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.
More people are looking at their nutritional intake, not only to improve wellbeing but also reduce their environmental impact. With this, comes a move to include foods that are not traditionally cultivated or consumed in Europe.
Assessing whether this growing volume of so called ‘novel foods’ are safe for human consumption is the task of the European Food Safety Authority. The EFSA points out, ‘The notion of novel food is not new. Throughout history new types of food and food ingredients have found their way to Europe from all corners of the globe. Bananas, tomatoes, tropical fruit, maize, rice, a wide range of spices – all originally came to Europe as novel foods. Among the most recent arrivals are chia seeds, algae-based foods, baobab fruit and physalis.’
Under EU regulations any food not consumed ‘significantly’ prior to May 1997 is considered to be a ‘novel food’. The category covers new foods, food from new sources, new substances used in food as well as new ways and technologies for producing food. Examples include oils rich in omega-3 fatty acids from krill as a new source of food, phytosterols as a new substance, or nanotechnology as a new way of producing food.
Providing a final assessment on safety and efficacy of a novel food is a time consuming process. At the start of 2021 the EFSA gave its first completed assessment of a proposed insect-derived food product. The panel on Nutrition, Novel Foods and Food Allergens concluded that the novel food dried yellow meal worm (Tenebrio molitor larva) is safe for human consumption.
Dried yellow meal worm (Tenebrio molitor larva) is safe for human consumption, according to the EFSA.
Commenting in a press statement, as the opinion on insect novel food was released, Ermolaos Ververis, a chemist and food scientist at EFSA who coordinated the assessment said that evaluating the safety of insects for human consumption has its challenges. ‘Insects are complex organisms which makes characterising the composition of insect-derived products a challenge. Understanding their microbiology is paramount, considering also that the entire insect is consumed,’
Ververis added, ‘Formulations from insects may be high in protein, although the true protein levels can be overestimated when the substance chitin, a major component of insects’ exoskeleton, is present. Critically, many food allergies are linked to proteins so we assess whether the consumption of insects could trigger any allergic reactions. These can be caused by an individual’s sensitivity to insect proteins, cross-reactivity with other allergens or residual allergens from insect feed, e.g. gluten.’
EFSA research could lead to increased choice for consumers | Editorial credit: Raf Quintero / Shutterstock.com
The EFSA has an extensive list of novel foods to assess. These include dried crickets (Gryllodes sigillatus), olive leaf extract, and vitamin D2 mushroom powder. With the increasing desire to find alternatives to the many foods that we consume on a regular basis, particularly meat, it is likely that the EFSA will be busy for some time to come.
Generally, food intake measurement relies on an individual’s ability to recall what and how much they ate, which has inherent limitations. This can be overcome using biomarkers, such as urine, which contains high amounts of data, and looks to be a promising new indicator of nutritional status.
Funded by the U.S. National Institutes of Health and Health Data Research UK, the group of scientists analysed levels of 46 different metabolites in the urine of 1,848 people in the U.S, publishing their findings in the journal Nature Food.
The team illustrated the effectiveness of using metabolites in urine as an alternative approach to obtaining information on dietary patterns. Analysing the urinary metabolic profile of the individuals, they found that the 46 metabolites in urine accurately predicted healthy / unhealthy patterns, making the link between 46 metabolites in urine, as well as the types of foods and nutrients in the diet.
Urine test sample
The team believes that this technology could inspire healthy changes as health professionals could be better equipped to provide dietary advice tailored to their individual biological make-up. As Dr Isabel Garcia-Perez, author of the research also from Imperial’s Department of Metabolism, Digestion and Reproduction explained: ‘Our technology can provide crucial insights into how foods are processed by individuals in different ways.’
To build on this research, the same Imperial team, in collaboration with Newcastle University, Aberystwyth University, and Murdoch University, developed a five-minute test to measure the health of a person’s diet.
This five-minute test can reveal differences in urinary metabolites, generating a dietary metabotype score for each individual. As part of this research, 19 people were recruited to follow four different diets ranging from very healthy to unhealthy. The experiments indicated that the healthier their diet, the higher the DMS score, associating higher DMS score with lower blood sugar and a higher amount of energy excreted in the urine.
Heart in hands
Professor John Mathers, co-author of research and Director of the Human Nutrition Research Centre at Newcastle University said: ‘We show here how different people metabolise the same foods in highly individual ways. This has implications for understanding the development of nutrition-related diseases and for more personalised dietary advice to improve public health.’
The banana colour scheme distinguishes seven stages from ‘All green’ to ‘All yellow with brown flecks’. The green, unripe banana peel contains leucocyanidin, a flavonoid that induces cell proliferation, accelerating the healing of skin wounds. But once it is yellowish and ready to eat, the chlorophyll breaks down, leaving the recognisable yellow colour of carotenoids.
Unripe (green) and ready-to-eat (yellow) bananas.
The fruits are cut from the plant whilst green and on average, 10-30 % of the bananas do not meet quality standards at harvest. Then they are packaged and kept in cold temperatures to reduce enzymatic processes, such as respiration and ethylene production.
However, below 14°C bananas experience ‘chilling injury’ which changes fruit ripening physiology and can lead to the brown speckles on the skin. Above 24°C, bananas also stop developing fully yellow colour as they retain high levels of chlorophyll.
Once the green bananas arrive at the ripening facility, the fruits are kept in ripening rooms where the temperature and humidity are kept constant while the amount of oxygen, carbon dioxide and ethene are controlled.
The gas itself triggers the ripening process, leads to cell walls breakdown and the conversion of starches to sugars. Certain fruits around bananas can ripen quicker because of their ethene production.
By day five, bananas should be in stage 2½ (’Green with trace of yellow’ to ‘More green than yellow’) according to the colour scale and are shipped to the shops. From stage 5 (’All yellow with green tip’), the fruits are ready to be eaten and have a three-day shelf-life.
A fruit market. Image: Gidon Pico
The very short shelf-life of the fruit makes it a very wasteful system. By day five, the sugar content and pH value are ideal for yeasts and moulds. Bananas not only start turning brown and mouldy, but they also go through a 1.5-4 mm ‘weight loss’ as the water is lost from the peel.
While scientists have been trying out different chemical and natural lipid ‘dips’ for bananas to extend their shelf-life, such methods remain one of the greatest challenges to the industry.
In fruit salads, to stop the banana slices go brown, the cut fruits are sprayed with a mixture of citric acid and amino acid to keep them yellow and firm without affecting the taste.
Bananas are a good source of potassium and vitamins.
The high starch concentration – over 70% of dry weight – banana processing into flour and starch is now also getting the attention of the industry. There are a great many pharmaceutical properties of bananas as well, such as high dopamine levels in the peel and high amounts of beta-carotene, a precursor of vitamin A.
Whilst the ‘seven shades of yellow’ underpin the marketability of bananas, these plants are also now threatened by the fungal Panama disease. This vascular wilt disease led to the collapse of the banana industry in the 1950’s which was overcome by a new variety of bananas.
However, the uncontrollable disease has evolved to infect Cavendish bananas and has been rapidly spreading from Australia, China to India, the Middle East and Africa.
The future of the banana industry relies on strict quarantine procedures to limit further spread of the disease to Latin America, integrated crop management and continuous development of banana ‘dips’ for extending shelf-life.
2019 has been declared by UNESCO as the Year of the Periodic Table. To celebrate, we are releasing a series of blogs about our favourite elements and their importance to the chemical industry. Today’s blog is about the importance of potassium in human health.
Potassium plays an essential role to health, being the third most important mineral in the body. The human body requires at least 1000mg of potassium a day in order to support key bodily processes.
Potassium regulates fluid balance in the body, controls the electrical activity of the heart, muscles, and helps in activating nerve impulses throughout the nervous system.
According to an article from Medical News Today Knowledge Center, the possible health benefits to a regular diet intake of potassium include maintaining the balance of acids and bases in the body, supporting blood pressure, improving cardiovascular health, and helping with bone and muscle strength.
These powerful health benefits are linked to a potassium rich diet. Potassium is present in all fruits, vegetables, meat and fish.
Receptors on a cell membrane.
Can it go wrong?
The body maintains the potassium level in the blood. If the potassium level is too high in the body (hyperkalemia) or if it is too low (hypokalemia) then this can cause serious health consequences, including an abnormal heart rhythm or even a cardiac arrest.
Fortunately, cells in the body store a large reservoir of potassium which can be released to maintain a constant level of potassium in blood.
What is hyperkalemia? Video: Osmosis
Potassium deficiency leads to fatigue, weakness and constipation. Within muscle cells, potassium would normally send signals from the brain that stimulate contractions. However, if potassium levels steep too low, the brain is not able to relay these signals from the brain to the muscles, the results end in more prolonged contractions which includes muscle cramping.
As potassium is an essential mineral carrying out wide ranging roles in the body, the low intakes can lead to an increase in illness. The FDA has made a health claim, stating that ‘diets containing foods that are a good source of potassium and that are low in sodium may reduce the risk of high blood pressure and stroke.’
This suggests that consuming more potassium might reduce the risks of high blood pressure and the possibility of strokes. However, more research on dietary and supplemental potassium is required before drawing towards a set conclusion.
Combatting malnutrition in all its forms – overweight and obesity as well as undernutrition and micronutrient deficiencies – is a global problem.
The European Academies Science Advisory Council (EASAC) recently published a report calling for urgent action on food and nutrition security: this action will need to include consideration of the options for changing European diets to mitigate climate change, conferring co-benefits for health.
The European Commission estimates 51.6% of the EU’s population is overweight. Image: Tony Alter/Flickr
EASAC brings together EU member states’ national science academies with the aim of offering evidence-based advice to European policy makers. EASAC provides a means for the collective voice of European science to be heard and its recent report is part of a global project led by the InterAcademy Partnership (IAP).
The analysis and recommendations for Europe are accompanied by parallel activities focusing on Africa, Asia and the Americas. The IAP report will be published later in 2018.
EASAC recommendations will incorporate global challenges and needs, not just those in Europe. Image: Pixabay
In the EASAC report we emphasise that research and innovation are central to finding solutions. We recommend being more ambitious in identifying and using scientific opportunities: How can the current evidence base shape understanding of both supply- and demand-side challenges? And how should the research agenda be defined, including basic research, to fill knowledge gaps?
Climate change will have negative impacts on food systems, necessitating the introduction of climate-smart agriculture such as the adoption of plant breeding innovations to cope with drought.
Climate-Smart Agriculture in Action. Video: Farming First
Agriculture and current diets also contribute significantly to climate change. Mitigating this contribution depends on land-sparing and agronomic management practices together with efforts to influence consumer behaviours associated with excessive greenhouse gas emissions from agriculture, including the over-consumption of calories and meat.
Among the core findings in our report is that food consumption will need to change to improve consumer health. It is important to explore individual responsiveness to nutrition and the links to health, and to consider the particular needs of vulnerable groups.
High meat production has been linked to increasing carbon emissions. Image: Pixabay
As part of the changes to food consumption patterns, a decrease in the consumption of animal protein could be important for both health and the environment but, globally, more research is needed to clarify these relationships and to measure sustainability related to consumption of healthy diets. We also call for policy makers to introduce incentives for affordable nutrition.
Agriculture has significant impacts on the environment. We call for the revamp of the Common Agricultural Policy to focus on innovation rather than subsidies, in order to play a key role in European competitiveness and the bioeconomy.
Alternatives to traditional forms of animal protein include food from the oceans, laboratory-grown meat and insects. Research is needed to understand and inform consumer attitudes to innovative food and diets.
Also, research objectives for the next generation of biofuels should include examining the potential of cellulosic raw materials. Further ahead, energy research must continue to explore how to engineer systems with improved photosynthesis.
Biofuels are derived from common crops, including wheat, corn and sugar. Image: Public Domain Pictures
Europe should not stall on opportunities for innovation coming within range. Breakthroughs in genome editing and other genetic research are crucial to the future of agriculture. European policy makers must capitalise on these scientific advances.
For improved plant and animal breeding, it is important to protect and characterise wild gene pools and to continue sequencing and functional assessment to unveil the potential of genetic resources. Precision agriculture offers many opportunities to improve productivity with reduced environmental impact. Large data sets are vital to support innovation and prepare for risk and uncertainty.
Open-source automated precision farming | Rory Aronson | TEDxUCLA. Video: TEDx Talks
Underpinning all our recommendations is the recognition that research and innovation must be better integrated, across disciplines and the public and private sectors, in order to better understand the interfaces between health, nutrition, food and other ecosystem services.
EASAC emphasises that efforts to increase food systems’ efficiency should not focus on increasing agricultural productivity by ignoring environmental costs.
A new type of wheat, chock full of healthy fibre, has been launched by an international team of plant geneticists. The first crop of this super wheat was recently harvested on farms in Idaho, Oregon, and Washington state in the US, ready for testing by various food companies.
Food products are expected to hit the US market in 2019. They will be marketed for their high content of ‘resistant starch’, known to improve digestive health, be protective against the genetic damage that precedes bowel cancer, and help protect against Type 2 diabetes.
How do carbohydrates impact your health? Video: TED-Ed
‘The wheat plant and the grain look like any other wheat. The main difference is the grain composition: the GM Arista wheat contains more than ten times the level of resistant starch and three to four times the level of total dietary fibre, so it is much better for your health, compared with regular wheat,’ says Ahmed Regina, plant scientist at Australian science agency CSIRO.
Starch is made up of two types of polymers of glucose – amylopectin and amylose. Amylopectin, the main starch type in cereals, is easily digested because it has a highly branched chemical structure, whereas amylose has a mainly linear structure and is more resistant.
Bread and potatoes are foods also high in starch. Image: Pixabay
Breeders drastically reduced easily digested amylopectin starch by downregulating the activity of two enzymes, so increasing the amount of amylose in the grain from 20 to 30% to an impressive 85%.
The non-GM breeding approach works because the building blocks for both amylopectin and amylose starch synthesis are the same. With the enzymes involved in making amylopectin not working, more blocks are then available for amylose synthesis.
‘Resistant starch is starch that is not digested and reaches the large intestines where it can be fermented by bacteria. Usually amylose is what is resistant to digestion,’ comments Mike Keenan, food and nutrition scientist at Louisiana State University, US. ‘Most people consume far too little fibre, so consuming products higher in resistant starch would be beneficial.’
He notes that fermentation of starch in the gut causes the production of short-chain fatty acids such as butyrate that ‘have effects throughout the body, even the mental health of humans’.
The GM wheat will hit US supermarkets in 2019. Image: Pxhere
The super-fibre wheat stems from a collaboration begun in 2006 between French firm Limagrain Céréales Ingrédients, Australian science agency CSIRO, and the Grains Research and Development Corporation, an Australian government agency.
This resulted in a spin out company, Arista Cereal Technologies. After the US, Arista reports that the next markets will be in Australia and Japan.