Extreme weather increasing level of toxins in food, scientists warn
As they struggle to deal with more extreme weather, a range of food crops are generating more of chemical compounds that can cause health problems for people and livestock who eat them, scientists have warned.
A new report by the United Nations Environment Programme (UNEP) says that crops such as wheat and maize are generating more potential toxins as a reaction to protect themselves from extreme weather.
But these chemical compounds are harmful to people and animals if consumed for a prolonged period of time, according to a report released during a United Nations Environment Assembly meeting in Nairobi.
"Crops are responding to drought conditions and increases in temperature just like humans do when faced with a stressful situation,” explained Jacqueline McGlade, chief scientist and director of the Division of Early Warning and Assessment at UNEP.
Under normal conditions, for instance, plants convert nitrates they absorb into nutritious amino acids and proteins. But prolonged drought slows or prevents this conversion, leading to more potentially problematic nitrate accumulating in the plant, the report said.
If people eat too much nitrate in their diets, it can interfere with the ability of red blood cells to transport oxygen in the body, the report said.
Crops susceptible to accumulating too much nitrate in times of stress include maize, wheat, barley, soybeans, millet and sorghum, it said.
DROUGHT, THEN RAIN
Some drought-stressed crops, when then exposed to sudden large amounts of rain that lead to rapid growth, in turn accumulate hydrogen cyanide, more commonly known as prussic acid, the report said.
Prussic acid – one of the ingredients used in some types of chemical warfare - interferes with oxygen flow in humans. Even short-term exposure can be debilitating for people, McGlade said.
Plants such as cassava, flax, maize and sorghum are most vulnerable to dangerous prussic acid accumulation, the report said.
Cases of nitrate or hydrogen cyanide poisoning in humans were reported in Kenya in 2013 and in the Philippines in 2005, McGlade said. In Kenya, two children died in coastal Kilifi after eating cassava that had raised levels of prussic acid in it following extreme rainfall, according to local media reports.
Aflatoxins, molds that can affect plant crops and raise the risk of liver damage, cancer and blindness, as well as stunting foetuses and infants, also are spreading to more areas as a result of shifting weather patterns as a result of climate change, scientists said.
McGlade said about 4.5 billion people in developing countries are exposed to aflatoxins each year, though the amounts are largely unmonitored, and the numbers are rising.
"We are just beginning to recognise the magnitude of toxin- related issues confronting farmers in developing countries of the tropics and sub-tropics," the report noted.
"As warmer climate zones expand towards the poles, countries in more temperate regions are facing new threats," it added.
In 2004, Kenya suffered severe outbreaks of aflatoxin poisoning, which affected more than 300 people and killed more than 100 following a prolonged drought, according to the International Livestock Research Institute.
EUROPE AT RISK
The UNEP report said Europe will be at growing risk from aflatoxins in locally grown crops if global temperatures rise by at least 2 degrees Celsius. The world is currently on a path to a more than 3 degree Celsius temperature rise, scientists believe.
An increase in toxic compounds in crops is likely to impact heavily on the world’s health system, which are already struggling with the effects of food insecurity, Dorota Jarosinska of the World Health Organization’s European Center for Environment and Health said in an interview with the Thomson Reuters Foundation.
Alex Ezeh, executive director of the African Population Health and Research Center, said the increase in toxins in crops was a big concern.
"Toxic crops can lead to neurological diseases among humans but the greatest challenge is the incidence of cancer,” he said in an interview.
The report proposes a list of eight ideas farmers and agricultural experts can adopt to try to limit damage from more crop toxins, such as mapping contamination hotspots and building better evidence about what is happening now with the toxins in their area.
Scientists also suggest that developing crop varieties designed to cope with extreme weather could help reduce the levels of toxic chemicals in food.
"Research centers with the Consultative Group on International Agricultural Research are developing seeds that are suitable in various regions that have been hit by climate change,” McGlade said.
New incentives needed to develop antibiotics to fight superbugs
Drugmakers are renewing efforts to develop medicines to fight emerging antibiotic-resistant bacteria, but creating new classes of drugs on the scale needed is unlikely to happen without new financial incentives to make the effort worth the investment, companies and industry experts said.
American military researchers on Thursday announced the first U.S. case of a patient with an infection found to be resistant to the antibiotic colistin, the drug often held in reserve for when all else fails.
That put a spotlight on the urgent need for new medicines that can combat what health officials have called "nightmare bacteria."
Drugmakers on Friday acknowledged that in the absence of a new way of compensating them, it simply does not make economic sense to pour serious resources into work on new antibiotics.
"The return on investment based on the current commercial model is not really commensurate with the amount of effort you have to put into it," said David Payne, who heads GlaxoSmithKline PLC's antibiotics drug group.
Other pharmaceutical companies expressed a similar sentiment.
In January, some 80 drugmakers and diagnostics companies, including Pfizer Inc, Merck & Co, Johnson & Johnson and Glaxo, signed a declaration calling for cooperation among governments and companies to create incentives to revitalize research and development of new antibiotics.
It proposed a new business model in which profit would not be linked to higher sales. For example, governments and health organizations could offer lump-sum rewards for development of a successful new antibiotic. A British government panel suggested this month that drug companies be offered up to $1.5 billion for successful development of a new antibiotic.
In the United States alone, antibiotic-resistant bacteria causes 2 million serious infections and 23,000 deaths annually, according to U.S. health officials.
Unrestrained overuse of current antibiotics by doctors and hospitals, often when they are not needed, and widespread antibiotic use in food livestock have contributed to the evolution of antibiotic-resistant bacteria.
But in recent years, major drugmakers have poured most of their research dollars into highly profitable medicines to fight cancer, rare diseases and hepatitis C. These drugs not only command high prices, they also are typically used far longer than antibiotics.
And the companies, which have come under intense criticism in recent months for continually raising prices on popular drugs, say it costs about as much to develop a new antibiotic as it does to bring to market new cancer drugs that can command more than $100,000 a year per patient.
"Drug companies can't make an economic case for investing in superbug drugs," said Erik Gordon, a professor at the University of Michigan's Ross School of Business.
Gordon said governments and foundations need to get more involved in research and funding to spearhead efforts to combat the problem.
To critics who argue that U.S. companies have enormous cash reserves that could be used to address a public health crisis, drugmakers say they have a fiduciary duty to shareholders to maximize profits.
ON THE R&D FRONT LINES
One reason companies are calling for alternative compensation is that aggressive sales and use of new antibiotics could help create ever more dangerous bacteria that develop resistance to the new medicines.
Glaxo and Merck are among the large pharmaceutical companies developing new antibiotics they hope can beat back resistant bugs, while Pfizer is working on vaccines aimed at reducing the need for their use.
Industry experts said small, lesser-known companies with promising approaches to tackling resistant superbugs included: Entasis Therapeutics, an AstraZeneca PLC spinoff, Tetraphase Pharmaceuticals Inc; and Achaogen Inc.
"We believe plazomicin, our lead drug in late-stage development, has the potential to play an important role in treating this dreaded superbug," Achaogen Chief Executive Kenneth Hillan said.
Allan Coukell, an antibiotics expert at the Pew Charitable Trusts nonprofit research and policy organization, said what is needed is a wave of new drugs based on new chemistry or that work in new ways.
"Most of what's being developed are variations on drugs that we've had for decades," Coukell said.
Pew has outlined what its calls a scientific roadmap to create a body of work around new drug discovery that companies and academic researchers could draw upon to help jumpstart the process of finding new antibiotics.
Glaxo said its experimental antibiotic gepotidacin, in midstage testing, belongs to an entirely new class of antibacterials.
"Based on that, we're predicting it would work against infections that could be caused by bacteria that are resistant to available antibiotics," Payne said.
Other companies with late-stage studies underway for antibiotics include: Cempra Inc, whose drug was recently validated in a Japanese trial; Medicines Co; and Paratek Pharmaceuticals Inc. J&J is also putting money into battling antibiotic resistance.
"If there is a bright side, it is that the world policymakers and health leaders have focused on this issue like never before," Coukell said. "But we've got a long way to go."
WHO rejects call for Olympics to be moved due to Zika
LONDON: The World Health Organization (WHO) on Saturday rejected a call for the Rio Olympic Games to be moved or postponed due to the threat posed by large outbreak of Zika virus in Brazil.
Responding to a call from more than 100 leading scientists, who said it would be unethical for the Games to go ahead as scheduled, the United Nations health agency said having the Games in Rio as planned would "not significantly alter" the spread of Zika, which is linked to serious birth defects.
"Based on the current assessment of Zika virus circulating in almost 60 countries globally and 39 in the Americas, there is no public health justification for postponing or cancelling the games," the WHO said in a statement.
In a public letter posted online on Friday, around 150 leading public health experts, many of them bioethicists, said the risk of infection from the Zika virus is too high for the Games to go ahead safely.
The letter was sent to Margaret Chan, the WHO's director-general, and said that the Games, due to be held in Rio de Janeiro in August, should be moved to another location or delayed.
"An unnecessary risk is posed when 500,000 foreign tourists from all countries attend the Games, potentially acquire that strain, and return home to places where it can become endemic," the letter said.
But the WHO rejected the call, saying Brazil "is one of almost 60 countries and territories" where Zika has been detected and that people continued to travel between these countries and territories for a variety of reasons.
"The best way to reduce risk of disease is to follow public health travel advice," it said.
The WHO's advice is that pregnant women should not travel to areas with ongoing Zika virus transmission, including Rio de Janeiro. It also advises everyone to make all efforts to protect against mosquito bites and to practice safe sex.
Zika infection in pregnant women has been shown to be a cause of the birth defect microcephaly and other serious brain abnormalities in babies.
The connection between Zika and microcephaly first came to light last fall in Brazil, which has confirmed more than 1,400 cases of microcephaly.
Medical experts want Rio Olympics delayed or moved due to Zika
- LONDON/WASHINGTON: More than 100 medical experts, academia and scientists on Friday have called for the Rio Olympic Games to be postponed or moved because of fears that the event could speed up the spread of the Zika virus around the world.Their assessment counters the view of some leading experts of infectious disease who say that as long as the necessary precautions are taken there is no reason to cancel the Games. On Thursday, Dr. Tom Frieden, director of the U.S. Centers for Disease Control and Prevention, declared there was no public health reason to cancel or delay this summer's Games.In a public letter posted online, the group of 150 leading public health experts, many of them bioethicists, said the risk of infection from the Zika virus is too high. The letter was sent to Dr. Margaret Chan, director-general of the World Health Organization, and urged that the Games, due to be held in Rio de Janeiro in August, be moved to another location or delayed."An unnecessary risk is posed when 500,000 foreign tourists from all countries attend the Games, potentially acquire that strain, and return home to places where it can become endemic," the letter said. It can be found at rioolympicslater.org/Bioethicists study ethical problems arising from biological or medical research. Professor Arthur Caplan, director of the division of medical ethics at New York University School of Medicine and one of four who authored the letter, said he is skeptical Brazil has the resources to protect the public and is equally skeptical of "general assurances" from public health officials.The letter called on the WHO to convene an independent group to advise it and the International Olympic Committee."I believe in informed consent," Caplan said in an interview. "Let's have an independent set of scientists look at this and let everyone hear the arguments."Citing the "greater concern for global health", the letter also said, "The Brazilian strain of Zika virus harms health in ways that science has not observed before."Speaking at a lunch at the National Press Club in Washington on Thursday, Frieden said there was no reason to delay the Olympics.He was responding to a paper by a Canadian professor published earlier this month in the Harvard Public Health Review which called for the Games to be canceled or moved because it could speed the spread of Zika."The risk is not particularly high other than for pregnant women," Frieden said.Zika infection in pregnant women has been shown to be a cause of the birth defect microcephaly and other serious brain abnormalities in babies.The connection between Zika and microcephaly first came to light last fall in Brazil, which has confirmed more than 1,400 cases of microcephaly.Frieden's view is shared by many infectious disease experts. A recent editorial in The Lancet Infectious Diseases journal noted that the Zika outbreak has been concentrated in northeastern Brazil, away from Rio. Moreover, it added, the infection-carrying mosquito is not particularly active in August and athletes and spectators are likely to spend their time in places purged of mosquito breeding sites."Available evidence indicates that for games participants, risk of exposure to Zika virus and subsequent adverse health outcomes will be low," it said.
Chronic sleep deprivation tied to more depression for young women
- One night of short sleep may lead to less depression the following day, but chronic short sleep is tied to greater depression overall for young women, according to a new study.“The overall message that poor quality and insufficient sleep lead to poor mood, which, in turn, worsens sleep was not surprising,” said lead author David A. Kalmbach of the University of Michigan Medical School in Ann Arbor.More noteworthy, he added, was that these relationships were evident in healthy, young women, not just insomniacs or depressed people.The researchers studied 171 female college students for two weeks, beginning with an in-person questionnaire assessment of anxiety and depression levels and continuing with daily self-reported measures of mood and anxiety. The women also reported their total sleep time, time to fall asleep, and ratings of sleep quality each night.On average, the women slept for seven hours and 22 minutes each night, taking 21 minutes to fall asleep. Overall, they rated their sleep quality “fairly good.”At the start of the study, a third of the women scored in the “at risk” range for depression and 17 percent had clinically significant anxiety.Women who averaged less sleep per night over the two-week period tended to report greater “anhedonic” depression symptoms, or the inability to enjoy pleasurable things. But they also tended to report more of these symptoms the day after a night of particularly long sleep, as reported in Sleep Medicine.One night of sleep deprivation may improve mood the following day. But unfortunately, “therapeutic effects of a night of sleep deprivation are typically short-lasting, and because chronic sleep deprivation increases depression-risk, the therapeutic benefit of sleep deprivation on depression is modest at best,” Kalmbach said.When women felt greater general distress, they took longer to fall asleep and slept more poorly. Higher levels of depression symptoms tended to come before a night of longer time to fall asleep, shorter total sleep time and poorer sleep quality.Depending on the cause of the sleep problems, treatment for depression and anxiety can improve sleep quality, Kalmbach told Reuters Health by email.“Unfortunately,” he added, “for depressed and/or anxious individuals who have successfully gone through psychiatric treatment and no longer have a diagnosis, what we see is that sleep problems often linger, because they do not fully resolve.”Treatments for sleep apnea and insomnia have helped ease depression symptoms, but treatments for sleep disorders are not a cure for depression or anxiety, he said.“Sleep and mood are similarly related in men and older women such that sleep problems worsen mood and vice versa, and that the relationship between depression and poor sleep is stronger than the relationship between anxiety and sleep,” he said.“People who are concerned with their sleep or believe they may have a sleep disorder should seek the help of a sleep physician or sleep psychologist to discuss treatment options,” Kalmbach said. “Early attention toward sleep problems is likely to lessen risk for depression or anxiety, which can develop over time when sleep problems are not addressed.”
U.S. health official says Zika not a reason to cancel Olympics
- The widespread Zika virus outbreak in Brazil does not pose enough of a threat to warrant canceling or putting off the Olympic Games set to be held in Rio de Janeiro in August, a leading U.S. health official said on Thursday ."There is no public health reason to cancel or delay the Olympics," Dr. Tom Frieden, director of the U.S. Centers for Disease Control and Prevention, said during a luncheon at The National Press Club in Washington.A controversial paper by a Canadian professor published earlier this month in the Harvard Public Health Review called for the Games to be canceled or moved because it said they would likely speed up the spread of Zika throughout the world. Several health experts have disputed the report as lacking evidence for such a move."The risk to delegations going and athletes is not zero, but the risk of any travel isn't zero. The risk is not particularly high other than for pregnant women," Frieden said.Zika infection in pregnant women has been shown to be a cause of the birth defect microcephaly and other serious brain abnormalities in babies.The World Health Organization has also said there is strong scientific consensus that Zika can also cause Guillain-Barre, a rare neurological syndrome that causes temporary paralysis in adults.
No comments:
Post a Comment