High intensity interval training, which has established heart health benefits, could also help prevent cognitive decline and dementia in older adults.
A University of Queensland study has found that it may increase blood flow in the brain even more effectively than continuous exercise.
It could therefore help protect against the decreased circulation and blood vessel function that occur inevitably with aging, which increases risk of cognitive decline, heart disease and stroke.
Interval training involves short bouts of intense physical activity alternating with periods of rest – and it appears that both aspects contribute to the benefits.
“One of the key takeaways from the study,” says researcher Tom Bailey, “was that both the exercise and the rest period were important for increasing brain blood flow in older adults.”
The experiment compared young males with an average age of 25 years and older men aged around 69. They cycled continuously for 10 minutes followed by 10 minutes of rest or for one-minute bouts alternated with one minute’s rest.
Continuous exercise improved cerebral blood flow more than interval training in the younger men but not the older adults, in which both activities had a similar impact on brain blood circulation.
The overall blood flow was higher in both groups during the interval training when measuring the entire activity and rest periods, even though perceived exertion was lower than during the continuous cycling.
This is good news for older adults who struggle to maintain non-stop exercise. It’s also encouraging to note that, contrary to previous suggestions, the interval training did not cause spikes in blood pressure.
“The benefits of exercise on brain function are thought to be caused by the increase in blood flow and shear stress, the frictional force of blood along the lining of the arteries, which occurs during exercise,” Bailey explains, suggesting that the interval training may have increased the shear stress and allowed the blood vessels to adapt to interval training.
He adds that this research will help to optimise exercise programs to improve brain function but points out that the study was short term and more research needs to look at longer term outcomes.
Disturbingly low levels of activity around the world have sparked the World Health Organisation to recommend that governments take policy action to get people moving more.
They urge all adults – including people over 65 – to do at least two and a half hours of moderate-intensity physical activity each week, for at least 10 minutes at a time, a minimum of 75 minutes of vigorous-intensity aerobic exercise, or a combination of both.
Mobility has numerous health benefits and helps older adults retain better health along with greater independence and quality of life. Aerobic exercise should be interspersed with strength training for optimal benefits to help avoid bone and muscle loss.
In 2008 the Australian government released its Closing the Gap Strategy, which laid out plans to achieve health equality for Aboriginal and Torres Strait Islander people by 2030.
How is it tracking?
Not well, according to a 10-year review by the Australian Human Rights Commission – if anything, the gap has grown.
Of all Australian population groups, Aboriginal and Torres Strait Islander people still suffer the worst health outcomes, and their lives are about 10 years shorter than the rest of the populace.
According to Robert Tickner from the Australian Red Cross, “It is a national disgrace that, despite our reputation as one of the world’s most bountiful food producers, so many Australians cannot get adequate, nutritious and affordable food.”
Poor nutrition is a key contributor to the overburden of health issues faced by Indigenous Australians, which include overweight and obesity, malnutrition, heart disease, type 2 diabetes, chronic kidney disease and tooth decay.
These diseases contribute to at least three-quarters of their mortality gap.
Food insecurity is a big part of the problem. Much of this is due to poverty. Many Indigenous Australians also live in remote communities where healthy food is hard to come by. What is available is expensive because of transport costs.
As a result, fresh fruit and vegetable intake is very low, and “discretionary foods” make up 41 percent of their daily energy intake. Sugar consumption – largely from sweetened drinks – is nearly 50 percent more than the World Health Organisation’s recommendations.
Combined with easy access to unhealthy food and drinks, poor education and nutrition literacy is also part of the problem.
Many community-based programs have helped, the most successful being those with multi-level strategies that encourage community involvement at every stage of their development and implementation to make sure they are culturally appropriate and address local needs.
Some programs have focussed on improving the food supply through local retail outlets, school and community gardens, food provision by community organisations, and community store nutrition policies.
Nutrition education can also help, if delivered in conjunction with making healthy food accessible through cooking education, budgeting advice, and group-based lifestyle programs.
But these are band aid solutions to the overarching problem: there have been no nationally coordinated nutrition ventures since the National Aboriginal and Torres Strait Islander nutrition strategy and action plan expired in 2010.
The situation can be traced to many historical factors; indeed, all the evidence suggests that before European settlement Indigenous Australians enjoyed good health and a varied diet of nutritious fresh plant and animal foods.
Now they suffer socioeconomic disadvantage with low income and unemployment, institutional racism, low access to primary health care and poor quality, overcrowded housing, all of which contribute to ill-health and mortality.
Health equality is a basic human right. Treating diseases and improving nutrition and food security are important, but the review argues that underlying structural factors also need to be tackled before Australia can close the gap.
Recognition of links between diet and mental health has snowballed in recent years. This includes the impact of nutrition on risk of dementia and Alzheimer’s disease.
Some individual nutrients have been singled out, such as vitamin B6 and omega-3. While these are important, by themselves they are no replacement for healthy dietary patterns.
In particular, the Mediterranean diet has been showered with accolades for its physical and mental health benefits.
Most people won’t argue with the fact that a healthy diet can ward off heart disease, diabetes, obesity and other chronic lifestyle ailments.
Not so many connect diet with mental health. But the brain is an organ, just like the heart, the liver and the pancreas.
It’s not just any organ. Although the brain accounts for only 2-2.7% of the body’s weight, it uses up 25% of the body’s glucose supply at rest – and this increases to 50% when it’s active.
As such, the brain is highly dependent on a regular supply of energy and nutrients from food. This fuels its structure and function, keeping us sharp and happy.
Not only does the brain need nutrients to work properly and create the neurotransmitters that keep it ticking over, it is directly influenced by signals from the gut through pathways known as the ‘gut-brain axis’.
These pathways are hormonal, neuronal and immunological. And there are trillions of little workers that help or hinder gut-brain messages: microscopic bacteria that dwell in the intestines.
These microbial communities are impacted by several factors including antibiotics, stress and excessive hygiene. They are also influenced by the food we eat.
Specifically, a diet high in sugar and processed food breeds less healthy bacteria while the beneficial microbes munch and proliferate on a whole food, high fibre diet.
There isn’t just one Mediterranean diet. Likewise, populations that live long healthy lives – with miniscule risk of dementia – have variations in their diets.
But there is no need for confusion; some basic underlying dietary principles are simple to follow.
The driving tenet is eating plenty of plant foods: fruit, vegetables, legumes, nuts, seeds and wholegrains. These are teeming with nutrients, antioxidants and fibre that promote a healthy gut and brain.
Fats are also important. In particular, extra virgin olive oil – a healthy monounsaturated fat – has numerous benefits attributed to its antioxidant properties. This oil has a high smoke point so can be used liberally for cooking as well as salads.
The diet typically includes moderate intakes of fish, which is associated with reduced risk of dementia, fermented dairy and red wine with meals. Importantly, it is low in sugar, processed foods and meat.
Nurturing a healthy lifestyle not only includes following these dietary principles; engaging in regular physical activity is also robustly linked to better physical and cognitive outcomes with aging.
Over the past decade, dementia has jumped from the fourth to the second leading cause of death in Australia – and for Australian women it has overtaken heart disease to become the top cause of death.
“With more than 436,000 Australians living with dementia and an estimated 1.45 million people involved in the care of someone with dementia, it is clearly one of the biggest public health challenges facing Australia,” said Maree McCabe, CEO of Dementia Australia.
McCabe highlights the urgent need for more investment into dementia awareness, research, treatment and care to address this major public health problem.
While memory and cognition decline with age – along with other physical faculties – dementia is not a normal part of aging.
Most common after the age of 65, dementia is a constellation of symptoms that affect brain function. It is a progressive disease with debilitating effects on thinking, memory, emotions, behaviour and ability to carry out daily activities.
Alzheimer’s disease is its most common form. Other versions include vascular dementia, dementia with Lewy bodies, Huntington’s disease, and alcohol-related dementia (Korsakoff’s syndrome – caused by vitamin B deficiency).
These all have different causes, and an early diagnosis is essential to try and identify if symptoms are treatable.
More importantly, many cases of dementia can be prevented.
It is estimated that a staggering one third to half of dementia cases can be prevented by changes in lifestyle behaviours – unhealthy habits that can slowly develop into dementia over an extended period of time.
A recent study conducted brain scans on 135 people over a 20-year period. Results showed that people with higher cholesterol had more white matter damage to the brain, suggesting poorer cognitive function and greater risk of dementia – independently of age, education and genetic dementia risk.
Lead researcher, Cassandra Szoeke, director of the Healthy Ageing Program at the University of Melbourne, says the effects are substantial, and are reinforced by another study that found the number of brain cells at age 50 can predict cognitive ability 10 years later.
Other new research that followed older adults for 15 years has shown that hardening of the arteries is a strong predictor of dementia risk.
These findings are consistent with studies showing that a healthy Mediterranean diet, high in plant foods and low in processed food, can lower risk of both heart disease and dementia.
Compelling evidence tells us that regular physical activity is an important way to stay physically and mentally healthy – even incidental daily activities and walking all add up.
And for people with dementia and restricted mobility, personalised exercise can also lift some of the burden, so it’s never too late to get moving.