Of all the risk factors for dementia and impaired cognitive function, diabetes and obesity have to be the two most important issues that we need to deal with now.
The burgeoning incidence of obesity and diabetes in the community and especially in young people is frightening. These young people are not just at increased risk of cardiovascular disease, cancer, and premature death. They have a far greater risk of developing cognitive impairment and dementia as adults.

What were the recent findings?

A study published in the July 30th issue of Diabetologia, reported that MRI brain scans of obese kids with type 2 diabetes show brain abnormalities, and on mental testing reduced cognitive performance. These kids will be functioning less well academically at school.

The study looked at a group of 18 obese adolescents with type 2 diabetes and another group of similarly obese adolescents who hadn’t yet developed significant insulin resistance or type 2 diabetes.
This is the first time that cognitive deficits as a consequence of obesity with diabetes have been shown in this age group. Previous studies have looked at older people where similar abnormal brain findings on scans had been attributed to be the result of vascular disease, rather then a direct effect on the brain by the diabetes itself.

Both groups of adolescents came from similar socio-economic backgrounds and ethnicity.

They were asked to complete some mental tests. The results of group with diabetes were significantly lower in the areas of memory, spelling and overall academic function. They also showed white matter abnormalities on brain scans.

Dealing with insulin resistance may be the key.

The results highlight the urgent need to address both obesity and diabetes. More and larger studies need to be undertaken to verify these findings and to then get government and health professional support so that effective health programs can be developed and implemented to deal with this rising tide of obesity and diabetes. The challenge will be to be able to help kids already diagnosed with insulin resistance, to improve their insulin sensitivity through weight management, healthy eating and exercise.

A separate study published in August, looked at the relationship between insulin resistance, type 2 diabetes and the development of plaques in the brain. Brain plaques are associated with the neurodegenerative disease of Alzheimer’s. Insulin resistance has been described as a pre-diabetic state. In insulin resistance, the insulin hormone our body produces is becomes less effective in exerting its effect on helping to lower the blood sugar to normal. This study followed an older population of 135 Japanese subjects aged over 67 years over a period of 10 to 15 years. They underwent several glucose tolerance tests to measure their blood sugar levels and were monitored for symptoms of Alzheimer’s disease over that time. After their deaths their brains were autopsied and it was found that those who had had at least three abnormal glucose tolerance tests had a greater risk of developing plaques in their brain. In other words, having insulin resistance was associated with an increased likelihood of the person developing brain plaques that are commonly found in patients with Alzheimer’s disease. Further studies will now need to be undertaken to see whether insulin resistance is associated as being a cause of this plaque formation.

The real risk of failing to take action now.

If we continue to fail to address the issues society currently has in terms of the level of our overall inactivity, obesity and diabetes then I believe we are setting ourselves up to add to the already significant social and economic burden of increasing rates of dementia we are anticipating over the next few decades.
It won’t just be the baby boomers that are at risk of dementia simply because of their increasing age. We have yet to count the impact of younger people already burdened with the significant health impairment of obesity and diabetes that will be adding to this toll.

References:

P.L. Yau, D.C. Javier, C.M. Ryan, W.H. Tsui, B.A. Ardekani, S. Ten and A. Convit. Preliminary evidence for brain complications in obese adolescents with type two diabetes mellitus. Diabetologica,2010;DOI; 10.1007/s00125-010-1857-y

T.Matsuzaki, K. Sasaki, Y.Tanizaki, J. Hata, K. Fujimi, Y. Matsui, A. Sekita, S.O. Suzuki, S. Kanba, Y. Kiyohara, and T. Iwaki. Insulin resistance is associated with the pathology of Alzheimer’s disease. The Hisayama Study. Neurology,2010;DOI:10.1212/WNL.0b013e3181eee25f

A little ray of sunshine for Parkinson’s disease may lie with Vitamin D.

Vitamin D is the vitamin we obtain through the action of ultraviolet light on our skin. Most of the vitamin D produced is then bound in the blood and only a tiny fraction remains free and able to bind to specific vitamin D receptors now known to be located in a number of target organs in the body including the brain.

Not only that, but the area of the brain with the highest density of Vitamin D receptors is in the Substantia Nigra. This is where highly specialized cells produce Dopamine, the brain neurotransmitter vital for regulating our mood, concentration, motivation and voluntary movement.
In Parkinson’s disease many of these highly specialized cells die and the loss of Dopamine manifests itself in the form of tremor, rigidity of movement, slowness of gait and cognitive decline. Plus, thirty percent of people with Parkinson’s disease develop dementia.
It is the second most common neurodegenerative disease in Australia and remains one of the most poorly understood.

So where does Vitamin D fit in with Parkinson’s disease?

The answer to that is not yet certain, but a recently published study has linked having a higher level of Vitamin D with up to a 65% reduction in the risk of developing Parkinson’s.

These results were in a long prospective study by Paul Knekt in Finland. He showed that in a group of 3173 people aged 50 to 79, followed up over a 29 year period, those with a higher level of Vitamin D had a 65% lower risk of developing Parkinson’s compared to those with the lowest levels.

However it should be noted that all of the subjects in this study actually had lower levels of vitamin D than is recommended. This may reflect the fact that Finland is not a country associated with a lot of sun exposure for its residents. So the suggestion is that having a lower level of Vitamin D may be a predisposing factor to an increased risk of Parkinson’s disease. There is no suggestion that having a low level is in fact a cause. The study remains a starting point to determine whether giving Vitamin D as a supplement would be useful.

One of the problems recognized is that Vitamin D deficiency is widespread, even in a sunny country such as Australia. It has been reported that half to two thirds of teenagers and adults in the US have lower than desirable levels. Because it is very difficult to get sufficient Vitamin D through our diet, having adequate sun exposure is essential to help us achieve and maintain a healthy level.

How much time do we need in the sun?

Five to fifteen minutes of sunlight exposure to the face and upper arms, four to six times a week is thought to be sufficient to prevent deficiency.
Those particularly at risk of deficiency here in Australia include the elderly living in residential care and dark skinned women, especially those who are veiled. The use of sunscreen (essential to protect us from skin cancer) unfortunately prevents the synthesis of Vitamin D in the skin. Application of Factor 8 will prevent up to 95% of Vit D conversion, so a short exposure without sunscreen is recommended and outside the high-risk times of 10 am to 3 pm.

Can we get Vitamin D from our food?

We can derive a limited amount of Vitamin D from food sources. However in cases of deficiency taking a supplement would be recommended.

Vitamin D2 can be found in:

Fatty fish such as mackerel, salmon and herring
Fortified margarines
Cod liver oil
Liver
Eggs

The role of Vitamin D in the brain

The association of Vitamin D and Parkinson’s disease is intriguing and as yet not fully explained. It is believed that Vitamin D acts as a hormone rather than a vitamin, in addition to its role in bone metabolism.

Current thinking is that it may exert a neuroprotective effect through its antioxidant properties, calcium regulation of nerve cells, enhanced nerve conduction, detoxification and immunomodulation.

A UK study looked at Vitamin D levels of a group of 858 Italian men and women over the age of 65 years. Of those with dementia, 50% were vitamin D deficient. Moreover, those with the greatest deficiency had a 60% increased risk of suffering cognitive decline over the 6-year follow up period.

The role of Vitamin D relating to Alzheimer’s disease was looked at in a 2008 study where 100 people with Parkinson’s disease were compared to 100 subjects with Alzheimer’s disease and 100 healthy controls. Here the fraction of patients with the lowest levels of Vitamin D was most marked in the Parkinson’s group (23%) compared to the Alzheimer’s group (16%) and healthy group (10%) indicating support for the notion that Vitamin D plays a role in affording some neuroprotection.

Meanwhile it remains prudent to ensure that we obtain adequate sun exposure to keep our Vitamin D levels up. So go on, it’s time to enjoy some time in the sun.

References:
Emory University (2008, October 17). Lack Of Vitamin D Linked To Parkinson’s Disease.
Archives of Neurology [2010] 67 (7) : 808-811 (Knekt P, Kilkkinen A, Rissanen H, Marniemi J, Sääksjärvi K, Heliövaara M.)

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.

My Dad, who is a retired vet, used to give many of his older canine patients Vitamin E, because he found it seemed to give them a bit more spring in their step and kept them going for longer.

Vitamin E is a powerful antioxidant found in nuts, seeds, eggs, whole grain foods, spinach, avocado, salad dressing and vegetable oils.

The role of Vitamin E in reducing the risk of dementia has been the subject of a number of studies. In the July edition of “Archives of Neurology” the results of a long-term study carried out by the Erasmus Medical Centre in Rotterdam, Holland, revealed the effect of four dietary antioxidants on dementia risk. Over 5000 people aged 55+ (who did not have dementia at the onset of the study), were followed for 9+ years. The study focused the intake of Vitamin E and C, beta-carotene and flavonoids.

In a previous study, the Rotterdam group had found that higher dietary intakes of Vitamin E and C were associated with a lower risk of Alzheimer’s and dementia.

The results of this longer term study though, showed that it was those people who consumed the highest amount of Vitamin E that had 25% less risk of developing dementia compared to those who consumed the least. The dietary intakes of Vitamin C, beta-carotene and flavonoids were not associated with changes in dementia risk. This was an unexpected finding, given the previous positive association link found with Vitamin C.

What about the use of Vitamin E as a supplement ?

Many clinicians routinely give their elderly patients high doses of Vitamin E and often in only one form. Vitamin E is actually a family of eight natural compounds and the one most commonly used is alpha–tocopherol.

A Swedish study looked at the levels of all eight natural vitamin E compounds in the blood of over 200 subjects. Here they found that those with the highest blood level of all of the vitamin E family had a reduced risk of developing dementia. This risk was reduced by between 45 to 54% depending on the individual Vitamin E component level.
Dr Mangialasche in this study noted that the protective effect of the vitamin appears to be related to the combination of the different forms, suggesting that it is the balance of the 8 compounds, which may have the most important neuroprotective effect.

Another study also looked at the role of dietary Vitamin E along with a combination of certain other nutrients which have also been associated with a lower risk of dementia and Alzheimer’s disease.

Columbia University NY revealed the results of a four year study of 200 subjects over the age of 65 (none of whom had dementia). They identified several dietary patterns with varying levels of 7 nutrients, previously associated with Alzheimer’s risk. These included saturated fats, monosaturated fats, omega 3 fatty acids, omega 6 fatty acids, Vitamin E, B12 and folate. One pattern in particular was found to be associated with a significantly lower risk of Alzheimer’s and this was noted to include a high intake of the following:

Salad dressing
Nuts
Fish
Tomatoes,
Poultry
Fruits
Cruciferous vegetables
Dark green leafy vegetables

This is pretty much the basis of the Mediterranean diet, which has previously been associated with a lower risk of Alzheimer’s and dementia.

The authors noted that the nutrients in the low risk dietary pattern reflected the multiple pathways in the development of Alzheimer’s disease.

i.e
• Vitamin B12 and folate help to reduce the body’s levels of homocysteine (a risk factor for Alzheimer’s)
• Vitamin E has a potent antioxidant effect
• Fatty acids assist in normal brain cell membrane function.

So where does that leave us now?

It may well be that including a higher amount of vitamin E rich foods in our diet may have a modest effect on reducing dementia risk. Unfortunately we don’t know yet, how much is to be recommended. Meanwhile eating whole foods in a healthy combination diet based on the Mediterranean model is probably the way to go.
Further studies are likely to continue to evaluate dietary intake of antioxidants and how they may modulate the risk of dementia.

References:
American Academy of Neurology (2008, April 17). Vitamin E May Help Alzheimer’s Patients Live Longer.
Johns Hopkins University Bloomberg School Of Public Health (2004, January 20). Vitamin Supplement Use May Reduce Effects Of Alzheimer’s Disease.
Francesca Mangialasche, Miia Kivipelto, Patrizia Mecocci, Debora Rizzuto, Katie Palmer, Bengt Winblad, Laura Fratiglioni. High plasma levels of vitamin E forms and reduced Alzheimer’s disease risk in advanced age. Journal of Alzheimer’s Disease, 2010
JAMA and Archives Journals (2010, July 13). Eating foods rich in vitamin E associated with lower dementia risk.

I was sitting in my GP’s office recently, being told something I didn’t want to hear. My blood pressure was too high and I needed to start medication with antihypertensives.

I didn’t want to have to take medication. I had always planned not to be on anything apart from fish oil and glucosamine supplements until I was at least 90 years old. I consider myself fit. I exercise daily, my weight is normal, I eat healthily, I don’t smoke and I keep an eye on how much wine I drink each week.

But my family history includes hypertension and stroke on both my mother’s and father’s side.
And I do recall a conversation with my obstetrician who was managing my pregnancy-induced hypertension a number of years ago. He said, “Jenny, you are likely to develop hypertension as you get older.” Harrumph. I heard, but didn’t want to listen. But who am I trying to kid?

I have what is called “essential hypertension”. The cause is as yet unknown.
I don’t like it. But I can deal with it and take my pills.
The reason why? Because I value my brain cells too highly not to. As a Doctor my medical training has taught me what the consequences of untreated hypertension are.

Hypertension has been described as a silent killer. You can’t feel if your blood pressure is too high. We rely on readings taken with a sphygmanometer to get an accurate idea of the state of our blood vessels.
The blood pressure reading essentially tells us the peak or systolic pressure our heart has to exert with each contraction to pump the blood around our body. The lower reading or diastolic pressure gives us the resting pressure of the circulatory system in between heartbeats.

If the readings are too high we run the increased risk over a period of time of blood vessel rupture causing a stroke or cerebrovascular accident. Other organs are affected as well, including the kidney, eye and heart. None of which is good news.

So, back to the brain and high blood pressure. Sure it’s good not to be at risk of stroke. But what about the effect of high blood pressure on memory and cognition?

Studies have shown that having high blood pressure can contribute to memory loss and other decline in brain function in people over the age of 45.

In one study of over 19000 participants aged 45 or older, they found that with each 10-point increase in diastolic pressure, the risk of cognitive difficulty increases by 7 points.

But how high is high?
We need to keep our diastolic pressure (the lower of the two reading indicating the pressure of the arterial system at rest) at below 90mmHg.

With around 25-30% of the Australia adult population having high blood pressure I am clearly not alone.
For the vast majority of people like myself we have “essential hypertension” where no specific cause is identified. However having high blood pressure causes problems by causing our arterial walls to thicken and lose their elasticity, leading to reduced blood flow and tissue death.

Having reduced blood flow to your brain becomes an issue when you need it to be working harder. For example when you want to be able to pay attention or work out a solution to a problem, the decrease of available blood flow to your brain leads to fewer brain cells being activated and an increased number of memory lapses happening as a result.

In older people, having high blood pressure can predict who is at risk of developing impaired executive function (organising, planning and decision making) and a greater risk of progressing to dementia. One study of 900 octogenarians showed that high blood pressure was associated with an increased risk of developing dementia when frontal lobe functioning was impaired

Because stroke and TIA are leading causes of risk of cerebrovascular disability followed by dementia, controlling hypertension is a simple and effective way to significantly potentially reduce the incidence of forecasted dementia in this group.

So attending to diagnosing and treating hypertension in midlife would appear to be essential to protect you from developing cognitive impairment further down the track.

If you are over 45 and haven’t had your blood pressure checked for a while, now would be a good time to make an appointment and get it checked by your GP.

If it is too high then some simple lifestyle changes could help:

• Keeping your weight in the healthy range
• Don’t smoke
• Reduce your alcohol consumption.
• Do some regular exercise
• Keeping your cholesterol in the normal range
• Eat less saturated fat.
• Use less salt in your diet.

Hypertension has no symptoms, but is easily managed and keeping it in the normal range could make a big difference to being able to save your brain.

References:
Shahram Oveisgharan; Vladimir Hachinski. Hypertension, Executive Dysfunction, and Progression to Dementia: The Canadian Study of Health and Aging. Arch Neurol, 2010; 67 (2): 187-192

JAMA and Archives Journals (2007, December 12). High Blood Pressure Associated With Risk For Mild Cognitive Impairment.

Radiological Society of North America (2007, November 29). High Blood Pressure May Heighten Effects Of Alzheimer’s Disease.