Interview with Tomas Lindahl on 6 December 2015, during the Nobel Week in Stockholm, Sweden.

What’s your story? What brought you to science?

Tomas Lindahl: What brought me to science? My early education and I started out as a medical student in Stockholm after going to a gymnasium in a suburb of Stockholm. And the reason I went into medicine was our family had an influential uncle, Gunnar Lindahl. He was a director of a big hospital in Sweden and not only because of that he advised my parents that if I as a teenager had to make a decision about the rest of my life, its too early, so the best is to go in to a broad carrier where you later on can find something to do that you really like to do yourself. And they suggested the best I could do was to start studying medicine because if you are compassionate about your human beings, like providing care, that’s fine, but if you like more theoretical questions that may arise in a laboratory, that’s also quite compatible with being medic.

So you put off the big decision for a few years what you are actually going to do with your life and that’s wise, because you are not always capable to decide that in the best possible way when you are sixteen years old. You are a much better bet when you are in your mid-twenties. So that is how I got into medicine and sure enough it turned out that I started liking the theoretical part of medicine, especially biochemistry and microbiology and that is what I specialized in. I had to do some medical studies, but I wasn’t particularly good at it and I realized that I would be happier to try to do something important in the laboratory. So that was the start of it.

Describe your Nobel Prize-awarded work in one minute.

Tomas Lindahl: I think many people are now aware of that in ourselves there is the carrier of genetic information and that’s the DNA. And if there are changes in the DNA, that causes mutations which are usually damaging. So the conclusion from those facts was that DNA should be very very stable, a fantastically stable chemical. We were the first ones that really started looking at could this be right? What kind of macromolecule would be so stable that it could carry all the genetic information without any risk for mistakes or errors? That’s just not possible, so we defined the errors that can occur spontaneously in DNA. If that was right, there had to be a repair mechanism to deal with these errors and we looked for such repair mechanisms and found them, these are enzymes that act on DNA by cutting away the damage bits so that the DNA can be repaired.

What questions remain to be answered in your research?

Tomas Lindahl: Directly in my own field the repair mechanisms are very diverse and important and we only know part of them. Its not just one type of DNA repair, there are many types of DNA repair and we have gradually defined some of them and so have my colleagues, but there are still additional problems that can happen to DNA, that just haven’t been looked at yet. So it’s a very wide-open field right now and I am sure that in a couple of years or already within five years there will be new progress and new enzymes found that act on the DNA in ways that we don’t know about today.

What’s the toughest challenge you’ve faced? How did you overcome it?

Tomas Lindahl: What has been a tough challenge in my life? Well, besides personal controversies that I guess most people go through. In science, the tough choice was when I had successfully entered the Karolinska Institute medical school in Stockholm and was on the way of becoming a doctor and then decided to do something risky. I stopped my medical studies half-way and said that I’ll make my own carrier in an area that doesn’t really officially exist. I will work in the lab and see what happens. And then I think I would probably have come down on my feet, I could have lost a number of years, gone back as a somewhat disappointed doctor at a later stage, but that didn’t happen.

What motivated you to pursue your research?

Tomas Lindahl: The main motivation was to find out how our cells work in the body. I think that is a fantastic challenge and very interesting to find out. How does life function? We are all composed of cells, but each cell – what drives it forward? And how can that happen? I don’t have any religious aspects on this at all, I think it is strictly a Darwinian evolution we are looking at, but that is fascinating, because we don’t know all the details yet. And we do need to understand all the details before we can device new medicines against many common diseases now. I am convinced that the solution to many of the major health problems in life are to be found in basic research. We just first have to find out how something works, and I would even have thought that it is fairly obvious. If you want to understand how something works, a watch or the human body, you understand how it operates, you don’t just go in and say I am going to do something applied with this, but you don’t do something applied with a watch that doesn’t show the time.

Where do you do your best thinking?

Tomas Lindahl: Where I do my thinking? Anywhere. You don’t come to work and sit down in the morning at the desk and say now I am going to think. Good scientific research is a bit like an absorbing hobby. You think about it all the time. And best ideas can come to you in a totally irrelevant place, over a weekend or a vacation, just as well as when you are in the laboratory. Then you have to go back to the lab and do some experiments to show that you are right or wrong, but the basic idea can come to you anywhere.

Have you had a eureka moment?

Tomas Lindahl: Probably. What I am being awarded for here is the understanding that DNA is not at all as stable as people have been thinking, because if our DNA is falling apart, as it does, there has to be some kind of repair mechanism or other strategy to deal with this. I was convinced about that, that we should start looking for repair of endogenous DNA damage, just what happens to our DNA in the cell without any direct provocation, by radiation or dangerous chemicals from the outside or something like that. Something that happens all the time to our DNA, and if that is so, that means we are repairing our DNA all the time, it actually turns over at a slow rate and that is not what the textbooks are telling you at all. We were doing these experiments and found that DNA is very labeled and once you convince yourselves that its not some kind of clumsy artifact but it’s a fact, then the obvious conclusion is that the cells must have figured out how to deal with this problem and they have.

Who was your most inspiring teacher?

Tomas Lindahl: An old professor at Karolinska Institute called Einar Hammarsten and his name was Einar, Einar Hammarsten, Swedish name Hammarsten. He was the teacher not only of me, but of some other very well-known Swedish scientists, Peter Reichard, who was a leading scientist at Karolinska Institute until his retirement a few years ago, he is a few years older than me. Hammarsten was inspiring because he was totally dedicated to experimental science and basic research. That was really basic science although, he was a powerful professor in a medical faculty. He realized at an early stage that you got to do basic research to figure out how things work and he would be in the lab many hours and show up over holidays and so because he was so fascinated by it all. And I found that very inspiring and so did other of his pupils, I am sure, because he was like an artist. You don’t ask a violist or a pianist Does it become boring to sit and practice every day? If you think it is boring, you should do something else.

What advice would you give yourself at 20 years old?

Tomas Lindahl: Probably, I can’t think of any better advice than the kind of carrier I’ve had, to reiterate, start studying medicine to get a broad education while you are thinking about what you are going to do. And then if you like basic science it is a fascinating area to work in. I am really pleased to have been able to do this and actually do some useful work in this field, I assume since I got an award for it now. Talent, you have to have a talent for what you want to do, I would have loved to be a great concert pianist, but I just don’t have the talent for it. But to become a scientist isn’t all that bad either.

What does intelligence mean to you?

Tomas Lindahl: It’s a difficult question because many people mean different things by intelligence. I think it’s ability to think outside the box, not to do what everybody else is doing, but come up with some new ideas. I don’t think intelligence is the same thing as some people have photographic memory and they can immediately memorize a page out of the phonebook. That’s an interesting party trick, but that is not what I mean by intelligence. If you talk to people and discuss with them and you immediately get challenged. It’s exciting to talk to such a person, that’s an intelligent person, because they are somebody who can put you on your toes and make you think about what you are saying.

I always had broad interests and I think that’s an important part to science, you should try to avoid being to specialised, especially when you are young. Take an interest in the arts, literature, anything in addition to the science you are doing. Because it helps you become more creative. If you just try to focus on one special little field and solve all the details in that little field, sometimes you will then come to end or stop, because you don’t have the background to think in a creative way what to do next. Instead of working very hard you should try to be creative and do things that you enjoy doing, reading good books for example. And I think it’s much better to read good books than watching TV. Some of my oldest friends have been literature critics and essayists and not in science.

Watch the interview

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