Program: Cutting edge IVF technique births eight healthy children

Olivia Willis: Norman, just to start things off lightly, how many years do you think you've got left?

Norman Swan: Well, are you sort of planning to take my seat?

Olivia Willis: The clock's ticking...

Norman Swan: This is a career question. I've often thought that I shouldn't walk in front of one of my producers, just in case they push me out under a tram. How much longer do I want to…well, really I'm pretty scared of dying, so I just want to keep it going for as long as possible.

Olivia Willis: So what do you do to keep yourself in the best shape possible? 

Norman Swan: Well, I make sure I get my cancer screening done, I know what my blood pressure is, I know what my cholesterol is. And more recently, rather than sitting in the car going to work, I sit on my bike, and it's not an electric bike.

Olivia Willis: Getting those…well, not steps, but pedals up.

Norman Swan: And I'm lucky I've never smoked. That's probably the best thing I've ever done for myself. What about you?

Olivia Willis: Oh, you know, all the things you've said, I think. I try and move my body as much as I can. I'm a big one for the Mediterranean diet. I do a bit of meditation when I go to yoga, for the mind. So all those kinds of things that we know and hear all the time. 

Norman Swan: It turns out though, according to a recent paper, that there are five risk factors that, if you don't have them, you can increase your lifespan by between 12 and 14 years. That's what's coming up on the Health Report. 

Olivia Willis: I'm Olivia Willis on Wurundjeri land.

Norman Swan: And I'm Norman Swan on Gadigal land.

Olivia Willis: Also on the show, some good news when it comes to RSV, or respiratory syncytial virus, with more than 60,000 pregnant women vaccinated since the rollout began in February.

Norman Swan: That's a good number. And also ADHD, a fascinating study which has looked at the effectiveness of drugs for ADHD over time and found that their effectiveness is reduced, but it's not all it seems to be. It's a fascinating interview, you should really stick by it, and also the person I'm interviewing is very critical about the way we currently diagnose ADHD. 

So let's start this week's news with the paper on what's called mitochondrial donation. What's going on here, Liv?

Olivia Willis: Yeah, so this is some pretty highly anticipated research looking at mitochondrial donation and the fact that eight healthy children in the UK have now been born using this technique. So mitochondrial donation, it's an IVF technique which is designed to be used in women who carry high levels of disease-causing mitochondrial DNA mutations.

Norman Swan: And we should just explain, the mitochondria are the energy factories inside cells. They have a limited amount of DNA. They have those mitochondrial genes, and they are passed down through women.

Olivia Willis: Yeah, that's right. So as you say, we inherit the mitochondria from our mothers, and children who are affected by mitochondrial disease have typically developmental delays. I think in Australia it's about 60 babies born each year will go on to develop mitochondrial disease, and there's no cure. So the IVF technique is basically about reducing the risk to children who would be born to women with mitochondrial mutations by essentially ensuring they don't pass on those mutations.

Norman Swan: And it's had a lot of over-simplistic headlines over the years. You know, 'three parents, one child', sort of thing. And it's relevant actually for Australia because one of the professors is also a professor of reproductive biology at Monash University.

Olivia Willis: That's right, yeah. So the UK was the first country to approve laws to allow this particular technology, that was in 2015, and then the national regulator there, the fertility regulator granted the kind of first licence for a fertility clinic to actually try this in 2017 at Newcastle University where research has really been pioneering this technique for many, many years.

Norman Swan: And we're the other country that allows it, potentially.

Olivia Willis: Yes, we passed the laws in 2022, I believe. But there's a group at Monash Uni, as you say, who's really at the forefront of this research in Australia, but they haven't yet received approval or the licence from the National Health and Medical Research Council to actually train embryologists to undertake this kind of process. So I believe they're starting a clinical trial, or they're recruiting for a clinical trial in the next year, pending receiving this approval.

Norman Swan: So what you start off with here are two fertilised eggs; one from the parents who want this procedure, and one from a generous donor who's donated a fertilised egg. Remember, the mitochondria are in what's called the cytoplasm, the kind of soup around the nucleus of an egg, and the nucleus contains the chromosomes and DNA that a child needs to develop and be themselves. So what they do is they have these two fertilised eggs, they take the nucleus out of the mother's fertilised egg, and then they transfer it (having removed the nucleus from the donor egg) into the donor fertilised egg. So what happens then is that you get the genetic material of the mother and father in this fertilised egg, but the soup, the mitochondria around this nucleus, the cytoplasm with the mitochondria in it is from the donor mother, and so you have safe mitochondria in that environment, and then you implant it as the embryo grows. 

Olivia Willis: And importantly what this research has shown is that the eight children who have been born using this technique—four boys, four girls, including one set of identical twins—they have shown no signs of the mitochondrial diseases that they were at risk of inheriting. So all eight were healthy at birth, meeting developmental milestones, and they've had genetic tests which show they have no or very low levels of mutant mitochondria, which is promising. 

Norman Swan: It's great. And what some people ask often in this situation is why can't you just do what's called pre-implantation genetic testing for mitochondrial disease. And the answer is quite complicated. You can actually do it, but it depends on the level of mutations in the mitochondria in the mother, and if that's very low and below a certain threshold where they can be really confident you're not going to transmit mitochondrial disease, then the pre-implantation genetic testing does work. But as soon as you get to high levels of mutations, the pre-implantation genetic testing really becomes very unreliable, you cannot rely on it, and therefore you need this technique. So let's see, and let's hope this technique spreads to Australia. Sounds like we'll be the next country.

Olivia Willis: It does. Moving on now to some other research this week, Norman, and this one is from the George Institute in Sydney, showing that food taxes and subsidies that make healthy foods cheaper and I guess ultra-processed foods more expensive, could really improve people's diets. 

Norman Swan: This is quite a sophisticated study looking, if you like, at price elasticity. So if you increase the price of a food, what do you do? Do you buy more of another food? You can have untoward consequences from this. So if you increase the price of one food, you could actually buy more of a cheaper food that's less healthy for you. So how do you move when prices move? And so it's a very sophisticated study looking at what people's behaviour is, economic behaviour is, in a sense, when prices move in certain foods. And without going into the research in a huge amount of detail, the good news here is that the price elasticity on, say, sugary drinks, when you change that price, it doesn't move towards an unhealthier food, it's pretty much a closed loop that if you don't buy the sugary drinks because of the price, you'll buy another healthier drink there, whereas with other foodstuffs you can get quite complicated movements in terms of where you go with your purchasing. But with unhealthy foods, it looks as though it's a closed loop, and therefore…and this is one of the reasons for them doing the studies, you can actually model the effect of changing taxes on sugary drinks, which Australian governments have resisted so far.

Olivia Willis: And I think the other important point this study shows is that in addition to moving people away from purchasing sugary drinks, if you add that tax to it, you can also actually encourage the purchasing of fresh fruit and vegetables if you subsidise those, if you lower the prices of them, which is another important piece of that puzzle if you're going to try and move behaviour around dietary choices.

Norman Swan: And in another study, well, it's really a survey result from the Australian Institute of Health and Welfare, they've looked at the rate of morbidity, in other words diseases amongst Australians and chronic conditions, and found that 40% of Australians or 9.7 million people are living with two or more chronic conditions at the same time. So this could be heart disease, it could be all sorts of conditions, so not just necessarily problems of the elderly. For example, 11% of young Australians aged 0 to 14 are living with multiple conditions, and that could be ADHD, autism spectrum disorder and so on. As you get on in life, it can be back problems, osteoarthritis, hearing loss, as well as coronary heart disease and so on. And this really goes to a story that we're just going to come to in a moment.