Prebiotics Help Magnesium Absorption in Teenagers

by | Jul 3, 2009 | 2009, Infant and Children's Health, Magnesium, Minerals

Written by Greg Arnold, DC, CSCS. In a small study in teenage girls, those taking a prebiotic had 18% greater magnesium absorption than the control group.

Magnesium is a mineral found to have a number of healthful properties, including helping control blood sugar (1), maintaining a healthy blood pressure (2), maintaining healthy HDL cholesterol levels (3) helping protect against Syndrome X* (4). The current recommendations for magnesium range from 80 mg per day in infants to 420 mg per day in men over 30 (5).

But magnesium intake has decreased by nearly 30% since 1900 (from 475-500 mg per day (6) to 280-350 mg per day (7)). This is due to the increase in processed food in our food supply since magnesium, though naturally obtained from whole seeds, grains, nuts and vegetables, is mostly lost during food processing (8)

Now a new study (9) has found that magnesium absorption may be improved through supplementation of prebiotics, which are the food for the “good bacteria” in our body that has been shown to help maintain bone health (10).  Food sources of prebiotics include oatmeal, flax, barley, onions, greens (dandelion greens, spinach, collard greens, chard, kale), berries, bananas, and legumes (lentils, kidney beans, chickpeas, navy beans, white beans, black beans) (11).

In the study, 14 girls between 12 and 15 years of age received 10 grams of a prebiotic called fructo-oligosaccharide (FOS) or placebo daily for 8 days. This was followed by 28 days of random supplementation in the prebiotic group that wound up averaging 7 grams per day of FOS intake. The researchers then measured calcium, magnesium, vitamin D and markers of bone breakdown on the 8th and 36th day through urine samples.

By the end of the 8th day there were no significant differences between the two groups. By the end of the 36th day of supplementation, those in the FOS group had 18% greater magnesium absorption than the placebo group.  Calcium, vitamin D, and bone breakdown markers did not change during the study. The researchers found the lack of change in calcium absorption “surprising” and stated that this may have been due to the fact that the patients had low calcium intakes (amounts were not measured by the researchers) and this has caused calcium absorption in the body to already be at a maximum (12). Therefore, calcium absorption could not be increased because they had not increased the calcium intake in the patients.

The researchers suggested that FOS increased magnesium absorption by improving the surface area for absorption in the large intestines (13). They concluded that “magnesium absorption was increased in 12- to 15-year-old girls by 18% after 36 days of an average 7 g/d of FOS intake.”

Source: van den Heuvel, Ellen GHM, et al. “Short-chain fructo-oligosaccharides improve magnesium absorption in adolescent girls with a low calcium intake.” Nutrition research 29.4 (2009): 229-237.

© 2009 Elsevier Inc. All rights reserved

Posted July 3, 2009.

References:

  1. Hu FB. Magnesium intake and risk of type 2 diabetes in men and women. Diabetes Care. 2004;27:134–140.
  2. Klag MJ. The effect of magnesium supplementation on blood pressure: a meta-analysis of randomized clinical trials. Am J Hypertens. 2002;15:691–696.
  3. Kulshretha SK. Can dietary magnesium modulate lipoprotein metabolism? Magnes Trace Elem. 1990;9:255–264.
  4. Furukawa, S., T. Fujita, et al. (2004). “Increased oxidative stress in obesity and its impact on metabolic syndrome.” J Clin Invest 114(12): 1752-61.
  5. “Magnesium” posted on the Office of Dietary Supplements website.
  6. Altura BM, Altura BT (1991–92). Cardiovascular risk factors and magnesium relationships to atherosclerosis, ischemic heart disease and hypertension. Magnesium Trace Elem 10, 182–192.
  7. USDA (1990). Continuing Survey of Food Intake by Individuals 1989 and 1990. USDA Public Use Data Tape USDA: Washington, DC.
  8. National Research Council (US) (1989). Recommended Dietary Allowances, 10th edn. National Academy Press: Washington, DC.
  9. Ellen GHM.  Short-chain fructo-oligosaccharides improve magnesium absorption in adolescent girls with a low calcium intake.  Nutr Res 2009; 29(4): 229-237.
  10. Abrams, S. A., I. J. Griffin, et al. (2005). “A combination of prebiotic short- and long-chain inulin-type fructans enhances calcium absorption and bone mineralization in young adolescents.” Am J Clin Nutr 82(2): 471-6.
  11. “Food-friendly bugs do the body good” posted on the Food Insight website.
  12. W.T. Lee, S.S. Leung, D.M. Leung, H.S. Tsang, J. Lau and J.C. Cheng, A randomized double-blind controlled calcium supplementation trial, and bone and height acquisition in children, Br J Nutr 74 (1995), pp. 125–139.
  13. H.W. Lopez, C. Coudray, M.-A. Levrat-Verny, C. Feillet-Coudray, C. Demigné and C. Rémésy, Fructooligosaccharides enhance mineral apparent absorption and counteract the deleterious effects of phytic acid on mineral homeostasis in rats, J Nutr Biochem 11 (2000), pp. 500–508.