Magnesium Intake Linked to Lower Fasting Blood Sugar in Older Adults: Study - Video

Prediabetes, a condition marked by elevated blood glucose levels that are not yet high enough for a diabetes diagnosis, represents a key opportunity for early intervention. A recent study published in Frontiers in Nutrition examined whether magnesium supplementation could improve glycemic control in older adults with both prediabetes and magnesium deficiency.

Magnesium plays a central role in glucose metabolism and insulin signaling, and deficiency has been linked to insulin resistance. Older adults are particularly vulnerable due to reduced nutrient absorption and higher rates of both prediabetes and hypomagnesemia. To explore this connection, researchers conducted a 16-week randomized controlled trial involving 71 older Chinese adults (mean age 69 years) with prediabetes and low magnesium levels. Participants received either 360 mg of elemental magnesium daily in the form of magnesium oxide or a placebo. Sixty-five individuals completed the study.

The primary outcome was change in fasting plasma glucose (FPG). Researchers also assessed insulin, C-peptide, insulin resistance (HOMA-IR), glycated hemoglobin (HbA1c), glycated albumin, and inflammatory markers including hs-CRP and IL-6.

Magnesium supplementation significantly increased serum magnesium levels compared to placebo, with an adjusted mean difference of 0.056 mmol/L. Fasting glucose levels were modestly reduced in the magnesium group, with an adjusted mean difference of –0.5 mmol/L. However, no significant differences were observed in HbA1c or other broader glycemic markers, suggesting the improvement in fasting glucose did not translate into sustained overall metabolic improvement over the 16-week period.

The intervention was well tolerated, with high adherence (approximately 92%) and no reported adverse events. While preliminary metabolomics analysis suggested changes in lipid metabolism and insulin resistance pathways, these findings remain exploratory.

Despite its strengths, including dietary monitoring and randomized design, the study was limited by a small sample size and short duration. Larger, longer-term trials are needed to determine whether magnesium supplementation offers clinically meaningful benefits in prediabetes management.

REFERENCE: Yang, J., Zhang, H., Li, Y., et al. (2026). Oral magnesium supplementation improves glycemic control in older Chinese adults with pre-diabetes and hypomagnesemia: a randomized controlled trial. Frontiers in Nutrition. DOI: https://doi.org/10.3389/fnut.2026.1765308. https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2026.1765308/full