Thinking of popping to your nearest specialist store for some sesame oil, turmeric, or soy? Some things haven't changed in 3,700 years, it turns out...
At least, that's what a growing new field of research, palaeoproteomics, suggests. Human mouths are full of bacteria, which continually petrify and form dental calculus — which can entrap and preserve tiny food particles. These remnants can be accessed and analysed thousands of years later, providing remarkable insight into the dietary habits of our ancestors.
Philip Stockhammer, an archaeologist at the Ludwig Maximilian University of Munich (LMU), has worked with Christina Warinner, a molecular archaeologist at Harvard University and the Max Planck Institute for the Science of Human History, and a team of researchers to apply this new method to the eastern Mediterranean, including the Bronze Age site of Megiddo and the Early Iron Age site of Tel Erani.
“Our high-resolution study of ancient proteins and plant residues from human dental calculus is the first of its kind to study the cuisines of the ancient Near East,” said Warinner, explaining its significance. “Our research demonstrates the great potential of these methods to detect foods that otherwise leave few archaeological traces. Dental calculus is such a valuable source of information about the lives of ancient peoples.”
High-resolution analyses of ancient dental calculus have given us a whole new perspective on the diets of Bronze Age people.
The research team took samples from a range of individuals and analysed which food proteins and plant residues were preserved in their teeth. “This enables us to find traces of what a person ate,” said Stockhammer. “Anyone who does not practice good dental hygiene will still be telling us archaeologists what they have been eating thousands of years from now!”
Of course, it's not quite as simple as looking at the teeth of those who didn't thoroughly clean them nearly four millennia ago and hoping the proteins survived. “Interestingly, we find that allergy-associated proteins appear to be the most stable in human calculus”, remarked Ashley Scott, LMU biochemist and lead author. That might be because of the known thermostability of many allergens. For instance, the researchers were able to detect wheat via wheat gluten proteins, which they independently confirmed with a different method using a type of plant microfossil known as phytoliths.
This substance has previously been used to identify millet and date palm in the same area during the Bronze and Iron Ages but phytoliths are not plentiful or even present in many foods, which is why this research is so exciting — palaeoproteomics means foods that have left few other traces, such as sesame, can now be identified.
Research suggests that the humble banana was eaten throughout the Mediterranean far earlier than first thought.
The method has allowed the team to identify that people at these sites ate, among other things, sesame, turmeric, soy, and bananas far earlier than anyone had realised. “Exotic spices, fruits and oils from Asia had thus reached the Mediterranean several centuries, in some cases even millennia, earlier than had been previously thought,” explained Stockhammer.
The finds mean that we have direct evidence for a flourishing long-distance trade in fruits, spices, and oils, from East and South Asia to the Levant via Mesopotamia or Egypt as early as the second millennium BCE.
More than that, the analyses "provide crucial information on the spread of the banana around the world. No archaeological or written evidence had previously suggested such an early spread into the Mediterranean region,” according to Stockhammer (although the sudden appearance of bananas in West Africa a few centuries later has previously led archaeologists to believe that such a trade might have existed, this is the first evidence).
The team acknowledged that other explanations are possible, including that the individuals concerned had travelled to East or South Asia at some point but there is evidence for other trade in food and spices in the Eastern Mediterranean — for instance, we know Pharaoh Ramses II was buried with peppercorns from India in 1213 BCE.
But it certainly seems like some foods might have been popular in the Mediterranean for much longer than we realised, which might be an interesting thought to accompany you next time you add some spices or bananas to your shopping basket.
Galen (129-216 CE) is one of the most famous and influential medical practitioners in history but he was also a scientist, an author, a philosopher, and a celebrity. He wrote hundreds of treatises, travelled and studied widely, was the physician to three emperors, and left a legacy of scientific thought that lasted for fifteen hundred years — even today, his work has an influence.
Header image Editorial credit: Eray Adiguzel / Shutterstock.com
He grew up in Pergamum, an intellectual centre of the Mediterranean world, in a wealthy family that encouraged him to pursue academia and funded his travels to learn in the best environments available, acquiring the latest techniques in medicine and healing.
He understood that diet, exercise, and hygiene were essential for good health and put that into practice in the four years he spent working for the High Priest of Pergamum's Gladiator School. This was a high profile and high pressure role and we know he reduced the death rate dramatically in his four years there. The recommendation he got helped secure him a position in Rome, capital of the empire.
He was not popular in the city — at one point, he seems to have been chased out by the local physicians, who strenuously disagreed with his methods — but he was eventually summoned by the emperor Marcus Aurelius to be his personal physician. He was described by the emperor as, “First among doctors and unique among philosophers".
Galen; Line engraving | Credit: Wellcome Images, Wikimedia Commons
Galen continued to navigate the difficult political environment of the imperial capital and was personal physician to two more emperors, while publishing prolifically and becoming one of the most well-known figures in the Roman Empire. Much of his work is lost to us but we still know a great deal about him, including that he had a flair for showmanship and controversy.
In the Greek world where he grew up, dissections had been common — of animals and humans. In Rome, this was not the case. In fact, human dissections were banned across the empire shortly before Galen arrived in the city. Undaunted, he gave a number of public anatomical demonstrations using pigs, monkeys, sheep, and goats to show his new city what they were missing (this was one of many incidents that contributed to local dislike of his methods as well as his increasing fame).
His legacy was huge, both because he recorded and critiqued the work of others in his field and because of the huge volumes of his own observations and theories. His texts were the foundation for much of medical education in the Islamic, Byzantine, and European worlds until the 17th Century.
The ban on human dissection likely limited his progress in some areas and many of his theories have (eventually) been disproved, such as the theory of the four humours — blood, black bile, yellow bile, and phlegm — based on Hippocrates' system and elaborated, as well as the efficacy of bloodletting.
Galen observed that cataracts could be removed.
In other areas, however, he was remarkably successful. He observed that the heart has four valves that allow blood to flow in only one direction, that a patient's pulse or urine held clues to their disease, that urine forms in kidneys (previously thought to be the bladder), that arteries carry liquid blood (previously thought to be air), that cataracts could be removed from patients' eyes, among others. He also identified seven of the 12 cranial nerves, including the optic and acoustic nerves.
His focus on practical methods such as direct observation, dissection, and vivisection is obviously still relevant to modern medical research. Indeed, scientists who disproved his theories, such as Andreas Vesalius and Michael Servetus in the 16th century, did so using Galen's own methods.
The study of his work remains hugely important to the history and understanding of medicine and science, as well as the ancient world. The Galenic formulation, which deals with the principles of preparing and compounding medicines in order to optimise their absorption, is named after him.
Nowhere on earth has the power to inspire awe and wonder in the endless outcomes of evolution than a natural history museum. It’s a bold claim, but where else can you find over 500m years of biodiversity?
In a good museum, visitors can literally walk around open mouthed in astonishment at seeing the biggest animals that ever lived – whales and dinosaurs – and specimens showing extraordinary biological processes, like how a two-metre tall kangaroo is born the size of a jelly bean.
But lurking within these wondrous collections are chemical legacies of the ways they were prepared and preserved that can make museums a risky place to work. Here are four of them…
One of the main challenges of caring for a biological collection is that everything is edible, and we have to work hard to ensure that insect pests like clothes moths, carpet beetles and silverfish don’t nibble our specimens out of existence. Unchecked, they can turn invaluable objects into dust. When it comes to taxidermy and skins, the practice until recently was to coat the inside of the skins with arsenic soap or other poisons such as heavy metals or even strychnine and cyanide.
A taxidermy ocelot at the University Museum of Zoology. Image: University of Cambridge/Chris Green
While these are extremely effective at killing pests, they have the potential to make us very ill. If a specimen is old but looks in good condition, it’s likely to have been treated in this way. Short story: don’t stroke a museum skin unless you know for sure it’s poison-free.
Another mainstay of museum collections is animals preserved in jars of fluid. The first step in preparing these specimens is called ‘fixation’, which keeps the animal in suspended animation by halting the decomposition process at a cellular level, causing cross-links between molecules (including DNA). Formalin is a solution of the toxic and carcinogenic gas formaldehyde.
Preserved fish collected by Charles Darwin on the voyage of the Beagle at the University Museum of Zoology. Image: University of Cambridge/Chris Green
3. Alcohol preservative
The second step in preparing fluid specimens is to store them permanently in a preservative, and the most common is a solution of ethanol. Vodka, gin, rum, brandy etc. are all solutions of alcohol, and indeed sailors on historic voyages of discovery would find that the naturalist on board had commandeered their booze rations to preserve an important specimen.
Today, we tend to use stronger solutions of ethanol – at 70% – as it is more effective. Ethanol is obviously consumable, so why is this in a list of dangers? The ethanol museums use is called industrial methylated spirits, or denatured alcohol: it has a tiny bit of methanol added.
The toxic methanol has no beneficial properties for preservation – it’s there simply to stop museum workers from drinking it (and means that it isn’t subject to the high tax rates of alcoholic drinks).
Geological collections come with a whole different suite of hazards. Many minerals are inherently poisonous, or can break down in museum conditions to release toxic gasses. Others are naturally radioactive. If you’ve got a lump of uranium ore in your collection, that’s a pretty obvious risk, but there are also certain locations that a lot of fossils come from that have relatively high levels of radiation.
Museums have to be careful about how these are stored as once we lock these fossils up in a museum drawer or cabinet, the concentration of radioactivity in that sealed environment builds up over time, releasing a dangerous cloud once the drawer is eventually opened.
I should say that museums are pretty clued up on managing these risks, and there is no danger to the visiting public. Just don’t lick anything.
Cassie Sims is a PhD researcher at Rothamsted Research in Harpenden, UK. Photo: Rothamsted
Rothamsted Research is the oldest agricultural research station in the world – we even have a Guinness World Record for the longest running continuous experiment! Established in 1843, next year we celebrate our 175th anniversary, and as a Chemistry PhD student at the institute today, I can’t wait to celebrate.
Wheat samples from the record-breaking Broadbalk experiment. Photo: Cassie Sims
Rothamsted is known for many amazing scientific accomplishments, and it has a rich history, which I have explored through many of the exhibitions put on by the institute for the staff every month or so.
One of the old labs set up for the exhibitions we hold at Rothamsted. Photo: Cassie Sims
Working in what was the Biological Chemistry department, I am following in the footsteps of Chemists such as Michael Elliott, who developed a group of insecticides known as pyrethroids. These are one of the most prolific insecticides used in the world, still widely used today and researched here at Rothamsted – in particular, the now-prevalent insecticidal resistance to them.
I was privileged to view an exhibit of Michael Elliott’s medals late last year at Rothamsted – one of the opportunities we are given as staff here. Recently, I was also able to view a collection of calculators and computers from the earliest mechanical ones, to Sir Ronald Fisher’s very own ‘Millionaire’ Calculator, which could multiply, add and subtract entirely mechanically.
Sir Ronald Fisher’s ‘Millionaire’ Calculator. Photo: Cassie Sims
In more recent times, Rothamsted has had an update (a little more than a lick of paint) with newer buildings, labs and equipment constantly being added. My office and lab are situated in the architecturally interesting Centenary building, which was built only 10 years ago. Some of the research has had an update too – plant science research is a bit more focused on molecular biology these days, and our chemistry has been significantly advanced over the last century by advances in analytical equipment.
A few years ago, Rothamsted was briefly the centre of media attention due to a ‘controversial’ GM field trial testing wheat made to emit (E)-β-farnesene, the aphid alarm pheromone, and whether the plants could repel aphids.
…they couldn’t, but this was one of the first type of GM trials of its type, and it was an interesting study that combined many disciplines of science, from molecular biology and plant science, to entomology and chemical ecology.
Rothamsted is not just about science, either – we have a few longstanding social traditions such as Hallowe’en parties and Harvest Festival, not forgetting of course my favourite; our summer Sports Day, which provides much entertainment in the form of serious research scientists participating in sack races to win some outstandingly tacky trophies. We also have an onsite bar (if that is what you could call it), which is a little more like a converted cricket club, and serves as a venue for most events, and has been the location of many of my great memories.
If I had to describe being a student at Rothamsted in one word, it would be weird! There is a lot of fun to be had, but we are also surrounded by an incredible history that we cannot forget as we forge a new path in our fields (literally and scientifically!).
I hope one day that I can leave some kind of mark here – but even if not, I will be happy to have been part of such a prestigious institute and to have worked alongside such great scientific minds.
What are the sustainability challenges being tackled by researchers at Rothamsted? Sir John Beddington, Chair of the Rothamsted Research Board gave this talk at SCI in London in September – part of our ongoing programme of free-to-attend public evening lectures.
A world with a rapidly increasing population needs a rapidly increasing food supply. However, with a limited amount of land to work with, farmers must maximise agricultural production on the land they have available.
Modern-day intensive agriculture techniques include mechanical ploughing, chemical fertilisers, plant growth regulators, pesticides, biotech, and genetic modification.
1. Crop production has rapidly expanded in the past few centuries
Farming has drastically changed since the time this picture was taken at the California Manzanar Relocation Centre in 1943. Image: Ansel Adams
Worldwide, the amount of cultivated land increased 466% between 1700 and 1980, with global food production doubling four times between 1820 and 1975. In 1940, the average farmworker supplied 11 consumers; in 2006, each supplied 144 customers. Two out of five American labourers were farmers in 1900, but now only one in 50 work in agriculture. In 1830, five acres of wheat took 250-300 hours of work to produce. By 1975, it only took 3¾ hours.
2. Crops can be grown without soil
Organic hydroponic culture in Ho Chi Minh, Vietnam. Image: Frank Fox
Using a crop-growing method called hydroponics, instead of putting plants in soil, a mineral solution is pumped around the roots. This makes it possible to grow crops in regions with low-quality soil or none at all, increasing the amount of space that can be used for agriculture. This technique also allows for the nutrients to be effectively recycled and eliminates the risk of soil organisms that cause disease.
3. At least 90% of the soy, cotton, canola, corn, and sugar beets sold in the US are GMOs
Since the 1970s, scientists have been working on genetically modifying crops to make them tougher, disease-resistant, more nutritious, and higher yielding. Though the first commercially available GMO came onto the market just 23 years ago, global markets have already been transformed by the ground-breaking innovation.
4. Regenerative grazing increases the health and productivity of pastures
Image: Tom Koerner/USFWS
Regenerative grazing - staggering grazing on different plots of land according to a calendar – has proven to increase soil health. By allowing plots to rest after grazing, the soil and anything living in it is able to recover before the next time it is used. Regenerative grazing cultivates fields with less bare soil and increases populations of earthworms and soil organisms. Not only that, it also eliminates the need for chemical fertiliser, increases grass growth by 14%, and causes a 10% decrease in carbon footprint per litre of milk.
5. Agricultural robots are transforming the industry
If you’re interested in the issues surrounding global food sustainability, you can watch the full video of Sir John Beddington’s recent SCI Andrew Medal Lecture: ‘Global Sustainability Challenges: Food, Water, and Energy Security’, here.