This species of shark lives for hundreds of years. Here’s one reason why.

By Clifton Leaf and Sy Mukherjee
July 27, 2017

The longest-living vertebrate on the planet isn’t a tortoise or a whale or even Mel Brooks. It’s a shark—the arctic-dwelling Greenland shark, to be precise. Or so a group of researchers contend in a paper published in Science last year.

Working out of labs in Denmark, Norway, Greenland, the UK, and the U.S., the marine scientists relied on radiocarbon dating to determine the age of Greenland sharks and concluded that the oldest of the animals they tested had lived nearly four centuries (um…give or take about 120 years).

While not everybody buys the assertion, there is other evidence to support the inordinate longevity of these ice-water creatures. Greenland sharks, which are born roughly 42 centimeters long, are very slow growing, getting about a centimeter longer every year. Adults, meanwhile, can easily range from 400 to 500 centimeters (from 13 to nearly 16 ½ feet). Do the math and that can put the oldest at just shy of the half-millennium mark.

So, why are these fish so durable? It has likely to do, at least in part, with their frigid artic environment—which likely slows down both their rate of growth and their metabolism. The notion that metabolic rate is tied to longevity (the less robust biochemical activity is in the species, generally speaking, the longer the lifespan) is an idea that traces back to 1927, to a trio of lectures given by Johns Hopkins biologist Raymond Pearl at University College, London. “If the average rate of metabolism or of energy expenditure is high the duration of life will tend to be shortened,” he said.

The lectures became a now-classic book, The Rate of Living, which largely kicked off the study of biogerontology. Pearl called this energy expenditure “a measure of ‘aliveness’ or vitality.” Which, of course, suggests an awkward syllogism: The more alive a species is, the shorter its life.

The metabolic theory, in turn, dovetails with another: the notion that as energy expenditure increases, so do the amount of “free radical” molecules or reactive oxygen species—which can damage DNA and other cell components. That gives us a handy mechanism—oxidative stress—by which active critters hasten their demise.

But there’s one mystery that has yet to be resolved: How did sharks get their feral, voracious, never-resting street rep if, in truth, many of their ilk are—how shall we put this—metabolically slow?

After all, it’s not just the ancient Somniosus microcephalus (Greenland shark) that’s a lethargic swimmer. So, too, is the nurse shark, which basically treats the ocean floor as a giant La-Z-Boy, grabbing the occasional lobster or conch as it crawls by, and barely breaking a sweat. The nurse shark’s metabolic rate is a mere 18% of the mako’s—and the breed is flourishing.

My takeaway? Take a breather this summer. Bring out your inner lazy shark. Enjoy a quiet lobster at the beach and don’t rush home. Who knows? Maybe you’ll live longer.

The news below.

Clifton Leaf, Editor in Chief, FORTUNE
@CliftonLeaf
clifton.leaf@fortune.com

DIGITAL HEALTH

U.S. scientists successfully modify human embryos. In a first, scientists at the Oregon Health and Science University have for the first time (in the U.S.) genetically modified a human embryo. The technology involved? You guess it, CRISPR, the groundbreaking gene-editing technique that’s been heralded as a potential avenue for treating diseases ranging from sickle cell to HIV/AIDS. Lead researcher Shoukhrat Mitalipov was reportedly able to successfully correct genes that would have caused inherited genetic diseases (the embryos were only allowed to develop for a few days). Before this effort, Chinese scientists had published reports of using CRISPR on human embryos. (Engadget)

FDA preps new plan for digital health software certification. Food and Drug Administration Commissioner Scott Gottlieb is continuing his gambit to drag the agency into the 21st century, particularly when it comes to digital health. Gottlieb has made reforming the mobile health and digital health application certification process a key priority. And now, the FDA is launching a new optional pre-certification program toward that end. “FDA’s traditional approach to moderate and higher-risk, hardware-based medical devices is not well suited for the faster and iterative design, development, and validation used for software products,” the agency writes in an update. “The Software PreCert Pilot Program is a voluntary program that will enable us to develop a tailored approach toward regulating this technology by looking first at the software developer and/or digital health technology developer, rather than primarily at the product, which is what we currently do for more traditional medical devices.”


INDICATIONS

AstraZeneca slammed in Thursday trading on key clinical trial failure. British pharma giant AstraZeneca’s shares tanked a staggering 15% in Thursday trading (no joke for a $70 billion-plus market cap company) after a devastating clinical setback for its cancer drug combination. A combination of durvalumab and tremelimumab was unable to best chemotherapy in a closely watched study of lung cancer patients called the MYSTIC trial—a major blow to the firm’s cancer immunotherapy ambitions. CEO Pascal Soriot sounded a brave note, arguing later data in 2018 on overall survival rates could prove positive. But that didn’t stop tongues from wagging about AstraZeneca potentially becoming a takeover target. (Fortune)

Gilead finally claims a stronger-than-expected quarter. Shares of biotech Gilead Sciences rose modestly in Thursday trading after the company notched a much-needed victory, beating out Wall Street expectations in its second quarter 2017 earnings report. This was largely driven by a much larger-than-expected bump in its hepatitis C franchise; however, Leerink analysts cautioned that the turnaround may be short-lived as Gilead continues to face competition in both its hepatitis C and HIV drug portfolios. (Barron’s)


THE BIG PICTURE

The latest Senate health care bill will be hashed out at some point today. It’s a day that ends in “day,” which means more votes on the Senate’s Godot-esque health care bill. After the failure of the first two efforts (a broad repeal-and-replace plan and yesterday’s smackdown of a more simple repeal, with the help of nine and seven GOP Senators, respectively) the Senate is literally, at this very moment, attempting to construct a so-called “skinny repeal” bill that GOP leaders hope can cobble together 50 votes. What might such a bill include? Reportedly, so far, a repeal of Obamacare’s individual mandate, a partial repeal of its employer mandate, some funding here and there for community health centers, and a provision addressing waivers that give states flexibility to opt out of various Obamacare requirements. But that last provision, which is extremely important to conservatives, may not actually be permissible under a Senate procedural rule called the Byrd Rule, as per the Senate parliamentarian. Then again, none of these details may really matter at all as GOP leaders like Sen. John Cornyn are now openly admitting they would like to pass something in order to continue the legislative process and get to a conference committee with the House of Representatives. Will 50 Senators get on board? We should find out soon.

Yemeni cholera outbreak spurs warring factions to ease paths to aid. According to the Associated Press, various warring sides in Yemen’s ongoing civil conflict have agreed to work to help aid organizations by clearing war-time obstacles as a cholera and malnutrition epidemic sweeps the nation. There have now been more than 400,000 documented cholera cases in Yemen and an estimated two million children there are acutely malnourished.


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