TL;DR

  • Magnesium helps the body use insulin and regulate blood sugar.
  • People with type 2 diabetes or insulin resistance usually have low magnesium levels.
  • Supplementation may improve blood sugar, cholesterol, and even nerve health.
  • Most Americans don’t get enough magnesium from food.

Read more about insulin insensitivity and type 2 diabetes.

Why Magnesium Is Important

Magnesium is a mineral that plays a role in hundreds of reactions in the body — including energy production, nerve function, and blood sugar control. When magnesium is low, insulin can’t do its job properly. This leads to insulin resistance, where the body must make more and more insulin to keep blood sugar in range.

Research dating back to the 1990s shows that high insulin levels can actually reduce magnesium absorption, creating a vicious cycle between low magnesium and poor blood sugar control [1].

Research on Magnesium and Type 2 Diabetes

Better Blood Sugar Control
In a clinical trial, 42 adults with type 2 diabetes took either 250 mg of magnesium daily or a placebo for three months. Those who took magnesium saw significant improvements in:

  • HbA1c (8.32 → 7.96%)
  • Insulin levels
  • C-peptide
  • HOMA-IR (insulin resistance marker)
    (Nutrients, 2018;11(1):44).

The researchers concluded that magnesium improved blood sugar control and insulin sensitivity [2].

Improved Cholesterol Profile

Magnesium can also help balance blood lipids. In one study, people with type 2 diabetes who took magnesium had lower total and LDL cholesterol and higher HDL cholesterol compared to placebo [3].

Prevention: From Prediabetes to Diabetes

People who get enough magnesium from food are less likely to develop diabetes. A long-term study in Diabetes Care found that higher magnesium intake lowered the risk of progressing from prediabetes to type 2 diabetes [4].

Surgery and Blood Sugar Stability

Magnesium given during surgery helped diabetic patients maintain steadier blood sugar and reduced insulin requirements [5].

Depression and Mood in Diabetes

Low magnesium is linked not only to insulin resistance but also to mood changes. A 12-week trial found that magnesium chloride was as effective as imipramine (a common antidepressant) for treating depression in elderly people with type 2 diabetes [6].

Nerve Health

Magnesium deficiency may increase the risk of diabetic neuropathy. Patients with nerve damage had lower magnesium in red blood cells, and improving levels may support nerve conduction [7].

How Common Is Magnesium Deficiency?

An estimated three out of four Americans do not get enough magnesium. Foods rich in magnesium include:

  • Leafy greens (spinach, kale)
  • Nuts and seeds
  • Beans and lentils
  • Avocados
  • Whole grains

Because insulin resistance can interfere with magnesium absorption, many people with type 2 diabetes may need extra magnesium from food or supplements.

Key Takeaways

  • Low magnesium and insulin resistance often occur together.
  • Supplementation can improve blood sugar, cholesterol, and nerve function.
  • Magnesium may also support mood and reduce inflammation.
  • Eating magnesium-rich foods supports long-term metabolic health.

References:

  1. (J Clin Endocrinol Metab., 1995;80(4):1376-81). Effects of insulin on plasma magnesium in noninsulin-dependent diabetes mellitus: evidence for insulin resistance
  2. Nutrients, 2018 Dec 26;11(1):44 The Effects of Oral Magnesium Supplementation on Glycemic Response among Type 2 Diabetes Patients
  3. (Magnes Res., 1994;7(1):43-47). Effects of oral magnesium supplementation on plasma lipid concentrations in patients with non-insulin-dependent diabetes mellitus
  4. Diabetes Care, 2014;37(2):419-427. Higher magnesium intake reduces risk of impaired glucose and insulin metabolism and progression from prediabetes to diabetes in middle-aged american
  5. Ann Card Anaesth., 2019;22(2):151-157 The effect of perioperative magnesium sulfate on blood sugar in patients with diabetes mellitus undergoing cardiac surgery: A double-blinded randomized study
  6. Magnes Res., 2008;21(4):218-223 Efficacy and safety of oral magnesium supplementation in the treatment of depression in the elderly with type 2 diabetes: a randomized, equivalent trial
  7. (Magnes Res., 2000;13(3):197-203) Are low magnesium levels in type 1 diabetes associated with electromyographical signs of polyneuropathy?