Should I take extra magnesium as a stand-alone supplement?
Magnesium seems like it is in every multiple vitamin/mineral supplement around, but maybe not always in sufficient quantities. Thus, paradoxically, because magnesium is so ubiquitous in multiple lines, it is easily overlooked as a single nutrient.
I sometimes think magnesium is good for everything, and it might be. It is a cofactor in more than 300 enzymatic reactions involving everything from energy metabolism to protein and nucleic acid synthesis. One of its most important roles may be in cardiovascular health. Experimentally induced low plasma levels of magnesium accelerate atherogenesis by increasing low-density-lipoprotein cholesterol (the ?bad? cholesterol) concentrations and by promoting inflammation.1
Recently, a large epidemiological study appeared to confirm the role magnesium has to play in relation to cardiovascular disease. In the Honolulu Heart Study, baseline dietary assessments were determined on 7,172 men who were then followed for 30 years and assessed for coronary heart disease. Results showed an increased risk of 1.5 times or more for CHD in groups with the lowest versus highest quintiles of magnesium intake (the lowest quintile was 50.3 to 186 mg/day; the highest was 340 to 1,183 mg/day).2 Because many Americans fail to meet the reference daily intake, or RDI, for magnesium (400 mg/day), supplementation is often an important source of this essential element. I think individuals at increased risk for heart disease should pay particular attention to getting enough magnesium.
Fish is good for the heart, but does the mercury found in fish cancel that benefit out?
Most people are aware these days of the FDA advisory to pregnant women and young children to limit their intake of fish in general, and not eat certain fish at all because the mercury content can harm developing nervous systems. Although the health risks of mercury in seafood are controversial, no limitations or recommendations have been made to other segments of the population.
The cardiovascular benefits of eating fatty fish that contain the omega-3 oils eicosapentaenoic acid and docosahexaenoic acid are fairly well substantiated, but does eating fish that have higher levels of mercury cancel out these benefits? Unfortunately, the answer is not a clear one.
There is contradictory evidence that mercury may be related to coronary heart disease. Some studies show a possible connection and others do not. In the well-known Physicians? Health Study that included thousands of U.S. doctors, mercury did not seem to be a significant CHD factor. Researchers selected individuals from this study with high mercury levels. After other risk factors for CHD were controlled, mercury exposure, while correlated with fish consumption, was not significantly associated with an increased risk of CHD.3 Other studies show otherwise.4 This conflicting data could indicate that high mercury intake does have an effect on cardiovascular disease, but only when other factors heighten mercury toxicity. While the safest thing may be to take a good-quality fish oil supplement, for now there is not significant data to suggest the heart-healthy benefits of fish are negated.
Can gluten sensitivity be related to more then just digestive symptoms?
While it is relatively common knowledge that gluten can cause inflammation in the gastrointestinal tract (i.e., celiac disease) and can be associated with other GI issues such as irritable bowel syndrome, it is less well understood that gluten sensitivity can be associated with significant neurological problems such as ataxia (a lack of coordination of muscular movements in the upper and/or lower limbs), peripheral neuropathy and even dementia.5
In fact, it has been shown that individuals diagnosed with ataxia who have a sensitivity to gluten antibodies respond favorably to a strict gluten-free diet.6 Some researchers suggest that gluten-related ataxia is the single most common cause of idiopathic ataxia.7 What is important to note is that these individuals do not necessarily have any signs or symptoms involving the digestive tract, so their physician may not be thinking about the possible association with gluten. With the prevalence of celiac disease estimated to be one in 300 (.3 percent) to one in 100 (1 percent),8,9 the need to be suspicious of gluten causing unexplained serious neurological symptoms is very real.
Dan Lukaczer, N.D., is director of clinical research at the Functional Medicine Research Center, a division of Metagenics Inc., in Gig Harbor, Wash.
1. Maier JA. Low magnesium and atherosclerosis: an evidence-based link. Mol Aspects Med 2003;24(1-3): 137-46.
2. Abbott RD, et al. Dietary magnesium intake and the future risk of coronary heart disease (the Honolulu Heart Program). Am J Cardiol 2003;92(6): 665-9.
3. Yoshizawa K, et al. Mercury and the risk of coronary heart disease in men. N Engl J Med 2002;347(22): 1755-60.
4. Chan HM, Egeland GM. Fish consumption, mercury exposure, and heart diseases. Nutr Rev 2004;62(2): 68-72.
5. Hadjivassiliou M, et al. Gluten sensitivity as a neurological illness. J Neurol Neurosurg Psychiatry 2002;72(5):560-3.
6. Hadjivassiliou M, et al., Dietary treatment of gluten ataxia. J Neurol Neurosurg Psychiatry 2003;74(9): 1221-4.
7. Hadjivassiliou M, et al. Gluten ataxia in perspective: epidemiology, genetic susceptibility and clinical characteristics. Brain 2003;126(Pt 3):685-91.
8. Grodzinsky E, et al. High prevalence of celiac disease in healthy adults revealed by antigliadin antibodies. Ann Allergy 1992;69(1):66-70.
9. Maki M, et al., Prevalence of celiac disease among children in finland. N Engl J Med 2003;348(25):2517-24.