Effects of microwave radiation on anti-infective factors in human milk.

Pediatrics · 1992 · Mixed · Low evidence

← Research stream

MixedLow evidencePaper 6295

Study snapshot

PublicationPediatrics · 1992

Study typeother

Reported directionMixed

Evidence ratingLow

Abstract

In intensive care nurseries it has become common practice to use microwave thawing of frozen human milk for more rapid accessibility. Twenty-two freshly frozen human milk samples were tested for lysozyme activity, total IgA, and specific secretory IgA to Escherichia coli serotypes 01, 04, and 06. The samples were heated by microwave for 30 seconds at a low- or high-power setting and then reanalyzed. One-mL aliquots of 10 additional human milk samples were microwaved at low (20 degrees C to 25 degrees C), medium (60 degrees C to 70 degrees C), and high (greater than or equal to 98 degrees C) setting before the addition to each of 1 mL of diluted E coli suspension. E coli growth was determined after 3 1/2 hours of incubation at 37 degrees C. Microwaving at high temperatures (72 degrees C to 98 degrees C) caused a marked decrease in activity of all the tested antiinfective factors. E coli growth at greater than or equal to 98 degrees C was 18 times that of control human milk. Microwaving at low temperatures (20 degrees C to 53 degrees C) had no significant effect on total IgA, specific IgA to E coli serotypes 01 and 04, but did significantly decrease lysozyme and specific IgA to E coli serotype 06. Even at 20 degrees C to 25 degrees C, E coli growth was five times that of control human milk. Microwaving appears to be contraindicated at high temperatures, and questions regarding its safety exist even at low temperatures.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeother

Effect directionmixed

PopulationHuman milk samples (freshly frozen)

Sample size32

Exposuremicrowave · 30 seconds (low- or high-power setting); additional aliquots microwaved at low/medium/high temperature settings

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

High-temperature microwaving (reported 72°C to 98°C) caused a marked decrease in activity of all tested anti-infective factors, and E. coli growth at ≥98°C was 18 times that of control human milk. Low-temperature microwaving (20°C to 53°C) showed no significant effect on total IgA or specific IgA to E. coli O1 and O4, but significantly decreased lysozyme and specific IgA to E. coli O6; even at 20°C to 25°C, E. coli growth was five times that of control human milk.

Outcomes measured

Lysozyme activity
Total IgA
Specific secretory IgA to Escherichia coli serotypes O1, O4, O6
E. coli growth after incubation

Limitations

Frequency and exposure metrics (e.g., microwave frequency, SAR) not reported in abstract
Sample-based laboratory study; no clinical outcomes reported
Small sample sizes (22 samples for immune factors; 10 samples for bacterial growth assay)
Temperature ranges/settings described, but detailed heating uniformity or exact protocols not provided in abstract

View raw extracted JSON

{
  "study_type": "other",
  "exposure": {
    "band": "microwave",
    "source": "microwave thawing/heating of human milk",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "30 seconds (low- or high-power setting); additional aliquots microwaved at low/medium/high temperature settings"
  },
  "population": "Human milk samples (freshly frozen)",
  "sample_size": 32,
  "outcomes": [
    "Lysozyme activity",
    "Total IgA",
    "Specific secretory IgA to Escherichia coli serotypes O1, O4, O6",
    "E. coli growth after incubation"
  ],
  "main_findings": "High-temperature microwaving (reported 72°C to 98°C) caused a marked decrease in activity of all tested anti-infective factors, and E. coli growth at ≥98°C was 18 times that of control human milk. Low-temperature microwaving (20°C to 53°C) showed no significant effect on total IgA or specific IgA to E. coli O1 and O4, but significantly decreased lysozyme and specific IgA to E. coli O6; even at 20°C to 25°C, E. coli growth was five times that of control human milk.",
  "effect_direction": "mixed",
  "limitations": [
    "Frequency and exposure metrics (e.g., microwave frequency, SAR) not reported in abstract",
    "Sample-based laboratory study; no clinical outcomes reported",
    "Small sample sizes (22 samples for immune factors; 10 samples for bacterial growth assay)",
    "Temperature ranges/settings described, but detailed heating uniformity or exact protocols not provided in abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "microwave radiation",
    "human milk",
    "microwave thawing",
    "lysozyme",
    "IgA",
    "secretory IgA",
    "Escherichia coli",
    "anti-infective factors",
    "neonatal intensive care"
  ],
  "suggested_hubs": [
    {
      "slug": "other",
      "weight": 0.2,
      "reason": "Microwave heating of human milk; not clearly tied to telecom RF/ELF exposure hubs."
    }
  ]
}

AI can be wrong. Always verify against the paper.

AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: Not supplied
PubMed: 1557249

Read the original paper →

Related papers

← Back to the Research Library