A Swedish professor of internal medicine and endocrinology, Fredrik Nyström is a firm believer in the notion that happiness can extend your life. Can a walk through a forest with a canine companion or quality time spent working on your car’s engine really make you healthier than someone who spends endless hours in the gym? It’s a controversial theory but he is determined to spread the good news.

How would you describe your philosophy?
Do what makes you happy because that feeling will ultimately make you healthier. In recent years, various studies have tracked people who are at roughly the same level of health – taking into account their body weight, their risk of cardiovascular disease and so on. And they show that those who simply say that they are happy really do live longer and with fewer complications compared to those who don’t have that belief.

This is an important finding. It means that you should sometimes allow yourself that extra bit of chocolate because if taking a bite out of the bar gives you a sense of contentment, that could translate into something that makes you healthier. You can see evidence for this in the obesity paradox: when you compare the mortality rate of people who are overweight or slightly obese to that of skinny people, you see that those in the former camp tend to live longer. It has to do with allowing yourself time to enjoy life – to bask in the sun, have a treat and drink wine. People tend to diminish their happiness by denying themselves the pleasures that are out there. That lowers the quality and length of their lives. 

You have a reputation for going against conventional wisdom and the positions of other doctors. Tell us about what surprises – and annoys – people most about your research. 
It’s probably when I mention that a moderate amount of alcohol is actually good for us. I am certain that this is true. Let’s start with the fact that drinking red wine with the evening meal is a fundamental part of the Mediterranean diet, which is the only diet that has been shown to reduce cardiovascular disease in a randomised trial (even when compared with a low-fat, alcohol-free diet). I have also shown through a randomised trial that cholesterol is lower among people who drink one or two glasses of wine every day for three months than among teetotallers. There is evidence that wine can substantially reduce glucose and blood pressure too. So I don’t think that it’s strange at all if drinking one or two glasses of wine ends up giving you a lower risk of something such as a microinfarct [a microscopic stroke].

It annoys the Swedish government quite a lot when I say this. These days the authorities tend to claim that no amount of alcohol is good for you. Members of the public get annoyed by this too. Let’s just say that there’s an ongoing debate but at least some people are listening to me. 

That’s definitely good news for those of us who enjoy a glass of wine in the evening. What about exercise? 
Everything in moderation: recent trials have clearly shown that there is a link between running too fast and atrial fibrillation [abnormal heart rhythm] in older people. There are also signs that you can do serious damage to your hips and knees.

Walking, on the other hand, is something that I really believe in. Lots of people track their steps and there’s nothing wrong with that. Walking to get steps seems like a good idea and I do it myself. But even better is the act of walking somewhere beautiful. Here in Sweden, we have forests that are freely accessible to anyone and it is very pleasurable to walk in them. And it’s the best when you’re with a dog. You have good company and can also let it run freely – so both you and your pet can gain happiness from the experience.

So it’s not so much the distance covered as the attempt to find small moments of happiness that matters? 
Yes – well, at least moments of being content. Happiness is a strong word. I’m over 60 years old now and if you feel happiness even for a second at my age, you should feel extremely grateful for that.

If you think that something is beautiful and it makes you feel better, you should try to thrive off those moments as much as you can. For example, it’s usually very cold in Sweden, so I try to savour the few opportunities that I have for sun here. 

I live outside a city with a view of a lake so it’s fantastic. Late spring, just when the summer is about to begin, is so beautiful, with different variants of green all over the place and birds singing full-throatedly. I try to take advantage of all of that. For people in northern countries, it’s all about making your own vitamin D. 

That’s your age cohort sorted. What about the younger generations? 
I have three children, who were born in the 1990s and 2000s. And I understand that they are the first generation that will be in worse health than their parents’ generations in roughly a century. It’s very sad and also totally unnecessary. The media has a hand to play in this, because all that we ever hear are reports about various crises. 

It is rare to hear positive news – and there is a lot of it, from improvements in healthcare to the generational shift against smoking and pollution disappearing from our cities. There are plenty of things moving in the right direction. People just don’t realise that all of this is happening and they don’t talk about it enough. 

What I try to pass on to my kids is a love of nature – and that it isn’t healthy to spend so much time on Tiktok or Youtube. That doesn’t make anyone happy. Take Sweden: it’s a fantastic country to wander around in and explore. This summer, my children are trying to master quite a large boat and they plan to sail over to an island in the Baltic Sea. It’ll be a challenge because of the waves, the lack of mobile signal and the risk that the winds from the west will push the boat off course. If that happens, they’ll end up in Estonia. But it’s an opportunity to enjoy nature and be free of their phones. 

To sum up, then: you think that general activity rather than stringent gym sessions, marathons or structured high-intensity exercise is key? 
Yes. Manual work is extremely important to me. I have built three houses with my own hands and rebuilt the engine of my second car from scratch several times. It relaxes me – and is the reason that I hate electric cars. I recommend having a hobby – anything other than just looking at your phone. For example, my wife has recently taken up pottery and my children are taking music lessons. It takes your mind off the tough things. Driving boats, mowing the lawn, walking the dog, planting flowers – these things make you content. I have so many colleagues in academia who are depressed from sitting around all day. You need an escape route. Go and fix your car.