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FDA Gives 'Qualified' Nod to Magnesium for Blood Pressure

Joseph Mercola


STORY AT-A-GLANCE


  • Johnson Nutrition Solutions LLC petitioned the FDA in 2016 for a qualified health claim to be applied to conventional foods and supplements, promoting support for diets high in magnesium to reduce the risk of high blood pressure

  • The FDA concluded in 2022 that the proposed language "supportive but inconclusive" was overstated and a mischaracterization of the strength of the evidence. Stating that "inconsistent and inconclusive" would be substituted for "supportive"

  • Additionally, the food must also meet the "low sodium" criteria. Noted research scientist Andrea Rosanoff, Ph.D., published over 10 years of comprehensive review data building on 40 years of work from Dr. Mildred Seelig showing low magnesium is linked to cardiovascular risk factors

  • Low magnesium levels are also associated with a higher risk of Type 2 diabetes, depression, anxiety, poor working memory and migraines


Guy Johnson, Ph.D., principal at Johnson Nutrition Solutions LLC, filed a petition with the FDA in 20161 on behalf of The Center for Magnesium Education and Research, requesting the FDA to issue a qualified health claim for conventional foods and dietary supplements that contain 20% of the daily value of magnesium. Based on hundreds of studies and papers,2 he proposed that magnesium could reduce the risk of high blood pressure and that he should be allowed to state that fact on certain foods and dietary supplements. Six years later, in January 2022, the FDA responded. In a press release,3 the FDA said: “… it does not intend to object to the use of certain qualified health claims regarding the consumption of magnesium and a reduced risk of high blood pressure (hypertension), provided that the claims are appropriately worded to avoid misleading consumers and other factors for the use of the claim are met.” Magnesium is the fourth most abundant element in your body4 and one of the seven essential minerals we cannot live without.5 It is involved in hundreds of biochemical reactions in the body,6 and deficiency can contribute to significant health problems.7 It is necessary for the healthy functioning of most cells, and especially your heart and muscles.8 Low levels can impede cellular metabolic function and mitochondrial function. According to one scientific review,9,10 which included studies dating as far back as 1937, low magnesium appears to be the greatest predictor of heart disease. Research published in 201711 shows even subclinical magnesium deficiency can compromise cardiovascular health. Magnesium is a necessary component for the activation of vitamin D12 and deficiency can hamper your ability to convert vitamin D from sun exposure or oral supplements. Despite hundreds of published studies showing a clear correlation between magnesium and high blood pressure, the FDA’s response to the petition, while likely expected, was disappointing. FDA Qualifies Its Support for Magnesium Heart Health Claims Johnson’s petition proposed that a qualified health claim could be made for conventional foods and dietary supplements indicating that magnesium plays a significant role in the modulation of blood pressure. His suggested statement for the food and supplement labels was:13 “Supportive but inconclusive scientific evidence suggests that diets with adequate magnesium may reduce the risk of high blood pressure (hypertension), a condition associated with many factors.” However, the FDA concluded that the wording of “supportive but inconclusive” in the proposed statement could mischaracterize the strength of the evidence of the role magnesium plays in cardiovascular health and possibly mislead consumers. So, instead, they suggested the following additional qualified health claims that they would approve:14

  • “Inconsistent and inconclusive scientific evidence suggests that diets with adequate magnesium may reduce the risk of high blood pressure (hypertension), a condition associated with many factors

  • Consuming diets with adequate magnesium may reduce the risk of high blood pressure (hypertension). However, FDA has concluded that the evidence is consistent and inconclusive

  • Some scientific evidence suggests that diets with adequate magnesium may reduce the risk of high blood pressure (hypertension), a condition associated with many factors. FDA has concluded that the scientific evidence supporting this claim is inconsistent and not conclusive.”

In other words, their “enforcement discretion” plan is to allow the “qualified health claims,” as long as disclaimers — in the form of their proposed additional qualifying language — are also included, to “prevent the claims from misleading consumers.”15 Starting on Page 9 of the 42-page letter, the FDA outlines 85 interventional studies they identified and used to make their determination that the proof that magnesium supports heart health is “inconclusive.” Of those 85 studies — there are more than 3,000 such studies listed in PubMed16 — they identified 47 from which conclusions could not be drawn. They listed these reasons for not using the studies:17

  • Magnesium may have been given intravenously or intramuscularly

  • There was no control group

  • Magnesium was used with other dietary supplements or dietary advice

  • Subjects were deficient in magnesium, which they determined was not relevant to the general population

Therefore, the FDA’s conclusions were drawn from 38 intervention studies looking at the relationship between magnesium and the risk of high blood pressure. In the majority of these studies, the FDA determined that there was no significant change in systolic, diastolic, or both blood pressure measurements between the control group and the intervention group. The FDA also reviewed 43 observational studies18 that looked at the effect on the risk of high blood pressure but discounted all 43 observational studies for various reasons.

  • Ten estimated magnesium intake from food, which the FDA discounted because nutrient content can vary based on a variety of factors including soil composition, cooking and storage.

  • Ten assessed magnesium intake from a combination of vitamin and mineral supplements, which the FDA wrote was not as accurate as measuring magnesium intake from a supplement providing only magnesium.

  • Twenty-two of the studies measured blood, urine or hair levels of magnesium, which the FDA wrote was inconclusive since these levels are not a reliable measure of magnesium.

  • One ecological study used magnesium levels in the municipal drinking water supply as an indicator but did not control for confounding factors such as sodium and potassium intake, body weight or smoking.

Foods Must Meet Low Sodium Criteria To Be Included After documenting the reasons for discounting the study results, the letter identified a secondary