FDA Allows Qualified Health Claim for Magnesium and Reduced Risk of High Blood Pressure
By Megan Maisano and Dana Engel Gerstein
The Food and Drug Administration (FDA) recently announced a new qualified health claim for magnesium. In a letter of enforcement discretion, released on January 10, FDA ruled that the current evidence supports a qualified health claim regarding the relationship between magnesium and reduced risk of high blood pressure (hypertension).
Health Claims: There are three label claims that are defined by statute or FDA regulations: health claims, nutrient content claims, and structure/function claims. Health claims specifically describe the relationship between a food, food component, or dietary ingredient and a reduced risk of disease or health-related condition. Based on the strength of the scientific evidence, health claims can be categorized as authorized or qualified.Authorized health claims must meet significant scientific agreement (SSA) standards or be based on authoritative statements from federal scientific bodies. Since 1990, FDA has authorized twelve health claims. One example of such a claim is the relationship between calcium, vitamin D, and osteoporosis (21 C.F.R § 101.72). Qualified health claims, however, stem from emerging evidence and do not meet SSA criteria. Unlike authorized health claims, qualified claims are not “approved” or published in the Code of Federal Regulations. Rather, in response to a petition submitted by a food manufacturer or other entity, FDA issues a letter of enforcement discretion with specific qualifying language to reflect the limitations of the claim’s scientific evidence. As of January 2022, there are thirty-eight current letters of enforcement discretion for qualified health claims.
Hypertension and Magnesium: High blood pressure remains a considerable public health concern in the United States. Hypertension, defined as blood pressure at or above 130/80 mmHg, affects 47% of adults and increases the risk for heart disease and stroke (the leading causes of death in the United States). There is a growing body of evidence on the relationship between magnesium intake and hypertension. Magnesium may exhibit a protective role in improving vascular stiffness, resistance, and circulating volume. Additionally, its deficiency has been linked to cardiovascular risk factors like hypertension. While magnesium is not a nutrient of public health concern, the average intake for Americans falls 30% below the recommended daily value (DV) of 420 mg.
Qualified Health Claim Development: The petition for the qualified health claim regarding magnesium and hypertension was submitted on behalf of The Center for Magnesium Education and Research, LLC in October of 2016. In responding to the petition, FDA reviewed forty publications that assessed thirty-eight intervention studies. While some intervention studies found statistically significant results, the larger body of evidence found no effect on blood pressure. Additionally, the results were inconsistent in regard to participant demographics and baseline blood pressure, study duration, and the dose and form of magnesium studied. Therefore, FDA determined that “there is some credible evidence suggesting a relationship between the intake of elemental magnesium from conventional foods and dietary supplements and reduced risk of high blood pressure (hypertension).” However, the evidence is “inconclusive and inconsistent.”
FDA’s Letter of Enforcement Discretion
In its forty-two-page letter of enforcement discretion, FDA outlined specific criteria that foods and supplements must meet in order to use the qualified health claim. First, the magnesium content much be equal to or greater than 20% of the DV in the reference amount customarily consumed (RACC). This equates to 84 mg or more of magnesium per RACC. Additionally, given the evidence that diets high in sodium are linked to increased risk of hypertension, qualifying foods must meet “low-sodium” criteria at less than 140 mg per RACC. Furthermore, in accordance with 21 C.F.R. § 101.14, foods that exceed disqualifying nutrient levels of total fat, saturated fat, cholesterol, or sodium cannot utilize the health claim. However, FDA made an exception for tree nuts which exceed the disqualifying level of total fat but contribute to a healthy eating pattern.
FDA permitted three qualified health claims with accompanying qualifying language:
- “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, the FDA has concluded that the evidence is inconsistent 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. The FDA has concluded that the scientific evidence supporting this claim is inconsistent and not conclusive.”
This language is consistent with previous qualified health claims. For example, there is a qualified health claim for omega-3 fatty acids (EPA and DHA) and reduced risk of coronary heart disease. FDA’s authorized statement for eligible foods and supplements is “Consuming EPA and DHA combined may help lower blood pressure in the general population and reduce the risk of hypertension. However, FDA has concluded that the evidence is inconsistent and inconclusive. One serving of [name of the food or dietary supplement] provides [ ] gram(s) of EPA and DHA.” 
Application of the Qualified Health Claim
According to the Office of Dietary Supplements at the National Institutes of Health, foods that offer a good source of magnesium include green leafy vegetables, legumes, nuts, seeds, and whole grains. However, based on the content criteria issued by FDA (20% DV), few foods will be able to apply this new claim. As such, these messages will most likely be utilized by dietary supplements.
* FDA rounding rules
**Foods must meet 20% DV of magnesium (84 mg per RACC or 50 g serving), meet low sodium criteria, and not exceed levels for disqualifying nutrients per RACC
Health claims offer a significant marketing opportunity to foods and dietary supplements. FDA established procedures for qualified health claims in order to more easily provide information regarding the relationship between diet and health, as long as messaging is not misleading.While the new qualified health claim for magnesium is based on limited evidence, its application may augment consumers with knowledge of the nutrient’s potential cardioprotective benefits. As many Americans do not meet the recommended DV of magnesium, such a claim may support improved intake.
 U.S. Food & Drug Admin., Label Claims for Conventional Foods and Dietary Supplements, https://www.fda.gov/food/food-labeling-nutrition/label-claims-conventional-foods-and-dietary-supplements (content current as of June 19, 2018).
 U.S. Food & Drug Admin., Guidance for Industry: Notification of a Health Claim or Nutrient Content Claim Based on an Authoritative Statement of a Scientific Body (June 1998), https://www.fda.gov/food/guidance-documents-regulatory-information-topic/guidance-industry-notification-health-claim-or-nutrient-content-claim-based-authoritative-statement (content current as of Sep. 20, 2018).
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 U.S. Dep’t of Agric., Agric. Research Serv., Nutrient Intakes from Food and Beverages: Mean Amounts Consumed per Individual, by Gender and Age, What We Eat in America, NHANES 2017-2018, (2020), https://www.ars.usda.gov/ARSUserFiles/80400530/pdf/1718/Table_1_NIN_GEN_17.pdf
 U.S. Food & Drug Admin., Letter, RE: Petition for a Qualified Health Claim for Magnesium and Reduced Risk of High Blood Pressure (Hypertension) (Docket No. FDA-2016-Q-3770) (Jan. 8, 2022), https://www.fda.gov/media/155304/download.
 U.S. Food & Drug Admin., FDA Announces Qualified Health Claim for Magnesium and Reduced Risk of High Blood Pressure (Jan. 10, 2022), https://www.fda.gov/food/cfsan-constituent-updates/fda-announces-qualified-health-claim-magnesium-and-reduced-risk-high-blood-pressure.
 U.S. Food & Drug Admin., FDA Announces New Qualified Health Claims for EPA and DHA Omega-3 Consumption and the Risk of Hypertension and Coronary Heart Disease (Jun. 19, 2019), https://www.fda.gov/food/cfsan-constituent-updates/fda-announces-new-qualified-health-claims-epa-and-dha-omega-3-consumption-and-risk-hypertension-and#:~:text=a.,s)%20of%20EPA%20and%20DHA.
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