Diabetes is a recognised risk factor for dementia.
It is also associated with a higher risk of depression and eating disorders.
What has now been found is that diabetes affects how much cholesterol our brain can make.

That’s right, our brain makes it’s own cholesterol that it uses to form synapses (the connections between brain cells). It is also used to form the vesicles or storage structures located at the synapse that contain the neurotransmitters, the brain’s chemicals that are passed from one brain cell to the next. We have a “fat” head and it is essential the brain can produce sufficient cholesterol for healthy brain function. Having too little cholesterol in the brain is associated with Alzheimer’s disease and other neurodegenerative conditions.

Studies using mice with type 1 (insulin deficient) diabetes looked at gene expression in an area of the brain called the hypothalamus. It was found that in these mice, gene expression for the synthesis of cholesterol was reduced. Treating them using insulin reversed the problem.
They also found that those mice with unable to synthesise brain cholesterol gained more weight and ate more, indicating that diabetes may affect those brain hormones associated with appetite regulation.

This finding adds to our understanding of the relationship between diabetes, cholesterol and healthy brain function. If you have diabetes, having tight glycaemic (sugar) control and maintaining a healthy weight are essential to help your overall brain health and to protect against future cognitive decline.

Ryo Suzuki, Kevin Lee, Enxuan Jing, Sudha B. Biddinger, Jeffrey G. McDonald, Thomas J. Montine, Suzanne Craft, C. Ronald Kahn. Diabetes and Insulin in Regulation of Brain Cholesterol Metabolism. Cell Metabolism, Volume 12, Issue 6, 567-579, 1 December 2010 DOI: 10.1016/j.cmet.2010.11.006

Diabetes is a global health problem of growing prevalence as western societies continue to become more obese and increasingly sedentary.

In Australia there are over one million people diagnosed with diabetes.

In the US there are now 23.5 million Americans with diabetes (that’s more than the current total population of Australia of 22.5 million). The even more scary fact is that there are the equivalent number with undiagnosed diabetes. For every one person with a diagnosis of diabetes another is unaware they have the condition.

One of my major concerns about this is the associated morbidity of greater risk of heart disease, kidney disease, eye disease, cancer and dementia.

Studies have now shown that those who have diabetes are at increased risk of suffering from a major depressive disorder and conversely, that those diagnosed with depression have an increased risk of developing diabetes.
A true double-edged sword.

A report in the Archives of Internal Medicine this week looked at over 65,000 women aged between 55 and 75 years in the US, over a ten-year period from 1996 to 2006.

They were given an initial questionnaire covering medical history and health practices with a follow up questionnaire every 2 years. Women who reported symptoms or were prescribed antidepressants or a medical diagnosis were classified as having depression. These women who reported a diagnosis of diabetes were given an additional questionnaire looking at symptoms, diagnostic tests and treatments.

Over the ten-year follow up 2800+ women developed depression and 7400 developed diabetes. Those with depression were found to have a 17% overall increased risk of developing diabetes. Those prescribed antidepressants had a 25% higher risk of developing diabetes compared to those without depression.
In those women with diabetes, there was a 29% increased risk of developing depression and those who used insulin were at particular risk 53% higher than those without diabetes.

This study adds to the evidence that these two conditions are closely related to each other and the level of the relationship depends on the relative severity or treatment of each condition

Lifestyle factors such as diet and weight have some influencing effect but the association was significant beyond these, which leads to the question of whether stress is related to the development of diabetes.
Both conditions are common in the middle aged and older populations so it would appear that early lifestyle interventions are crucial to truly try to mitigate the risks. Meanwhile the underlying mechanism of this association of diabetes and depression require more studies to understand the link.

By losing 5-7% of excess weight and undertaking 150 minutes (that’s roughly 20 minutes per day) of moderate intensity exercise, it is possible to reduce your relative risk of type two diabetes by 60%.

The bonus of doing this of course comes by also diminishing an associated risk of depression, heart disease, kidney disease, eye disease, cancer and dementia.

So where do you fit in with this?

Ref:
JAMA and Archives Journals (2010, November 24). Depression may be both consequence of and risk factor for diabetes. ScienceDaily. Retrieved November 25, 2010

Statisticians have been telling us how Western societies are facing a tsunami of people developing dementia and Alzheimer’s over the next couple of decades. This is associated with our ageing population; we are all living longer, so our relative risk of developing dementia rises as well.

What worries me though is the fact that we seem to be ignoring the impact that the dramatic increase in people living with Type 2 diabetes and obesity will have on these figures.

Both diabetes and obesity are known risk factors for dementia.
Adults who develop diabetes before the age of 65 have twice the risk of developing dementia compared to non-diabetics and also have an increased risk of depression.

It is our children that worry me the most. Twenty years ago the number of kids diagnosed with Type 2 diabetes was in the order of 2%. It was an extremely rare condition. Now 30 to 50% of all those diagnosed with Type 2 diabetes are between the ages of 9 and 19 years. Those aged in their thirties, have seen a 70% increase in the number of people diagnosed.
The scary thing also, is that it is known that there are an even greater number of people with undiagnosed diabetes in the general population.

What is Type 2 diabetes?

When we eat a meal, the carbohydrates in it are broken down and released into our blood stream as sugar, leading to an increase in the blood sugar level. This then stimulates the pancreas gland to release insulin hormone which works to restore the blood sugar level back to normal by sending the glucose to tissues that need it for energy, or for storage. If the body is repeatedly overloaded with excess glucose, the body’s ability to respond to the insulin is diminished, leading to a condition called insulin resistance. Increasing amounts of insulin then get produced, but it can no longer exert its effect. This is the condition of Type 2 diabetes where blood sugar levels are consistently too high and associated with elevated insulin levels.

It is distinguished from Type 1 diabetes where the specialised glands in the pancreas are unable to produce insulin.

When are we going to wake up to this risk?

If you have diabetes, you have a higher risk of cognitive decline and dementia.

In a study of 2300 older women aged 70 to 78, non-diabetics on mental testing scored twice as high as diabetics. It was also found that the longer the person had had diabetes, the more poorly she performed.

In another multiethnic, multicenter study of 10,000 people, the results of cognitive tests taken 6 years apart were compared. In the 40 to 70 year age group, diabetes was again linked to greater cognitive decline.

What does diabetes do to the body and brain?

Diabetes affects multiple organs in the body including the blood vessels, heart eyes, brain and kidneys and is insidious in how it gradually erodes cognitive ability. Elevated blood sugar levels contribute to hardening of the arteries, (atherosclerosis) which increases the risk of heart disease and stoke. In the brain, this vascular damage is linked to an increase in small infarcts (injury to small arterioles in the brain) or tiny strokes. Having persistently elevated blood sugar contributes to damage of our brain cells, brain atrophy and cognitive impairment. The loss of brain cells is especially prominent in the area of the hippocampus, the specialised brain area concerned with memory and learning.
Diabetic patients who have developed diabetic retinopathy have been shown to have twice the risk of developing cognitive impairment.

Excess insulin also contributes to the brain damage. It has been discovered that the brain has it’s own insulin receptors. Increased insulin levels have been linked to increased levels of amyloid, the protein associated with plaques found in Alzheimer’s. Excess insulin also has a role in stimulating inflammation, and reducing the levels of acetylcholine an essential neurotransmitter for memory.

But it’s not just diabetics who are at risk of impaired brain function and reduced mental performance. It has been shown that drinking a sugary glucose drink will adversely affect your ability to perform memory tests. So the key is to avoid big swings in blood sugar levels.

Because we know that diabetes is associated with an increase risk of cognitive impairment and dementia, it is vital that the message gets out to all those at risk.

The good news though, is that we know that good lifestyle choices can have a hugely beneficial effect on blood sugar control.

The aim is to

• Keep blood sugar levels in the normal range
• Maintain a healthy body weight
• Eat a nutritious and brain healthy diet low in saturated fat
• Exercise for 30 minutes a day by walking or other moderate intensity activity.

My question to you is this. Can we afford not be taking immediate steps to educating people to fully understand the consequences of “accepting” the recent global increases in obesity and diabetes?

Our sweet tooth is killing our brain.

Refs:
Roberts et al. Association of Duration and Severity of Diabetes Mellitus With Mild Cognitive Impairment. Archives of Neurology, 2008; 65 (8): 1066 DOI: 10.1001/archneur.65.8.1066
University of Southern California (2009, January 28). Getting Diabetes Before 65 More Than Doubles Risk For Alzheimer’s Disease.

In my last blog post I talked about the effect that smoking in general has on our memories.

Now it’s time to move on to the impact that passive smoking has on our brains, and those of our children.
And to look at the effect smoking has on those young adolescents and adults who actually take up smoking themselves.

Passive Smoking, Diabetes and Dementia risk

Passive smoking is associated with an increased risk for developing impaired glucose intolerance, a precursor for diabetes, which is itself, a risk factor for dementia.

A US study on 4500 subjects over a 15 year period, gave the following results in percentages those who developed impaired glucose tolerance.

22% of the smokers
17% of the passive smokers (ie living with a smoker)
14% of ex smokers
12% of non-smokers

In other words, the passive smoking group had a higher risk of developing impaired glucose tolerance even compared to the ex smokers.

And smokers themselves had almost twice the risk of non-smokers.

Another valid reason to give up the smokes.

We are witnessing an explosion in the number of people with obesity and diabetes, both major risk factors for impaired cognitive performance and dementia.

Why add to that risk by continuing to smoke?

Passive smoking, dementia and reduced academic performance.

Passive smoking;

• can lead to cancer in non-smokers.
• can lead to the development of heart disease in non-smokers.
• can lead to an increased risk of impaired glucose metabolism, a precursor for diabetes in non-smokers.

Heart disease and diabetes are associated with increased risk of dementia.

In the BMJ (British Medical Journal) of February 2009 it was stated that “second hand smoke (ie passive smoking) increases a person’s risk of dementia and other forms of cognitive impairment and also is associated with poorer cognitive performance in children and adolescents”

Good grief. If ever there was an incentive to give up smoking for the sake of your kids, surely this has to a big one!

The message is stark.

Passive smoking is linked to increasing your risk of dementia.

It also reduces academic performance in younger children and adolescents.

Dr. Mark Eisner for the University of California agreed in his statement that the evidence is emerging: parental smoking may impair a child’s cognitive development.

Prolonged exposure to passive smoking can lead to cardiovascular disease, increased risk of stroke and cognitive decline.

If I am repeating the message, it is because I think it is crucial to understand this.

Still in the US, a study by Leslie Jacobsen at Yale showed that adolescents who smoke showed inaccuracies and impairments of their working memory.

It was even suggested that teenagers who smoke are perhaps going to need additional educational support because of this.

Plus, it was the boys (who tend to start smoking earlier than girls) who were found to be most impaired in tests of selective and divided attention.

This was highlighted further by a study just published, by Prof Weiser of the Tel Aviv University Dept of Psychiatry and Sheba Medical Centre at Tel Hashomer Hospital.

The study looked at 20,000 young men enlisted in the Israeli army who were all healthy young adults aged between 18 and 21 years.

Around 28% smoked one or more cigarettes a day, 3% were ex smokers and 68% non-smokers.

They found that the average IQ for the non-smokers was 101
The average for the smoking group was 94
For those who smoked a packet or more a day they scored even lower at 90.

In an average population of healthy young men an IQ score would be expected to be between 84 and 116.

In his group socio-economic background was not a factor. These were all healthy young adults from a variety of backgrounds.

Plus, they were able to show that in twin brothers where one was a smoker and the other was not, the non-smoking twin on average registered a higher IQ

If we don’t want our kids to be dumbed down, then we seriously need to encourage them not to take up smoking in the first place as well as seeking to minimise any potential exposure to passive smoking.

As parents we all want the best for our kids and to see them grow and succeed in life.
Why would we knowingly diminish their ability to do well academically by either smoking ourselves or allowing them to smoke as teenagers?

If you are an adult who smokes, giving up will not only benefit your health, it will also benefit the health of your family in terms of protecting their brain.

Remember passive smoking is as deadly as smoking itself.

Yet another valid reason to give up the smokes.

Yul Brynner the actor, left us a number of years ago in 1985.
He died from lung cancer.

His message was clear and still as relevant as ever.

“Just don’t smoke.”

What action are you going to take to protect yourself and your family?

What decision are you going to take right now and commit to, in order to protect your brain health and that of your children in relation to smoking and passive smoking?

How can you keep your kids safe and discourage them from taking up smoking?

Just don’t smoke and keep your brain and your kids brains protected from passive smoking.

A good friend of mine has been battling with her weight for years. She has been on every diet known to man kind, read all the diet books, cooked all the diet recipes for herself and her family and yet her weight bounces up and down like the veritable yo-yo.

I don’t think her partner has ever dieted in his life. He works hard, plays hard, exercises. He enjoys his food and stays slim and trim.

Unfair?

Perhaps. But now scientists may have discovered why repeated dieting fails.

Most dietary advice indicates that it would be prudent to cut down on known “fattening” foods and increase exercise. And yes this may produce the desired effect until the diet is stopped, old eating patterns return and so does the weight along with a bit extra for good measure.

We also know that comfort eating to deal with stress, accounts for much obesity.

Increased levels of obesity and increased levels of diabetes put us at greater risk of developing dementia as we get older.

In this research, Scientists from the Scripps Research Institute in Boston took two groups of rats. One group as the control just had their regular rodent food. The other group was fed “normal” food for 5 days and alternated with 2 days of “sweet” food, the equivalent of us enjoying a few servings of high fat, high sugar desserts.

The dieting group on their normal diet ate less and avoided stress related situations (What that is in rat terms I don’t actually know!)

When on the high sugar diet they coped better with anxiety provoking situations, but also ate more. Plus those in the diet group when on “normal” food were found a much higher level of a stress neuropeptide CRF x5 that of the control group. This stress hormone returned to normal when the rats went back onto the high sugar diet again.

Aha!

How often have you heard the excuse of people tucking into a huge bowl of ice cream or consuming that family bar of chocolate because they feel stressed?

OK I confess, I’ve done it too.

But maybe we do it not because we actually are stressed. It’s that our brain is telling us we feel stressed (by having a higher level of the stress neuropeptide CRF in our system) because you are showing withdrawals to the high sugar/fat foods that we have intermittently.

In other words, frequent changes to our diet being “good” for a period of time followed by going back to our usual eating patterns works against us big time because of the changes that occur as a result of this, in our brain.

So sadly for my friend until she can lose the diet books and choose to implement a healthy eating plan she will continue with her vicious circle of dieting and overeating. Her continued efforts of deprivation and compensatory binge eating will not only deprive her of continued successful weight management but more importantly make her at risk of heart disease and poorer cognitive function, particularly as she gets older.

The key to deactivating the stress response by our brain is losing the idea of dieting, as that for most of us conjures up deprivation and not being allowed to eat certain foods that we like. And for most of us what we know we “mustn’t have” is instantly more desirable!

By eating a varied diet including all the fabulous brain foods such as fish, fruits, vegetables and nuts we can work towards maintaining a healthy weight, enjoying  mood stability and better thinking.