摘要:

Arachidonic-acid-derived eicosanoids modulate the production of pro-inflammatory and immunoregulatory cytokines. Overproduction of these cytokines is associated with both septic shock and chronic inflammatory diseases. The n-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid, which are found in fish oils, suppress the production of arachidonic-acid-derived eicosanoids and EPA is a substrate for the synthesis of an alternative family of eicosanoids. Thus, dietary fats which are rich in n-3 PUFAs have the potential to alter cytokine production. Animal studies have provided a great deal of evidence that feeding plant or fish oils rich in n-3 PUFAs does alter the ex vivo production of tumour necrosis factor (TNF), interleukin 1 (IL-1), IL-6 and IL-2, but many contradictory observations have been made; it is most likely that the discrepancies in the literature result from differences in the cell types and experimental protocols used. Human studies provide more consistent data: several studies have shown that supplementation of the diet of healthy volunteers results in reduced ex vivo production of IL-1, IL-6, TNF and IL-2 by peripheral blood mononuclear cells. Similar findings have been made in patients with rheumatoid arthritis and multiple sclerosis. Animal studies indicate that dietary fish oil reduces the response to endotoxin and to pro-inflammatory cytokines, resulting in increased survival; such diets have been beneficial in some models of bacterial challenge, chronic inflammation and auto-immunity. These beneficial effects of dietary n-3 PUFAs may be of use as a therapy for acute and chronic inflammation and for disorders which involve an inappropriately activated immune response.

ISSN:0250-6807    

DOI:10.1159/000177997

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

The absorption of long-chain polyunsaturated fatty acids (LCP) with particular respect to docosahexaenoic (DHA) and arachidonic acid (AA) has been studied in 39 very-low-birth-weight infants appropriate for gestational age after a 10-day feeding period. The infants were fed either a LCP-supplemented formula (n = 11), or a LCP-free formula (n = 11) or breast milk fortified with protein and carbohydrates to have similar protein and energy intakes as in the formula-fed infants (n = 17). Total fat content and fatty acid profile were measured in the human milk, the two formulas, and in the stool samples. After a 10-day feeding period, the fecal excretions of total fat, DHA and AA were measured during a 3-day balance period. The total fat apparent absorption rates were similar in all groups (84.1, 82.1 and 80.6% of intake, respectively). The DHA and AA intakes were significantly (p < 0.01) higher in the group fed the fortified breast milk than in the group fed the LCP-supplemented formula (DHA: 75.5 ± 12.4 vs. 50.2 ± 4.2 mg/72 h; AA: 45.5 ± 5.8 vs. 30.2 ± 2.7 mg/72 h). There was a tendency for lower apparent absorption rates for both LCPs studied in the group fed fortified breast milk when compared to the group fed LCP-supplemented formula (AA: 70.6 ± 10.9 vs. 73.0 ± 8.7% of intake, DHA: 69.0 ± 10.6 vs. 74.2 ± 9.5% of intake), but the differences were not significant. As consequence of the different intakes, the net absorption of the two studied LCP fatty acids were significantly (p < 0.01) higher in the breast milk group than in the group fed the LCP-supplemented formula (DHA: 52.6 ± 6.1 vs. 36.8 ± 4.5 mg/72 h; AA: 31.4 ± 3.1 vs. 22.4 ± 2.3 mg/72 h). The data demonstrate that DHA and AA are absorbed from the studied LCP-supplemented formula at least as effectively as from human milk. The net absorption of these LCP depend on the amount of dietary intake, and seems to be influenced by the dietary

ISSN:0250-6807    

DOI:10.1159/000177998

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

We demonstrated for the first time in a Moroccan population that fasting during Ramadan, the ninth lunar month of the Muslims’ year, affected lipid and lipoprotein metabolism in a group of 32 healthy adult male volunteers. This investigation was conducted to study the changes in serum total cholesterol, triglycerides, cholesterol in high-density lipoprotein (HDL) and low-density lipoprotein (LDL), glucose, and body weight during Ramadan. The results showed a significant decrease (7.9%, p < 0.001) in serum total cholesterol concentration during Ramadan as compared with the prefasting period. Also, we obtained a significant decrease of serum triglyceride concentration (30%, p < 0.001) during Ramadan fasting as compared to the period before Ramadan. The reduction of both serum triglycerides and total cholesterol was maintained 1 month after Ramadan. By the end of Ramadan, serum HDL cholesterol had markedly increased (14.3%, p < 0.001) and remained elevated 1 month after Ramadan in contrast to LDL cholesterol which showed a significant decrease (11.7%, p < 0.001) also maintained 1 month after Ramadan. Mean body weight declined by 2.6% (p < 0.01) on day 29 of Ramadan, whereas during Ramadan, the diet pattern used by our subjects showed an increase of total energy intake due to carbohydrates (+1.4% of total energy), proteins (+0.4% of total energy) but not fat (-0.7% of total energy) compared to a usual diet used throughout the rest of the year. Moreover, the fat diet is high in monounsaturated (p < 0.05) and polyunsaturated fatty acid in contrast to saturated fatty acid which significantly (p < 0.05) decreased during Ramadan. These findings suggest that feeding behavior that occurs during Ramadan beneficially affects plasma lipids and lipoprotein

ISSN:0250-6807    

DOI:10.1159/000177999

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Background: Changes in body fat mass during pregnancy and its effects on total DDT concentration i.e. the, sum of pp’-DDT (pp’-dichlorodiphenyltrichloroethane), and pp’-DDE pp’-dichlorophenyldichloroethylene), in maternal milk and abdominal fat were studied in humans. Methods: Forty mothers that delivered by Caesarean section and chose to breast feed consented in providing samples (abdominal fat and breast milk) for determination of organochlorine pesticides. Constitutional variables, such as the number of children, and estimators of body fat mass, based on height and body weight (before and after pregnancy), were measured. Results: Body mass index before and after pregnancy, as well as percent change in body weight, showed no significant difference in total DDT concentration in abdominal fat or breast milk. The only variable to significantly affect either body load of pesticides (abdominal fat) or its excretion (milk fat) was the number of children (p = 0.0117 and p = 0.0324, respectively). Correlation coefficients between DDT (in adipose tissue and milk fat) and variables related to body fatness (body mass index) were low and not significant. However, a close relationship was found between total DDT in adipose tissue and milk fat (r = 0.709; p =

ISSN:0250-6807    

DOI:10.1159/000178000

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

The effects of pectin on jejunal and ileal morphology and ultrastructure were studied using adult male mice fed a semisynthetic diet containing 8% (w/w) cellulose or pectin for 30 days. No significant differences in the jejunal villus height between the 2 groups were found, but the jejunal crypt depth, and both the ileal villus height and crypt depth of the mice fed the pectin diet were significantly greater than those of the mice fed the cellulose diet. There were evident ultrastructural differences in the jejunal absorptive cells between 2 dietary groups: numerous intercellular spaces were observed in the jejunal absorptive cells of the mice fed the pectin diet, but not the cellulose diet. Moreover, the ileal absorptive cells of the mice fed the pectin diet contained numerous peroxisomes, whereas there were few in these cells of mice fed the cellulose diet. The functional characteristics of the ileum of the mice fed the pectin diet might be different from those fed the cellulose diet.

ISSN:0250-6807    

DOI:10.1159/000178001

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

We have previously observed changes in colon cell proliferation in growing rats fed different levels of dietary fat as beef tallow or corn oil. Here we measured cellular proliferation at 18 and 30 weeks in the colon of rats fed beef tallow or corn oil and treated with the chemical carcinogen azoxymethane. Additionally, we assessed colon cell membrane lipid composition after 18 weeks on the defined diets and tumor incidence at 30 weeks. Dietary fat type and quantity significantly affected colon cell proliferation. Membrane phospholipids and free fatty acids were significantly affected by fat type. Tumor incidence was not affected by diet type. We conclude that dietary fat induces changes in cell membrane lipid composition and proliferation in the colon and these changes may be related to the development of tumors.

ISSN:0250-6807    

DOI:10.1159/000178002

出版商:S. Karger AG    

年代:1997

数据来源: Karger