LONGTIME FRIENDS Credit: Linda Wang/C&EN

Paul Greengard says he isn’t necessarily convinced he should be part of this story. He’s been told it’s about chemists who are still working in their 90s. With blue eyes twinkling, he offers a playful smile and points out that he’s only 89 and is usually described as a neuroscientist.

COVER STORY Sustained by Science Pondering A Push Toward Retirement

To the latter point, Greengard’s research on the biochemistry of neurodegenerative and psychiatric diseases puts him squarely in chemistry’s camp. And this December he’ll mark the milestone birthday that will put him in an elite group of scientists who continue their work in some capacity into their 90s and beyond.

Becoming a nonagenarian is an achievement worth celebrating. But being willing and able to continue working at an age when most of a person’s contemporaries have been retired for decades demonstrates a special devotion to one’s work. Some of the scientists run active research groups. Others stay engaged through collaborations and writing. Doing science, these chemists say, keeps them active and sharp.

NOT QUITE A NONAGENARIAN [+]Enlarge Credit: Piotr Redlinski

“No artist stops working, and I think really dedicated scientists—unless their health doesn’t allow it—are the same way,” Greengard says. “We’re in a creative profession, so it never even occurred to me to stop.”

Advancing age doesn’t appear to be slowing Greengard down either. He works, on average, six days a week from 9 AM to 10 PM—the same schedule he’s worked for decades.

With a splendid view of Manhattan’s East Side, Greengard’s lab at Rockefeller University takes up the entire ninth floor of a research building. For the past decade, his group—currently 65 members—has published an average of 15 peer-reviewed papers each year. And he continues to receive funding from the National Institutes of Health as well as from private foundations. (For more on NIH and older scientists, see page 14.)

Greengard shared the 2000 Nobel Prize in Physiology or Medicine, a distinction that has attracted many scientists to work with him. But he confesses that with his advancing age, he sometimes worries about what would happen to the people who work for him if he were suddenly not around.

Nevertheless, he’s eager to talk about the progress his group is making on major depressive disorder and understanding how selective serotonin reuptake inhibitors achieve their antidepressive effect. “That’s one of the things that keeps me coming to the lab instead of reading Tolstoy, which I would love to do,” he says. “I just love this a little more.”

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Credit: Ty Finocchiaro / C&EN

Fifty blocks uptown, Koji Nakanishi is headed into his office at Columbia University, where he is an emeritus professor. He cruises through the door with a sleek black walker, opens his bag, and tosses the latest issue of Science on his desk.

The office is dominated by a wall of shelves loaded with ox figurines—everything from fine porcelain collectibles to plastic Fisher-Price toys. The collection, Nakanishi explains, arose because the year of his birth, 1925, is the Year of the Ox in the Chinese zodiac. In an adjacent room, birthday cards marking Nakanishi’s 90th cover a large table from corner to corner. They’re from well-wishers all over the world.

Because of a fall earlier this year, Nakanishi was forced to mark that auspicious day, which was May 11, in the hospital. But he’s since rallied, and his friends and colleagues held a belated birthday party for him at the end of June.

Nakanishi says that he’s slowed down compared with just a few years ago. But, he points out, “my motivation has not changed.” He’s still interested in learning about natural products, particularly the ginkgolides, which have been used to treat migraines. He says he’s on the verge of publishing one of his most exciting research papers. It’s a collaboration spearheaded by Hunter College chemistry professor Akira Kawamura to identify the ginkgolides’ target in the brain.

“I like working,” Nakanishi says, noting that he’s grateful to his parents for instilling a strong work ethic in him. “It’s my natural state.”

The same might be said for Jack D. Dunitz, 92. Although the crystallographer officially retired from his professorial duties at the Swiss Federal Institute of Technology (ETH), Zurich, 25 years ago, he still makes his way into the office most weekdays. Macular degeneration, a condition causing impaired vision, has kept him from driving in recent years, but by taking a bus, a train, and then another bus, he’s able to make the trip from his home to ETH Zurich in just under an hour.

“I am aware that it does me good to have discipline in my life, where I go out of the house and do something and try to do it nearly every day,” he says.

Earlier this year he wrote a piece commissioned by IUCrJ, an online journal published by the International Union of Crystallography. Dunitz says he made it a provocative essay, pointing out that a close intermolecular contact between a pair of atoms in a crystal is not necessarily evidence of a bonding interaction between them (IUCrJ 2015, DOI: 10.1107/s2052252515002006).

HEALTHY LIFESTYLE [+]Enlarge Credit: Caltech

The crytallographer says he is now struggling with his scientific memoirs. He recently published an essay about the first 10 years of his research career, when he worked with Dorothy Crowfoot Hodgkin as a postdoc; listened to Linus Pauling give his first lecture on the α-helix, a protein motif; solved the crystal structure of ferrocene; and was one of the first to view the double-helix model of DNA constructed by James Watson and Francis Crick. “They were exciting times,” Dunitz says. He’s currently reconstructing the subsequent 50 years of his research career.

“I very much appreciate the generosity of my colleagues here [at ETH Zurich] who provide me with this wonderful office,” Dunitz says. “Being here brings me into occasional contact with young students and researchers. They come and ask me some question or other. That keeps me in touch with young people. That’s an enormous privilege.”

Rudolph A. Marcus, who will turn 92 this week, also cites working with students as one of the things that keeps him coming into his office at California Institute of Technology every day. Marcus runs an active research group of five people. A theorist, he is currently tackling problems as diverse as the mass-independent isotope effect in ozone formation, “on water” catalysis in organic emulsions, the intermittent fluorescence of semiconductor quantum dots, the biological motor ATP synthase, and charge carriers in perovskites.

Marcus also teaches classes, which he finds particularly stimulating. “I find, in the courses I teach, that sometimes questions come up, both from the students and from myself, that lead to added or even new insights,” he says. That’s how his work on electron-transfer theory, for which he won the 1992 Nobel Prize in Chemistry, came about. A student in a graduate course asked an insightful question about whether a particular theory could be applied to understand some experiments in polyelectrolytes. This got Marcus thinking about electrostatics, which he then began to explore.

Marcus doesn’t regard the fact that he continues to do research in his 90s as anything special. “Intellectually, I feel as absorbed in my work as I did many years ago, and I think that’s probably true for anyone who is active in their 90s,” he says. He’s also driven by cogitating on problems in chemistry. “I go to sleep at night thinking about some chemistry-based problem. Trying to understand—that’s the key thing.”

It’s a common refrain among the chemists who continue to work into their 90s and beyond. “I still want to solve problems,” says Fred A. Kummerow, a 100-year-old food scientist at the University of Illinois, Urbana-Champaign (UIUC).

For nearly six decades Kummerow waged a campaign against artery-clogging trans fats. He finally declared victory last month when the Food & Drug Administration announced these fats will have to be eliminated from foods in the U.S. by 2018.

Kummerow’s latest problem is ferreting out what happens in the frying oil that’s used in fast-food restaurants. He wants to know if the oil builds up harmful compounds over time and at what point the oil needs replacing. Now, he says, there’s really no good scientific way for making that decision. He also hopes to develop a frying fat that doesn’t oxidize as rapidly as what’s currently used.

Although he officially retired from UIUC in 1978, Kummerow continues to work as an adjunct professor. These days, he mostly writes, publishing about one paper annually. Last year, he published the book “Cholesterol is Not the Culprit: A Guide to Preventing Heart Disease,” coauthored with his daughter Jean.

And Kummerow practices what he preaches. Eggs—cooked in butter, never margarine—are among his breakfast staples. He says a good diet and exercise are key to a long life. He makes a point of getting up to an hour of exercise daily.

SOURCE [+]Enlarge Credit: Jimmie Crawford/RTI International

Regular exercise also figures into Mansukh C. Wani’s routine. Wani, a principal scientist emeritus at the North Carolina-based nonprofit RTI International, says he hits a local gym several times a week to work out. Wani also goes into the office on weekdays and frequently on weekends. A codiscoverer of the natural products Taxol (paclitaxel) and camptothecin, Wani will be honored at a special symposium celebrating his 90th birthday during the American Society for Pharmacognosy meeting later this month.

Wani says he’s motivated to continue working when he sees how millions of people have benefited from paclitaxel and chemotherapy drugs based on camptothecin. “Nothing could be more satisfying than this,” he says. “What keeps me going is the fact that I’m anxious to see, hopefully before I die, this camptothecin analog I am working on become an FDA-approved drug for pancreatic cancer.”

Wani marvels at how advances in instrumentation have transformed the way natural products chemistry is done. He says it took 18 months to isolate paclitaxel from the bark of the Pacific yew tree—a feat that could be done today in a matter of weeks, thanks to modern chromatography. Likewise, the advent of nuclear magnetic resonance spectrometry and mass spectrometry has turned the years-long exercise of determining a complex molecule’s structure into a job that can also be accomplished within weeks.

Although he doesn’t work at the bench any longer, Wani remains active by consulting for a number of small companies working on developing natural products, particularly camptothecin, into drugs. He’s also part of a National Cancer Institute progam project on the discovery of anticancer agents from natural products.

“People might call me crazy,” Wani says. “I must admit, for good or for bad, that I do not have another hobby. There’s nothing more attractive than doing this work.”

“The idea of keeping active has always been a central issue with me,” agrees 95-year-old E. Gerald Meyer of his desire to continue working. “Keeping active mentally and physically is just something I do.” He jokes that he is “still foolishly working.”

An emeritus chemistry professor, Meyer retired from his duties as the University of Wyoming’s dean of arts and sciences and vice president of research in 1990. But he still maintains an office at the school that he visits most weekdays.

Meyer is also applying his chemistry expertise as president and chief executive officer of Advanced Coal to Chemicals Technologies, a company that uses a “cracking” process to convert coal to char, liquid organic chemicals, and inorganic chemicals. The work started in China but has moved to the U.S. where a demonstration plant will be built. The work takes Meyer to China several times a year.

Long trips are par for the course, as far as Meyer is concerned, whether they’re taken via a vehicle with two wings or two wheels. Some may recall photos published in C&EN of Meyer poised on his motorcycle (June 13, 2005, page 5; July 24, 2006, page 41). He even took the bike to the 2005 American Chemical Society Northwest Regional Meeting in Fairbanks, Alaska. He planned to do a 1,300-mile trek while there but missed a ferry along the way and turned the trip into an 1,800-mile odyssey.


Although he gave up the motorcycle when he turned 92, Meyer still remains active within ACS. He maintains that being a member is valuable to chemists over the course of their careers. “I’m disappointed that some young faculty members don’t see the benefit of being ACS members,” Meyer says. “I think we in the American Chemical Society need to make it better understood that it’s important for young chemists to be members.”

His longtime friend and fellow nonagenarian Helen Murray Free agrees. She’s paying for the student memberships of her two granddaughters who are studying chemistry in college. “I figure that’s more worthwhile than a scarf” as a gift, she says.

At 92, Free has been active in ACS for many decades, but she admits that she’s winding down. “I’m increasing my bridge-playing powers. I’m reading a lot of books,” she jokes.

Best known for developing diabetes self-testing kits, she still gives informal talks on her work. The week C&EN caught up with her, she had an engagement speaking at a camp for kids with diabetes.

Edward C. Taylor, an emeritus chemistry professor at Princeton University, has also been ratcheting down his working hours. He wants to spend more time with his children, grandchildren, and great-grandchildren and recently relocated from New Jersey to Minnesota to do so.

Taylor continues to write. Most recently, he wrote a chapter for the first volume in the series “Successful Drug Discovery” about his work on the cancer drug Alimta (pemetrexed). The volume came out in May. Now, he’s working on an article about collaboration between academic labs and pharmaceutical companies.

Taylor recalls that when he started doing chemistry in the 1940s, chemists studying heterocyclic molecules “were viewed as being out of the mainstream, to put it kindly,” he says. But drugs and natural products are loaded with heterocycles, Taylor points out, “and now, it’s one of the most important topics in the whole field of organic chemistry.”

Seeing new molecules and wondering how he could make them still gives Taylor a charge. “The only thing that makes me feel that I am getting old is the fact that I’m not capable of tackling those problems any longer. But nothing can prevent me from thinking about them,” he says.