages us but “wear and tear”. Biological age measures wear and tear. It is a more comprehensive and personal measure of health than chronological age and is a better predictor of longevity. A 2023 study found that biological age changes and temporary increases, such as during surgery and stress, reverse when you recover.
Lifestyle-related diseases that accumulate with age, such as cardiovascular disease, obesity, dementia and chronic kidney disease are driven by “wear and tear”. This results in inflammation, altered gut microbiota composition and increased oxidative stress. Oxidative stress is when there are too many free radicals (unstable atoms that damage cells) in your body.
New science based on epigenetic clocks and lessons from winter animals could help us treat patients with diseases caused by “wear and tear”. We could use drugs that could slow down aging.
For example, metformin is the main first-line medication to treat type-2 diabetes. It controls inflammation, insulin sensitivity and slows down DNA damage caused by oxidative stress. There is growing evidence that it may help manage other “wear and tear” diseases such as cardiovascular disease and long-term use of the drug may be associated with lower cognitive impairment.
It may benefit human medicine to learn more about winter to treat traumatic brain injuries, severe blood loss, preservation of muscle and bone mass and provide better protection during organ transplantation.
A 2018 study found that mimicking winter conditions for storage of kidney tissues from deceased donors appeared to improve their preservation. Skeletal muscle degeneration is often determined by genes, but these genes appeared to be inactivated in hibernating bears.
Animals and longevity
There are long-lived, non-wintering animals that we can also learn from, such as the Greenland shark, the naked mole rat, the Iceland clam and the Rougheye rockfish. These species have developed better mechanisms that protect them against aging. Protection against inflammation, oxidative stress and protein modifications that occur with age appears to be a mechanism that generally benefits all long-lived animals.
Genetic studies of rough-eye rockfish, which can live for over 200 years, suggest that a food group called flavonoids is associated with longevity. Citrus fruits, berries, onions, apples and parsley are high in flavonoids, which have anti-inflammatory properties and protect against organ damage, for example, from chemicals or aging.
A 2023 study of rough-eye rockfish found that one set of genes potentially linked to longevity was associated with flavonoid metabolism. So long-lived fish may have something to teach us about what to eat to live longer.
Lessons from nature and winter animals tell us that cell preservation, metabolism regulation and genetic adaptations play a key role in longevity. Our lifestyle and eating habits are our best tools for mimicking some of these mechanisms.
Forty victories
There is so much we still don’t understand about hibernation but we do know that regular sleep is also linked to longevity. For example, a study in March 2023 showed that you can add five years to the life of men and two and a half years if you are a woman with good quality sleep. The researchers defined good quality sleep as getting seven to eight hours of sleep a day, without the need for sleeping medication and waking up feeling rested at least five days a week.
Animals vary enormously in their sleep patterns, from bears and marmots hibernating for eight months of the year to elephants that only get two hours a day.
How elephants can get so old while sleeping so little is still a mystery to scientists.
Discovering how nature resolved these extremes may help scientists find new ways to improve human health.
This article from The Conversation is republished under a Creative Commons license. Read the original article.
Peter Stenvinkel receives funding from Astra Zeneca, Fresenius, Baxter, Novo Nordisk, Bayer, Invizius, Vifor for lectures and scientific advisory boards
