One of the most controversial discussions in the pet world is the link between diet and heart health – sadly, there are a number of reasons why heart function can be compromised, including genetics. Here at My Pet Nutritionist, we don’t think you can look at a health issue without considering the normal functioning of the system, so we thought we’d explore heart health in a little more detail. Let’s get cracking. The Cardiovascular System The cardiovascular system includes the heart and blood vessels (veins and the arteries). The function of the heart is to pump blood. The right side of the heart pumps blood to the lungs, where oxygen is added to the blood and carbon dioxide is removed from it. The left side pumps blood to the rest of the body, where oxygen and nutrients are delivered to tissues, and waste products are transferred to the blood for removal by other organs (like the kidneys). The heart is a hollow, muscular organ, divided into 4 chambers. There are upper chambers on both the left and ride sides of the heart called the left and the right atria. There are also 2 lower chambers called the left and right ventricles. A series of valves keep blood flowing in one direction through the heart. Each ventricle has an inlet and outlet valve. A heartbeat is actually the sounds of different valves closing. How does a Heart Beat? The heart beats because of electrical currents. Rhythmic electrical impulses or discharges cause the contraction of muscle fibres in the heart. At rest, the discharge is around 120 times per minute in a cat and 60-120 times per minute in the dog. Heart sounds are produced by the rapid acceleration and deceleration of blood and the resulting vibrations in the heart due to the circulation of blood. In dogs, 2 heart sounds can normally be distinguished. Calcium plays important roles in the electrical activity and pumping function of the heart. Calcium particles enter the heart muscle during each heartbeat and contribute to the electrical signal. When calcium is removed, relaxation is triggered. Potassium too plays a vital role at a cellular level. It’s movement in and out of cells helps maintain a regular heartbeat. Low levels of potassium lead to irregular contractions. When there is a high level of a compound in the body, it is termed, hyper, when there are low levels of a compound in the body, it is termed hypo. Sadly, too high and too low levels of all the above can result in irregularities in heart function. Hypokalaemia – low potassium Severe hypokalaemia is likely to cause skeletal muscle weakness, cardiac arrhythmias, and electrocardiographic abnormalities. Causes: Excessive diuretic therapy Vomiting and diarrhoea Diabetes Medications – steroids Conditions including Cushing’s Syndrome and liver failure. Hyperkalaemia – high potassium In this case, cardiac arrhythmias are common. Causes: Insulin deficiency Certain medications (NSAID’s, ACE-inhibitors) Potassium containing antibiotics Hypercalcaemia – high calcium Hypercalcaemia may present as fatigue, depression, confusion, anorexia, nausea, vomiting, constipation, peptic ulceration, or pancreatitis. Cardiac arrhythmias can occur. Causes: Parathyroid related Vitamin D intoxication Hyperthyroidism Vitamin A intoxication Cancer-related Renal failure Hypocalcaemia – low calcium Cardiac arrhythmias will be noted. Causes: Decreased intake of Vitamin D Vitamin D malabsorption Parathyroid related Acute renal failure Sodium is also important for heart health. It initiates contraction in muscles, in both skeletal and cardiac. Sodium deficiency is associated with restlessness, tachycardia, polyuria, and dry and tacky mucous membranes. The current minimum requirement for sodium has been established at 13.3mg/kg bw for dogs, but a higher quantity is suggested for bitches during gestation and lactation. In addition, greyhounds and sled dogs are allocated a higher requirement based on their high levels of exercise. At present, commercially available dog foods provide sodium intakes in excess of minimum requirements. Whilst some posit that dogs are increasingly adaptable to sodium intake, a study carried out in 2003 identified 82 dogs with dilated cardiomyopathy. They established that those with congestive heart failure ate significantly more sodium than those dogs without congestive heart failure. It pays to note that 25% of total daily sodium intake came from treats and table scraps, however. Findings Here Heart Murmurs Heart murmurs are vibrations that can be heard coming from the heart or major blood vessels and generally are the result of turbulent blood flow or vibrations of heart structures, such as part of a valve. Murmurs are typically described by their timing, their intensity, and their location. Not every murmur indicates a heart disorder, however. A heart murmur is like when you hit some white water on a usually calm river. Congenital Murmurs and Acquired Murmurs Congenital murmurs are associated with heart defects that the pet was born with. However, sometimes the defect is only detected later in life. An acquired murmur is a murmur that a pet acquires during their life. These can be benign, but more often (especially in dogs) are associated with developing heart disease. Heart Disease causing Murmurs Mitral valve disease (MVD) is a common acquired heart disease accounting for about 75% of cardiac disease seen in dogs in general practice. Prevalence of MVD increases with age and can be seen in high-risk breeds such as the Cavalier King Charles Spaniel. It is most common in small-medium sized breed dogs. Dilated cardiomyopathy (DCM) is the other main acquired heart disease seen in dogs. It can be primary in origin or secondary to dietary deficiencies or doxorubicin toxicity (chemotherapy medication). DCM has been reported in Dobermans and Golden Retrievers but other large or giant breed dogs have also been described. DCM is characterised by ventricular dilatation and systolic dysfunction. This poor systolic function means that a heart murmur is often low grade in its intensity. As DCM is regularly considered an inherited condition, it has been posited that certain breeds may need higher concentrations of amino acids like taurine and l-carnitine. Taurine and Heart Healt Taurine is the most abundant intracellular sulphur-containing amino acid. Although it can be
Whilst looking at micronutrients separately can be a somewhat reductionist view of both health and disease, we can’t deny that in many conditions we see here at My Pet Nutritionist, deficiencies may appear. We haven’t covered a specific nutrient for a while, so we thought we’d start again with Folate. Folate is a water-soluble B vitamin that is naturally present in some foods, added to others, and available as a dietary supplement. Folate, formerly known as folacin and sometimes vitamin B9, is the generic term for naturally occurring food folates. Folic acid is the fully oxidized monoglutamate form of the vitamin that is used in fortified foods and most dietary supplements. In short, folate is the natural form, folic acid is the synthetic form. In 1930, Lucy Wills found that marmite could cure macrocytic anaemia in pregnant women, since then we have consistently reinforced the role of folate as a key nutrient for health (and particularly for maternal health and foetal development). Folate comes from the latin folium, largely because folates were first isolated from spinach. Vitamin B9 or folate functions as a coenzyme, which in short means it assists enzymes to catalyse a reaction. B9 plays a role in: Producing nucleic acids (like DNA), Forming blood cells in bone marrow, Ensuring rapid cell growth in infancy, adolescence, and pregnancy, Controlling blood levels of the amino acid homocysteine, Utilizing amino acids in building new proteins. In short, B9 is important in normal blood formation, immune function, cell division and tissue growth. Signs and Symptoms of Deficiency Atrophy of the digestive tract epithelium; reduced absorption of nutrients, diarrhea, anorexia and weight loss, Reduced production of platelets can increased risk of abnormal bleeding, Impairments in white blood cell development can reduce immune response, Elevated blood homocysteine, Impaired foetal growth, Behaviour changes – depression, irritability. Anaemia Folate Deficiency Anaemia Anaemia is a blood disorder where the number of red blood cells is lower than usual. Red blood cells carry oxygen to all parts of the body, so in cases of anaemia, oxygen doesn’t get to tissues and organs. Without oxygen, they can’t carry out the functions they are supposed to. In addition, low folate levels can cause megaloblastic anaemia where red blood cells are larger than normal. As they are larger, they aren’t always able to leave the bone marrow, and so they can’t enter the blood stream to deliver oxygen where it needs to go. Causes of Folate Deficiency It goes without saying that a diet low in naturally occuring folates can result in folate deficiency, but deficiencies usually occur due to small intestinal disease or pancreatic insufficiency. In addition, they can also occur due to chronic use of certain medications. Like vitamin B12, folate is bound to protein so it must be freed by processing or digestion. Digestion starts in the stomach, but then soon calls upon the pancreas to help out with the production of digestive enzymes. Folate is chiefly absorbed in the small intestine so any dysfunction or inflammation here will result in malabsorption. This is why folate deficiency is often seen in inflammatory bowel disease. Gut Guardian Folate deficiency is regularly noted in cases using: Anticonvulsant medication, Sulfasalazine – to treat IBD/colitis, Diuretic medication, Homocysteine Homocysteine is an amino acid that is usually changed into other amino acids ready to be used by the body, but this process depends on other coenzymes and folate is one of them. When folate is low, homocysteine levels can creep up. High homocysteine levels have been associated with: Heart disease, Kidney disease, Arthritis, Neurodegeneration, In humans, we pay a lot of attention to a gene known as MTHFR, for us, this gene can have a glitch which means we don’t convert folate to its active form. As a result, those with MTHFR mutations can suffer with high homocysteine levels. We are still building our understanding in canines, but it appears dogs too can suffer genetic glitches which can affect how well they metabolise and utilise folate. A study carried out in 2014 explored the link between homocysteine levels in dogs and cardiovascular disease, inflammatory conditions, skin and kidney disease. They established breed differences in homocysteine levels, suggesting a genetic component to folate handling, like in humans. In addition, they concluded a strong relationship between high homocysteine levels and skin disease in dogs. Findings Here Folic Acid Supplementation Folic acid often remains unmetabolized in the body, this is the synthetic supplement form. As it is not a normal metabolite, it must first be reduced before it can enter the folate cycle. There are also schools of thought that folic acid competes with naturally occurring folates. For this reason, supplementation should ideally be folate in it’s methylated form. You also bypass the potential issue of genetic glitches. But, if there are no genetic glitches which affect how well your dog metabolises folate, then feeding a nutrient dense, fresh food diet should be sufficient. Sources of Folate: Dark leafy greens – spinach, broccoli, Liver, Seafood, Seeds, Eggs, Nuts, High levels of folate can often mask B12 deficiency, so take a look at our B12 blog for more information. Why Your Dog Needs Vitamin B12 Summary If your dog is suffering with digestive dysfunction, it may affect how well he utilises nutrients, so tackling this is essential. Folate deficiency is often seen in cases of inflammatory bowel disease and pancreatic dysfunction. Natural Guide for Inflammatory Bowel Disease Pancreatitis: Natural Guide for Pets 7 Steps to Optimal Gut Health If you would like more information on vitamin deficiencies in your dog, then check out our blog here: Does My Dog Have a Vitamin Deficiency As always if you are concerned about your dog’s diet, whether he is getting the right nutrients he needs, or indeed whether he is utilising them as needed, then check out our services to see if we can help explore some of these questions with you. Thanks for reading, Team MPN x
It always takes a couple of years for data to start filtering through, but in 2018, a survey of veterinary professionals believed that rates of obesity are increasing year on year. It is thought that 51% of dogs and 44% of cats in the UK are overweight. That is just over half of the population of dogs and nearly half of the population of cats. These numbers are up on the last data sourced in 2015. 100% of veterinary professionals are concerned about the prevalence of obesity and the health issues it can lead to. In the words of James Smith PT, we’d love to tell you it’s as simple as a calorie deficit, but here at My Pet Nutritionist, we know that obesity is in fact a multifactorial condition, which can make it a hard nut to crack. But we also know that the health of your pet depends on it. So, we’re not about to grab a hammer, instead we’re going to take a look around the cookware store and find the right nutcracker to do the job. Fancy a trip? The Health Issues Associated with Obesity: Being overweight increases the risk factors for developing: Cancer Diabetes Heart disease Osteoarthritis and degeneration of joints Urinary bladder stones Surgery complications Respiratory difficulties Kidney disease All things considered, its easy to see why obesity significantly reduces lifespan and why it is something that really needs to be addressed. What is obesity? Obesity is defined as an accumulation of excessive amounts of adipose tissue. It is generally a state of positive energy balance. When food is ingested, it is digested and metabolised. The body uses the nutrients it needs and converts the main macronutrients to energy. All energy in the body is produced by the breakdown of ATP, adenosine triphosphate. ATP is found in all cells in all the body, but as it is a large molecule, not so much can be stored. In nearly every living thing, this energy comes from the metabolism of glucose. There are three relevant energy systems. 1. ATP-P This is where the body uses all the ATP it has stored in its cells. This is the simplest energy production process; and if we were to consider it in human terms, this is the system that your 100m sprint would utilise. 2. Glycolytic System This system runs on glycogen, which is stored glucose. In human terms, this system provides moderate power and moderate duration. Both the ATP-PC and Glycolytic system are anaerobic, meaning they don’t require oxygen to produce ATP. 3. Oxidative Syste This system, as its name suggests does involve the use of oxygen to product ATP. This system cannot produce energy as quickly as the other two, but it can produce it continually and for a longer duration. This system can use stored carbohydrates and fats for fuel. In human terms, this would be the system that the marathon runner would access! So, in short, glucose is used as energy, but unused glucose can be converted to glycogen to be stored in the liver and muscles. If there is still leftover, then it is converted into fatty acids and stored in adipose tissue. This makes evolutionary sense; there would be a reserve during periods of low food availability. However, as you have noticed, fat too can be used as an energy source, and protein can be broken down into amino acids and then converted to glucose in a process known as gluconeogenesis. This is where the calorie in, calorie out idea comes from. An overabundance of any of the three macronutrients, can be converted into fat for later use. And the idea that obesity comes from reduced activity comes from the reasoning that those reserves aren’t actually used. On a simplistic level, this makes absolute sense and for the pet who is starting to look a little more round than usual, a simple reduction to their daily intake or a longer walk, may just tuck that waist in a little more. But there are many more factors at play here. Fat is the New Norm Do you know your pet is overweight? In an 8000-household study, 68% of surveyed owners report thinking their pet is the perfect weight. 67% of surveyed owners did not see obesity as a concern. Interestingly, a recent report from the NHS in the UK identified that 67% of men and 60% women were overweight or obese. 20% of Year 6 children were also classified as obese. Findings here Whilst we acknowledge there are faults in BMI scores, it still highlights a valid point. Sadly, pet obesity has many parallels with human obesity and according to the NHS, fat is the new norm for humans. As we know, we learn from experience and so, if we are consistently exposed to something, it becomes accepted. If we are consistently exposed to round pets, without a waistline, do we accept it? But, our pets need a waistline. They should tuck-in behind their ribs, and underneath. Whilst you shouldn’t be able to see their ribs, you should be able to feel them. They should not look rectangular from any angle, side or above. What treats are you offering your pet? Whilst for us humans, a decadent chocolate pot may be a weekend treat, dog treats have somewhat lost their novelty. Treats can be a useful resource during training, and in some cases, high value are necessary, but for some, treats are used as a way to prevent feelings of guilt when pets are being left home alone. Depending on how many times you leave the house, these can soon add up! 1. Table scrap We’ve all been there, those eyes looking up at you whilst you’re eating. Whilst that cubic inch of cheese only warrants 68 calories of your daily 2500 (call it 3%), for your 9kg Scottie Dog, that’s nearly 20% of their daily calorie allowance. If begging at the table is an issue, it is possible to remove the pets to
If you are interested in your own nutrition, chances are you’ve come across chia seeds in some sort of smoothie. Touted as a super-food, Chia, also known as Salvia Hispanica, packs a whole lot of punch in those small seeds! Not only beneficial to us humans, but chia can be a beneficial supplement for our canine friends. What is Chia? The word Chia is an adaptation of the Spanish word “chian” or “chien.” Originating from Nahuati, it means oily. This gives you a good way of remembering the benefits of the herbaceous plant; the seeds have a particularly high fat content. Grown worldwide, it tends to favour mountainous regions in Argentina, Peru, Paraguay, Ecuador, Mexico and Australia. It is also grown in Europe, but in greenhouses. Nutritional Composition Chia seeds are high in nutritional value, and seemingly across the board! Their high fibre content, gram for gram, exceeds that of nuts, cereals and other seeds. They pack a whopping 35g of fibre per 100g, flaxseed coming in a close second with 27-28g per 100g. Corn and rice come in around 6-8g of fibre per 100g! Findings here High consumption of fibre has been linked with reduced risk of heart disease, diabetes and a range of cancers. Not only that, but dietary fibre contributes to feelings of satiety so it’s helpful in weight management. Findings here Protein content comes in around 24g per 100g, but what is impressive is the range of amino acids contained! Chia seeds contain arginine, leucine, phenylalanine, valine and lysine. They also contain endogenous amino acids, mainly glutamic and aspartic acids, alanine, serine and glycine. Your dog’s body utilises amino acids to make proteins which help him break down food, grow and develop, repair body tissue and perform a range of other body functions. They can also be used as a source of energy. There are 9 amino acids which cannot be made by the body and as such need to come from food. These are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. As you compare, Chia seeds contain many of the essential amino acids needed in the body. You then have non-essential amino acids which the body can produce by itself; these include alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine. There are also certain acids that are deemed conditional, so if you are particularly interested, you can research this further. If we return to the content of chia seeds, arginine is involved in protecting the intestine and in nervous system function. It also has a role in blood pressure regulation. Glycine has a role in most bodily functions. It is a precursor in intestine proliferation, energy generation in skeletal muscle, immune system function, nervous system function and cardiovascular protection. Findings here Chia seeds are also high in a range of minerals. Phosphorus 860-919mg/100g Essential for bone and teeth formation. Findings here Calcium 456-631mg/100 Calcium is essential in bone and teeth health, blood clotting, nerve impulse, regulating heart rate and maintaining general homeostasis in cells. Findings here Potassium 407-726mg/100g Necessary for the normal functioning of cells, nerves and muscles. Findings here Magnesium 335-449mg/100g Essential in bone and teeth formation and for normal nerve and muscle function. Findings here Their vitamin content is as follows: Vitamin B1 0.6mg/100g Vitamin B2 0.2mg/100g Niacin 8.8mg/100g It’s not surprising that with the mineral content of chia seeds, studies have shown that long term dietary intake of chia is associated with increased bone density. Findings here Chia seeds are also particularly high in Omega 3 Fatty Acids. Studies show around 65% of the oil content is Omega 3! No other food to date has even come close to the same content. Omega 3 has a range of benefits in the body. It promotes healthy cells, immune system, eyes, brain, joints, skin and coats. When discussing the nutritional benefits of Chia specifically, studies have shown the following: They are cardio protective They may help to control diabetes Potential to decrease LDL cholesterol and increase HDL cholesterol Control blood pressure Stabilise blood glucose levels Vision support Supports cognitive function and brain development Anti-inflammatory Anti-viral Findings here Their anti-inflammatory properties have been found of benefit in cases of joint pain and rheumatoid arthritis. Findings here Studies have also shown chia seeds have been supportive when used as a complementary treatment for chronic kidney disease. Findings here It’s easy to see why chia are touted as a super-food. They do pack a whole lot of nutritional punch, for both you and your dog. They are easy to store, and they don’t taste of much, which makes them easy to slip in with even the fussiest of eaters. Chia is non-allergenic, so suitable for most dogs. Of course, check with a health care professional before feeding them. Be mindful, chia can absorb multiple time sits own weight in water, so if you aren’t feeding in a gel form (seeds soaked in water before feeding), ensure your dog has access to fresh water. If you want to check out our what we do, check us out. Consultations Thanks for reading. Team MPN x
Vitamin B12, also known as cobalamin, is a water-soluble vitamin which means no matter how much it is absorbed; any excess will be excreted via urine. It is critical for a range of functions in the body and if you have looked in any multivitamin aisles in the supermarket, it is one of the well-known B complex vitamins. A common deficiency in human vegetarians,disorders of cobalamin metabolism are seemingly increasing in small animal medicine. The causes of deficiency range from chronic gastrointestinal disease to hereditary disease, but what is clear is the health impact of low levels. Suboptimal B12 levels result in: Blood cell count abnormalities Disorders of lipid and protein metabolism Failure to thrive Anorexia Lethargy Vomiting Mood disorders/cognitive decline Slow healing Shortness of breath Muscle weakness Unsteady movement Increased homocysteine levels Functional folate deficiency Because the human body’s stores of B12 can seemingly last 3-6 years, low levels may take a while to be noticed. This seems to be true in our four-legged friends too. So, without further ado, let’s take a look at why it’s so important. Vitamin B12 is essential for DNA and RNA synthesis and for cellular energy production. All cells in all bodies need to know what they are doing and they need energy to do them! There are no known naturally occurring bioactive forms of B12 in plant sources. This is because B12 is synthesised by the bacteria in the gastrointestinal tract of animals, and then absorbed by the host animals. B12 is concentrated in their tissues, which is then eaten by other animals. Sources of B12 include red meat, fish, dairy and eggs. This is why human vegetarians and vegans are often low in it. Once ingested, dietary protein is partially digested by pepsin (digestive enzyme) and hydrochloric acid (HCI). Here Cbl (cobalamin) is released and binds to another protein called haptocorrin. Haptocorrin is then digested by pancreatic proteases (things that breakdown protein); freeing Cbl which can then bind to intrinsic factor. This then forms the B12 complex which travels through the small intestine. Here, there are receptors for intrinsic factor. The complex is internalised into the ileal enterocyte, and then released into the plasma, binding to a plasma protein. B12 is then delivered to those body parts that use and need it. And, there are certain many parts of the body that need and use it. Methionine Cycle B12 plays a vital role in the methionine cycle, which is involved in a range of cellular functions, particularly converting homocysteine to methionine. Methionine can be converted into sulphur-containing molecules which protect tissues,modify DNA, and ensure correct functioning of cells. Methionine also plays a role in creating new proteins in the body, which is essential when older proteins degrade. Whilst it has a role in a range of functions, there have been suggestions that cancer cells too are methionine dependent. Yet, when methionine is replaced with its precursor homocysteine, cancer cell growth is inhibited. Findings here That said, methionine is a key player in producing glutathione. Glutathione is often referred to as the body’s master antioxidant. It is composed of the three amino acids cysteine, glycine and glutamate. Glutathione is an important part of the body’s defence systems. Free radicals are like the exhaust fumes of work, work that the body carries out on a day to day basis. An imbalance in free radicals can result in oxidative stress, something which glutathione can alleviate. Glutathione depletion is often linked with low immune function and increased infection. It has also been found to be protective of skin, lens, cornea and retina damage. Findings here The balance of homocysteine is important,and B12 (along with B6) has the greatest effect on those levels. High levels of homocysteine are often linked to the early development of heart disease, along with Alzheimer’s (in humans), birth defects, blood clots, endothelial damage, and stroke. Resistance to Insulin Mouse studies have suggested that restricted B12 and methionine resulted in an increased resistance to insulin. Insulin is the gatekeeper for glucose getting into cells. Without insulin, glucose remains in the blood without a party to go to. It is argued that the restriction resulted in the lower availability of molecules that are vital to the process of DNA methylation (regulator of gene expression). These gene expressions were modulators underlying the development of resistance to insulin. Findings here Lipid (Fat) Metabolis Low levels of B12 have been noted to increase levels of adiposity, triglycerides, and total cholesterol. It is suggested that deficiency inhibits the oxidation of fatty acids. In these cases, there is also an increase in pro inflammatory cytokines. Findings here The dysregulation of lipid metabolism raises another interesting element. The nervous system has a rich lipid composition. Myelin sheaths are sleeves of fatty tissue that protect nerve cells. These nerve cells carry messages around the body. This is why low levels of B12 can lead to peripheral neuropathy. Without sufficient B12, the myelin sheath is damaged (demyelination) resulting in the disruption of nerve signals between the spinal cord and different parts of the body. This is the same mechanism that occurs in degenerative myelopathy. Whilst it is generally deemed a genetic condition in dogs (specific to certain breeds), in human studies, low levels of B12 have been associated with the condition. B12 deficiency is often a differential diagnosis to degenerative cervical myelopathy in humans too. Findings here Humans with low B12 often report progressive tingling in fingers and toes, without the ability to speak, it is unclear whether these symptoms affect our dogs too, but certainly poses food for thought in itchy cases. Findings here Anaemia The most recognised deficiency of B12 is anaemia. B12 is involved in the formation of healthy red blood cells; anaemia is when the body doesn’t have enough of them. Pernicious anaemia is usually a result of malabsorption of B12 due to a lack of intrinsic factor, the protein found in the stomach. Without enough B12, the red blood cells don’t divide normally (thanks to
One of the most abundant minerals in the body along with calcium and phosphorus, magnesium is essential to bodily function. Whilst there is some disagreement on the numbers, anywhere from 60-70% of the body’s magnesium is found in bone; the rest is in cellular fluid and soft tissue. Absorbed primarily in the small intestine,it soon finds its way to regulate muscle contraction (including the heart),blood pressure, insulin metabolism and to synthesise DNA, RNA and proteins! Not only that but it plays a key role in the nervous system for nerve transmission and neuromuscular coordination. It has also been found to protect against excitotoxicity. Rarely heralded for these qualities, it is an easy nutrient to miss; several human nutrition textbooks certainly do. So, let us explore this trusty element (Mg)in a little more detail and how it is particularly important to overall health. What is Magnesium? Magnesium is a chemical element; it is found in the Earth’s crust and found dissolved in sea water with sodium and chlorine. It is essential to all cells in the human body and activates some 300 enzymatic reactions necessary for metabolism. It interacts with ATP (energy carrying molecule), DNA and RNA. Plants too require magnesium to synthesise chlorophyll (the green pigment found in plants), which is essential for photosynthesis. Magnesium helps promote the absorption and metabolism of other minerals such as calcium, phosphorus, sodium and potassium. Not only that but it also plays a role in the utilisation of B-complex vitamins and vitamins C and E. Magnesium is the second most abundant mineral in your dog’s body, after potassium. It has a role throughout the body, so let’s start at the top. Signs of Magnesium deficiency Possible signs your pet is deficient: Muscle cramps Seizures Nervousness Low stress tolerance Anxiety Depression ‘Behavioural issues’ GI upset (often constipation with low levels) Loss of appetite and nausea Pancreatic dysfunction decreased glucose tolerance Fatigue Heart arrhythmia Hypertension Urinary disorders in cats The Role of Magnesium in Neurological Disorders Magnesium is essential in nerve transmission and neuromuscular conduction. It is also thought to be protective of excessive excitation that can lead to neuronal cell death. What this means is, it is thought to be of benefit in cases of chronic pain, anxiety and depression. It’s all to do with neurotransmitters. Neurotransmitters are in short, the body’s chemical messengers. They are the molecules used by the nervous system to shuttle messages between neurons, and from neurons to glands or muscles. Communication between neurons occurs at tiny gaps called synapses. One neuron (presynaptic neuron) releases a chemical (neurotransmitter) that is received by the other one (post synaptic neuron), which subsequently alters that neuronal function. Receptors can be designated as either excitatory or inhibitory; excitatory if they increase the likelihood of an action potential, and inhibitory if they decrease the likelihood a neuron will fire an action. The body thrives when it is in balance, maintaining homeostasis. Think of it as if you got into the car and just carried on driving, ignoring stop signs, junctions, other cars etc. Chaos would ensue. Inhibitory neurotransmitters are the highway code, stop signs, roundabouts etc; they ensure balance. There are two particularly relevant neurotransmitters, GABA (gamma-aminobutyric acid) and glutamate. Glutamate is excitatory and GABA is inhibitory. GABA counters Glutamate; they are the ying:yang of neurotransmitters. GABA relaxes and sedates, which is why low levels of GABA are often linked to anxiety or mood disorders (in humans). Magnesium is thought to modulate glutamatergic neurotransmission. Low magnesium levels have been suggestive of a supportive environment for excitotoxity; in short, there was too much glutamate at the party which resulted in cell death. Not surprisingly, this results in neurological decline/disorder. Magnesium seems to inhibit the receptors which glutamate acts on. Through this mechanism, it is also thought that GABA availability is increased. Findings here (Interestingly, the mineral zinc also down regulates glutamate response). Findings here In humans, many studies have demonstrated that magnesium is neuroprotective; this is particularly relevant for anxious or fearful dogs. Findings here Magnesium and the Heart Magnesium deficiencies have been linked with cardiovascular disorders, including high blood pressure and abnormal rhythms. There are a number of mechanisms in which magnesium supports heart health and function. Magnesium naturally competes with calcium which is essential in generating heart muscle contractions. Calcium stimulates the muscle and magnesium counters it; helping them to relax (this is also why magnesium is used in cases of spasms). When magnesium levels are low, calcium can overstimulate heart muscles causing a rapid or irregular heartbeat. As we have mentioned, magnesium is key to maintaining balance. Findings here There are also studies that suggest low levels of magnesium have been linked to low HDL (good) cholesterol, high triglycerides, and total cholesterol. This suggests that magnesium could be protective in cases of heart disease. Findings here Magnesium and Oxidative Stress and Free Radicals Oxidative stress is defined as the imbalance between oxidants and antioxidants; potentially leading to damage. Oxidants are reactive species,and some are free radicals. Reactive species are important in many physiological processes, but the over production can cause problems. It is thought that magnesium may attenuate free radical production in one of two ways. Firstly, it may directly inhibit free radical production and secondly, it may facilitate the scavenging of free radicals. Low magnesium levels have been linked with reduced antioxidants like glutathione, vitamin C, vitamin E and selenium. In short, low magnesium has been linked to greater levels of free radical production and low-level production of other antioxidants. Findings here Magnesium, Glucose Metabolism, and Insulin Resistance When food is eaten, it makes its way through the stomach and into the intestines; it is converted into glucose or blood sugar (the body’s fuel). In response, the pancreas produces insulin which helps cells absorb glucose for energy, now, blood sugar levels start to fall. High glucose calls for high levels of insulin and if this is repeated regularly, the body can stop responding to insulin; or stop producing it all together. Magnesium plays a
