Food biomarkers are measurable substances in the body that indicate intake, metabolism, or biological response to specific foods or dietary patterns. They are widely used in nutritional research, dietary assessment, precision nutrition, and public health.
🧪 Types of Food Biomarkers
| Type | Function | Example |
| Intake Biomarkers | Directly reflect consumption of specific food or nutrients | Urinary sodium (salt), proline betaine (citrus) |
| Exposure Biomarkers | Show internal dose from a food component | Aflatoxins (contaminants in grains/nuts) |
| Effect Biomarkers | Indicate physiological response to dietary intake | LDL cholesterol (effect of saturated fat) |
| Susceptibility Biomarkers | Reflect genetic/metabolic predisposition to diet effects | FTO gene variants |
🍽️ Examples by Food Group
| Food or Nutrient | Biomarker | Sample Type |
| Fruit (citrus) | Proline betaine | Urine |
| Fish (omega-3 fats) | EPA/DHA (eicosapentaenoic, docosahexaenoic acids) | Plasma phospholipids |
| Cruciferous vegetables | S-methylcysteine sulfoxide | Urine |
| Red meat | Creatinine, carnitine | Plasma, urine |
| Whole grains | Alkylresorcinols | Plasma |
| Coffee | Caffeic acid metabolites | Urine |
| Tea | Catechins, theaflavins | Urine/plasma |
| Dairy | Pentadecanoic acid (15:0), heptadecanoic acid (17:0) | Plasma fatty acids |
| Alcohol | Ethyl glucuronide | Urine |
| Sugar-sweetened beverages | Urinary sucrose/fructose | Urine |
🧬 Applications
- Validate self-reported dietary data
- Understand diet-disease relationships
- Identify nutritional status and deficiencies
- Guide personalized dietary interventions
- Support public health nutrition policies
🧫 Detection Techniques
- Mass spectrometry (MS)
- Nuclear Magnetic Resonance (NMR)
- Gas or liquid chromatography (GC/LC)
- ELISA or immunoassays for protein-based markers
List of validated food intake biomarkers These biomarkers have been confirmed in human studies for their specificity, reproducibility, and correlation with food intake.
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· ✅ Validated Food Biomarkers by Food Group
| Food or Food Group | Biomarker(s) | Biological Sample | Notes |
| Citrus fruits | Proline betaine | Urine | Highly specific to citrus intake |
| Whole grains (wheat, rye) | Alkylresorcinols (AR-C17:0, AR-C21:0) | Plasma, serum | Specific to rye and wheat |
| Fish (fatty fish) | EPA, DHA (omega-3 fatty acids) | Plasma, red blood cells | Reflects marine fatty acid intake |
| Coffee | Caffeic acid metabolites, trigonelline | Urine, plasma | Specific to coffee, not tea |
| Tea (green, black) | Catechins, theaflavins, 4-O-methylgallic acid | Urine, plasma | Reflects black or green tea intake |
| Cruciferous vegetables | S-methyl-L-cysteine sulfoxide, sulforaphane metabolites | Urine | Found in broccoli, cabbage, etc. |
| Red meat | Creatine, carnosine, 3-methylhistidine | Urine, blood | May also reflect muscle mass |
| Dairy | Pentadecanoic acid (15:0), heptadecanoic acid (17:0) | Plasma fatty acids | Specific to milk fat consumption |
| Legumes | S-methylcysteine, pipecolic acid | Urine | Common in pulses and legumes |
| Nuts | Urolithins (from ellagitannin metabolism) | Urine | Specific to walnuts, pomegranate, etc. |
| Alcohol (ethanol) | Ethyl glucuronide (EtG), phosphatidylethanol (PEth) | Urine, blood | Short- and long-term ethanol intake markers |
| Sugar-sweetened beverages | Urinary sucrose and fructose (intact) | Urine | Reflects recent sugary drink consumption |
| Wine | Tartaric acid | Urine | Specific to grape-based products |