Report Title

The Effect of Diet on the Variation of Blood and Urine Heavy Metal Biomarkers Among National Health and Nutrition Examination Survey (NHANES) Subjects: A Secondary Data Analysis

Collective Title

Master of Science in Nutrition and Dietetics Research Reports 2021


Background: Heavy metals are non-essential elements that provide no biological benefit to the human body. Heavy metals such as lead, mercury, arsenic, and cadmium are toxic to humans even in trace amounts. Humans are exposed to various heavy metals through ingestion of contaminated food and water supplies. Heavy metals can accumulate in body organs and displace essential minerals leading to detrimental health effects such as neurological, endocrine, and immune dysfunction, that can result in long-term damage.

Objective: The purpose of this graduate student research study was to examine the effect of diet on the variation of blood and urine lead, mercury, arsenic, and cadmium biomarkers among National Health and Nutrition Examination Survey (NHANES) participants.

Design: Secondary Data Analysis

Statistics: Using SPSS version 25.0, all food groups were stratified, and the data was fitted to a crude linear regression. Means of heavy metals in blood and urine were computed and percent variability of heavy metals accounted for by diet were expressed as R2 values. All analysis were considered significant at p < 0.05.

Results: Diet accounts for a small variation in blood and urine heavy metal levels (2.2-7.6%). Blood mercury and blood cadmium measured higher than the acceptable limits at 1.10 (±2.24) and 0.31 (±0.44) micrograms, respectively.

Conclusion: Factors including industrial exposure, air or water pollution, cigarette smoke, household exposure, medications, lead-based paint, improperly coated foods, and occupation may account for >90% variation in blood and urine heavy metal levels. Heavy metals have been shown to displace our bodies essential minerals such as zinc, magnesium, and calcium. It is extremely important that health professionals educate their patients about heavy metals. Further statistical analysis should be conducted to account for the effect of confounding factors and to further elucidate the relationships between foods and heavy metals present in blood and urine biomarkers.

LLU Discipline

Nutrition and Dietetics


Nutrition and Dietetics


School of Allied Health Professions

First Advisor

Edward Bitok

Second Advisor

Gurinder Bains

Third Advisor

Noha Daher

Fourth Advisor

JeJe Noval

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Heavy Metals--Bioaccumulation; Contaminated food; Diet--Nutritional aspects;


Research Report

Page Count

20 p.

Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Research Reports

Collection Website


Loma Linda University. University Libraries.