Tania Flack investigates what can go wrong with the body’s control centre – and how you can prevent problems before they start.

The brain can be looked upon as the control centre of the body, masterfully coordinating a range of complex physiological processes, receiving messages and responding to our environment, ensuring our survival, creating our emotions and storing our precious memories. But what happens when things go wrong?

Brain fog and difficulty concentrating are so common in our busy world, where information overload, continuous multi-tasking, poor sleep and fatigue all negatively impact the function of the brain. Combine this with the inflammation and oxidative stress caused by the standard Western diet and sedentary lifestyle, and we may well have a perfect recipe for neurological disaster.

Once considered the territory of advanced old age, dementia and Alzheimer’s disease are on the rise in Australia and are slowly but surely making their presence known among younger generations.

Recently these diseases have claimed many well loved public figures including Robin Williams, Glen Campbell, David Cassidy and our own, seemingly invincible, Malcolm Young of AC/DC fame, at the tender age of 64.

So what can we do to protect and even enhance our brain health and when should we start putting preventive measures in place?

Top 13 brain busters

  • Stress
  • Excess alcohol
  • Lack of sleep
  • Lack of exercise
  • Obesity/overweight
  • Diabetes
  • Insulin resistance
  • Unbalanced gut microbiome
  • High intake of saturated fats
  • Inflammatory diet
  • Smoking
  • High blood pressure
  • Heart rhythm abnormalities

Alzheimer’s and dementia

Dementia is the second leading cause of death in Australia, contributing to 5.4% of all deaths in men and 10.6% of all deaths in women. Each day, approximately 244 people are diagnosed with dementia in Australia, and without a significant medical breakthrough it is projected that over one million Australians will be living with dementia in 2056. If that comes to pass, it is expected to cost Australian taxpayers over $36.8 billion dollars, significantly impacting our national health budget.

Alzheimer’s disease is the most common cause of dementia, accounting for approximately 70% of all cases in Australia. It robs us of our memories by depositing amyloid beta-plaques and neurofibrillary tangles in the brain, which impair nerve synapses so signals cannot pass between the cells.

According to the Australian Alzheimer’s Association, once someone reaches the age of 65 their risk of developing Alzheimer’s disease doubles every five years, and while common among the elderly it can even affect people in their forties in rare cases.

Symptoms of Alzheimer’s disease may include difficulty remembering certain places, people or events, changes in mood or personality, trouble completing tasks that were once easy, and problems with communication.

Vascular dementia is the second leading cause of dementia in Australia. It is usually caused by a stroke or a series of mini-strokes due to tiny blood clots repeatedly blocking vessels in the brain. This leads to the death of brain cells and causes slow and steady decline in brain function. It is strongly associated with obesity, diabetes, heart arrhythmias, atherosclerosis (narrowing of blood vessels), and high blood pressure.

Smoking significantly increases the risk of vascular dementia.

Symptoms can include behavioural changes, difficulty understanding, disorientation, and inability to create new memories. Thanks to the clearly defined risk factors, it has the best scope for preventive care through diet and lifestyle modification.

Lewy body dementia shares many similarities to Alzheimer’s disease and is the third leading cause of dementia. It is characterised by the presence of Lewy bodies, which are abnormal sphere-shaped structures that interfere with cell signalling and ultimately damage brain cells.

Sufferers may experience hallucinations, mood disruption and changes in alertness and attention.

There is a well-established connection between metabolic syndrome and dementia, including both vascular dementia and Alzheimer’s disease. Metabolic syndrome is diagnosed when someone has central obesity (a waist measurement over 102 cm for men and 88 cm for women) accompanied by other factors such as high blood pressure, diabetes and high cholesterol. It is essentially a disease of Westernised cultures, where a sedentary lifestyle, combined with a diet high in refined carbohydrates, sugar, saturated fat and processed foods, disrupts normal metabolic function.

Like dementia, metabolic syndrome is on the rise, statistics from 2014-2015 show that a staggering 64% of all Australians are overweight or obese, which is the primary cause of metabolic syndrome.

READ: Natural brain boosters

Alzheimer’s and insulin resistance

While the exact cause of Alzheimer’s disease is unclear, researchers have identified a range of possible contributing factors, including environmental, biochemical and immune-mediated influences.

Most recently, research has identified problems with insulin signalling, glucose utilisation and energy metabolism within the brain as a potential cause, and the findings of myriad of both human and animal studies have contributed to the mounting evidence. Such is the weight of this evidence some researchers have described Alzheimer’s disease as ‘Type III diabetes’ or brain-based insulin resistance.

So how does this work? Insulin can be considered a transport molecule whose primary role is to facilitate the entry of glucose into the cell to provide energy. Insulin is produced in the pancreas and released into the bloodstream when glucose is absorbed from the food we eat. When insulin is present it helps unlock a cellular ‘door’ that allows glucose to enter the cell. In type I (autoimmune) diabetes, the pancreas fails to make enough insulin to facilitate this process, and in type II diabetes the receptor sites on the cells become damaged, so insulin is unable to connect with the cell and open the door.

In both cases, cells become starved of fuel and glucose floats around in the body at high levels, causing oxidative stress, which damages cells. The brain’s primary source of fuel is glucose, so when insulin fails to do its job the brain cells literally ‘starve’, which causes oxidative stress, destroying the cells inbuilt regulatory processes and ultimately leading to the death of brain cells.

The deposition of amyloid-beta plaques and neurofibrillary tangles is thought to be due to disruption of normal cell biochemistry, which in turn leads to further increased insulin resistance.

Metabolic syndrome causes a perfect biochemical storm of insulin resistance, oxidative stress and inflammation, which are all pivotal factors in the development of both vascular dementia and Alzheimer’s disease.

Insulin may also play a role in the development of Lewy body dementia and studies show that disruption of insulin-like growth factor may be involved.

Brain fog and the gut

Could your gut play a role in how clearly you think on a day-to-day basis? The research certainly suggests this is true.

We know that cognitive function declines in the presence of low grade systemic inflammation; this is one of the reasons your memory and mental performance suffer when you have a cold or a flu virus.

However, these are usually self-limiting, so the brain fog will lift as you get better. In the case of inflammation caused by an unbalanced gut microbiome, however, the effects are longer-lasting. We all carry trillions of bacteria in our gut, and in a healthy person these bacteria are essentially self-policing, in that they keep a healthy balance by nature of their diversity so no one group overpowers the other.

However, stress, a diet high in saturated fat and processed foods, antibiotics, chemicals, pesticides, alcohol, and sugar can all contribute to an overgrowth of opportunistic bacteria.

Some bacteria produce microscopic particles of endotoxin that can pass across the gut barrier, into the bloodstream, causing low-grade continuous inflammation.

One placebo-controlled, double-blind, cross-over study involving 12 healthy young men introduced endotoxins from bacteria into their bloodstream, and within 24 hours their inflammatory markers increased up to seven times their normal level and their memory was significantly impacted.

It is never too early to start looking after your brain health. Focus on maintaining excellent cardiovascular health, stay active, get enough rest and manage stress. You should see your local health practitioner for personalised support if you have a family history of dementia.

This article first appeared in Nature & Health magazine.
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