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]

Why being depressed can make your brain shrink!

For many sufferers, depression brings on many kinds of emotions and feelings including anxiety, guilt and shame, so it’s not surprising that many people fail to seek help. Often, many of the feelings that are associated with depression are, in part, caused by a general lack of understanding of the condition, not only by the sufferer, but by family members, friends, employers and colleagues. And yet the majority of people will experience some psychological problems during their lives. In fact very few people will go through life without experiencing some form of mental trauma of some description. But what is it that goes on in your head when you are feeling depressed?

There is increasing scientific focus on the mechanisms that occur within the body and brain of depressed patients. Indeed, it is becoming much clearer that inflammation significantly contributes to the cause and progress of depression, and that this triggers a myriad of processes that all contribute to the symptoms associated with the condition. It is difficult to comprehend that inflammation can trigger depression, because it is generally thought of as a response to injury or irritation that is characterised by physical processes such as pain and swelling.

However, inflammation need not be physical or obvious, and inflammatory processes and brain-immune interactions are now known to be involved in the development of major depression. Inflammation is certainly suggested to contribute to the dysfunction of biological systems involved in the production of important neurotransmitters (brain hormones) such as serotonin and noradrenalin. Indeed, increased levels of inflammatory products called cytokines (produced by immune cells, and involved in relaying messages between cells) have consistently been reported in patients with depression. Pro-inflammatory cytokines have many physiological functions but, significantly, have been reported to modulate central nervous system functions including a process called neurogenesis, which is simply the method by which nerve cells are generated. Excessive inflammation, and the production of cytokines amongst other things, causes a series of processes that ultimately damage neurones leading to their death. When cells within the brain die, this causes atrophy, or shrinking, by which there is loss of brain gray matter. Structural brain changes detected by a process called MRI scanning in depressed patients have been reported in several brain regions.

However, there appears to be hope offered through supplementing with fish oil. EPA is an omega-3 fatty acid known to help the symptoms of depression and reduce levels of inflammatory cytokines, whilst producing beneficial anti-inflammatory products. There is increasing scientific interest in the ability of EPA to prevent neuronal cell death and therefore reduce or prevent gray matter loss. Much of the pioneering work has focused on the role of EPA in Huntington’s disease with extremely promising results. Given the evidence that omega-3 fatty acids are beneficial for conditions in which there is reduced gray matter atrophy, such as Huntington’s disease, supplementing with ethyl-EPA may have further positive benefits on gray matter volume in individuals with depression, and further studies to support this hypothesis are certainly warranted.

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.

Song C, Wang H. Cytokines mediated inflammation and decreased neurogenesis in animal models of depression.Prog Neuropsychopharmacol Biol Psychiatry. 2010 [Epub ahead of print]

Omega 3 and depression

IMG_0650There is growing evidence for the role of omega3 fish oil, not only in the etiology of major depression, but also as a treatment method. Given the numerous and undesirable side effects associated with conventional pharmaceutical treatments it is no wonder that many individuals actively seek natural alternatives, and the pure EPA fish oil (eicosapentaenoic acid – EPA) may just be what the doctor ordered.

Indeed, several studies have highlighted that abnormal cell membrane fatty acid composition is related to risk and incidence of major depression, and that supplementation with omega-3, and specifically with EPA, appears to normalize fatty acid levels and reduce the symptoms associated with this condition. However different studies can report different findings, and whilst several studies may appear to give varied and often conflicting results, performing a meta-analysis gives an indication of general findings by ‘pooling’ the data from several studies to give an overall picture and therefore adding clarity to a concept.

A recent meta-analysis of 14 studies comparing the levels of polyunsaturated fatty acids between depressive patients and control subjects found that omega-3 polyunsaturated fatty acid levels were significantly lower in those individuals suffering from depression (Lin et al, 2010). Because the primary sources of these long-chain omega-3 fats are fish and shellfish, it is not surprising that those individuals with the highest consumption are the least likely to suffer from depression (Suominen-Taipale et al, 2010). Treating people who suffer with depression using fish oils is therefore a viable method for alleviating symptoms whilst restoring omega-3 levels. Given that low levels of omega-3 are also associated with increased risk of cardiovascular disease, as well as several other chronic disorders and conditions, the overall health benefits of raising omega-3 levels reach out much further as a nutritional approach to improving health.

Encouragingly, improvements in depressive symptoms can be seen as quickly as 8 weeks after commencing treatment. Indeed, a group of Montreal researchers have recently confirmed that taking omega 3 fish oil supplements, at doses higher than that normally consumed in an average diet, is superior to placebo in treating symptoms and that results can be observed within a two month time period (Lespérance et al, 2010). The results of this particular study also confirm EPA to be the predominant active ingredient responsible for the benefits of omega-3.

A meta-analysis of 28 trials investigating as to whether either EPA or docosahexanoeic acid (DHA) or both are responsible for the reported benefits showed that those trials in which EPA was the predominant or only fatty acid used, gave the most significant findings. Furthermore, it was suggested that the effects of 1g daily of EPA could be enhanced and prolonged by the addition of gamma-linolenic acid (GLA), an omega-6 fatty acid found in evening primrose oil (Martins 2009). Given that 1 in 4 individuals will suffer from depression at some point in their life, it is encouraging to know that there is a safe and natural way not only to treat depression but also as a method that could reduce the possibility of developing the condition in the first place.

 

Lespérance F, Frasure-Smith N, St-André E, Turecki G, Lespérance P, Wisniewski SR. The Efficacy of Omega-3 Supplementation for Major Depression: A Randomized Controlled Trial. J Clin Psychiatry 10.4088/JCP.10m05966blu

Lin PY, Huang SY, Su KP. A Meta-Analytic Review of Polyunsaturated Fatty Acid Compositions in Patients with Depression. Biol Psychiatry. 2010 May 7. [Epub ahead of print]

Martins JG EPA but not DHA appears to be responsible for the efficacy of omega-3 long chain polyunsaturated fatty acid supplementation in depression: evidence from a meta-analysis of randomized controlled trials. J Am Coll Nutr. 2009 28:525-42.

Suominen-Taipale AL, Partonen T, Turunen AW, Männistö S, Jula A, Verkasalo PK.Fish consumption and omega-3 polyunsaturated Fatty acids in relation to depressive episodes: a cross-sectional analysis. PLoS One. 2010 May 7;5:e10530.

Vegetarian, Vegan Omega 3 Sources

Vegetarian Omega 3

I’m giving a talk in a couple of weeks at the Bristol Eco Veggie Fayre on plant based sources of Essential Fatty Acids, focusing mainly on echium oil. If you want to find out more about how echium seed oil compares with other oils such as flax and hemp, check out this new website which has some really good comparisons www.vegetarian-omega3.com. It would be great to see some of you at the Veggie fayre; my talk is being held in the Veggie Nutritional Room on Sunday 30th at 2pm. It’s a fun day out for all the family, with lots of good veggie food and free samples of vegetarian friendly products to take home!

Irritable bowel syndrome, serotonin levels and the role of diet

Irritable bowel syndrome (IBS) is becoming an increasingly common gut disorder in which the sufferer typically experiences: abdominal pain, cramping, bloating, excess wind, diarrhoea, and/or constipation, or an alternating combination of the two. Whilst the severities of these symptoms vary considerably between individuals, IBS has a profound effect on the sufferer’s quality of life. Many of the day to day activities that the majority of us take for granted can pose much more of challenge when you have IBS. You no longer simple take your body for granted, with careful forward planning essential in order to cope with the unpleasant, and often, embarrassing symptoms. Understanding IBS and what triggers the variety of symptoms is paramount to developing coping strategies.

It is thought that people with IBS have an abnormal gastrocolic response. This is the physiological reflex that controls the movements of the gastrointestinal tract (GI tract). Simply put, this mechanism controls the movement (peristalsis) that pushes food through and out of the gut. In IBS, simply eating or drinking can cause an over reaction of this process resulting in painful cramps, often resulting in diarrhoea.

Whilst the action of eating causes an increase in gut mobility, eating large meals seems to cause excessive cramping and bouts of diarrhoea, so a key tip is to try to eat small amounts and to try to eat regularly. Many people with IBS also find there are specific dietary triggers that can result in discomfort and bowel dysfunction. Knowing what foods to include, and what foods to avoid, can make a dramatic impact on regulating or avoiding specific symptoms.

Several gut peptides (types of protein), and neuropeptides are involved in the control of the gastrocolic reflex, of which serotonin is one such example. Serotonin, a neurotransmitter peptide, is generally known for its role in the regulation of mood, appetite, sleep, and some cognitive functions including memory and learning. However approximately 80% of the serotonin is actually produced in the body by the enterochromaffin cells found in the gut lining. The function of serotonin within the gut is to control muscle contractions, thereby functioning to maintain the movement of the intestines. Importantly however, many IBS sufferers can directly link stress to the onset of symptoms and it appears that there may, in some cases, be a link between serotonin, stress and IBS.

During a stressful experience there is a complex set of interactions between the hypothalamus (a part of the brain), the pituitary gland (also part of the brain) and the adrenal glands (at the top of each kidney). Several types of neurotransmitters are involved in this system, collectively known as the HPA-axis, which is thought to be dysfunctional in individuals with several conditions including fibromyalgia, chronic fatigue syndrome and depression to which IBS is often linked. Sufferers of these conditions can have numerous abnormalities in their hormonal, metabolic and brain-chemical activity including levels of serotonin. Dysregulation of the serotonin system has been found in individuals with IBS, with low levels associated with constipation, and high levels with diarrhoea (Sikander et al, 2009).

The link between stress, diet and IBS means that suffers can help reduce symptoms not only by modifying their diet, but also from reducing tension and stress through simple relaxation techniques such as: meditation, yoga and the Alexander Technique. Certainly living with IBS is far from pleasant, but with the right diet and learning how to manage stress, there is no reason why IBS should not be controllable. Let you control your IBS and not your IBS control you!

FOODS TO INCREASE FOODS TO AVOID
Carbohydrates
Complex carbohydrates, also known as starchy foods, are broken down slowly in the body to produce energy and are much kinder to the GI tract. This includes foods such as rice, oats and barley as well cooked vegetables.
Carbohydrates
Avoid foods high in fast releasing sugars such as unrefined grains, confectionary, cakes and biscuits. Avoid raw vegetables, salads and raw fruit.
Fats
Increasing omega-3 from oily fish (mackerel, sardines, pilchards, salmon) or through supplements can help alleviate inflammation and calm the guts. Try including evening primrose oil as a source of GLA, an anti-inflammatory omega-6 fatty acid
Fats
Avoid saturated fats from red meat and dairy food and fried food as these are classic triggers that exacerbate the symptoms of IBS
Protein
Lean chicken, pork, turkey and fish can supply good animal protein.
Protein
Avoid protein from red meat.
Fibre
Soluble fibre absorbs excess fluids forming a gel which bulks out faeces and can therefore help to reduce diarrhoea. By bulking out faeces, soluble fibre keeps the muscles of the GI tract gently stretched thus giving them something to grip on during a peristaltic motion and helps to avoid painful spasms. This in turn can help relieve constipation by softening and pushing through any impacted faecal matter.
Fibre
Insoluble fibre (bran, raw fibrous vegetables, salad greens, unpeeled fruits) can trigger painful gastrointestinal spasms
Fluids
Drink plenty of fluid to avoid constipation. The following teas can help eliminate gas and bloating but also can relax the intestine smooth muscle: peppermint, fennel, ginger and chamomile.
Fluids
Coffee, tea (even decaffeinated) and alcohol are powerful GI tract irritants, and can have the same effects as fats and insoluble fibres. Also avoid sugary carbonated drinks or drinks containing the sweeteners sorbitol or xylitol.
Probiotics
Available as dietary supplements and foods such as yogurt, with most products containing one of two types of bacteria – Lactobacillus or Bifidobacterium. Probiotics are often combined with prebiotics to form synbiotics. Prebiotics are simply non-digestible food ingredients that selectively stimulate the growth and activity of beneficial microorganisms already in the colon.

Sikander A, Rana SV, Prasad KK. (2009) Role of serotonin in gastrointestinal motility and irritable bowel syndrome. Clin Chim Acta. 403:47-55.

Low-carbohydrate diet – The Atkins diet

The Atkins diet has caused quite a debate with regards to its use and safety ever since Dr. Atkins launched his ‘Diet Revolution’ in 1972. So what’s wrong with it exactly? For starters, the diet totally excludes all carbohydrates, which are actually an absolutely vital component of our diet. By excluding them, the body must rely on protein and fat, not only as a source of energy, but also for vital nutrients and macronutrients. Therefore, by completely depleting the body of carbohydrate we also decrease our intake of many essential vitamins and minerals as well as fibre and another important type of carbohydrate called ‘non-starch polysaccharide’ which is absolutely essential for normal gut function.

In addition, high intake of fat, especially saturated fat derived from animal products, can increase both lipid and cholesterol levels, both of which are know to increase the risk of developing heart disease. By combining a high fat diet with one that is low in fibre results in a diet that carries an even stronger risk of developing heart disease. Furthermore, consuming too much protein is known to put strain on the kidneys, which can result in possible renal injury. Because the body cannot store protein, once the body’s needs are met, any excess must then be removed. This excess protein is converted by the liver into compounds, like urea, which are finally eliminated through the kidneys as part of urine. High protein intake also causes loss of calcium from the bones into the blood with corresponding implications on bone health.
High protein diet.gifGenerally, whilst the immediate positive benefit attributed to the Atkins diet is quick and relatively easy weight loss, the long-term consequences on cardiac, renal, bone and liver health must be all be taken into consideration. However, the ‘new’ version of the Atkins diet differs from its older counterpart in that rather than excluding carbohydrate completely, after a certain amount of weeks (depending on weight loss targets), carbohydrate is slowly reintroduced. The diet then continues, but as a ‘low-carbohydrate’ diet.

On the whole, this would appear to be a better option to restricting carbohydrate completely. However, it’s still a diet that is very low in fruit, vegetables and fibre, so in terms of digestive health, it’s not in keeping with fibre and ‘complex’ carbohydrate recommendations. Complex carbohydrates are important because they are broken down into glucose slowly, therefore providing a gradual steady stream of energy throughout the day. Eating a diet that has plenty of complex carbohydrate can help reduce the chances of developing type II diabetes for example.

The simple truth is that anyone carrying too much weight has most likely consumed more calories than they should have for some period of time. Whilst you can lose weight on anything that helps you to eat less, it does not mean it’s good for you. If you want to lose weight you need to look the amount of energy you put into your body and compare it to the amount of energy you burn. Men need approximately 2500 Kcal daily and women 2000 Kcal daily. So what do we need these calories for? Our daily calorie intake can be divided into the 3 following areas: firstly, basal metabolic rate (BMR) is the minimum amount of energy needed for our bodies to function on a daily basis and includes things like our heart beating and our breathing. Secondly is something called diet induced thermogenesis (DIT) which is the energy used when we digest our food. Finally, we need energy for physical activity, to move and to exercise and the more active a person is, the more energy they use.

Consuming more calories than we need will simply make the body store them as fat for ‘later use’. With our chaotic modern lifestyles, many of us exercise much less than we should, driving places rather than walking, with many of us having office jobs that require little, if no physical activity. The down side of all this is that sedentary individuals are much more likely to be overweight than active ones. All in all, it’s pretty easy in today’s world to pile on the pounds. Fad diets simply target vulnerable individuals who want a quick fix, and whilst the Atkins may deliver in regards to weight loss, the long-term consequences for our health may outweigh the short-term benefits. If you are really keen to shed those pounds, think about easy changes you can make to you life style and try being more active as well as adjusting what you eat to your level of activity. You simply don’t need as much energy to sit on the sofa watching television as you would playing sport for example. Being active also has numerous other benefits for our stress levels, not to mention its release of ‘happy hormones’.

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

Omega 3s and Fatty Liver Disease

Whilst most people in the UK are familiar with alcohol-related liver disease as a result of heavy drinking, which is on the rise, many of us are unaware of the problems associated with another form of liver disease, non-alcoholic fatty liver disease (NAFLD) – also known as non-alcoholic steatohepatitis (NASH). A recent review of four human studies by a group based at the University of Edinburgh found that long-chain omega-3 fatty acids not only improve liver health and function, but also increase insulin sensitivity in people suffering from fatty liver disease.

I’ve recently published an article on Omega 3s and fatty liver disease and the study led by Dr Gail Masterton and I would be very interested to hear your feed back!

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

The mood food connection

Each year on 10th October, the Mental Health Foundation marks the day by raising awareness about mental health and well-being. Whilst we would probably all consider ourselves as reasonably tolerant and open minded, there is still quite a significant stigma about depression. If we haven’t experienced depression directly, it’s highly probable that we know someone, perhaps a friend, relative or workmate, who suffers. Mental Health Statistics report that 1 in 4 British adults experience at least one diagnosable mental health problem in any one year and 1 in 6 of us experiences this at any given time. In 2001 the World Health Organisation (WHO) estimated that approximately 450 million people worldwide have a mental health problem, of which 154 million are affected by depression.One of the major side effects of depression is that the way we think about food changes and this can influence how we eat – both the types of food and how often. Because food can directly influence our mood, our diet is even more fundamental when we’re feeling low.

The Glycemic Index

The brain needs energy supplied at an even rate in order to function optimally. Sudden peaks in blood sugar will adversely affect behaviour, anxiety, depression, and fatigue, so it is particularly important for people with depression to keep their blood glucose levels even. Although commonly known for its diabetes and weight loss benefits, the glycemic index (most commonly referred to as GI index), which ranks carbohydrates according to their effect on blood glucose levels, is a good guide to informing us which foods to include as part of a healthy diet, and indeed which foods to limit.

While all carbohydrate foods are eventually broken down into glucose, quick-release simple carbohydrates (such as high sugar foods, glucose and fructose) are broken down more quickly into glucose than complex carbohydrates (such as wholemeal grains), releasing glucose rapidly into the bloodstream. Repeated ‘spikes’ of glucose can decrease insulin sensitivity, increasing the risk of type 2 diabetes, as well as promoting oxidative stress in the veins and arteries – a cause of coronary heart disease. After the highs come the energy-sapping blood sugar lows and, frequently, strong urges to reach for another sugary carbohydrate snack to perk us up. Indeed individuals who suffer from atypical depression (a subtype of depression) often overeat and report an almost irresistible craving for carbohydrates.

White sugar and other refined carbohydrates, such as those found in processed white bread and white pasta, white rice and most convenience foods, supply few nutrients to the body but use up important B vitamins, which are essential for our nervous and immune systems, as well as healthy digestion. Avoiding refined foods and sugar, as well as consuming foods with a low GI value, will help to keep blood sugar levels even. Perhaps a more accurate reference guide to prevent blood sugar spikes is the Glycemic Load(GL) ranking system, which is based on a food’s GI value and average portion size. For example, whilst an apple is not low GI, it has a low GL and will barely influence blood sugar levels.

Micronutrient deficiencies

It is extemely common for depression sufferers to have low levels of B vitamins and essential minerals such as zinc, selenium and magnesium. These water-soluble vitamins and minerals must be consumed daily to avoid depletion. Deficiency can, in turn, hinder the body’s ability to utilise specific omega-3 fatty acids, which are known to lift our mood by elevating serotonin and regulating levels of this important neurotransmitter.

EPA, a long-chain omega-3 fatty acid found in fish oil, not only influences serotonin and dopamine in the brain, but is also converted to powerful anti-inlammatories via a series of enzyme-mediated steps. It is these enzymes that rely on the presence of B vitamins and essential minerals in order to function, without which the body’s production of natural anti-inflammatories is minimal, and can even result in the production of inflammatory substances. Combining a good nutritional vitamin and mineral supplement with 1 gram EPA daily (or 4 capsules Vegepa) can help to balance serotonin levels and alleviate the symptoms of depression.

Carbohydrate cravings are also linked with low levels of chromium, which helps to regulate blood sugar levels and reduce cravings. This is because for blood sugar to provide energy, it must be escorted into each of our cells where the energy conversion takes place. Insulin then ‘unlocks’ the cell, allowing glucose to pass in. But there is a missing link. Insulin doesn’t work properly unless biologically active chromium is present as a cofactor (much like a catalyst).

With many modern food processing methods, up to 80% of chromium is lost – particularly with whole wheat and raw sugar when they are processed to white flour and refined sugar. If we regularly opt for these refined foods over their healthy wholegrain relatives, chromium levels within the body can easily become depleted.

Whilst it is likely a low priority during episodes of low mood to concentrate on our eating habits, following a few general guidelines can help to restore healthy brain chemistry and minimise sugar-induced mood swings.

– Avoid processed foods.

– Keep red meat to a minimum or eat organic (red meat is high in inflammatory omega-6 unless animals are fed on natural grass).

– Drink plenty of water, as the brain needs to be hydrated to function at its best.

– Don’t forget your ‘five a day’. Make sure you get plenty of vitamins and minerals by eating a wide variety of fresh fruit and vegetables. If you eat them raw they’ll supply even more nutrients.

– Eat two portions of oily fish weekly to top up on omega-3, containing the natural antidepressant EPA, or take 2 capsules of Vegepa morning and night.

If you found this article interesting, you might like to read more about anti depression foods.

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