Mercury, genes and the link with Alzheimer’s disease

cropped-IMG_7188-1.jpgMethyl mercury, a pollutant produced by various industrial activities, is a potent neurotoxin that has now caused serious contamination issues within our oceans. As a fat soluble molecule, methyl mercury enters the food chain and accumulates in the flesh of the fish that then may end up in our supermarkets. Consuming larger, longer living fish on a regular basis is now known to pose a serious health hazard, especially for children and pregnant women who are consequently advised to limit (or even avoid) the intake of some species such as fresh tuna or marlin.

The accumulation of mercury within the body can have profound long-term effects on the nervous system, and has been linked to a variety of conditions including Alzheimer’s disease where it is believed to play a part in nerve cell death. Lipoproteins, such as high density lipoprotein (HDL) and low density lipoprotein (LDL), are combinations of lipids (fat) and proteins that function to transport fat around via the blood, a function that is generally associated with cholesterol, and therefore cardiovascular health. However, approximately 1 in 7 people carry a gene that causes their body to produce a particular lipoprotein called apoE4, known to play a significant role in the development of Alzheimer’s disease. Those who inherit the apoE4 gene from one parent are three times more likely than average to develop Alzheimer’s disease, with those who inherit the gene from both parents having a tenfold risk of developing the disease (Donix et al, 2010). There are multiple hypotheses as to why those carrying the apoE4 gene are more likely to develop Alzheimer’s than those who carry the apoE3 or apoE2 genes; one such hypothesis regards the role that these lipoproteins play in mercury transport within the body, as mercury accumulation in the brain hasbeen linked to the progression of Alzheimer’s. Like all proteins, apolipoprotein is made of chains of amino acids. Cysteine is of particular relevance, as this amino acid contains sulphur, a member of a class of substances called ‘mercaptans,’ the Latin name for “mercury capture.” Because apoE2, the protective form of apoE, contains two cysteine amino acids, it is particularly efficient at removing mercury from the system. In contrast, apoE3 has only one cysteine, and apoE4 none, making it the most ineffective at removing excess mercury from the body.

Given that fish oils are thought to offer protection against neuronal death and therefore the onset of dementia, it seems that ingesting them in high doses may negate any beneficial therapeutic effects unless they are highly purified to ensure all heavy metals are removed. The growing omega-3 market means there are more products of differing qualities and strengths, and the processes used to isolate and purify oils can also differ quite significantly. It would certainly be advisable to choose fish oil supplements that have been purified under pharmaceutical grade conditions to ensure the product not only offers the best possible health benefits, but can also guarantee to be contaminant free.

Refrences

Dórea JG. Environmental contaminants as biomarkers of fish intake: a case for hair mercury concentrations. Eur J Clin Nutr. 2010 Sep 1. [Epub ahead of print]

Albert I, Villeret G, Paris A, Verger P. Integrating variability in half-lives and dietary intakes to predict mercury concentration in hair. Regul Toxicol Pharmacol. 2010 Aug 27. [Epub ahead of print]

Remembering the importance of lifestyle choices

There has been a flurry of journal publication lately focusing on methods that can help stave off cognitive impairment and dementia. According to the most recent study, published in this month’s British Medical Journal, making dietary and lifestyle changes that ultimately reduce the risk of developing diabetes and depression, could have a significant impact on an individual’s future risk of developing dementia (Ritchie et al, 2010). The study, led by French researcher Dr Karen Ritchie, of the French National Institute of Medical research, analysed the lifestyle and health of 1,433 people over the age of 65 living in the south of France over a period of seven years. Whilst there is an element of genetic risk associated with the development of dementias such as Alzheimer’s disease, the role of diet and lifestyle are long known to be of significance, and that risk can be manipulated through specific changes. Dr Ritchie was quoted as saying “health chiefs should focus on encouraging literacy, prompt treatment of depressive symptoms and early screening for glucose intolerance and insulin resistance”. The study also highlighted the importance of consuming plenty of fruit and vegetables associated with a more ‘Mediterranean’ style of eating, which would also involve the consumption of foods such as seafood which is rich in neuroprotective omega-3s. In regards to the protective role that long term education has on brain health, this recent publication supports the findings of a study published in last months journal Brain. This study involved examining the brains of 872 participants in ECLIPSE (Epidemiological Clinicopathalogical Studies in Europe), a collaboration between three large population-based studies of ageing, in which a positive association was found between education and a reduced risk of developing dementia symptoms (Brayne et al, 2010). What was particularly interesting about this study was that education had no protection on dementia itself, but only on the symptoms. When the brains of individuals were examined, those individuals who had stayed in education still, showed the pathological and molecular signs of dementia, although whilst living, those individuals showed no physical symptoms of dementia. This would suggest that education in early life appears to enable some people to cope with a lot of changes in their brain before showing dementia symptoms.

So what do we learn from this? It seems that the same messages re-emerge over and over. That exercise, education and adoption of a ‘healthy’ diet offer protection against a myriad of diseases and conditions that are often considered to be just a part of growing old. However whilst it appears that we have a lot more say in our long term fate, putting into practice the advice offered by scientist may take both time and dedication as many of us are very settled in our ways. Educating people is the first step in initiating long term lifestyle changes.

Ritchie K et al. (2010) Designing prevention programmes to reduce incidence of dementia: prospective cohort study of modifiable risk factors. BMJ August 2010

Brayne C et al. (2010) Education, the brain and dementia: neuroprotection or compensation? Brain 133:2210-2216

EPA fish oil and its role in Alzheimer’s disease risk

I have recently written an article on EPA fish oil and its role in Alzheimer’s disease, as there are currently around 700,000 people in the UK with dementia (it is believed that these figures are set to rise to one million in the next 10 years because of the ageing population) and new research adds to the weight of evidence that suggests that people who regularly include fish as part of their diet have a lower risk of developing dementia and, in particular, Alzheimer’s disease.

The human brain is a complex organ that controls our senses, our movements, receives information, analyses information, and stores this information as memories. Dementia, simply put, means ‘deprived of the mind’ and, contrary to what many of us consider an acceptable part of growing old, memory loss and dementia are not a natural part of the ageing process. Scientists are now suggesting that the omega-3 EPA, found in fish oil, can help. Like any organ, the brain needs nurturing, and if we provide our brain with the correct nutrients then we can help to ensure the function of our brain remains at its most efficient.

For those of you interested in finding out more about how EPA helps preventing memory loss, offering help for Alzheimer’s sufferers, the full article is available here: EPA fish oil and its role in Alzheimer’s disease risk

Use of anti-psychotics in dementia patients leads to premature death

Currently there are around 700,000 people in the UK with dementia and it is believed that these figures are set to rise to one million in the next 10 years because of the ageing population. The National Institute of Health and Clinical Excellence (NICE) guidance is that people with dementia should only be offered antipsychotic drugs if they are severely distressed or there is an immediate risk of harm to the person or others. However the use of sedatives in dementia has repeatedly been condemned due to the increasing evidence that the use of such drugs in dementia patients significantly increases their risk of death. One such study published earlier this year followed 165 patients with Alzheimer’s disease living in care homes in Oxfordshire, Tyneside, London and Edinburgh. Patients who were already taking anti-psychotics either continued on their treatment, or given a dummy pill for a year and then followed up over a period of three years. After two years, 46% of patients who had been treated with anti-psychotics were alive compared with 71% on the placebo. Three years after the start of the study, fewer than a third of people on anti-psychotics were alive compared to nearly two-thirds taking the placebo (Ballard et al, 2009). A recent review ordered by the Department of Health outlines the over prescription of antipsychotic drugs to treat aggression and agitation in people with dementia and contrary to NICE guidance. The review authored by Professor S. Banerjee goes as far as suggesting that up to two thirds of those individuals with dementia receiving anti-psychotic drugs are prescribed them unnecessarily.

So why is it that pharmaceutical drugs, with such well documented findings in terms of their negative health effects, continue to be prescribed? It certainly appears that they are offered as a ‘quick fix’ regardless of the long term consequences. Originally discovered in the 1950s, anti-psychotics were found to block receptors in the dopamine pathway and used quite successfully in the treatment of schizophrenia and bi-polar disorder before being introduced as treatment for dementia where their actions serve as nothing other than “chemical restraints”. It seems shameful that pharmaceutical companies can benefit in such situations whilst nutraceutical companies struggle to get clearance for health claims from the Medicines and Healthcare products Regulatory Agency (MHRA). This government agency is responsible for ensuring that medicines and medical devices work and are acceptably safe, and consistently rejects claims for many well-known safe and commonly used nutritional products.

The benefits of fish oil and the role of long-chain fatty acids in brain chemistry and in dementia are generally accepted but not endorsed. Ironically the side effects of consuming fish oils include only relatively minor complications (gastrointestinal upset, nausea, headaches) when compared with the potentially very serious sides effects of some pharmaceutical products. Given that long-chain fatty acids are involved in the dopamine pathway influencing dopamine concentration, number of vesicles and D2 receptors, and have been beneficial in studies where the dopamine pathway is known to be involved such as schizophrenia and attention deficit hyperactivity disorder (ADHD), would it not be prudent to suggest a role of fatty acids as a regular or add-on treatment in individuals with dementia? The recent positive findings of the role of eicosapentaenoic acid EPA in reducing cerebral atrophy in Huntington’s disease is certainly indicative that non-pharmaceutical products need to be investigated and that their role in dementia, not only in the treatment but in the prevention of the condition, is sadly underrated at the expense of the patient.


Ballard C, Hanney ML, Theodoulou M, Douglas S, McShane R, Kossakowski K, Gill R, Juszczak E, Yu LM, Jacoby R; DART-AD investigators. (2009) The dementia antipsychotic withdrawal trial (DART-AD): long-term follow-up of a randomised placebo-controlled trial. Lancet Neurol. 2009 8:151-7.

Puri BK, Bydder GM, Manku MS, Clarke A, Waldman AD, Beckmann CF. (2008) Reduction in cerebral atrophy associated with ethyl-eicosapentaenoic acid treatment in patients with Huntington’s disease. J Int Med Res. 36:896-905

DHA, Fish and Alzheimer’s: Press Misinformation

The general public are reliant on the media for their most recent update on “what to eat and what not to eat” and so it’s terribly important that studies are reported objectively and fairly – and, of course, that we are given the whole picture. It is not a very new concept that eating fish such as salmon, sardines and mackerel may offer an element of protection against developing dementia and indeed the media has reported on a number of studies showing that people who consume a significant amount of oily fish or fish oil are less likely to develop Alzheimer’s disease. This week’s headline, “Fish may not be Alzheimer’s answer” suggests, however, that Alzheimer’s patients may not benefit from eating fish, despite this “brain food” reputation.

Our understanding of the significant health benefits associated with fish oil supplementation has come a long, long way since scientists’ original discovery, back in the 1950s, that cod liver oil was a rich source of fatty acids. Researchers have since then progressed far beyond the basic understanding that fish oil is a promoter of general good health, and moved onto the next phase of innovation – investigating which particular elements within this oil are biologically active and whether a physical deficiency in this bioactive element results in some degree of physical deterioration. Indeed, fish oil contains two major fatty acids EPA and DHA and it is only really in recent years that these important fatty acids have been investigated individually rather than dumping them in the same boat with the generic label of omega-3.

DHA is the most abundant omega-3 fatty acid in cell membranes, present in all organs and most abundant in the brain and retina. In contrast, EPA is present in minute quantities. It could be easily assumed that DHA is the more dominant of the two fatty acids and put all of our focus here. However whilst DHA has a primarily structural role, EPA plays an important functional role. In actual fact whist EPA and DHA are both considered to be important regulators of immunity, platelet aggregation and inflammation, their influencing bi-products arise from very different pathways and it is therefore not surprising that their mechanism of action will differ.

So what is my problem with the latest headline? Well what’s very misleading with this is the loose use of the word “fish”. The study didn’t even have a vague whiff of fish about it but was conducted using a DHA supplement and a dummy placebo. The importance of this is that the information put forward to eager ears gives the impression that all that mackerel eating is a waste of time. But hear me out. This study took but one of the major fatty acids associated with fish oil, showed no benefit, but happily used the word fish to summarise the findings. If we recall, fish oil contains two important fatty acids, DHA and EPA. It is becoming increasingly clear that the marked differences between the effects of EPA and DHA mean that we can no longer generalise the effects of ‘fish oil’ as a reservoir of omega-3. EPA not only plays a major role in cell signalling but also contributes to the compaction and stabilisation of neurones. Indeed previous studies have shown that high plasma EPA concentration may decrease the risk of dementia and that EPA can actually reduce the atrophy associated with the shrinking brain. I’m not objecting to their findings that DHA is not the fatty acid which plays a role in dementia, rather it’s the fact that the message implies that it we should now question or even rule out the protective role of fish altogether. But when we dig deeper and unravel the scientific evidence and put that on our plates to eat, we see that things are a little more convoluted than we initially thought – well, if you read the recent headlines, that is. Just because the bigwigs are now telling us that DHA won’t save our brains (this week at least) it doesn’t mean that we should now disregard our efforts to include fish as part of our diets in our bid to prevent age-related mental decline. I, for one, shall be continuing to get my twice weekly portions in and I hope you will too. Do remember that once again, it’s not black or white, to fish or not to fish.

Coffee debate update

So the coffee debate continues. Today’s headline in The Telegraph shouts an enthusiastic message that drinking coffee could reverse the signs of Alzhiemer’s disease. The trial led by Dr Gary Arendash, an American neuroscientist presents evidence that indicates that caffeine not only helps to stave off the disease, but can actually treat it. The defining hallmark of Alzheimer’s disease is the accumulation of β-amyloid protein plaques in the the areas of the brain responsible for memory (the cortex and hippocampus). These ‘sticky’ deposits are known to damage nerve cells, interfere with nerve signalling and therefore memory. Caffeine, it appears, actually reduces the production of β-amyloid protein and therefore would reduce the production of plaques. So that’s the good news folks. The bad news is that this groundbreaking research was conducted using mice. Not bad news as such if you’re a coffee drinking mouse who can’t remember where you’ve left your cheese. These findings do however support an earlier study published in January this year. Led by Marjo H. Eskelinen the study found that among 1,400 Finnish adults followed for 20 years, those who drank three to five cups of coffee per day in middle-age were two-thirds less likely than non-drinkers to develop dementia, including Alzheimer’s disease. So for the time being I shall continue to enjoy my morning cafetière, not only because I enjoy the ritual and the taste but because it may, just may help me retain my memory in years to come.

Coffee Controversy: is it good or is it bad for you?

I seem to have witnessed recently several identical conversations regarding coffee drinking. Is it good or bad for you? It’s not the coffee debate per say that intrigues me but this need for something to be so black or white, good or bad. I think it depends in part on where or from whom we get our information and the message that source wants to portray. It is true that coffee has well-documented side effects including anxiety, insomnia, tremor and palpitations. But on the plus side drinking coffee appears to improve alertness and some reports suggest that drinking 3 cups a day may even, reduce the risk of type 2 diabetes, protect against cancer and offer protections against dementia including reducing the risk of developing Alzheimer’s and Parkinson’s disease. So we have the good and the bad.

Coffee, however, like the majority of food stuffs we consume, is a complex composition. The side effects often associated with a steaming cup of java are actually the result of caffeine, which belongs to a group of stimulants called xanthenes. In moderation, caffeine can have very positive effects. It gives us more energy, heightens our ability to concentrate and makes us think more clearly and can even elevate our mood. That doesn’t sound so bad. But as with most things it merely boils down to moderation. If we drink caffeinated coffee in moderation it can increase alertness and mental stamina. If we drink too much too quickly, however, we are faced with the unpleasant side effects: nausea, confusion and excitability, which can be wholly unpleasant.

As with most things in life it’s not as simple as black or white. We need to look at the diet as a whole. Most foods we eat will have positive and negative factors, of which we are constantly being reminded by the tabloid headlines. Often telling just one side of the story, these messages can be somewhat confusing and frequently leave people rather bewildered as to what to consume and what to avoid. It’s a case of being sensible, taking everything in moderation and listening to the messages your body tells you. If you get the shakes after your morning espresso then that’s your body saying stop now, that’s enough.

A diet rich in fish oils could extend your life, research shows

Researchers from Norway and France found that elderly people who consume plenty of omega-3 acids, found in oily fish such as salmon, not only performed better in cognitive function tests than those who do not, but also demonstrated greater longevity than those who don’t regularly consume fish.

Norwegian researchers studied 254 frail, elderly patients and measured their dietary intakes of omega-3 fatty acids using plasma phospholipid concentrations of EPA. Patients’ omega-3 consumption was analysed and they were asked to return for further analysis after a period of three years. The results later showed that those tested with the lowest plasma phospholipid EPA levels were approximately 40 per cent more likely to die.

The French researchers observed 1214 healthy participants over a period of four years, 65 of which developed dementia. The results showed that only those with higher blood levels of EPA were linked with the reduced risk (31 per cent) of contracting dementia.

The omega-3 fatty acid EPA (eicosapentaenoic acid), which occurs naturally in oily fish such as salmon, mackerel and tuna, is responsible for a range of health benefits, from combating heart disease to boosting intelligence.
Despite this, most people eat just a fifth of the amount recommended for good health. The fact of the matter is that most people do not consume enough oily fish to reap the benefits of fatty acids, so supplementation with fish oils is a more viable option for many.
Vegepa is a patented formulation of completely natural long-chain omega fatty acids. It contains a unique ratio of ultra-pure EPA (the omega-3 eicosapentaenoic acid) and cold-pressed, non-raffinated, virgin evening primrose oil (containing the omega-6 gamma-linolenic acid). As such, Vegepa combines the benefits that both these natural substances bring to the body.

Fatty acids play an important part in the functioning of every living cell in the body. Specifically they may help the body in several ways including: improving the circulatory system, aiding concentration, maintaining a well-balanced state of mind and keeping joints in good condition.

The EPA in Vegepa is derived from fish oil – the highest yielding source of long-chain omega-3 fats. This fatty acid forms a vital part of the diet as it enables the body to produce many substances that are necessary for health and well-being.

The evening primrose oil (EPO) in Vegepa is derived from the cold pressing of evening primrose seeds. When EPO is unprocessed and unrefined it is a rich source of botanical triterpenes hormone-like substances, which play an important role in immune function. Just two capsules daily provide 560 mg EPA and 200 mg organic EPO, and help to reverse fatty acid deficiencies by nourishing the brain’s phospholipids. Vegepa is available from all good health food shops, or online at www.igennus.com

The Alzheimer’s Society provides a national help line on 0845 3000 336 and website www.alzheimers.org.uk.