RESUMEN
BACKGROUND: Omega3 polyunsaturated fatty acids (PUFAs) are related to several diseases, including smoking. The aim of this study was to evaluate the relationship between omega-3 intake and tobacco smoking, taking into account the qualitative differences in dietary intake between smokers and non-smokers, the amount of the ingested PUFA and their red blood (RBC) contents. We also looked for an association between omega-3 RBC content and smoking, and also between omega3 intake and the level of nicotine dependence. METHODS: Using a cross-sectional study, we included 50 current smokers (group I) and 50 lifetime non-smokers (group II), aged 18-75 years. We screened them at the Toronto Western Hospital and the Centre for Addiction and Mental Health (Toronto, Canada). The subjects completed a questionnaire with demographic data, lifestyle habits and details of food intake. The PUFAs measured in the RBC membranes were alphalinolenic acid, eicosapentaenoic acid (EPA), docosapentaenoic acid and docosahexaenoic acid (DHA). In order to perform an adjusted comparison between smokers and non-smokers we used the ANCOVA model. RESULTS: After adjusting for confounding factors, non-smokers showed higher consumption of PUFAs, especially salmon: 800 g (0-7.740) than smokers 430 g (0-2.150) P < 0.001. They also had higher DHA levels compared to smokers: 4.81% (2.79-10.21) and 4.13% (2.33-7.73), respectively, p < 0.05. The other PUFAs showed no significant differences between the two groups. CONCLUSIONS: Smokers ate less fish rich in omega3 fatty acids than non-smokers, showing and inverse and significant relationship between omega3 intake and smoking. Smokers had lower levels of DHA and EPA, a not previously reported finding. Considering that PUFAs probably interfere in smoking habit, the increase in omega-3 consumption may become a perspective in prevention or treatment of smoking. However, this inference must be evaluated through specific studies.
Asunto(s)
Ácidos Grasos Omega-3/sangre , Conducta Alimentaria , Fumar , Adulto , Anciano , Canadá , Estudios Transversales , Suplementos Dietéticos , Ingestión de Alimentos , Recuento de Eritrocitos , Ácidos Grasos Omega-3/administración & dosificación , Femenino , Productos Pesqueros , Humanos , Masculino , Persona de Mediana Edad , Tabaquismo/sangreRESUMEN
Mycobacteria are potent adjuvants, can survive intracellularly and have been safely used for many years as vaccines against tuberculosis and leprosy. They are thus important potential vectors for recombinant vaccines. Many of their adjuvant properties are mediated following phagocytosis by dendritic cells (DC), which are in turn critical for priming naïve T cells. Although the maturation of DC in response to mycobacteria, such as Mycobacterium bovis bacillus Calmette-Guérin (BCG), is well described the subsequent responses of autologous T cells to mycobacterium-infected DC remains uncharacterized. In our experiments DC infected with BCG expressed more co-stimulatory molecules than tumour-necrosis factor-alpha (TNF-alpha) -treated DC and stimulated more potent mixed leucocyte reactions. When autologous T cells were co-cultured with BCG-exposed DC they became highly activated, as determined by display of CD25, CD54 and CD71 on both CD4+ and CD8+ cells. In contrast, the response of T cells to TNF-alpha-matured DC was significantly less. Cytokine production from T cells cultured with BCG-exposed DC was enhanced with elevated secretion of interleukin-2 (IL-2), IL-10 and interferon-gamma (IFN-gamma) and was produced by both CD4+ and CD8+ lymphocytes as determined by intracellular staining. In particular, IFN-gamma secretion was increased from 50 pg/ml to 25 000 pg/ml and IL-10 secretion increased from 20 pg/ml to 300 pg/ml in BCG-exposed DC co-cultures. Blocking antibodies to B7.1 and B7.2 or IL-12 significantly reduced the secretion of IFN-gamma and reductions were also seen in the expression of CD25 and CD71 by CD4+ cells. These data demonstrate that mycobacterially infected DC are particularly potent activators of autologous T cells compared to TNF-alpha-exposed DC and that the resultant T cells are functionally superior.