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Objective:To investigate the effects of omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation on muscle mass and strength improvement through systematic review and meta-analysis.Methods:Electronic databases, namely Cochrane Library database, MEDLINE, EMBASE, CENTRAL, China National Knowledge Infrastructure, and Wanfang were searched for publications in English and Chinese from database establishment to June 20, 2022. All randomized controlled trials involving any n-3 fatty acid (fish oil capsules, pure fish oil and oral nutritional supplements) interventions for more than 4 weeks among adults aged ≥ 18 years were included in the analysis. The effects of n-3 PUFA on muscle mass and strength were compared with controls using RevMan 5.4. The mean differences (MDs) or standardized mean differences (SMDs) with 95% confidence intervals (CI) were calculated and pooled effects were assessed. The quality of the included studies was evaluated using the Cochrane risk-of-bias tool.Results:27 trials were included, with both healthy adults and patients with various types of cancer, with chronic obstructive pulmonary disease and on hemodialysis due to chronic renal failure. Most trials were judged as "low" to "high" risk of bias. The meta-analysis showed that n-3 PUFA supplementation significantly improved the lean body mass in the group without physical activity intervention compared to the control group, while showing no significant increase in muscle mass or handgrip strength in overall participants. There was no significant difference between intervention and control groups in subgroup analyses based on health/disease condition, intervention duration, route of administration and dosage and risk of bias. However, significant increases in mid-arm muscle circumference (MAMC) and lower body strength (MD = 0.8, 95% CI: 0.26 to 1.34, P = 0.005; SMD = 0.45, 95% CI: 0.21 to 0.69, P = 0.0002) were observed in n-3 PUFA supplement group. Conclusions:This meta-analysis indicates that n-3 PUFA supplementation does not improve muscle mass or handgrip strength in healthy adults as well as patients, but do improve MAMC and lower body strength. The limited sample size and prominent heterogeneity of the included studies impede the extrapolation to clinical practice and warrants individual analysis based on population characteristics. Well-designed large-scale RCTs are required to verify these findings.
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Objective To investigate the improvement effect of n-3 polyunsaturated fatty acid (n-3 PUFA) on rat nonalcoholic fatty liver disease(NAFLD) induced by high fat diet.Methods Thirty Wister male rats were divided into the control group,model group and n-3 PUFA group.The high fat feeding was adopted to establish NAFLD model.After 20 weeks of experiment,7 cases were extracted from each group for detecting serum and liver total cholesterol (TC) and triacylglyceride(TG);other 3 cases were performed the liver HE staining,the levels of MCP-1,iNOS,TNF-α mRNA protein were detected by using the Real time quantitative PCR(qPCR) and Western blot.Results The TC and TG levels in serum and livers of the model group were significantly higher than those in the control group(P＜0.01),but which were evidently decreased after adding n-3 PUFA(P＜0.05).The HE staining clearly observed the rat hepatic cells fatty degeneration in the model group,while polyunsaturated fatty acid had obvious improvement effect on it.The inflammatory molecule MCP-1,iNOS,TNF-α gene expression levels in the model group were significantly higher than those in the control group(P＜0.05),while the expression levels of MCP-1,iNOS and TNF-α in the n-3PUFA group were significantly decreased compared with the model group.Conclusion High fat feeding can cause the severe fatty degeneration in rat liver,but polyunsaturated fatty acid can play obvious improvement effect.
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Objective To investigate the improvement effect of n-3 polyunsaturated fatty acid (n-3 PUFA) on rat nonalcoholic fatty liver disease(NAFLD) induced by high fat diet.Methods Thirty Wister male rats were divided into the control group,model group and n-3 PUFA group.The high fat feeding was adopted to establish NAFLD model.After 20 weeks of experiment,7 cases were extracted from each group for detecting serum and liver total cholesterol (TC) and triacylglyceride(TG);other 3 cases were performed the liver HE staining,the levels of MCP-1,iNOS,TNF-α mRNA protein were detected by using the Real time quantitative PCR(qPCR) and Western blot.Results The TC and TG levels in serum and livers of the model group were significantly higher than those in the control group(P＜0.01),but which were evidently decreased after adding n-3 PUFA(P＜0.05).The HE staining clearly observed the rat hepatic cells fatty degeneration in the model group,while polyunsaturated fatty acid had obvious improvement effect on it.The inflammatory molecule MCP-1,iNOS,TNF-α gene expression levels in the model group were significantly higher than those in the control group(P＜0.05),while the expression levels of MCP-1,iNOS and TNF-α in the n-3PUFA group were significantly decreased compared with the model group.Conclusion High fat feeding can cause the severe fatty degeneration in rat liver,but polyunsaturated fatty acid can play obvious improvement effect.
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Objectives To investigate the correlation between dietary fatty acids intake of pregnant women and neonatal anthropometry at birth. Methods Women in early pregnancy were recruited with appropriate value of weight gain in pregnancy. Instant photography was used to assess the dietary situation in both the second trimester and the third trimester to calculate the intakes of food, energy, macronutrients, and fatty acids. The body weight, height and BMI at birth were evaluated with Z scores. The correlation between dietary fatty acids of pregnant women and neonatal anthropometry at birth were analyzed. Results There were 516 pregnant women recruited in this study. The average intakes of polyunsaturated fatty acids (PUFA) and the proportion of total fatty acids in the two trimesters were 15 . 09 g/d, 23 . 93% and 17 . 18 g/d, 24 . 86%. In the second trimester the intakes of n-6 and n-3 PUFA were 14 . 23 g/d and 3 . 45 g/d, and in the third trimester, n-6 and n-3 PUFA were 16 . 08 g/d and 3 . 81 g/d, the average intakes in the third trimester were signiifcantly higher than those in the second trimester (P??0 . 05 ). The intake of DHA ( 64 . 43 mg/d) in the second trimester was lower than that in the third trimester 75 . 12 mg/d, (P??0 . 05 ).The dietary intakes of n-3 PUFA, n-6 PUFA and n-6/n-3 ratio in the second trimester were positively correlated with neonatal BMI r=0 . 142~0 . 189 , P??0 . 05 ). Conclusions The dietary ratio of n-6/n-3 PUFA in the second trimester was positively correlated with neonatal BMI, suggesting that moderately increasing the intake of n-3 PUFA may play a positive role in reducing childhood obesity.
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Objective This study aims to investigate the effects of high-fat diet rich in perilla oil on the expression of key genes that regulate hepatic VLDL synthesis in obese rats .Methods Sixty healthy male 5-week old SD rats were randomly divided into 2 groups.The rats in the normal control group (NC, n=12) were given normal diet, and the rats in the high fat group ( HF, n=48) were given a pure high fat diet in order to induce rat models of obesity .In the intervention period, the obesity model rats were randomly divided into 4 subgroups including consistent high fat group (CHF) and three intervention groups depending on perilla oil substitution rate of lard in CHF:20%PO, 50%PO and 100%PO.The serum triglyceride (TG) of the rats was measured after 4 weeks.Real-time PCR was applied to measure microsomal triglyceride transfer protein ( Mtp) and apolipoprotein B ( Apob) mRNA, and western blot assay was used for detecting the expression of MTP and APOB in the liver .Results Compared with the NC group , the CHF rats exhibited significantly high fat deposi-tion.The serum TG was markedly higher and the MTP and APOB were decreased at gene and protein levels in the CHF group compared with the NC group .After the intervention , PO remarkably reduced the level of serum TG and decreased he-patic fat deposition as it showed by pathological examination .At the gene and protein levels , MTP and APOB were upregu-lated by PO to different degrees .Conclusions All the three PO intervention can promote VLDL synthesis and secretion , and decrease the hepatic fat deposition in the obese rats .Furthermore , PO upregulates the expression of MTP at gene and protein levels in a dose-dependent manner .
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Objective Sperm quality can be affected by many factors .The aim of this study was to observe the effects of di-etary n-6/n-3 polyunsaturated fatty acids ( PUFAs) on sperm concentration and motility . Methods Twenty healthy B6 male mice were equally randomized to a control and an experimental group to be fed with standard diet and standard diet +10%arachidonic acid (AA), respectively, both for 8 weeks.Then the testes and epididymal tails of the mice were collected for observation of the changes in the microstructure of the epididymal tissue and determination of sperm motility and concentration . Results Compared with the con-trol group, the experimental animals showed significantly decreased serum levels of α-linolenic acid ( ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), and linoleic acid (LA) (P <0.01), but dramatically increased the levels of AA and n-6/n-3 PUFAs (P<0.01).The latter also exhibited remarkable reduction in sperm concentration (7 ×106/mL vs 80 ×106/mL, P<0.01), sperm motility (27%vs 86%, P<0.01). Conclusion High levels of dietary n-6/n-3 PUFAs ratios reduce sperm concentration and motility in mice .
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N-3 polyunsaturated fatty acid supplementation has been recognized to affect the peripheral oxygen delivery system with increasing blood rheology. The purpose of the present study was to investigate whether n-3 polyunsaturated fatty acid supplementation, using purified perilla oil rich in α-linoleic acid, improves aerobic capacity in young women. Eighteen young, sedentary female college students were divided into an n-3 polyunsaturated fatty acid supplemented control group (PUFA-C, n=10) and an n-3 polyunsaturated fatty acid supplemented trained group (PUFA-T, n=8). All subjects took 20g of perilla oil (11g of n-3 polyunsaturated fatty acid) in addition to the usual diet throughout the experimental period of 4 weeks. PUFA-T subjects exercised for 30 min on a bicycle ergometer (intensity, 60% of VO<sub>2</sub>max) 4 times a week for 4 weeks. Maximal oxygen uptake (VO<sub>2</sub>max) and oxygen uptake at the ventilatory anaerobic threshold level (VT) significantly (p<0.05) increased after treatment in both groups. However, the endurance time in the exhaustive exercise test significantly (p<0.05) increased in the PUFA-T group only. Increasing rates of VO<sub>2</sub>max and VT with treatment for the PUFA-C group were lower than those for the PUFA-T group (VO<sub>2</sub>max, 12.6% vs 14.4%, VT, 9.7% vs 16.9%). After treatment, these values returned to baseline levels within 2 months of the recovery period without n-3 polyunsaturated fatty acid supplementation in both groups. Only for the PUFA-T group, VO<sub>2</sub>max and VT at 2 months after the treatment period were significantly (p<0.05) higher compared with baseline levels. These results suggest that n-3 polyunsaturated fatty acid supplementation might have a beneficial effect on improving aerobic capacity with increasing peripheral oxygen delivery. However, n-3 polyunsaturated fatty acid supplementation was less effective than aerobic training.
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Objective To study the effects of different n-6/n-3 polyunsaturated fatty acid ratio on the lipid metabolic gene expression and MAPK activity in breast cancer cell lines. Methods MCF-7 and MDA-MB-231 cells were treated with n-6 polyunsaturated fatty acid, or n-3 polyunsaturated fatty acid, or the mixture of n-6/n-3 polyunsaturated fatty acid at ratio of 1∶1, 5∶1, 10∶1. The cell proliferation capacity was detected by MTT, the expression of lipid metabolic gene (COX-2, 5-LOX, PPAR? and PPAR?) were assayed by RT-PCR, MAPK phosphorylation levels were detected by Western blotting. Results COX-2 mRNA expression was not found in MCF-7 cells. As compared to normal control group, pure n-6 and 10∶1 n-6/n-3 promoted cell proliferation, up-regulated the expression of COX-2, 5-LOX, PPAR? and PPAR? mRNA , increased MAPK phosphorylation levels in MCF-7 and MDA-MB-231 cells (P
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Objective To examine the effects of different n-6/n-3 polyunsaturated fatty acid(PUFA) ratio in gap junctional intercellular communication (GJIC) in breast cancer cell lines. Methods After MCF-7(ER + )and MDA-MB-231(ER - )cells were treated respectively with n-6/n-3 polyunsaturated fatty acid ratio (1-10), Ki-67 expression in nuclear by immunocytochemistry, connexin 26 and 43 expression in cytoplasm and membrane by Western blotting, and GJIC by scrape-loading dye transfer method were performed. Results Immunocytochemistry showed that pure n-6 and 10∶1 n-6/n-3 increased Ki-67 expression (P