People deficient in magnesium suffer higher rates of certain cancers and of degenerative conditions like cardiovascular disease, high blood pressure, diabetes, and osteoporosis. Magnesium deficiency is also associated with increased risk of metabolic syndrome (Belin RJ, He K 2007).

And sadly, Americans' junky diets mean that more than one in two of us lacks enough of this essential mineral, which supports muscles, nerves, heart rhythms, and bone density.

Fish and other food sources of magnesium
The results of the new research should prompt everyone to seek out good magnesium sources.

All figures are per 3 oz serving:

  • Halibut and Sablefish rank high among food sources, at 90 mg and 60 mg respectively.
  • Salmon, tuna, shellfish, and our other seafood offerings contain 20 to 30 mg.
  • Almonds and Cashews (75 mg) and other nuts.
  • Soybeans (75 mg) and other beans (35 mg).
  • Brown rice (40 mg) and other whole grains.
  • Leafy greens such as spinach, collards, and chard (about 75 mg).

Sources: NIH 2008; USDA 2008

Thanks to new test tube research, we are closer to understanding why magnesium is critical to health and healthy aging.

The effects of magnesium deficiency on human cells were studied recently by renowned UC Berkeley researcher Bruce Ames, Ph.D., and David Killilea, Ph.D., of Children's Hospital in Oakland.

Magnesium-poor cells age prematurely

Drs. Ames and Killilea looked at the long-term effects of moderate magnesium deficiency on common cells called fibroblasts, which form the structural foundation for tissues throughout the body.

They found that while the cells still survived and divided normally when cultured in a medium containing meager supplies of magnesium, the cells aged faster than ones grown with ample amounts of the mineral (Ames BR Killilea DW 2008).

Ames and Killilea found specific markers of accelerated aging in the magnesium-deprived cells.

This evidence supports Ames' recently published hypothesis that nutrient-deficient cells save scarce nutritional resources for essential metabolic processes and neglect processes needed to ensure optimal lifespan and health-span (Ames BR Killilea DW 2008; Ames BR 2006).

For example, the magnesium-starved cells suffered premature decay of their telomeres: structures that protect a cell's chromosomes from cancerous abnormalities, and whose eventual decay seems to determine cellular and human life spans.

Unfortunately, moderate magnesium deficiency does not produce obvious symptoms and is easy to overlook, so be sure to get plenty from foods and/or supplements.

The US RDA for men and women is around 400 mg. Avoid combining magnesium supplements with magnesium-containing laxatives or antacids.

Signs of excess magnesium intake are rare, and resemble those of magnesium deficiency: changes in mental status, nausea, diarrhea, appetite loss, muscle weakness, difficulty breathing, extremely low blood pressure, and irregular heartbeat (NIH 2008).


  • Agence France-Presse (AFP). Study links magnesium deficiency to faster aging. April 8, 2008. Accessed online April 10, 2008 at
  • Ames BN. Low micronutrient intake may accelerate the degenerative diseases of aging through allocation of scarce micronutrients by triage. [Proc. Natl. Acad. Sci. USA (2006) 103:17589-94]
  • Belin RJ, He K. Magnesium physiology and pathogenic mechanisms that contribute to the development of the metabolic syndrome. Magnes Res. 2007 Jun;20(2):107-29. Review.
  • Killilea DW, Ames BN.Magnesium deficiency accelerates cellular senescence in cultured human fibroblasts.Proc Natl Acad Sci U S A. 2008 Apr 7; [Epub ahead of print]
  • Office of Dietary Supplements, National Institutes of Health (NIH). Magnesium. Accessed online April 10, 2008 at
  • USDA National Nutrient Database for Standard Reference. Accessed online April 10, 2008 at