Talk About a Global Obesity Problem: Animals Are Getting Fatter Too
Obesity is a growing global health problem, and we all know why, don't we? It's the fault of corporations that sell corn syrup, and a starkly unequal society (why would you want to quit smoking if you're trapped below the poverty level?) Or, if you prefer a different flavor of self-righteousness, how about: a lack of personal responsibility and moral fiber (nobody made you eat all those fries, mister). Ideologues on the left and on the right like to claim they have this one covered. So what I liked about this paper is the way it plays havoc with the usual talking points. It reports that over the past 50 years, as American people became fatter, so did American chimpanzees, rats, marmosets, dogs, cats and other animals. That can't be because the chimps took office jobs and the cats got into eating out. Our public conversation about the causes of obesity is missing something.
In the paper, published last month in the Proceedings of the Royal Society B, Yann Klimentidis and his co-authors looked at animals' adult body weight over the past five decades in 24 populations of eight different species that live around people—from wild rats in Baltimore to captive chimpanzees. Every one showed an increase in average body weight over time. As Carrie Arnold reported, the average weight of lab mice in the study rose 12 percent per decade, and captive marmosets gained an average of 9 percent per decade. Chimps, for some reason, are doing especially badly, as Travis Saunders noted at Obesity Panacea: Their average body weight has risen 33 percent per decade.
What's causing this multi-species obesity epidemic? If it were humanity—if, for instance, people used to eating more themselves were giving more food to their dogs and cats and lab rats—then untamed populations shouldn't have been affected. But the researchers found that feral animals were also getting pudgier. The street rats in Baltimore showed an average weight increase of nearly 7 percent per decade. That's more than the captive rats in the study, whose average gain was 3 percent.
In any event, research protocols track precisely how animals are housed and fed, so Klimentidis et al. are sure that lab animals' steady weight gain wasn't caused by changes in their food or activities.
So what is the underlying cause? The answer, say the researchers, is to ideologues what garlic is to a vampire: We don't know. A good overview of the possibilities is here (hat tip to Saunders, who recommends this very interesting paper). David Allison of the University of Alabama, one of the Royal Society B study's authors, told Arnold he thinks the answer or answers likely will be found in industrial chemicals and viruses. It appears that the question's wide open, to (I hope) the consternation of people who want us to believe they have figured obesity out.
Klimentidis, Y., Beasley, T., Lin, H., Murati, G., Glass, G., Guyton, M., Newton, W., Jorgensen, M., Heymsfield, S., Kemnitz, J., Fairbanks, L., & Allison, D. (2010). Canaries in the coal mine: a cross-species analysis of the plurality of obesity epidemics Proceedings of the Royal Society B: Biological Sciences DOI: 10.1098/rspb.2010.1890
Keith, S., Redden, D., Katzmarzyk, P., Boggiano, M., Hanlon, E., Benca, R., Ruden, D., Pietrobelli, A., Barger, J., Fontaine, K., Wang, C., Aronne, L., Wright, S., Baskin, M., Dhurandhar, N., Lijoi, M., Grilo, C., DeLuca, M., Westfall, A., & Allison, D. (2006). Putative contributors to the secular increase in obesity: exploring the roads less traveled International Journal of Obesity, 30 (11), 1585-1594 DOI: 10.1038/sj.ijo.0803326
Upstreamism advocate Rishi Manchanda calls us to understand health not as a "personal responsibility" but a "common good."
- Upstreamism tasks health care professionals to combat unhealthy social and cultural influences that exist outside — or upstream — of medical facilities.
- Patients from low-income neighborhoods are most at risk of negative health impacts.
- Thankfully, health care professionals are not alone. Upstreamism is increasingly part of our cultural consciousness.
- Climate change is no longer a financial problem, just a political one.
- Mitigating climate change by decarbonizing our economy would add trillions of dollars in new investments.
- Public attitudes toward climate change have shifted steadily in favor of action. Now it's up to elected leaders.
Researchers hope the technology will further our understanding of the brain, but lawmakers may not be ready for the ethical challenges.
- Researchers at the Yale School of Medicine successfully restored some functions to pig brains that had been dead for hours.
- They hope the technology will advance our understanding of the brain, potentially developing new treatments for debilitating diseases and disorders.
- The research raises many ethical questions and puts to the test our current understanding of death.
The image of an undead brain coming back to live again is the stuff of science fiction. Not just any science fiction, specifically B-grade sci fi. What instantly springs to mind is the black-and-white horrors of films like Fiend Without a Face. Bad acting. Plastic monstrosities. Visible strings. And a spinal cord that, for some reason, is also a tentacle?
But like any good science fiction, it's only a matter of time before some manner of it seeps into our reality. This week's Nature published the findings of researchers who managed to restore function to pigs' brains that were clinically dead. At least, what we once thought of as dead.
What's dead may never die, it seems
The researchers did not hail from House Greyjoy — "What is dead may never die" — but came largely from the Yale School of Medicine. They connected 32 pig brains to a system called BrainEx. BrainEx is an artificial perfusion system — that is, a system that takes over the functions normally regulated by the organ. The pigs had been killed four hours earlier at a U.S. Department of Agriculture slaughterhouse; their brains completely removed from the skulls.
BrainEx pumped an experiment solution into the brain that essentially mimic blood flow. It brought oxygen and nutrients to the tissues, giving brain cells the resources to begin many normal functions. The cells began consuming and metabolizing sugars. The brains' immune systems kicked in. Neuron samples could carry an electrical signal. Some brain cells even responded to drugs.
The researchers have managed to keep some brains alive for up to 36 hours, and currently do not know if BrainEx can have sustained the brains longer. "It is conceivable we are just preventing the inevitable, and the brain won't be able to recover," said Nenad Sestan, Yale neuroscientist and the lead researcher.
As a control, other brains received either a fake solution or no solution at all. None revived brain activity and deteriorated as normal.
The researchers hope the technology can enhance our ability to study the brain and its cellular functions. One of the main avenues of such studies would be brain disorders and diseases. This could point the way to developing new of treatments for the likes of brain injuries, Alzheimer's, Huntington's, and neurodegenerative conditions.
"This is an extraordinary and very promising breakthrough for neuroscience. It immediately offers a much better model for studying the human brain, which is extraordinarily important, given the vast amount of human suffering from diseases of the mind [and] brain," Nita Farahany, the bioethicists at the Duke University School of Law who wrote the study's commentary, told National Geographic.
An ethical gray matter
Before anyone gets an Island of Dr. Moreau vibe, it's worth noting that the brains did not approach neural activity anywhere near consciousness.
The BrainEx solution contained chemicals that prevented neurons from firing. To be extra cautious, the researchers also monitored the brains for any such activity and were prepared to administer an anesthetic should they have seen signs of consciousness.
Even so, the research signals a massive debate to come regarding medical ethics and our definition of death.
Most countries define death, clinically speaking, as the irreversible loss of brain or circulatory function. This definition was already at odds with some folk- and value-centric understandings, but where do we go if it becomes possible to reverse clinical death with artificial perfusion?
"This is wild," Jonathan Moreno, a bioethicist at the University of Pennsylvania, told the New York Times. "If ever there was an issue that merited big public deliberation on the ethics of science and medicine, this is one."
One possible consequence involves organ donations. Some European countries require emergency responders to use a process that preserves organs when they cannot resuscitate a person. They continue to pump blood throughout the body, but use a "thoracic aortic occlusion balloon" to prevent that blood from reaching the brain.
The system is already controversial because it raises concerns about what caused the patient's death. But what happens when brain death becomes readily reversible? Stuart Younger, a bioethicist at Case Western Reserve University, told Nature that if BrainEx were to become widely available, it could shrink the pool of eligible donors.
"There's a potential conflict here between the interests of potential donors — who might not even be donors — and people who are waiting for organs," he said.
It will be a while before such experiments go anywhere near human subjects. A more immediate ethical question relates to how such experiments harm animal subjects.
Ethical review boards evaluate research protocols and can reject any that causes undue pain, suffering, or distress. Since dead animals feel no pain, suffer no trauma, they are typically approved as subjects. But how do such boards make a judgement regarding the suffering of a "cellularly active" brain? The distress of a partially alive brain?
The dilemma is unprecedented.
Setting new boundaries
Another science fiction story that comes to mind when discussing this story is, of course, Frankenstein. As Farahany told National Geographic: "It is definitely has [sic] a good science-fiction element to it, and it is restoring cellular function where we previously thought impossible. But to have Frankenstein, you need some degree of consciousness, some 'there' there. [The researchers] did not recover any form of consciousness in this study, and it is still unclear if we ever could. But we are one step closer to that possibility."
She's right. The researchers undertook their research for the betterment of humanity, and we may one day reap some unimaginable medical benefits from it. The ethical questions, however, remain as unsettling as the stories they remind us of.
A plan to forgive almost a trillion dollars in debt would solve the student loan debt crisis, but can it work?
- Sen. Elizabeth Warren has just proposed a bold education reform plan that would forgive billions in student debt.
- The plan would forgive the debt held by more than 30 million Americans.
- The debt forgiveness program is one part of a larger program to make higher education more accessible.
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