A new study has found that the use of intranasal insulin produced an improvement in memory and cognitive function in a small group of people with either amnesic cognitive impairment or mild to moderate Alzheimer’s disease.

The role of insulin in Alzheimer’s has been extensively investigated. In the brain, abnormalities of insulin levels and activity have been known to be associated with the pathophysiology of Alzheimer’s. Type two diabetes (where a person has abnormal resistance to insulin) is a recognised risk factor for Alzheimer’s disease.

Having a normal blood sugar is important for our normal thinking skills and memory.
I’m sure many of us recognise how we don’t think so well either when we are really hungry when our blood sugar levels are really low, or conversely when we get that sugar high after eating a high sugar snack. The sugar fix is the signal for our body to release the hormone insulin which then restores our blood sugar to normal.

Using the insulin intranasally allowed the researchers to supply the brain with an extra shot of insulin, without producing any peripheral effect on blood sugar levels. This was important as the symptoms associated with having too low a blood sugar are not insignificant and include dizziness, confusion, heart palpitations, feeling anxious and altered vision.

In the study the intranasal insulin was administered over a 4 month period. One hundred and four subjects received either a 20 IU or 40IU dose of insulin or a placebo saline spray daily.
Those given the 20 IU insulin dose showed an improvement in memory that wasn’t apparent with the higher dose and both groups showed less decline in cognitive skills compared to the control group. There was also an improvement in functional ability for example in being able to handle money in those with Alzheimer’s who received the insulin spray.

This is a fabulous early study, which is now being followed up to involve a larger group of people over a longer period of time.

But the key for managing early Alzheimer’s disease, still remains in having an early diagnosis. This remains elusive for the present.

Intranasal treatments for delivery medication directly to the brain are not new. Earlier this year I blogged about how one research team have been investigating the use if intranasal Viagra as a means of preventing Alzheimer’s and stroke.

Ref:
Suzanne Craft; Laura D. Baker; Thomas J. Montine; Satoshi Minoshima; G. Stennis Watson; Amy Claxton; Matthew Arbuckle; Maureen Callaghan; Elaine Tsai; Stephen R. Plymate; Pattie S. Green; James Leverenz; Donna Cross; Brooke Gerton. Intranasal Insulin Therapy for Alzheimer Disease and Amnestic Mild Cognitive Impairment: A Pilot Clinical Trial. Archives of Neurology, 2011; DOI: 10.1001/archneurol.2011.233

The answer appears to be “yes”.

I am often asked about the role of fish oil supplements and whether we should be all taking them on a regular basis.
Some challenge my suggestion that we should all be eating fish several times a week for our cognitive health. “But where is the proof that eating fish or taking fish oil capsules can protect your brain” they ask.

A large number of studies from around the world have now supported the positive findings indicating the benefit to memory and cognition we gain from eating fish.
Fish provides us with an excellent source of Omega 3, an essential fatty acid that we can only derive from our diet. The brain uses Omega 3 in forming part of the cell membrane that surrounds every neuron or brain cell. In other words it is a vital component contributing to the structural integrity of all our neurons.

But many people struggle for a number of reasons to eat enough fresh fish. Taking fish oil as capsules or in liquid form appears to be a suitable alternative. Some fish oil manufacturers claim taking fish oil is good for cognitive health.

But is there proof?
Findings from a new study reported at the International Conference on Alzheimer’s Disease in Paris recently, suggest that taking fish oil does indeed confer protection to the brain against cognitive decline.

This was demonstrated in two ways. Firstly those taking fish oil regularly were found to maintain a higher brain volume, especially in the area of the cortex and hippocampus: two areas concerned with memory and thinking.

The other finding was that those taking fish oil supplements, tested higher on baseline cognitive functioning tests throughout and after the study.

The study included 819 individuals who had normal cognition, mild cognitive impairment or Alzheimer’s disease. Of this group, 117 subjects reported taking fish oil supplements regularly.

It was noted, that the benefits were only a positive association for those without cognitive impairment. This confirms previous findings, that fish oil supplementation is of no clinical benefit once cognitive impairment is present.
It was also only a positive association in those individuals who were APOE4 negative. So there is a genetic influence on the outcome.

In the general population, testing for APOE4 is not routine, one reason being that testing positive for the gene has no bearing on whether the gene will or will not be expressed and 60% of those with Alzheimer’s disease do not carry this gene.

So should we be taking fish oil supplements?
Regardless of whether we know our APOE4 status or not, it appears that that are substantial potential benefits to do so. I have been using fish oil supplements now for a number of years and intend to continue.

What about you? Do you take supplements and if not, does this research persuade you to consider using them?

Ref:
Lifespan (2011, August 17). Fish oil’s impact on cognition and brain structure identified in new study. ScienceDaily. Retrieved August 28, 2011, from http://www.sciencedaily.com­ /releases/2011/08/110817120220.htm

Berries are loaded with powerful antioxidants and blueberries in particular have exceptionally high levels of flavonoids. The deep blue colour of blueberries comes from the anthocyanin they contain and it is this sub-group of flavonoids, which have been found in other research to be beneficial in terms of helping us to maintain our memory and cognitive function.

Enjoying blueberries and the other deeply pigmented red berries and stone fruit has been recommended for a while, as being a useful to help protect us against dementia.
New research from Harvard now indicates that regularly eating berries may also lower your relative risk of developing Parkinson’s disease.

Parkinson’s disease is a neurodegenerative disease primarily affecting motor function but is also associated with a 30% incidence of dementia.

In this study, the researchers used a dietary questionnaire for 49,281 men and 80,336 women. They then analysed the association between amount of flavonoid intake from food and the risk of developing Parkinson’s disease.
They also analysed the consumption of five major food sources known to be high in flavonoid content i.e. berries, apples, red wine, tea, oranges and orange juice. The participants were followed over 20 to 22 years.

What were the findings?

In the male group it was found that those in the top 20% tier of flavonoid consumption were 40% less likely to develop Parkinson’s than those in the bottom 20% tier of consumption.

Interestingly in the ladies group, no such relationship between flavonoid consumption and risk of Parkinson’s was demonstrated.

However, in examining the effect of the different subgroup of flavonoids, it was found that regular consumption of anthocyanin from berries was associated with a lower risk of Parkinson’s disease in both men and women.

The message: eat more berries

This is the first human study to look at the link of flavonoids, (especially anthocyanin) in food and the risk of developing Parkinson’s disease. The findings suggest that men and women who regularly eat berries may have a lower risk of developing Parkinson’s disease. It also appears that men can to continue to further reduce their risk by eating a greater proportion of other flavonoid rich foods in general, including apples and oranges, tea, red wine (in moderation) and chocolate.

Ref:
Xiang Gao, MD, PhD Harvard School of Public health. American Academy of Neurology (2011, Feb17)

What does having high blood pressure, a big belly, high blood sugar, high triglycerides, low HDL cholesterol and high LDL cholesterol give you?

The answer?

Metabolic syndrome.

Metabolic syndrome is as the name suggests, a syndrome made of up a combination of three or more or the above risk factors. It is linked to having a higher risk of heart disease.

But if you look at each of these risk factors on their own, they are all risk factors for dementia. So it is probably no surprise to learn that someone with metabolic syndrome has a higher risk of developing memory loss, as they get older.

Recent research confirms the risk of memory loss from metabolic syndrome

A French study recently published in the journal Neurology tested a population of over 7000 people from three French cities looking to identify those with metabolic syndrome.

They found that 16% of the cohort met the criteria for metabolic syndrome. All of the participants took part in a series of memory and cognitive function tests two and four years later.

The tests included a memory test, a visual working memory test and a word fluency test.

What they found was that those 16% with metabolic syndrome

• Were 20% more likely to show cognitive decline
• Were 13% more likely to have cognitive impairment with the visual working memory test
• Were more likely to have poorer working memory if they had high triglycerides and lower HDL cholesterol
• Were associated with poorer visual working memory and word fluency if they had actual diabetes (not high blood sugars alone)

The key message from this study is that having metabolic syndrome is a major risk factor for memory loss because of the multiplier effect of the associated components, which go to make up this condition.

It seems fairly obvious that good management of those with metabolic syndrome is vital to preserve their cognition for advancing age.
What is encouraging though, is that many of the individual components can be relatively easily managed with good patient education and self-motivation.

High blood pressure can be addressed through losing weight, increasing physical activity, and medication if necessary.
High blood sugars and diabetes require dietary intervention and education, plus normalising weight, increasing exercise and using medication if required. Tight glycaemic control is the aim.

Blood lipids require follow up with repeated blood levels, dietary advice and intervention, exercise and medication as required.

Those big bellies may also require help with nutritional advice, exercise and follow up.

There are a number or recurrent themes of management which boil down to two of the key elements used in improving brain fitness, namely
good nutrition and exercise.

Better management of the metabolic syndrome will help to slow down age related memory loss or delay the onset of dementia in this high-risk group.

Ref:
C. Raffaitin, C. Féart, M. Le Goff, H. Amieva, C. Helmer, T. N. Akbaraly, C. Tzourio, H. Gin, P. Barberger-Gateau. Metabolic syndrome and cognitive decline in French elders: The Three-City Study. Neurology, 2011; DOI: 10.1212/WNL.0b013e31820b7656

Do you drink green tea?

Do you drink it because you like it? Or because you know it’s good for you? Or both?

Green tea has been used in traditional Chinese medicine for many hundreds of years. Tea (Camellia sinensis) still remains the most commonly drunk beverage across the world after water. Tea contains polyphenols (higher levels are found in green tea), potent antioxidants that in the teapot at least have been shown to have potent anti carcinogenic, hypocholesterolaemic and neuroprotective properties.

How does this work to protect our brain?

The brain is highly metabolically active and produces many free radicals (including a substance called hydrogen peroxide) which if unchecked can cause brain cell damage.
In earlier animal studies, green tea polyphenols were shown to ameliorate the effect of these free radicals and improve cognition in cognitively impaired animals.
A study in 2005 of an elderly group of Japanese people showed that drinking green tea over a two-year period provided them with a degree of cognitive protection.

As with many foods that have been identified as containing powerful biochemical substances useful to maintain our health, the question has been “Do these properties persist once we have consumed the foods and they have undergone digestion?”

What is the effect of digestion in altering the bioavailability and effectiveness of these green tea polyphenols?

A team from Dundee and Newcastle in the UK set up a study to answer that. They firstly developed a technology to simulate human digestion and then looked at how this affected a green tea extract passing through, assessing its ongoing ability to protect against the free radical hydrogen peroxide and beta amyloid toxicity.

What they were able to show was that this “digestion” actually appeared to enhance the neuroprotective and anti carcinogenic properties of the green tea.

The next logical step will be to look at this effect in human digestive studies.

Meanwhile for all you green (and black) tea lovers, it appears that drinking your favourite beverage really is good for your brain and well-being.

Ref:
E.J. Okello, G.J. McDougall, S. Kumar, C.J. Seal. In vitro protective effects of colon-available extract of Camellia sinensis (tea) against hydrogen peroxide and beta-amyloid (Aβ(1–42)) induced cytotoxicity in differentiated PC12 cells. Phytomedicine, 2010; DOI: 10.1016/j.phymed.2010.11.004