We know a lot about the opposite ends of life – youth and old age – but we don’t know nearly enough about the long middle years in between. For Fit Planet contributor Professor David Cameron-Smith, it is one of his primary motivations as a Chair in Nutrition at the University of Auckland.

Where is the frontier of your research right now?

The surprising frontier is that people have not taken ageing and middle age at all seriously – we’re the forgotten people. Agedness has been the focus – trying to live longer and to survive the end years. But ageing itself has not been the focus. It’s been the domain of people who’ve given us pills and potions, it’s a marketer’s dream, but in terms of science it’s a black hole. And it’s one of my primary interests.

We’ve learned a lot about how muscles repair, how we can prepare prior to exercise, how we can recover afterwards, how we can get maximum benefits from it. But most of that research has begun and ended in either athletes or the very old.

So what do we know about those great middle years, once youth has faded but before age really sets in?

Overall, people’s physical ability is declining, so not many can actually be like the person in the ad, and run over the sand with a surfboard. And even if they could they’d be too knackered to actually surf. If we do engage in vigorous or difficult physical activity, we suffer for weeks in all sorts of ways. We’re stuck in a rut where we’re becoming cognitively impaired, losing our marbles slowly, not getting enough sleep, not waking up refreshed, not dealing with the stresses and issues of our lives … and that’s where the fitness and lifestyle industry needs to go, of course. Science need to give more to the forgotten middle years of our lives.

You are particularly interested in what happens to our muscles as we age, so what do we know?

We know far more about bones than muscles. Bones are important, but really only if you fall over. Muscles are so much more important for so many reasons. They are the “sink” of our nutrients, the engine that burns the stuff that keeps the weight down. You’ve got to have a decent sized motor to suck the petrol to stay lean, and you’ve got to have the physical mass and capability to get up and enjoy life.

What we know, and what is well established, is that far more people are doing sedentary jobs, so there is a whole generation of people who’ve got skinny legs and no backside. So every person who slides their knees under a desk every day is under-muscled. We are a society of under-muscled people.

The second thing we know is that we do start to lose muscle, all of us, from our mid-30s. It is a slow, inevitable decline, but the rate of decline is what we can influence. No, there will be no one breaking world records for the 100 metres or the marathon over the age of 35. But they can definitely compete and be the best they can be.

So what is the best general advice for people wanting to arrest that decline?

Sadly, muscle just becomes stiffer and it becomes fatter. So, smaller, fatter, stiffer – those are the three joys you have to look forward to growing older. But it’s all about physical activity. Children run from room to room, adults don’t. Physical activity and a combination of all forms of physical activity, is the answer. If you’re going to the gym and only doing one thing, one circuit or one type of class, that’s great, but you’ve got to mix and match. Everything from walking to sprinting to lifting weights, riding a bike and any form of physical activity, any form of muscular loading, is great.

How long should you exercise in terms of retaining that muscle mass and strength?

At the end of the day every single second helps. The research shows that exercise done in small chunks is just as good as exercise done in a continuum for cardio-vascular fitness and general health and wellbeing. Yes, to maximize your performance, there are specificities around periodization, rest intervals, loading, frequency, speed of movement, type of movement – that’s the domain of athletes. But for all of us who want to look good, feel good, be good, it’s a combination of everything.

Does science have a better handle on nutrition and how it affects health and muscle retention?

The best advice and the best information is to look to cultures and environments where people live healthy, successful lives, and where they demonstrate the best quality of life – where they have a self-belief in their quality of life. There are a number of traditional cultures that fit that – the Mediterranean diet is one example, the French paradox [a low incidence of coronary heart disease despite a diet rich in saturated fats], some parts of Italy, some parts of China and some parts of Japan.

What do those cultures share when it comes to diet and nutrition?

One, food is to be celebrated and shared. So they eat in a communal setting – not all of the time, there’s not necessarily a formula to it, except for the fact that food is part of their culture. It is celebrated, it is enjoyed, and it’s generous! There’s more on the table than you need.

Two, it’s organic, it’s local, it’s built around vegetables. The reality is that the majority of successful diets have fruits, vegetables, grains and cereals as part of them. So you can never go past fruits, vegetable, beans, legumes, the basics. On top of that you add the delicacies that make a cuisine – cheese, chocolate, meat, preserves, the list goes on. These all feature in those diets, but only in terms of the next level up.

Three, there are not a lot of calories. They don’t snack and nibble all the time. It’s structured around well-described and formulated meals. It varies from culture to culture whether the main meal is lunch or dinner, but when you look at the amount of food actually consumed, they are the true adherents of moderation.

You are particularly interested in protein, so what do we know about its role in our muscular health?

We’ve tended to ignore what proteins can do in terms of health. So my own research is focused on how proteins can help you rebuild and repair muscle. There are several questions there: how much protein, and what type of protein? We’re still a long way short of understanding the most effective protein mixes that help you rebuild and repair muscles.

The third question is around the role of protein more generally in our body’s health. Protein has had an undervalued role in terms of health, but that’s not to say we should be eating more protein.

So what can science usefully tell us about how to use protein?

Maybe we should be thinking about the types of protein we have in our diet, and maybe we should be exploring both animal and vegetable proteins more than we have been doing – starting to think about ways in which we can produce higher quality, better quality protein. That means exploring the value of lean red meat. We know the research shows it is important in older people, but the question is how important it is for the rest of us. With yoghurts and fermented foods, we’re starting to understand the value of what traditional cultures used to do, ferment things, break them down. There is a whole new generation of research starting to understand the value of protein.

So what is the practical goal or outcome of your research?

We’re sold all-wheel-drive cars on the basis of us somehow getting back a fabulous lifestyle of getting out there into the great outdoors and exercising. But the sad reality is that most people are experiencing real, significant and real decline in many facets of their health. And we should be so much more aspirational about living for the here and now. I want to keep surfing, roller-blading, I want to bungy jump, I want to do a high kick, rhumba, whatever. So that’s where the frontier needs to be, and we need to be learning so much more – how we can be the best we can be, that vision of people running across the sand with a surfboard under their arm, but with grey hair. Or no hair.

Professor David Cameron-Smith

  • Professor David Cameron-Smith will be a regular contributor to Fit Planet. A transplanted Australian, he obtained a PhD in nutritional biochemistry from Deakin University, and undertook postdoctoral training at the Royal Prince Alfred Hospital, Sydney. His research interests include the importance of nutrition in the maintenance of optimal health in an ageing population, and the impact of nutrition in regulating the function of muscles.

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