Study Suggests Greenland’s Norse Farmers Imported Wood
Archaeologists have used wood taxa analysis to distinguish between imported, drift and native wood from five Norse farmsteads on Greenland.
Historical records have long suggested that medieval Norse colonists on Greenland (AD 985–1450) relied on imported material such as iron and wood.
Until now, it has not been fully recognized where these imports of wood came from.
To study timber origins and distribution on Greenland, Lísabet Guðmundsdóttir from the University of Iceland examined the wood assemblages from five Norse sites in western Greenland, of which four were medium sized farms and one a high-status episcopal manor.
All sites were occupied between AD 1000 and 1400 and dated by radiocarbon dating and associated artifact types.
A microscopic examination of the cellular structure of the wood previously found by archaeologists on these sites enabled the identification of tree genus or species, and the results were published in the journal Antiquity.
The results show that just 0.27% of the wood examined were unambiguous imports, including oak, beech, hemlock and Jack pine. Another 25% of the total wood studied could be either imported or driftwood, including larch, spruce, Scots pine and fir.
Because hemlock and Jack pine were not present in Northern Europe during the early second millennium AD, the pieces identified from the medieval contexts in Greenland must have come from North America.
This confirms the historical sources, that the Norse did acquire wood from the east coast of North America. The sagas indicate that the explorers Leifurheppni, Þorleifurkarlsefni and Freydísall brought back timber from Vínland to Greenland.
In addition to the possibility of import, driftwood was one of the most important raw materials in Norse Greenland, making up over 50% of the combined assemblage.
Wood also came from Europe, likely including the oak, beech and Scots pine from this assemblage. Some may have come as ready-made artifacts, such as barrel staves, while reused ship timber could have been brought to use in buildings on Greenland.
A team of researchers affiliated with several institutions in Denmark and Greenland, working with another colleague from Australia, has found that early humans living in Greenland ate a much more varied diet than previously believed. The study is published in Nature Human Behavior.
Scientists studying the history of Greenland have often wondered how early humans could have survived in such a cold climate. Prior research has shown that there have been four major migrations to Greenland: The Saqqaq, the Dorset, the Norse and the Thule—only the Thule became permanent residents.
The first group, the Saqqaq people, arrived approximately 4,500 years ago and remained in Greenland until a strong cooling period drove them away after 1,700 years.
Prior research efforts have suggested they ate fish, seals and perhaps even some types of whales, despite their limited toolset.
In this new effort, the researchers took a closer look at the diet of the Saqqaq and the diets of the other groups that followed them—their work involved conducting a DNA analysis of bone fragments collected from “kitchen middens,” a term used in Greenland to describe mounds of bones left behind by humans as they were discarded after meals.
In studying approximately 2,500 bone shards, the researchers found they were able to identify 42 species of creatures eaten by early humans, many of which came as a surprise.
The team found, for example, DNA from an extinct species of reindeer—one that was much smaller than those that live in Greenland today. They also found evidence of multiple types of whales: fin, sperm, narwhal and bowhead.
Bowheads were the most prevalent, which, the researchers note, makes sense because they are relatively easy to kill. In all, the researchers found evidence of 20 mammal species, nine kinds of fish (including a surprising number that was quite small, suggesting the use of nets) and 13 types of birds.
The DNA evidence reveals not just the types of creatures that were captured and eaten by early people, the researchers note, but also sheds light on the technical know-how of those who succeeded in hunting them.
One of the great mysteries of late medieval history is why did the Norse, who had established successful settlements in southern Greenland in 985, abandon them in the early 15th century?
The consensus view has long been that colder temperatures, associated with the Little Ice Age, helped make the colonies unsustainable.
However, new research, led by the University of Massachusetts Amherst and published recently in Science Advances, upends that old theory. It wasn’t dropping temperatures that helped drive the Norse from Greenland, but drought.
When the Norse settled in Greenland on what they called the Eastern Settlement in 985, they thrived by clearing the land of shrubs and planting grass as pasture for their livestock. The population of the Eastern Settlement peaked at around 2,000 inhabitants but collapsed fairly quickly about 400 years later.
For decades, anthropologists, historians and scientists have thought the Eastern Settlement’s demise was due to the onset of the Little Ice Age, a period of exceptionally cold weather, particularly in the North Atlantic, that made agricultural life in Greenland untenable.
However, as Raymond Bradley, University Distinguished Professor of geosciences at UMass Amherst and one of the paper’s co-author, points out,
Before this study, there was no data from the actual site of the Viking settlements. And that’s a problem.
Instead, the ice core data that previous studies had used to reconstruct historical temperatures in Greenland was taken from a location that was over 1,000 kilometres to the north and over 2,000 meters higher in elevation.
“We wanted to study how climate had varied close to the Norse farms themselves,” says Bradley. And when they did, the results were surprising.
Bradley and his colleagues travelled to a lake called Lake 578, which is adjacent to a former Norse farm and close to one of the largest groups of farms in the Eastern Settlement. There, they spent three years gathering sediment samples from the lake, which represented a continuous record for the past 2,000 years.
“Nobody has actually studied this location before,” says Boyang Zhao, the study’s lead author who conducted this research for his PhD in geosciences at UMass Amherst and is currently a postdoctoral research associate at Brown University.
They then analyzed that 2,000-year sample for two different markers: the first, a lipid, known as BrGDGT, can be used to reconstruct temperature.
“If you have a complete enough record, you can directly link the changing structures of the lipids to changing temperature,” says Isla Castañeda, professor of geosciences at UMass Amherst and one of the paper’s co-authors.
A second marker, derived from the waxy coating on plant leaves, can be used to determine the rates at which the grasses and other livestock-sustaining plants lost water due to evaporation. It is therefore an indicator of how dry conditions were.
What we discovered is that, while the temperature barely changed over the course of the Norse settlement of southern Greenland, it became steadily drier over time.
Norse farmers had to overwinter their livestock on stored fodder, and even in a good year, the animals were often so weak that they had to be carried to the fields once the snow finally melted in the spring.
Under conditions like that, the consequences of drought would have been severe. An extended drought, on top of other economic and social pressures, may have tipped the balance just enough to make the Eastern Settlement unsustainable.
Scientists at Smith College and the University at Buffalo also contributed to the research, which was supported by the National Science Foundation, UMass Amherst, the Geological Society of America, and the Swiss National Science Foundation, changes our understanding of early European history, and highlights the importance of continuing to explore how environmental factors influence human society.
The new findings change our understanding of early European history and highlight the importance of continuing to explore how environmental factors influence human society.
The Vikings are remembered as fierce fighters, but even these mighty warriors were no match for climate change. Scientists recently found that ice sheet growth and sea-level rise led to massive coastal flooding that inundated Norse farms and ultimately drove the Vikings out of Greenland in the 15th century.
The Vikings first established a foothold in southern Greenland around A.D. 985 with the arrival of Erik Thorvaldsson, also known as “Erik the Red,” a Norwegian-born explorer who sailed to Greenland after being exiled from Iceland.
Other Viking settlers soon followed, forming communities in Eystribyggð (Eastern Settlement) and Vestribyggð (Western Settlement) that thrived for centuries. (At the time of the Vikings’ arrival, Greenland was already inhabited by people of the Dorset Culture, an Indigenous group that preceded the arrival of the Inuit people in the Arctic, according to the University of California Riverside).
Around the 15th century, signs of Norse habitation in the region vanished from the archaeological record.
Researchers previously suggested that factors such as climate change and economic shifts likely led the Vikings to abandon Greenland.
Now, new findings show that rising seas played a key role, by submerging miles of coastline, according to data presented Wednesday (Dec. 15) at the annual conference of the American Geophysical Union (AGU), held this week in New Orleans and online.
Between the 14th and 19th centuries, Europe and North America experienced a period of significantly cooler temperatures, known as the Little Ice Age.
Under these chilly conditions, the Greenland Ice Sheet — a vast blanket of ice covering most of Greenland — would have become even bigger, Marisa Julia Borreggine, a doctoral candidate in the Department of Earth and Planetary Sciences at Harvard University, said in a presentation at the AGU conference.
As the ice sheet advanced, its increasing heaviness weighed down the substrate underneath, making coastal areas more prone to flooding, Borreggine said.
At the same time, the increased gravitational attraction between the expanding ice sheet and large masses of sea ice pushed more seawater over Greenland’s coast.
These two processes could have driven widespread flooding along the coastline — “exactly where the Vikings were settled,” Borreggine said.
The scientists tested their hypothesis by modeling estimated ice growth in southwestern Greenland over the 400-year period of Norse occupation and adding those calculations to a model showing sea-level rise during that time. Then, they analyzed maps of known Viking sites to see how their findings lined up with archaeological evidence marking the end of a Viking presence in Greenland.
Their models showed that from about 1000 to 1400, rising seas around Greenland would have flooded Viking settlements by as much as 16 feet (5 meters), affecting about 54 square miles (140 square kilometers) of coastal land, Borreggine said.
This flooding would have submerged land that the Vikings used for farming and as grazing pastures for their cattle, according to the models.
However, sea-level rise was probably not the only reason the Vikings left Greenland.
Other types of challenges can cause even long-standing communities to collapse, and a perfect storm of external pressures — such as climate change, social unrest and resource depletion — may have spurred the Vikings to abandon their settlements for good, Borreggine said.
“A combination of climate and environmental change, the shifting resource landscape, the flux of supply and demand of exclusive products for the foreign market, and interactions with Inuit in the North all could have contributed to this out-migration,” she said. “Likely a combination of these factors led to the Norse migration out of Greenland and further west.”
Massive Greenland shark believed to be up to 512 years old has been found
Greenland sharks are now the longest-living vertebrates known on Earth, scientists say. Researchers used radiocarbon dating to determine the ages of 28 of the animals and estimated that one female was about 512 years old. The team found that the sharks grow at just 1cm a year, and reach sexual maturity at about the age of 150.
The research is published in the journal Science. Lead author Julius Nielsen, a marine biologist from the University of Copenhagen, said: “We had our expectations that we were dealing with an unusual animal, but I think everyone doing this research was very surprised to learn the sharks were as old as they were.”
The former vertebrate record-holder was a bowhead whale estimated to be 211 years old. But if invertebrates are brought into the longevity competition, a 507-year-old clam called Ming holds the title of the most aged animal.
Greenland sharks are huge beasts, that can grow up to 5m in length. They can be found, swimming slowly, throughout the cold, deep waters of the North Atlantic.
With this leisurely pace of life and sluggish growth rate, the sharks were thought to live for a long time. But until now, determining any ages was difficult. For some fish, scientists are able to examine ear bones called otoliths, which when sectioned, show a pattern of concentric rings that scientists can count as they would the rings in a tree.
Sharks are harder, but some species, such as the Great White, have calcified tissue that grows in layers on their backbones, which can also be used to age the animals.
“But the Greenland shark is a very, very soft shark – it has no hard body parts where growth layers are deposited. So it was believed that the age could not be investigated,” Mr Nielsen told the BBC. However, the team found a clever way of working out the age.
“The Greenland shark’s eye lens is composed of a specialised material – and it contains proteins that are metabolically inert,” explained Mr Neilson.
“Which means after the proteins have been synthesised in the body, they have not renewed anymore. So we can isolate the tissue that formed when the shark was a pup, and do radiocarbon dating.”
The team looked at 28 sharks, most of which had died after being caught in fishing nets as by-catch. Using this technique, they established that the largest shark – a 5m-long female – was extremely ancient. Because radiocarbon dating does not produce exact dates, they believe that she could have been as “young” as 272 or as old as 512. But she was most likely somewhere in the middle, so about Greenland sharks are now the longest-living vertebrates known on Earth, scientists say. Researchers used radiocarbon dating to determine the ages of 28 of the animals and estimated that one female was about 512 years old. years old. It means she was born between the years 1501 and 1744, but her most likely date of birth was in the 17th century.
“Even with the lowest part of this uncertainty, 272 years, even if that is the maximum age, it should still be considered the longest-living vertebrate,” said Mr Nielsen.
Conversely, if her age is at the upper end of the scale, she will have out-lived Ming the clam – although her age has a greater probability of lying in the middle.
The team believes the animals only reach sexual maturity when they are 4m-long. And this new, very lengthy age range, suggests this does not occur until the animals are about 150 years old. The researchers say this has consequences for the future conservation of the animals. Because of their extreme longevity, Greenland sharks may still be recovering from being over-fished before WW2. The sharks’ livers were once used for machine oil, and they were killed in great numbers before a synthetic alternative was found and the demand fell.
“When you evaluate the size distribution all over the North Atlantic, it is quite rare that you see sexually mature females, and quite rare that you find newborn pups or juveniles,” Mr Nielsen explained.
“It seems most are sub-adults. That makes sense: if you have had this very high fishing pressure, all the old animals – they are not there anymore. And there are not that many to give birth to new ones.
“There is, though, still a very large amount of ‘teenagers’, but it will take another 100 years for them to become sexually active.” Another author of the study, Prof Christopher Ramsey, director of Oxford Radiocarbon Accelerator Unit at the University of Oxford, said that radiocarbon dating could be used to determine the ages of other animals, but was not likely to be chosen as the primary method.
“For many animals, we have other methods to determine age,” he said.
“Also, the radiocarbon method is not very precise, and so is only really relevant for very long-lived species.” He added that the statistical method used to determine the sharks’ ages was Bayesian statistics.
“Bayesian statistics were first worked out by the Rev Bayes in the 18th Century. This means he will have been working on this when some of these oldest sharks were young.”
Scientists stunned to discover plants beneath mile-deep Greenland ice
In northwestern Greenland in 1966, US Army scientists drilled through nearly a mile of ice and pulled up a fifteen-foot-long tube of dirt from the bottom. Then this frozen sediment was lost in a freezer for decades. It was accidentally rediscovered in 2017.
In 2019, University of Vermont scientist Andrew Christ looked at it through his microscope — and couldn’t believe what he was seeing: twigs and leaves instead of just sand and rock. That suggested that the ice was gone in the recent geologic past — and that a vegetated landscape, perhaps a boreal forest, stood where a mile-deep ice sheet as big as Alaska stands today.
Over the last year, Christ and an international team of scientists — led by Paul Bierman at UVM, Joerg Schaefer at Columbia University, and Dorthe Dahl-Jensen at the University of Copenhagen — have studied these one-of-a-kind fossil plants and sediment from the bottom of Greenland. Their results show that most, or all, of Greenland, must have been ice-free within the last million years, perhaps even the last few hundred thousand years.
“Ice sheets typically pulverize and destroy everything in their path,” says Christ, “but what we discovered was delicate plant structures — perfectly preserved. They’re fossils, but they look like they died yesterday. It’s a time capsule of what used to live on Greenland that we wouldn’t be able to find anywhere else.”
The discovery helps confirm a new and troubling understanding that the Greenland ice has melted off entirely during recent warm periods in Earth’s history — periods like the one we are now creating with human-caused climate change.
Understanding the Greenland Ice Sheet in the past is critical for predicting how it will respond to climate warming in the future and how quickly it will melt. Since some twenty feet of sea-level rise is tied up in Greenland’s ice, every coastal city in the world is at risk. The new study provides the strongest evidence yet that Greenland is more fragile and sensitive to climate change than previously understood — and at grave risk of irreversibly melting off.
“This is not a twenty-generation problem,” says Paul Bierman, a geoscientist at UVM in the College of Arts & Sciences, Rubenstein School of Environment & Natural Resources, and fellow in the Gund Institute for Environment. “This is an urgent problem for the next 50 years.”
The new research was published March 15 in the Proceedings of the National Academy of Sciences.
Beneath the Ice
The material for the new PNAS study came from Camp Century, a Cold War military base dug inside the ice sheet far above the Arctic Circle in the 1960s. The real purpose of the camp was a super-secret effort, called Project Iceworm, to hide 600 nuclear missiles under the ice close to the Soviet Union. As a cover, the Army presented the camp as a polar science station.
The military mission failed, but the science team did complete important research, including drilling a 4560-foot-deep ice core. The Camp Century scientists were focused on the ice itself — part of the burgeoning effort at the time to understand the deep history of Earth’s ice ages. They, apparently, took less interest in a bit of dirt gathered from beneath the ice core. Then, in a truly cinematic set of strange plot twists, the ice core was moved from an Army freezer to the University of Buffalo in the 1970s, to another freezer in Copenhagen, Denmark, in the 1990s, where it languished for decades — until it surfaced when the cores were being moved to a new freezer.
For much of the Pleistocene — the icy period covering the last 2.6 million years — portions of the ice on Greenland persisted even during warmer spells called “interglacials.” But most of this general story has been pieced together from indirect evidence in mud and rock that washed off the island and was gathered by offshore ocean drilling. The extent of Greenland’s ice sheet and what kinds of ecosystems existed there before the last interglacial warm period — that ended about 120,000 years ago — have been hotly debated and poorly understood.
The new study makes clear that the deep ice at Camp Century — some 75 miles inland from the coast and only 800 miles from the North Pole — entirely melted at least once within the last million years and was covered with vegetation, including moss and perhaps trees. The new research, supported by the National Science Foundation, lines up with data from two other ice cores from the center of Greenland, collected in the 1990s. Sediment from the bottom of these cores also indicates that the ice sheet was gone for some time in the recent geologic past.
The combination of these cores from the center of Greenland with the new insight from Camp Century in the far northwest gives researchers an unprecedented view of the shifting fate of the entire Greenland ice sheet.
The team of scientists used a series of advanced analytical techniques — none of which were available to researchers fifty years ago — to probe the sediment, fossils, and the waxy coating of leaves found at the bottom of the Camp Century ice core. For example, they measured ratios of rare forms — isotopes — of both aluminum and the element beryllium that form in quartz only when the ground is exposed to the sky and can be hit by cosmic rays. These ratios gave the scientists a window into how long rocks at the surface were exposed vs. buried under layers of ice. This analysis gives the scientists a kind of clock for measuring what was happening in Greenland in the past.
Another test used rare forms of oxygen, found in the ice within the sediment, to reveal that precipitation must have fallen at much lower elevations than the height of the current ice sheet, “demonstrating ice sheet absence,” the team writes.
Combining these techniques with studies of luminescence that estimate the amount of time since sediment was exposed to light, radiocarbon-dating of bits of wood in the ice, and analysis of how layers of ice and debris were arranged — allowed the team to be clear that most, if not all, of Greenland, melted at least once during the past million years — making Greenland green with moss and lichen, and perhaps with spruce and fir trees.
And the new study shows that ecosystems of the past were not scoured into oblivion by ages of glaciers and ice sheets bulldozing overtop. Instead, the story of these living landscapes remains captured under the relatively young ice that formed on top of the ground, frozen in place, and holds them still.
In a 1960’s movie about Camp Century created by the Army, the narrator notes that “more than ninety percent of Greenland is permanently frozen under a polar ice cap.” This new study makes clear that it’s not as permanent as we once thought. “Our study shows that Greenland is much more sensitive to natural climate warming than we used to think — and we already know that humanity’s out-of-control warming of the planet hugely exceeds the natural rate,” says Christ.
“Greenland may seem far away,” says UVM’s Paul Bierman, “but it can quickly melt, pouring enough into the oceans that New York, Miami, Dhaka — pick your city — will go underwater.”
Oldest fossils on Earth discovered in 3.7bn-year-old Greenland rocks
According to recent research, tiny sediment ripples on an ancient seafloor, captured inside a 3.7 billion-year-old rock in Greenland, possibly the earliest fossils of living organisms ever found on Earth.
The research, led by Allen Nutman, head of the School of Earth and Environmental Sciences at the University of Wollongong in Australia, described the discovery of what looks like tiny waves, 0.4 to 1.5 inches (1 to 4 centimeters) high, frozen in a cross-section of the surface of an outcrop of rock in the Isua Greenstone Belt in southwestern Greenland, a formation made up of what geologists regard as the oldest rocks on the Earth’s surface.
The researchers said the ripples are the fossilized remains of cone-shaped stromatolites, layered mounds of sediment, and carbonates that build up around colonies of microbes that grow on the floor of shallow seas or lakes.
According to the scientists, the new discovery, detailed online today in the journal Nature, supports theories that life on Earth originated during the so-called Hadean eon more than 4 billion years ago, a period of intense volcanic activity when large meteorites and icy comets frequently bombarded Earth. This was also the time when the first bodies of water formed on the planet’s surface.
The rock outcrop was found only after a series of warm summers in southwestern Greenland caused large patches of snow at the site to melt earlier than normal, revealing rocks that had not been examined by researchers since the Isua Greenstone Belt was first explored in the 1980s, Nutman told Live Science.
“Most of the rocks there are very deformed and modified by later mountain-building processes, but you do find just very tiny little areas that have survived with their original volcanic or sedimentary structures not destroyed,” Nutman said. “But this is the first one of the surviving structures where we actually have stromatolites.”
Remarkably, the structures were found in an outcrop of metamorphic rock that was once subject to intense underground heating and pressure, which distorted their original shapes and changed their chemical composition.
“The overall features, such as the shape of the stromatolites, are preserved,” Nutman said. “But some of the finer details of the very fine layering have certainly been erased — although, as we show in the paper, there are vestiges of that left.”
Sediment structures that look like stromatolites can form without the involvement of microbial life, but the researchers said they examined the chemistry and minerals in the rocks and were able to establish that they contain the fossilized remains of a colony of ancient microbes.
The 3.7-billion-year-old structures described in the new study are about 220 million years older than the fossils previously regarded as the oldest known fossils on Earth. Those 3.5-billion-year-old stromatolites, found in sedimentary rocks in Western Australia, precipitated over billions of years without metamorphic heating. Abigail Allwood, an astrobiologist at NASA’s Jet Propulsion Laboratory in Pasadena, California, whose 2006 study about the Australian fossils established their biological origin, said the new study will likely face close scrutiny.
“These kinds of discoveries always do [cause controversy], especially when they first come out, and in this case, it’s particularly amazing because they were found in metamorphic rocks that have been significantly altered and transformed from their original characteristics,” Allwood told Live Science.
Allwood reviewed the new study by Nutman and his colleagues for a separate opinion piece published in the journal Nature. Allwood’s 2006 study is cited in the new paper, but she did not contribute directly to the latest research.
“It’s remarkable that they have found [the structures], and they’ve done a good job of analyzing what’s there — but the alteration that the rocks have seen means that there’s just a whole lot of stuff that you’d typically like to see to make such an extraordinary claim, that just isn’t preserved,” she said.
Life or nonlife?
Geochemist Balz Kamber, chair of geology and mineralogy at Trinity College Dublin in Ireland, has also studied the stromatolite fossils from Western Australia. He told Live Science that the new finds would no doubt face further scientific tests to assess the strength of the claims for a biological origin. But he added that the new structures appear to be a far better prospect for evidence of ancient life than another set of fossils reported nearly two decades ago on Greenland’s Akilia Island, which were later shown not to have a biological origin.
Kamber also said there can be little doubt that the conical structures identified in the new research are the result of sedimentation on the floor of a marine environment, regardless of whether they can be shown to have a biological origin. This means that the structures are not only evidence of standing bodies of water on the Earth’s surface 3.7 billion years ago, but also bodies of land crossed by rivers that carried chemical solutes into the ancient oceans, he said.
Both Kamber and Allwood also said the new findings have implications for the field of astrobiology and the search for evidence of past life on other planets — particularly on Mars. Kamber said these potential clues about the very early emergence of life on Earth in the Hadean period supports his own recent research, published earlier this year, about the prospects for life in the water-filled craters caused by meteorite and comet impacts on the early Earth.
“I think the enclosed impact basins at the tail end of the bombardment at 3.8 [billion] to 3.85 billion years ago would have made great places for life to emerge from,” he said.
Allwood added that there is also clear evidence that, at the time the rocks at Isua were forming 3.7 billion years ago, conditions on Mars were similar to those on early Earth.
“[T]here were similar environments in bodies of water standing at the surface of Mars, offering a similar kind of environment to the ones that hosted the early evidence of life on Earth, at Isua and younger,” she said.
Until now, there had been a gap between the start of the fossil record on Earth and the youngest areas on Mars, where there was good evidence for standing bodies of water in the past.
“And you had to imagine that life could have arisen there before they dried up — but now at least we may have one example in the fossil record showing us that life can arise that quickly,” Allwood said.
Surprise: Ancient Inuit Mummy Scans Reveal Possible Heart Disease
While omega-3 diets are rich in fish, The 500-year-old Inuit mummies discovered in Greenland tell scientists of their suffering from clogged arteries that they are intended to protect from plaque build-up in the arteries.
Atherosclerosis is a condition in which the walls of arteries become blocked with fat and calcium and it is known this condition was suffered at least 6,000 years ago but none of the humans remains studied thus far was known to eat a marine-based diet. Now, however, researchers have studied four Inuit mummies and found evidence of arterial clogging.
Atherosclerosis is the build-up of plaques of fat, cholesterol, and calcium in one’s arteries and the disease is a leading cause of death in modern wealthy countries, thought to be caused by poor dietary control.
However, a new paper published in the journal JAMA Network Open challenges this commonly held notion after scientists studied the remains of four 16th-century Inuit hunters found in Greenland who also suffered from clogged-up arteries, despite their diets being rich in omega-3 fatty acids.
While the condition is often seen as resulting from modern lifestyles and diets, evidence of atherosclerosis has been found in human remains dating back as far as around 4,000 BC, but none of those tested bodies had eaten a diet rich in omega-3 fatty acids.
Four incredibly well-preserved 16th-century Inuit mummies who ate omega 3-rich diets were tested with a view to seeing if the fatty acid improved arterial health, and the results suggest diets rich in omega-3 may not assure resistance to arterial plaque build-up, leading to the researchers considering that other factors might be at play.
According to a report in The Daily Mail, a team of scientists led by cardiologist L. Samuel Wann of Ascension Healthcare in Milwaukee studied the Inuit mummies taken from the collections of the Peabody Museum of Archaeology and Ethnology in Cambridge. Originally discovered on the island of Uunartaq, off the coast of Greenland in 1929 and dated to the 1500s, the mummies include two men and two women between the ages of 18–30.
Living in stone huts supported with whale bones and seal skins, the kayak hunters would have used wooden spears, bows, and arrows to kill fish, marine mammals, birds, and caribou, and with their greatly marine-based diets, their veins would have surged with omega-3 fatty acids.
But CT scans of the mummies’ insides were analyzed by Dr. Wann and his team of four cardiologists and two radiologists which showed ‘calcified atheroma’ which is an accumulation of fatty plaque material in the arteries, similar to modern humans with atherosclerosis.
The condition, and the diseases it can cause, is the single biggest cause of death in the developed world and is responsible for one in three fatalities.
Over time, blood vessels harden and narrow, which restricts the flow of blood around the body, and when these plaque deposits rupture they form a blood clot that can further block the flow of oxygenated blood which can result in a stroke or heart attack.
According to the Heart Research Institute atherosclerosis often begins in childhood and worsens with age damaging the endothelium, a thin layer that keeps the inside of our arteries smooth.
Once damaged, ‘bad’ cholesterol accumulates in the artery wall the body sends immune cells to clean up this cholesterol, which can then get stuck in the damaged site and this is what builds up over time leading to blockages.
This new study presents evidence for the “presence of calcified plaques in the mummified remains of 3 young Inuit individuals living 500 years ago,” the researchers wrote in their paper, and that omega 3 rich diets might not guarantee against plaque buildup as currently believed.
However, according to Discover Magazine, the researchers urge caution for other factors that might be at play, like environmental smoke produced by the use of indoor fires.