Dietary n-6:n-3 fatty acid ratio and vitamin E on immune response and T cell subpopulations of healthy geriatric Beagles
Thirty-two healthy female Beagles aged 7 to 10 years were fed for 17 weeks foods combining a low (1.4:1) or high (40:1) n-6 to n-3 fatty acid ratio with low, medium or high alpha-tocopheryl acetate, and were inoculated with keyhole limpet hemocyanin at weeks 13 and 15, to determine effects on immune function and T cell subpopulations. Dogs on low vitamin E had lower CD8+ T cell percentages and higher CD4+:CD8+ ratios than dogs on medium or high vitamin E, and the largest DTH skin response occurred with low n-3 and medium vitamin E. The authors conclude an optimum vitamin E level stimulates CD8+ T cells regardless of fatty acid ratio, while n-3 fatty acids blunt its effect on DTH.
Record
| Design | controlled trial |
|---|---|
| Status | completed |
| Intervention | Foods with low (1.4:1) or high (40:1) n-6 to n-3 fatty acid ratios in combination with three concentrations of all rac-alpha-tocopheryl acetate |
| Intervention class | diet or supplement |
| Comparator | Factorial comparison across the diet groups (no separate untreated control stated) |
| Dose regimen | n-6 to n-3 fatty acid ratio 1.4:1 or 40:1; all rac-alpha-tocopheryl acetate low 17 mg/kg of food, medium 101 mg/kg, high 447 mg/kg; keyhole limpet hemocyanin inoculation at 13 and 15 weeks |
| Duration | 17 weeks |
| Dogs | 32 |
| Breed | Beagle |
| Age | 7- to 10-year old |
| Other | healthy female |
| Primary outcome | Immune functions and T cell subpopulations (percentages of CD8+ T cells, CD4+ to CD8+ ratio) and delayed-type hypersensitivity (DTH) skin test response |
| Result (as reported) | After 12 weeks, dogs consuming low concentrations of alpha-tocopheryl acetate had lower percentages of CD8+ T cells and higher CD4+ to CD8+ ratios than dogs on medium or high concentrations; dogs consuming low n-3 fatty acids with medium alpha-tocopheryl acetate had the largest DTH response. The authors conclude that an optimum amount of dietary alpha-tocopheryl acetate, regardless of the n-6 to n-3 ratio, stimulates the CD8+ T cell population, and that its effects on the DTH response are blunted by dietary n-3 fatty acids. |
| Tags | diet, vitamin-e, omega-3, immunosenescence, t-cells, beagle |
Notes: Borderline inclusion: the abstract objective names immune function in healthy dogs rather than aging, but the title and the 7- to 10-year-old geriatric population place it in the immunosenescence context. The abstract does not describe randomization; the PubMed publication type lists Randomized Controlled Trial. No full text in the corpus.
Sources and verbatim quotes
Effects of dietary n-6 and n-3 fatty acids and vitamin E on the immune response of healthy geriatric dogs. (2003) PMID 12828263 (results)
To determine the effect of dietary n-6 to n-3 fatty acid ratios and alpha-tocopheryl acetate concentration on immune functions andT cell subpopulations in healthy dogs.
Thirty-two 7- to 10-year old female Beagles.
For 17 weeks, dogs were fed food that contained low (1.4:1) or high (40:1) ratios of n-6 to n-3 fatty acids in combination with 3 concentrations of all rac-alpha-tocopheryl acetate (low, 17 mg/kg of food; medium, 101 mg/kg; high, 447 mg/kg).
Dogs were inoculated twice with a keyhole limpet hemocyanin suspension at 13 and 15 weeks.
After 12 weeks, dogs consuming low concentrations of alpha-tocopheryl acetate had lower percentages of CD8+ T cells, compared with dogs consuming medium or high alpha-tocopheryl acetate concentrations. Also, dogs consuming low alpha-tocopheryl acetate concentrations had higher CD4+ to CD8+ T cell ratios.
Dogs consuming low concentrations of n-3 fatty acids with medium concentrations of alpha-tocopheryl acetate had the largest delayed-type hypersensitivity (DTH) skin test response.
An optimum amount of dietary alpha-tocopheryl acetate concentration, regardless of the dietary n-6 to n-3 fatty acid ratio, stimulates the CD8+ T cell population. Effects of an optimum amount of dietary alpha-tocopheryl acetate concentration on the DTH response are blunted by dietary n-3 fatty acids.
Reproduce: canine_trial_search(trial_id="n6-n3-fatty-acids-vitamin-e-immune-geriatric-beagles-2003") in dog-geroscience-mcp; dataset canine-trial-registry.