Low Magnesium Intake
Associated with Increased Risk for Type 2
Diabetes
This study supports the dietary
recommendation to increase consumption of
major food sources of magnesium, such as whole
grains, nuts, and green leafy vegetables.
Low dietary magnesium intake may be
associated with an increased risk for type 2
diabetes, according to a recent American
study.
Magnesium, an important micronutrient found in
many unprocessed foods, is a necessary
cofactor for several enzymes that function in
glucose metabolism. Hypomagnesaemia commonly
occurs in patients with type 2 diabetes, and
short-term metabolic studies have suggested
that magnesium supplementation provides a
beneficial effect on insulin action and
glucose metabolism.
These observations together with additional
studies have led to the proposal that
magnesium deficiency may represent a risk
factor for type 2 diabetes. To test this
hypothesis, Ruy Lopez-Ridaura, MD, of Harvard
School of Public Health, Boston,
Massachusetts, and colleagues evaluated the
association between magnesium intake and type
2 diabetes over a long-term period in a large
population of health professionals.
Previous analyses from the Harvard group have
suggested an inverse relationship between
magnesium intake and type 2 diabetes risk.
However, the researchers note that these
initial studies did not fully control for
other confounding factors.
In the present analysis, a food frequency
questionnaire was used every 2-4 years to
monitor magnesium intake in 85,060 women and
42,872 men for a duration of 18 and 12 years,
respectively. In addition, participants were
asked if and when they had ever been diagnosed
with diabetes at the time of each
questionnaire. Data for known diabetes risk
factors were also recorded.
Four thousand eighty-four cases of type 2
diabetes were documented in the women and
1,333 in the men during the study period.
Statistical analyses revealed a significant
inverse association between magnesium intake
and risk of type 2 diabetes in both groups.
After adjusting for age and energy intake, the
relative risk (RR) for diabetes was 0.55 (95%
confidence interval [CI], 0.50-0.61] in women
and 0.56 [CI, 0.47-0.67] in men.
The association remained significant after
adjusting for additional diabetes risk
factors, such as BMI, family history, physical
activity, smoking status, alcohol consumption,
hypertension and hypercholesterolemia (RR
women, 0.66, 0.60-0.73; RR men, 0.67,
0.56-0.80, P < .001 for trend).
Adjustment for other dietary minerals did not
weaken the association.
The researchers suggest that the study
provides strong and consistent evidence for an
association between magnesium deficiency and
diabetes risk. "This study supports the
dietary recommendation to increase consumption
of major food sources of magnesium, such as
whole grains, nuts, and green leafy
vegetables," they conclude. Diabetes
Care 2004 Jan;27:1:134-140
