Magnesium

Kaydees behavior has been slightly deteriorating again, and some muscle problems have re-appeared. I realised that I have been lazy about keeping on top of what I am giving her to eat, especially while away, she has just been getting kibble. SO I have read more about magnesium in the diet, and thought perhaps other people might find this interesting too.

Magnesium
Most of this information has been obtained from a human perspective, gleaned from a google internet search.

What it is:
Magnesium is a mineral needed by every cell in the human body and is required for more than 300 biochemical reactions. Magnesium is usually referred to as a "macromineral" (The other macrominerals that all humans must get from food are calcium, phosphorus, sodium, potassium and chloride).
Most of our magnesium is found in our bones (60-65%) combined with calcium and phosphorus. Magnesium is also found in our muscles (25%), with only a very small amount, approximately 1%, found in our blood. The human body regulates the level of magnesium in the blood to keep it at a fairly constant level. This makes detecting deficiencies difficult, as blood tests will not show up a deficiency until reserves stored in the bones and muscles are severely depleted.
Like all minerals, magnesium cannot be made in our body and must therefore be plentiful in our diet in order for us to remain healthy.

What it does:
Nerve and Muscle Relaxation
Magnesium and its fellow macronutrient, calcium, act together to help regulate the body's nerve and muscle function. In many nerve cells, magnesium serves as a chemical gate blocker - as long as there is enough magnesium around, calcium can't rush into the nerve cell and activate the nerve. This gate blocking by magnesium helps keep the nerve relaxed. If our diet provides us with too little magnesium, this gate blocking can fail and the nerve cell can become over-activated. When some nerve cells are over-activated, they can send too many messages to the muscles and cause the muscles to over-contract. This chain of events helps explain how magnesium deficiency can trigger muscle tension, muscle soreness, muscle spasms, muscle cramps, and muscle fatigue.
Other functions of magnesium:
Many chemical reactions in the body involve the presence of an enzyme. Enzymes are special proteins that help trigger chemical reactions. Over 300 different enzymes in the body require magnesium in order to function. For this reason, the functions of this mineral are especially diverse. Magnesium is involved in the metabolism of proteins, carbohydrates, and fats. It helps genes function properly. Some fuels cannot be stored in our muscle cells unless adequate supplies of magnesium are available.
The metabolic role of magnesium is so diverse that it is difficult to find a body system that is not affected by magnesium deficiency. Our cardiovascular system, digestive system, nervous system, muscles, kidneys, liver, hormone-secreting glands, and brain all rely on magnesium for their metabolic function.

What happens when there is a deficiency:

Early signs of magnesium deficiency in humans include loss of appetite, nausea, vomiting, fatigue, and weakness. As magnesium deficiency worsens, numbness, tingling, muscle contractions and cramps, seizures, personality changes, abnormal heart rhythms, and coronary spasms can occur. Severe magnesium deficiency can result in low levels of calcium in the blood (hypocalcemia). Magnesium deficiency is also associated with low levels of potassium in the blood (hypokalemia).
Because magnesium plays such a wide variety of roles in the body, the symptoms of magnesium deficiency can also vary widely. Many symptoms involve changes in nerve and muscle function. These changes include muscle weakness, tremor, and spasm. In the heart muscle, magnesium deficiency can result in arrhythmia, irregular contraction, and increased heart rate.
Because of its role in bone structure, the softening and weakening of bone can also be a symptom of magnesium deficiency. Other symptoms can include: imbalanced blood sugar levels; headaches; elevated blood pressure; elevated fats in the bloodstream; depression; seizures; nausea; vomiting; and lack of appetite.


What factors might contribute to a deficiency of magnesium?
In addition to poor dietary intake, problems in the digestive tract are the most common cause of magnesium deficiency. Magnesium is water soluble, so anything causing increased elimination of water from the body may also cause the loss of magnesium, although healthy kidneys should be able to recoup most the magnesium from fluids before they are eliminated from the body. Digestive tract problems causing magnesium loss include malabsorption, diarrhea, and ulcerative colitis. Many kinds of physical stresses can contribute to magnesium deficiency, including cold stress, physical trauma, and surgery. Kidney disease and alcoholism can contribute to a deficiency of this mineral.
There is anecdotal evidence that stress and very high activity levels can also cause a higher requirement for magnesium, and that ‘hypey’ excitable dogs could suffer from deficiencies.

How to get enough:

In humans, eating a variety of whole grains, legumes, and vegetables (especially dark-green, leafy vegetables) every day will help provide recommended intakes of magnesium and maintain normal storage levels of this mineral.

In dogs, most of the high magnesium recommended human foods do not form part of a normal balanced canine diet, although I would have thought a fish based diet would be better, I have not found any figures on this. It might be useful to know that whole grain rice has some magnesium but white rice has hardly any. However, even if whole grain rice is used in the production of high quality ‘complete’ dogs foods, my big question is, is this enough for high energy, ‘hypey’ dogs that are regularly competing in agility? Adding fish to the diet may be very beneficial, as many types of fish are known to be high in magnesium (and also omega 3 oils which also have many health benefits). Finely, freshly ground sunflower and pumpkin seeds should also provide good quantities of magnesium. Finely chopped dark green leafy vegetables served with eggs (to aid digestion and absorption of the magnesium) may also be beneficial. Although you would expect to find magnesium in bones, I have not come across any dietary figures for the levels of magnesium to be found in bone, only that ‘the amount of bone magnesium is only 1/40 to 1/50 that of calcium (Duckworth et al., 1940). However, it is reported that there is relatively little magnesium to be had from eating meat, therefore it does seem likely that a meat based canine diet would not provide enough magnesium.

How do other nutrients interact with magnesium?
The relationship between magnesium and calcium is one of the most actively researched, and yet not fully understood mineral-to-mineral relationships. On one hand, magnesium is required in order for calcium to maintain a balanced role in the body's metabolism. On the other hand, magnesium can compete with calcium and prevent calcium from trigger certain events, like the relay of a nerve message or the contraction of a muscle.
Because of the complex relationship between calcium and magnesium, healthy diets almost always need to contain foods rich in both minerals. Magnesium also has an important relationship with potassium, and helps regulate the movement of potassium in and out of our cells. Finally, because magnesium can be attached to certain building blocks of protein (called amino acids), increased intake of protein can sometimes help improve the body's magnesium status.

Although on one hand it may take a long time for magnesium deficiency to show up as there are stores in the muscles and bones, once the diet is enriched in magnesium, it will also take a long time before those stores are replenished.
Magnesium deficiency may be of significance to performance dogs who may have a higher requirement for this mineral (especially ‘highly strung’ personalities), because foods that contain high amounts of magnesium do not form part of many normal commercially available ‘complete dog food’ ingredients lists. Additionally, dogs are not good at digesting high fibre, high carbohydrate foods, where magnesium may be found (they do not chew foods or have amylase enzymes in their saliva), therefore adding high magnesium content foods, such as spinach and seeds, may only be useful if they are prepared by grinding them up first (do not boil!)

Impact of Cooking, Storage and Processing
The impact of cooking and processing on magnesium can vary greatly from food to food, since magnesium is found in different forms in different types of food. In some foods, where a greater percent of magnesium is found in water-soluble form, blanching (boiling or steaming for 1-4 minutes), steaming, or boiling of these foods can result in a substantial loss of magnesium. For example, about one third of the magnesium in spinach is lost after blanching. Similarly, when navy beans are cooked, they lose 65% of their magnesium.
In other foods that are rich in magnesium, like almonds or peanuts, there is very little loss of magnesium either from roasting or from processing into almond or peanut butter (as long as the whole almond or peanut is used).

What forms of magnesium are found in dietary supplements?
Magnesium can be purchased as a dietary supplement in one of two basic forms: chelated or non-chelated. "Chelated" means connected with another molecule. In the case of magnesium, the most common chelates fall into the category of amino acid chelates. In these supplements, magnesium is attached to a building block of protein (called an amino acid). The most widely-available amino acid chelates are magnesium glycinate, magnesium aspartate, and magnesium taurate.
Magnesium can also be attached to an organic acid (like citrate) or to a fatty acid (like stearate). The non-chelated forms of magnesium include magnesium oxide, magnesium sulfate, and magnesium carbonate. There is some research evidence that the chelated forms of magnesium (like magnesium citrate) are better absorbed than the non-chelated forms (like magnesium oxide).
Food Sources
Nutrient Rating System Chart
Have a look at:
http://www.whfoods.com/genpage.php?tname=nutrient&dbid=75



References
· Abbott LG, Rude RK. Clinical manifestations of magnesium deficiency. Miner Electrolyte Metab 1993;19:314-322 1993.
· Bengtsson BL. Effect of blanching on mineral and oxalate content of spinach. J Food Technol 1969;4:141-145 1969.
· Duckworth J, Warnock GM: The magnesium requirements of man in relation to calcium requirements, with observations on the adequacy of diets in common use. Nutr Abstr Rev 12:167-183, 1942.
· Duckworth S, Godden W, Warnock GM: The effect of acute magnesium deficiency on bone formation in rats. Biochem J 34:97-108, 1940.
· Groff JL, Gropper SS, Hunt SM. Advanced Nutrition and Human Metabolism. West Publishing Company, New York, 1995.
· Iseri LK, French JH. Magnesium: Nature's physiologic calcium blocker. Am Heart J 1984;108:188-193 1984.
· Lindberg JS, Zobitz MM, Poindexter JR, et al. Magnesium bioavailability from magnesium citrate and magnesium oxide. J Am Coll Nutr 1990;9:48-55 1990.
· Meiners CR, Derise NL, Lau HC, et al. (1976). The content of nine mineral elements in raw and cooked mature dry legumes. J Arg Food Chem 1976;24:1126-1130 1976.
· National Research Council. Recommended dietary allowances. 9th edition. National Academy of Sciences Press, Washington, DC, 1980;134-136 1980.
· Pearson HA, Campbell V, Berrow N, et al. Modulation of voltage-dependent calcium channels in cultured neurons. Ann N Y Acad Sci 1994;747:325-335 1994.
· Shils ME. Magnesium. In: Shils ME, Olson JA, and Shike M. Modern nutrition in health and disease. 8th Edition. Lea and Febiger, Philadelphia, 1994;164-184 1994.
· Touyz RM. Role of magnesium in the pathogenesis of hypertension. Mol Aspects Med 2003 Feb 6;24(1-3):107-36.
· Wester PO. Magnesium. Am J Clin Nutr 1987;45(suppl):1305-1312 1987.

September

I have taken Kaydee back to the osteopath, and he found plenty more to work on. So the plan now is to go back to lead walking for a while, rest her for a few weeks, take her back to be checked, then start her build up for Olympia. Will she ever be problem free?
I also had some work done on my ankles, as they have got very stiff and my achilles has been so tight I worried it might tear. Here I am after my second visit, and now I can spring down the stairs when I get up with no problems, how fantastic is that?! Hope to get back into some running now, I have let myself go, and feel the need to be fitter!

August update

Sorry I have no news on the course as yet, I think Stuart is on holiday. However, I have seen a lot of people at shows so know people are still keen! I have been to a few shows recently, and just when I'm getting into the swing of it again, there is only one left! :-(
Kaydee has been going quite well, she has qualified for the last Olympia semis, but now she won't be going to them..... because she qualified for Olympia at the KC International Festival semi !!!! Wooohoooo!!!! I can still hardly believe it! Even more amazing, Becky also ran at that semi and managed to come 6th so is first reserve, so if Kaydee can't run on the big day, Becky can take her place! Kay came second in grade 7 agility at the Agility Club show, and in the grade 7 jumping at Burridge, but then suddenly couldn't weave for a week in the run up to the KC Fest, which caused me a lot of stress! I went a long way round in the course to give her every chance of completing the weaves in the semi, which payed off, although I nearly lost her in the sequence of 3 jumps at the end of the course. She nearly missed the penultimate jump, I got her back, then she nearly back jumped it, but phew we just made it clear! At the KC Fest her weaves were not reliable, although she got a couple of nice places when she managed them. Becky on the otherhand, although not quick enough to get many places any more, has been doing clear round after clear round bless her, and she did make it through to the British Open finals. (Kay was placed 31st but only 30 went through!) DIN started with wild wet and windy weather, my awning was nearly a gonner but I came back at just the right moment and managed to rescue it. I was judging one day so there were not many runs for my girls, just a champ and four others. Perhaps I will go to Northern Week next year instead, you can do that many runs in just one day! Becky did some lovely runs again, but with places to only 8 she came away with nothing, and Kay and I only managed some 'nearlys'. The last day Kay went peculiar and I worried she was injured again. After pulling her out of the ring took her back to the van to find she had broken into the new bag of food that I had bought for Becky, and she had eaten a huge amount. I was worried sick that she would have a problem, but luckily she suffered nothing more than missed runs, great thirst, and having a lot of pooing to do the next day. Naughty girl!

Course news

We now have possible dates, the first two weekends in November, or one day a week over four weeks.
Stuart writes:
'The course will involve the Mobilisation of all joints and relevant muscles and the necessary anatomy and joint physiology to enable the techniques to be applied safely and effectively.
It will probably need to be covered over more than one weekend, probably at least two, or one day per week for four weeks etc. The cost will be in the region of £100 pounds per day per person allowing for ten people.
If the course takes place here in Wantage, I have a hall so there would be no hall hire charge. '

Please let me know what you think about this!

Becky

Thanks to everyone who has asked about Becky! She has been very poorly, but made a good recovery and is fine now. She was due to run in the Olympia semi finals last Friday. When I got home after taking Kaydee to the Thursday semi, she had been sick a number of times, but I thought (hoped!) that she would be OK by Friday. However on waking early the next day I found that she was very poorly indeed, she was tucked up and miserable, her stomach was hard, she felt hot and clammy and was trying to crawl behind and under the furniture. Someone had been talking about torsions the night before, and with that seeding horrible premonitions in my head I went into a panic, she looked so very ill. Huge apologies to Dave Ray, who had a horrible (blubbing female) phone call and very early awakening last Friday morning, as I thought that a reserve would need as much time as possible to get there ......

Update on Kaydees progress

Thanks to everyone who has asked about Kaydee! She is now back in training (although at the moment she is only doing about a third of her training, and of course I worry all the time and keep looking for any signs of discomfort!). All in all I have to say she is looking good, and is in much better shape than me! She has a mostly raw food diet now and is looking really good on it. She has started competing again, a week ago at St Edwards she came 5th in the Olympia qualifier, which I was thrilled about, and then she looked even better in her grade 7 agility and came 4th. Last Thursday she went to Stoneleigh for day one of the Olympia semis (she qualified at Ribble in January just before her 5 month lay off!). I was really pleased with her, she came 2nd in the morning invitation run with solid contacts. In the main event she did a lovely run, and although she clipped the long jump (my fault - it was the penultimate jump and I got carried away and pushed her too hard off the end of the dog walk, it was only a short stride and she couldn't quite stretch to it after stopping on the contact, I should have let her put another short stride in), she was comfortably within the qualifying time, in fact she had about a second over the third placed dog. She had this weekend off, but there are loads of shows booked for the next couple of months.....

Course

Just to let everyone know, I saw the osteopath yesterday and he is now spending some time putting a course together for us. (Us being people interested in learning how to keep our agility dogs in good physical balance, learning how to feel that our dogs muscles and joints are aligned and in perfect working order, and using joint manipulation and massage as part of a regular routine). He is keen that we understand exactly what we are doing and why, and was also keen to stress that it is not just rubbing/massaging the muscles as part of the warm up/cool down but a much more in depth understanding that he wants to put across. Of course this is not a course in canine osteopathy, but should put us in a good position to keep our dogs in good working order, and to feel any problems that may start developing and prevent them from developing into anything more serious.
Until he has worked out the details, I do not know how long the course will be or the cost, but he was talking about running it after the agility season and over a couple of Saturdays.
I have been really impressed with the strength and depth of his knowledge and abilites while witnessing how fantastic his work on Kaydee has been.
For all those nice people that have asked about her, she was very unfit after such a long period off, but I have taken a month to bring her slowly back into agility training and she is looking good now..... I will try and get a bit of video up if I can work out how so that you can see for yourselves!