A disease that breeds disease: why is type 2 diabetes linked to increased risk of cancer and dementia?

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Rachel Climie, Baker Heart and Diabetes Institute and Jonathan Shaw, Baker Heart and Diabetes Institute

In Australia, more than 1.1 million people currently have type 2 diabetes.

A host of potential complications associated with the disease mean a 45-year-old diagnosed with type 2 diabetes will live on average six years less than someone without type 2 diabetes.

This week we published a report bringing together the latest evidence on the health consequences of type 2 diabetes.

Aside from demonstrating the complications we know well – like the link between diabetes and heart disease risk – our report highlights some newer evidence that suggests type 2 diabetes is associated with an increased risk of cancer and dementia.

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Common complications of type 2 diabetes

Type 2 diabetes, which typically develops after the age of 40, is usually due to a combination of the pancreas failing to produce enough of the hormone insulin, and the cells in the body failing to adequately respond to insulin.

Since insulin is the key regulator of blood glucose (sugar), this causes a rise in the blood sugar levels.

Risk factors for developing type 2 diabetes include being overweight, being physically inactive, having a poor diet, high blood pressure and family history of type 2 diabetes.

Being overweight is a risk factor for type 2 diabetes – but not all people with type 2 diabetes are overweight.
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People with type 2 diabetes are about twice as likely to develop heart disease than people without type 2 diabetes.

While heart attacks, due to blockages in the coronary arteries, are perhaps the better recognised form of heart disease, heart failure, where the heart muscle is unable to pump enough blood around the body, is becoming more common, especially in people with type 2 diabetes.

This is due to a number of factors, including better treatment and prevention of heart attacks, which has allowed more people to survive long enough to develop heart failure.

People with type 2 diabetes are up to eight times more likely to develop heart failure compared to those without diabetes.

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Got pre-diabetes? Here’s five things to eat or avoid to prevent type 2 diabetes

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Meanwhile, diabetes is the most common cause of kidney failure and vision loss in working age adults, and accounts for more than 50% of foot and leg amputations.

But beyond these common and familiar complications of diabetes, there’s mounting evidence to suggest type 2 diabetes increases the risk of other diseases.

Emerging complications of type 2 diabetes

People with type 2 diabetes are approximately two times more likely to develop pancreatic, endometrial and liver cancer, have a 30% higher chance of getting bowel cancer and a 20% increased risk of breast cancer.

Increased cancer risk is of particular concern for the growing number of people under 40 living with type 2 diabetes. In Australia, this group saw a significant increase in deaths from cancer between 2000 and 2011.

Dementia, too, is a recently recognised complication of type 2 diabetes. A meta-analysis involving data from two million people showed people with type 2 diabetes have a 60% greater risk of developing dementia compared to those without diabetes.

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Type 2 diabetes increasingly affects the young and slim; here’s what we should do about it

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Why the increased risk?

It’s important to acknowledge the studies we looked at are observational and can’t tell us diabetes necessarily caused these conditions. But they do suggest having diabetes is associated with an increased risk.

The two leading theories for why cancer risk is increased in people with type 2 diabetes relate to glucose and insulin.

Many types of cancer cells use glucose as a key fuel, so the more glucose in the blood, potentially, the more rapidly cancer will grow.

Alternatively, insulin can promote the growth of cells. And since in the early stages of type 2 diabetes insulin levels are elevated, this might also promote the development of cancer.

It’s especially important people with diabetes take up cancer screening programs.
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There are several possible explanations for the link between diabetes and dementia. First, strokes are more common in people with type 2 diabetes, and both major and repeated mini-strokes can lead to dementia.

Second, diabetes affects the structure and function of the smallest blood vessels throughout the body (the capillaries), including in the brain. This may impair the delivery of nutrients to a person’s brain cells.

Third, high glucose levels and other metabolic disturbances associated with diabetes may, over time, directly affect the way certain types of brain cells function.

Room for improvement

Despite well-established recommendations for the management of type 2 diabetes, such as guidelines for medication use, healthy diet and regular physical activity, there remains a significant gap between the evidence and what happens in practice.

A study from the US showed only one in four patients with type 2 diabetes met all the recommended targets for healthy levels of glucose, cholesterol and blood pressure.

Australian data has shown having diabetes is associated with 14% increased likelihood of discontinuing cholesterol medication after one year.

In our report, we showed increasing the use of a range of effective medications would prevent many hundreds of people with diabetes developing heart disease, strokes and kidney failure each year.

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Unscrambling the egg: how research works out what really leads to an increased disease risk

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With the burden of diabetes complications in our community casting such a large shadow in terms of death rates, disability and impact on the health system, we need greater education and support for people with living diabetes, as well as health professionals treating the condition.

For people with type 2 diabetes, close monitoring for other diseases such as cancer through screening programs is particularly important.

And alongside managing their blood sugar levels, it’s essential Australians with type 2 diabetes are supported to keep risk factors for complications, such as blood pressure and cholesterol, at healthy levels.

A healthy diet and regular physical activity is a good place to start.

Rachel Climie, Exercise Physiologist and Research Fellow, Baker Heart and Diabetes Institute and Jonathan Shaw, Deputy Director, Baker Heart and Diabetes Institute

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Six things you can do to reduce your risk of dementia

Challenging and training your brain is important to prevent dementia risk.
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Helen Macpherson, Deakin University

An ageing population is leading to a growing number of people living with dementia. Dementia is an umbrella term for a group of symptoms including memory impairment, confusion, and loss of ability to carry out everyday activities.

Alzheimer’s disease is the most common form of dementia, and causes a progressive decline in brain health.

Dementia affects more than 425,000 Australians. It is the second-ranked cause of death overall, and the leading cause in women.

The main risk factor for dementia is older age. Around 30% of people aged over 85 live with dementia. Genetic influences also play a role in the onset of the disease, but these are stronger for rarer types of dementia such as early-onset Alzheimer’s disease.

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What causes Alzheimer’s disease? What we know, don’t know and suspect

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Although we can’t change our age or genetic profile, there are nevertheless several lifestyle changes we can make that will reduce our dementia risk.

1. Engage in mentally stimulating activities

Education is an important determinant of dementia risk. Having less than ten years of formal education can increase the chances of developing dementia. People who don’t complete any secondary school have the greatest risk.

The good news is that we can still strengthen our brain at any age, through workplace achievement and leisure activities such as reading newspapers, playing card games, or learning a new language or skill.

Even playing cards can strengthen your brain.
Photo by Inês Ferreira on Unsplash

The evidence suggests that group-based training for memory and problem-solving strategies could improve long-term cognitive function. But this evidence can’t be generalised to computerised “brain training” programs. Engaging in mentally stimulating activities in a social setting may also contribute to the success of cognitive training.

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Read more:
What is ‘cognitive reserve’? How we can protect our brains from memory loss and dementia

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2. Maintain social contact

More frequent social contact (such as visiting friends and relatives or talking on the phone) has been linked to lower risk of dementia, while loneliness may increase it.

Greater involvement in group or community activities is associated with a lower risk. Interestingly, size of friendship group appears less relevant than having regular contact with others.

3. Manage weight and heart health

There is a strong link between heart and brain health. High blood pressure and obesity, particularly during mid-life, increase the risk of dementia. Combined, these conditions may contribute to more than 12% of dementia cases.

In an analysis of data from more than 40,000 people, those who had type 2 diabetes were up to twice as likely to develop dementia as healthy people.

Managing or reversing these conditions through the use of medication and/or diet and exercise is crucial to reducing dementia risk.

Exercise is protective for heart health and diabetes, as well as against cognitive decline.
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4. Get more exercise

Physical activity has been shown to protect against cognitive decline. In data combined from more than 33,000 people, those who were highly physically active had a 38% lower risk of cognitive decline compared with those who were inactive.

Precisely how much exercise is enough to maintain cognition is still under debate. But a recent review of studies looking at the effects of taking exercise for a minimum of four weeks suggested that sessions should last at least 45 minutes and be of moderate to high intensity. This means huffing and puffing and finding it difficult to maintain a conversation.

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Could too much sitting be bad for our brains?

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Australians generally don’t meet the target of 150 minutes of physical activity per week.

5. Don’t smoke

Cigarette smoking is harmful to heart health, and the chemicals found in cigarettes trigger inflammation and vascular changes in the brain. They can also trigger oxidative stress, in which chemicals called free radicals can cause damage to our cells. These processes may contribute to the development of dementia.

The good news is that smoking rates in Australia have dropped from 28% to 16% since 2001.

As dementia risk is higher in current smokers compared with past smokers and non-smokers, this provides yet another incentive to quit once and for all.

6. Seek help for depression

Around one million Australian adults are currently living with depression. In depression, some changes occur in the brain that may affect dementia risk. High levels of the stress hormone cortisol have been linked to shrinkage of brain regions that are important for memory.

High blood pressure can increase the risk of dementia.
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Vascular disease, which causes damage to blood vessels, has also been observed in both depression and dementia. Researchers suggests that long-term oxidative stress and inflammation may also contribute to both conditions.

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You’ve been diagnosed with depression, now what?

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A 28-year study of more than 10,000 people found that dementia risk was only increased in those who had depression in the ten years before diagnosis. One possibility is that late-life depression can reflect an early symptom of dementia.

Other studies have shown that having depression before the age of 60 still increases dementia risk, so seeking treatment for depression is encouraged.

Other things to consider

Reducing dementia risk factors doesn’t guarantee that you will never develop dementia. But it does mean that, at a population level, fewer people will be affected. Recent estimates suggest that up to 35% of all dementia cases may be due to the risk factors outlined above.

This figure also includes management of hearing loss, although the evidence for this is less well established.

The contribution of sleep disturbances and diet to dementia risk are emerging as important, and will likely receive more consideration as the evidence base grows.

Even though dementia may be seen as an older person’s disease, harmful processes can occur in the brain for several decades before dementia appears. This means that now is the best time to take action to reduce your risk.

Helen Macpherson, Research Fellow, Institute for Physical Activity and Nutrition, Deakin University

This article was originally published on The Conversation. Read the original article.

What is ‘cognitive reserve’? How we can protect our brains from memory loss and dementia

Engaging in cognitively stimulating activities can help build your resilience to cognitive decline.
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Michael Ridding, University of Adelaide

As we get older we have a greater risk of developing impairments in areas of cognitive function – such as memory, reasoning and verbal ability. We also have a greater risk of dementia, which is what we call cognitive decline that interferes with daily life. The trajectory of this cognitive decline can vary considerably from one person to the next.

Despite these varying trajectories, one thing is for sure: even cognitively normal people experience pathological changes in their brain, including degeneration and atrophy, as they age. By the time a person reaches the age of 70 to 80, these changes closely resemble those seen in the brains of people with Alzheimer’s Disease.

Even so, many people are able to function normally in the presence of significant brain damage and pathology. So why do some experience symptoms of Alzheimer’s and dementia, while others remain sharp of mind?

It comes down to something called cognitive reserve. This is a concept used to explain a person’s capacity to maintain normal cognitive function in the presence of brain pathology. To put it simply, some people have better cognitive reserve than others.

Evidence shows the extent of someone’s cognitive decline doesn’t occur in line with the amount of biological damage in their brain as it ages. Rather, certain life experiences determine someone’s cognitive reserve and, therefore, their ability to avoid dementia or memory loss.

How do we know?

Being educated, having higher levels of social interaction or working in cognitively demanding occupations (managerial or professional roles, for instance) increases resilience to cognitive decline and dementia. Many studies have shown this. These studies followed people over a number of years and looked for signs of them developing cognitive decline or dementia in that period.

As we get older we have a greater risk of developing impairments in cognitive function, such as memory.
from shutterstock.com

Cognitive reserve is traditionally measured and quantified based on self reports of life experience such as education level, occupational complexity and social engagement. While these measures provide an indication of reserve, they’re only of limited use if we want to identify those at risk of cognitive decline. Genetic influences obviously play a part in our brain development and will influence resilience.

Brain plasticity

The fundamental brain mechanisms that underpin cognitive reserve are still unclear.
The brain consists of complex, richly interconnected networks that are responsible for our cognitive ability. These networks have the capacity to change and adapt to task demands or brain damage. And this capacity is essential not only for normal brain function, but also for maintaining cognitive performance in later life.

This adaptation is governed by brain plasticity. This is the brain’s ability to continuously modulate its structure and function throughout life in response to different experiences. So, plasticity and flexibility in brain networks likely contribute in a major way to cognitive reserve and these processes are influenced by both genetic profiles and life experiences.

A major focus of our research is examining how brain connectivity and plasticity relate to reserve and cognitive function. We hope this will help identify a measure of reserve that reliably identifies individuals at risk of cognitive decline.

Strengthening your brain

While there is little we can do about our genetic profile, adapting our lifestyles to include certain types of behaviours offers a significant opportunity to improve our cognitive reserve.

Activities that engage your brain, such as learning a new language and completing crosswords, as well as having high levels of social interaction, increase reserve and can reduce your risk of developing dementia.

Regular physical activity increases cognitive reserve.
Jenny Hill/Unsplash, CC BY

Regular physical activity also improves cognitive function and reduces the risk of dementia. Unfortunately, little evidence is available to suggest what type of physical activity, as well as intensity and amount, is required to best increase reserve and protect against cognitive impairment.

There is also mounting evidence that being sedentary for long periods of the day is bad for health. This might even undo any benefits gained from periods of physical activity. So, it is important to understand how the composition of physical activity across the day impacts brain health and reserve, and this is an aim of our work.

Our ongoing studies should contribute to the development of evidence-based guidelines that provide clear advice on physical activity patterns for optimising brain health and resilience.

Michael Ridding, Professor, University of Adelaide

This article was originally published on The Conversation. Read the original article.

My Fight with CFS … Part 1

I have Chronic Fatigue Syndrome (CFS), or as I prefer to call it, Chronic Fatigue Immune Dysfunction Syndrome (CFIDS). It is an extremely misunderstood and debilitating illness. I have read that the average time for a person to be ill with CFS is 18 months. I have had it for 18 years more or less. It has cost me a lot to be suffering from this illness and it impacts on my life on a daily basis. Some days are not too bad, while others are extremely terrible.

My journey with CFS began in the aftermath of the Newcastle earthquake of the 28^th December 1989. In early 1990, while working at Hawkins Masonic Village repairing roofs damaged by the earthquake (it was raining and many roofs were leaking), I began to feel persistently unwell. I decided to see my doctor who put it down as some sort of stomach bug, most likely Gastroenteritis. After two weeks of medication it was becoming clear that I did not have Gastroenteritis and something more sinister was the cause of my intensifying illness.

Within weeks I had begun to develop all of the debilitating symptoms of CFS and what was worse for me they were all intensifying their effects upon me. What was wrong with me was now something of a mystery, but it was clear I was very ill and getting worse.

When I was younger I had Hyperthyroidism and so the doctor assumed that this was what was wrong with me again, despite the fact that blood tests indicated I no longer had an issue with that disorder. I was placed on medication for Hyperthyroidism and monitored. The medication had no effect on my illness and my patience with ‘witch doctoring’ was running out. I pleaded with my doctor to send me to someone else – a specialist. But who would be useful to see?

A friend had recently been diagnosed with CFS by an Immunologist and eventually I prevailed with my doctor to send me to him. Eventually I was able to set up an appointment and so my time with Doctor Sutherland of the Royal Newcastle Hospital Immunology Department had begun.

By this time I was suffering a myriad array of symptoms, with varying degrees of intensity depending on what week I was asked. Among the most debilitating of these symptoms was a persistent headache that no amount of painkilling or other medication had any impact upon. The headache was like a migraine that wouldn’t go away. It would last for an 18 month stretch this first time, bringing with it an intolerance of bright light, noise, etc. These things caused me immense head pain.

I was also suffering numerous nose bleeds (which I often get when I am very ill), fevers and chills, brain fog (a situation where you seem to know what is going on yet you have an inability to act in a logical manner – some times the sense of knowing what is happening disappears altogether), painful eyes, chronic fatigue in the muscles and extreme soreness, tiredness to the point of sleeping at a drop of a hat (I was sleeping for over 18 hours a day with no relief to my tiredness, headaches, etc), loss of strength in my limbs, constant nausea, inability to think or concentrate, etc.

By this time I was already having time away from work, with being away for weeks at a time being the norm – thankfully they were quite understanding of the fact that I was very ill.

At my lowest point during these first two years I was reduced to being bed-ridden, using a cane for stability when walking and at times was unable to walk. I was sleeping above 18 hours a day with no benefit from it.

During this time of extreme illness I was subjected to innumerable blood tests and other tests, which all revealed little at all as to the cause of my illness. A process of careful elimination under the care of Dr. Sutherland brought the diagnosis of CFS, as well as a psychological evaluation.

There was no cure to be found, with the only helpful advice having come from Dr. Sutherland. He told me to try and rest, then to slowly build myself up again. Walk one block for a week, then two blocks the following week, etc. If I overdid it I would be back in a heap again in no time. I needed to be able to read my own situation to know when I should try to rebuild my life. This advice has helped me through the last 18 years.

I struggled with the illness for 18 months or so and I also struggled with the enigma associated with the illness. That I was sick was not believed by all and this has been a constant stereotype I have been confronted with throughout my illness. I often found myself questioning whether I was sick or whether it was some mental thing. It was a relief when a doctor finally gave me a name for the illness and confirmed I was indeed very ill.

There were times (as there has been since) when I thought that dying would be a better alternative than to be as sick as I was, with no life and the prospect of endless years of severe illness. Suicide was something that popped into my head from time to time, but thankfully it didn’t stay there for long.

At times I found myself not knowing what I was doing, where I had been, etc. At one point I waited behind a parked car, waiting for it to turn the corner only to realise ½ an hour or so later that the car was parked. I found myself having gone shopping with a load of groceries I didn’t need and never had used before. It was like having a form of early onset Dementia.

After about 18 months I began to get better – or so I thought. I was well enough to knock back participation in a trial medication experiment for CFS sufferers which would involve a lengthy stay in hospital and a 50% chance I would receive the placebo.  I declined the invitation being concerned I would loose my job as a result of being in hospital for so long.

My health began to improve and I thought I was finally over the illness. During this time I lost contact with Dr. Sutherland who left the hospital because of a dispute with NSW health at the time. Many doctors left the public system at the time.

NEXT: The illness returns

Old People Allowed to Be Rude

I never knew that being old made it allowable to be rude. However, this would seem to be the growing acceptable trend with older people. It would appear to me that this is the seeming policy in Aged Care these days, as well as in Retirement Villages, general public places, etc. You are no longer allowed to challenge poor behaviour in the elderly because they are old. Does being old give you a right to abuse people and to be rude ~ I wouldn’t have thought so, but apparently it is becoming an acceptable practice/trend.

Isn’t it interesting that in an age where any form of physical discipline of children is regarded as being child abuse, that the rate of poor behaviour in children is increasing to an alarming level? I have heard it said, that a lot of older people with Dementia-type illnesses return to a child-like state. But it seems to me, that by virtue of becoming old, a good number of older people are also being allowed to misbehave by society and are not being challenged concerning their behaviour simply because they are ‘old.’

Perhaps this is just another example of the way modern society is heading ~ a culture of disrespect for others and a strong sense of self-centredness.

I have a theory about all this ~ there is nothing really new under the sun. What earlier generations once called ‘sin,’ and what the Bible still does, modern society appears to be happy to call it becoming more self-aware and in touch with your needs, expressing healthy concern for self and meeting what self requires. I think I prefer the Biblical explanation. It is quite simply an expression of rebellion against God and disobedience to his law – in other words, sin.