Healthy eating, exercise, and looking after your heart: Professor Yoram Barak

Q. If dementia is a neurological condition, why is looking after your physical health so important?

A. I think the question embodies the age-old split between the mind and the body. People tend to think that neurological conditions or psychiatric disorders are part of the brain and have nothing to do with the body and the other way around. Now we know that the brain-body connection is way more complex than we ever believed. The connection between our gut and our immune system and our hormonal system, and especially our cardiovascular system and brain health, are crucial and strong. By focusing solely on the brain and itself we’ll be missing out a significant number of interventions that affect our so-called physical body and directly and indirectly improve our brain health.

The best example we can give is diabetes. Most people are aware that there is type 1 and type 2 diabetes. Endocrinologists and people who specialise in the treatment of people struggling with diabetes call Alzheimers disease type 3 diabetes. We know that type 2 diabetes is a huge risk factor for Alzheimers disease – not only to indirect effects such as potentially obesity or sedentary behaviour, but to the complicated interaction between insulin, insulin growth factors, and insulin resistance as it affects our grey matter and supporting neurons in the brain. So, my message would be we need to begin to think of dementia, and Alzheimers disease particularly, as a systemic disease. And that opens the door for a large number of preventive interventions and interventions that can help slow down the disease.

Q. What are some of the aspects of physical health that are important to reduce the risk of dementia?

A. Thank you for a question focusing on the reduction in the risk of dementia, because I think that is mainly where we are going. And there are many physical aspects that can help with the general, if you like, slowing of the ageing process. At the end of the day, Alzheimers disease is an age-associated disorder. If we can somehow affect the trajectory of ageing, we will be affecting also the trajectory of Alzheimers disease or preventing in part the development of Alzheimers disease. But anti-ageing interventions will help prevent to a degree the rates and prevalence of Alzheimers disease. What are the main interventions that we are focused on? Major pathways to slow down ageing, if you like, are exercise and nutrition. The other question, which is always asked, is about physical exercise. How much, at what intensity, what are the real effects? And we’ve learned a lot about that over the last decade.

So, here are two messages. One is moderate exercise is reasonable to or reduce the risk of Alzheimers disease. You don’t have to be an ultra-marathonist to achieve that. B, daily exercise is hugely important. There have been some studies showing that what the Americans call weekend warriors – people who don’t do anything for five days, and then for two days over the weekend exercise a lot. That is okay for young people. It’s not a good strategy when you are middle-aged or older. You should be exercising daily. Do not take for granted that the general public’s idea, what they believe exercise is, is exercise. I frequently come across people who say, ‘oh, I don’t need to jog or walk or lift weights or cycle because I do a lot of vacuuming, and a lot of housework’.

With all due respect, intensive vacuuming of your home, that is not the exercise we are talking about. And last but not least, a really, I think, opportunity that came from research in Japan and Germany showing that if you exercise – for example, if you cycle or if you walk or if you jog – if you do that for the same amount of time and the same intensity in the city or in an urban environment compared to rural or in the forest… in the bush, in a park, the benefits to your brain are much greater if you exercise in nature rather than on the busy streets of your town or local community. And in New Zealand, we have so many opportunities to just go into a park, a conservation area, the bush, and there we will be the extra benefits of exercise.

Q. What does good physical health look like as you age?

A. You know, it’s kind of the million-dollar question. Essentially, the WHO – the World Health Organization – defines health not only as the lack of disease, but also having good quality of life and having a purpose in life. So good physical health goes beyond just not being dysfunctional. It has to do with balance. Because falls are a major, major negative event in older people’s lives. Good physical health has to do with maintaining intimacy and sexuality. And good physical health, of course, has to do with flexibility and stamina. So the combination of all of those comes together to maintain high quality of life and physical wellbeing. Do we have, if you like, a quick fix? One set of exercises that can affect maybe all of these functions that I mentioned? Essentially, yes. Harvard School of Medicine published a nice little article with video clips recommending the best exercises to maintain your core strength. Your core body strength will affect all of the domains that we need for maintaining good physical condition. So make this part of your daily routine.

More on brain health

• Brain health and poverty: Dr Etu Ma’u
• Sleeping and your brain: Associate Professor Rosie Gibson