INDIA
The focus of research on the potential health benefits of tea has increasingly moved from the leaf in the cup to extracted biochemical compounds in the test tube. One of these is the “magic molecule” EGCG (epigallocatechin-3-gallate) in green tea that shows powerful potential for cancer treatment.
Add to this quantum dots. These are tiny nanoparticles that recent studies have found kill cancer cells in vitro -- a term that is Latin for “within the glass”: in the lab test tube or petri dish, and on mice, using extracted cancer cells. It contrasts within vivo – within the living human body. Here, biochemical, metabolic side effect interactions and many other factors may dissipate or alter the encouraging lab results. That said, nanoparticles extracted from tea open up new horizons of application, including transforming the dangerous processes by which the particles are made and used in a wide range of industrial applications and foods.
Nanoparticles have a diameter of 1-100 nanometers. Quantum dot is the label for those around 10 nm in size. The width of a human hair is 40,000 nanometers. They have special physical, chemical and optical properties that are a product of their small size and large proportional surface area. The particles are in wide use in coloring TV screens, solar panel radiation absorption, medical imaging, materials reinforcement, drug delivery within the body, removal of contamination in groundwater and elimination of bacteria in foods and textiles. The famous adage of the science fiction writer Arthur C. Clarke, seems application to the world of nano: “Any sufficiently advanced technology is indistinguishable from magic.” This is all magical.
But it is also black magic. Producing nanoparticles is complex, hazardous and difficult to control. Many of the base materials are metals and ceramics with high potential for toxicity. They easily became environmental hazards due to the ease with which they bind to and catalyze other molecules and penetrate cell membranes. Many effects are unknown: CeO2 (cesium dioxide) particles in fuel additives are under investigation by the EPA safety research unit for environmental, ecological and health impacts, for instance.
This all may seem to have little to do with tea but several lab studies are making tea more than just relevant. The lab evidence is that certain quantum dots can be safely and inexpensively made using green tea extract as a stabilizing medium. This in itself greatly reduces risks of toxicity. Between 2010 and 2019, it has been successfully used to make silver and gold nanoparticles, by incubating. For instance, silver nitrate.
A collaborative research project between teams at the UK University of Swansea and India’s KSR Institute of Technology and Bharathiar University successfully used tea extract to incubate a cadmium sulphide and sodium sulphide mix to produce quantum dots as an alternative to chemical methods. (2018 reports.) Instead of removing the tea and disposing of it as waste, the researchers left it as part of the quantum dot composition. They then tested the dots for antibacterial properties, bioimaging application potential.
And for their impact on the growth of cancer cells. The results were a surprise. The dots are able to penetrate cancer cells through tiny nanopores. They can then be nanocarriers of cancer cell killers. In this instance, properties of the green tea reached the cells and destroyed as many as 80%. The exact causes are unclear and follow on studies will be needed before quantum dots derived from green tea are shown to be a practical and effective part of cancer prevention and cure. It’s magic.
Glyphosate
Glyphosate is the most widely used herbicide worldwide and the key ingredient in Roundup, the highly effective weed killer. Its effectiveness and impact on tea crop yields are illustrated by the three-year legal ban on its use in Sri Lanka, officially ended in 2018. Industry tea associations reported the cost of overgrowth of weeds and high manual labor costs as totaling $100 million in the first eighteen months, with corresponding erosion of export revenues.
The global market for glyphosate is expected to grow slightly faster than that of total tea production between now and 2024: around 5.5% annually versus general forecasts of tea increasing by 4.5%, the overall 2000-2016 average. The main drivers of the growth will be the need to increase crop yield per hectare to meet the demands of population increases and the likely expansion of GM (genetically modified) crops, for which Roundup has become a key resource in improving efficiency. GM is expected to enable technological developments in breeding plants for weed resistance and to increase consumer awareness and acceptance. GM crops are forecast to grow at 6%.
All these figures are expert judgments but still not reliable predictors. There are just too many uncertainties to permit extrapolation from historical trends. The most obvious are climate change and the escalating scale and disruptions of a shift in seasonal rain patterns, widespread drought, deforestation and loss of biodiversity.
What does seem clear is that the glyphosate market will move very much in sync with that of GM crops. Here, the issues center on safety. The immediate rationale for the sudden ban in Sri Lanka was a concern that glyphosate is cancerous and was the cause of widespread reports of epidemics of kidney disease in agricultural communities. The consensus in the scientific community has been that this was not accurate, but the issues of GM, Roundup, and cancer remain a constant public concern. There are documented though largely out of date disagreements among health and safety regulators about the science. The most noted is the contrast between the World Health Organization’s 2015 declaration that “Glyphosate is probably carcinogenic to humans” and that of the European Union Food Safety Authority in 2017 that it is not likely to cause DNA damage or cancer.
Here are a few other research claims that have been widely reported:
Animal studies suggest that it may disrupt beneficial gut bacteria in humans and that harmful oes may be resistant to it.
Farmers and others who work closely with glyphosate, especially those who do not use gloves, and the ones showing most adverse effects, including residues in the blood and urine and problems in pregnancy.
A longitudinal study that tracked 57,000 farmers for 20 years found no evidence of any health risks.
Regulators in most nations publicly affirm there is no link with cancer, with around 800 scientific studies and reviews supporting their conclusions.
Many advocacy groups are not convinced and the landmark punitive damages in multiple US court cases, ranging from $300 million to $2 billion, show that public and legal opinion remains in flux. That may or may not lead to new regulatory restrictions, development of alternatives herbicides or consumer resistance. For now, the estimate of market growth for glyphosate of about 5% a year seems a likely base forecast.