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]

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.