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A combined DHA-rich fish oil and cocoa flavanols intervention does not improve cognition or brain structure in older adults with memory complaints: results from the CANN randomized, controlled parallel-design study.
Vauzour, D, Scholey, A, White, DJ, Cohen, NJ, Cassidy, A, Gillings, R, Irvine, MA, Kay, CD, Kim, M, King, R, et al
The American journal of clinical nutrition. 2023;118(2):369-381
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At a population level, interventions that delay the onset of dementia by 2 years are predicted to reduce the number of dementia patients by 20%. Prospective cohort studies have consistently reported cognitive and neurophysiological benefits of the fish-derived omega-3 long-chain polyunsaturated fatty acids (PUFAs), EPA, and DHA and plant-derived flavanols (FLAVs). This study hypothesised that 12-month administration of a combination of 500 mg cocoa FLAVs with 1.5g omega-3 long-chain PUFAs would improve cognitive function in a mixed subjective cognitive impairment and mild cognitive impairment cohort. This study is based on the results of the CANN randomised controlled trial. A total of 258 participants were recruited and randomised to control or test intervention. Following baseline measurements, 125 participants were randomised into the active OM3FLAV intervention group and 121 into the control group. Results showed that the 1-year intervention with EPA and DHA and cocoa FLAVs did not improve cognition or protect the brain against atrophy in older adults with evidence of memory deficits. Authors concluded that given the complexity of neuropathological processes underpinning cognitive decline and dementia risk, multidomain, multinutrient, or whole diet approaches may be needed to positively impact the cognitive trajectory in the medium term (months to 3 years).
Abstract
BACKGROUND There is evidence that both omega-3 long-chain polyunsaturated fatty acids (PUFAs) (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) and cocoa flavanols can improve cognitive performance in both healthy individuals and in those with memory complaints. However, their combined effect is unknown. OBJECTIVES To investigate the combined effect of EPA/DHA and cocoa flavanols (OM3FLAV) on cognitive performance and brain structures in older adults with memory complaints. METHODS A randomized placebo-controlled trial of DHA-rich fish oil (providing 1.1 g/d DHA and 0.4 g/d EPA) and a flavanol-rich dark chocolate (providing 500 mg/d flavan-3-ols) was conducted in 259 older adults with either subjective cognitive impairment or mild cognitive impairment. Participants underwent assessment at baseline, 3 mo, and 12 mo. The primary outcome was the number of false-positives on a picture recognition task from the Cognitive Drug Research computerized assessment battery. Secondary outcomes included other cognition and mood outcomes, plasma lipids, brain-derived neurotrophic factor (BDNF), and glucose levels. A subset of 110 participants underwent structural neuroimaging at baseline and at 12 mo. RESULTS 197 participants completed the study. The combined intervention had no significant effect on any cognitive outcomes, with the exception of reaction time variability (P = 0.007), alertness (P < 0.001), and executive function (P < 0.001), with a decline in function observed in the OM3FLAV group (118.6 [SD 25.3] at baseline versus 113.3 [SD 25.4] at 12 mo for executive function) relative to the control, and an associated decrease in cortical volume (P = 0.039). Compared with the control group, OM3FLAV increased plasma HDL, total cholesterol ratio (P < 0.001), and glucose (P = 0.008) and reduced TG concentrations (P < 0.001) by 3 mo, which were sustained to 12 mo, with no effect on BDNF. Changes in plasma EPA and DHA and urinary flavonoid metabolite concentrations confirmed compliance to the intervention. CONCLUSIONS These results suggest that cosupplementation with ω-3 PUFAs and cocoa flavanols for 12 mo does not improve cognitive outcomes in those with cognitive impairment. This trial was registered at clinicaltrials.gov as NCT02525198.
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Type 2 diabetes preventive effects with a 12-months sardine-enriched diet in elderly population with prediabetes: An interventional, randomized and controlled trial.
Díaz-Rizzolo, DA, Serra, A, Colungo, C, Sala-Vila, A, Sisó-Almirall, A, Gomis, R
Clinical nutrition (Edinburgh, Scotland). 2021;40(5):2587-2598
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Older people have a higher risk of developing Type 2 diabetes (T2D) due to the possibility of β-cell dysfunction due to ageing. Sardines are believed to be protective against the development of T2D. Therefore, this randomised controlled trial evaluated the preventative effects of a sardine-rich diet in elderly prediabetic patients. For one year, both the sardine group (SG) and control group (CG) followed a T2D prevention diet, with the SG consuming 200 g of sardines each week. Both groups improved body weight, BMI, waist and hip circumference, and body composition. Taurine, EPA, DHA, omega-3 fatty acid, calcium, iodine, zinc, phosphorous and fluoride, vitamin B12 and D, and lycopene and tocopherols were found to be higher in the SG than the CG, indicating the sardines were protective against T2D. In SG, HDL cholesterol and adiponectin levels were significantly increased, and blood pressure and triglycerides were decreased, signalling a reduced risk of T2D and cardiovascular disease. In addition, SG showed a reduction in HOMA-IR and an Omega-3 fatty acid was substituted for Omega-6 fatty acids in the erythrocyte membrane, suggesting a reduced risk of T2D. Further robust research is required to confirm the protective effect of a sardine-enriched diet against T2D. It may be useful to healthcare providers to comprehend how a sardine-enriched diet could improve obesity, T2D and CVD markers in pre-diabetic elderly patients.
Abstract
BACKGROUND Fish could play a role in preventing type 2 diabetes (T2D) but there has been little specification about the type of fish and the preventive mechanism involved in its health claim. The sardine is a source of omega-3 and taurine that, in isolation or in synergy, would produce T2D-delaying through different molecular mechanism. HYPOTHESIS The consumption of twice a week of sardine, during one year would reduce T2D-developing risk in a population with prediabetes (preDM) and old age. DESIGN 152 subjects with fasting glucose between 100-124 mg/dL aged ≥65 yo were recruited from three primary care centers in Barcelona and were randomly distributed among two interventional groups: control group (CG) and sardine group (SG). Both groups received same T2D-prevention nutritional during a year but only SG had to add 200 g of sardine per week. All variables were collected before to start and at the end of the diet. (ClinicalTrials.gov: NCT03557541). RESULTS 152 people were randomized into CG (n=77) and SG (n=75) with 18 and 12 drop outs respectively. Subjects in SG, significantly compared to CG, decreased percentage classified-individuals in a very high risk group to develop T2D according to FINDRISC (p=0.035). In addition to increasing HDL-cholesterol and adiponectin and decreasing triglycerides (p<0.05) and blood pressure (<0.05), SG showed a lower HOMA-IR (p=0.032). The consumption of sardine characteristics nutrients as omega-3, EPA and DHA, vitamin D, fluorine and taurine were higher for SG (p<0.05). These results agreed with the increased of taurine, fatty acid (FA) omega-3 and bile acids circulating metabolites (p<0.05). Changes erythrocyte membrane FA were detected only in SG with a decrease of 5 omega-6 FA (p<0.001) and an increase of 3 omega-3 FA types (p<0.001). CONCLUSION We conclude that a year T2D-prevention diet with sardine supplementation has a greater protective effect against developing T2D and CV events.
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Effectiveness of a Multicomponent Intervention in Primary Care That Addresses Patients with Diabetes Mellitus with Two or More Unhealthy Habits, Such as Diet, Physical Activity or Smoking: Multicenter Randomized Cluster Trial (EIRA Study).
Represas-Carrera, F, Couso-Viana, S, Méndez-López, F, Masluk, B, Magallón-Botaya, R, Recio-Rodríguez, JI, Pombo, H, Leiva-Rus, A, Gil-Girbau, M, Motrico, E, et al
International journal of environmental research and public health. 2021;18(11)
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Life habits such as smoking, physical activity, and diet affect glycaemic control. The objective of this multicentre randomised cluster trial (EIRA study) was to evaluate the effectiveness of multicomponent educational interventions on glycaemic control in Type 2 diabetic patients. Interventions in multicomponent individual, group and community settings included smoking cessation, the Mediterranean diet and physical activity, as well as an assessment of the quality of life. Participants had unhealthy lifestyles prior to the intervention. The study was conducted in 26 primary healthcare centres in seven health departments in Spain over a period of 12 months. A brief intervention aimed to change the habits of the participants, including increasing physical activity, quitting smoking and adhering to the Mediterranean diet. After 12 months of intervention, there were no statistically significant improvements in glycaemic control, physical activity, sedentary lifestyle, smoking, or quality of life. However, adherence to the Mediterranean diet was statistically significant. Further research is needed to determine the effectiveness of multicomponent interventions in improving glycaemic control. The clinical applicability of multicomponent interventions to tackle type 2 diabetes, obesity, and unhealthy lifestyles should be considered by healthcare providers.
Abstract
Introduction: We evaluated the effectiveness of an individual, group and community intervention to improve the glycemic control of patients with diabetes mellitus aged 45-75 years with two or three unhealthy life habits. As secondary endpoints, we evaluated the inverventions' effectiveness on adhering to Mediterranean diet, physical activity, sedentary lifestyle, smoking and quality of life. Method: A randomized clinical cluster (health centers) trial with two parallel groups in Spain from January 2016 to December 2019 was used. Patients with diabetes mellitus aged 45-75 years with two unhealthy life habits or more (smoking, not adhering to Mediterranean diet or little physical activity) participated. Centers were randomly assigned. The sample size was estimated to be 420 people for the main outcome variable. Educational intervention was done to improve adherence to Mediterranean diet, physical activity and smoking cessation by individual, group and community interventions for 12 months. Controls received the usual health care. The outcome variables were: HbA1c (main), the Mediterranean diet adherence score (MEDAS), the international diet quality index (DQI-I), the international physical activity questionnaire (IPAQ), sedentary lifestyle, smoking ≥1 cigarette/day and the EuroQuol questionnaire (EVA-EuroQol5D5L). Results: In total, 13 control centers (n = 356) and 12 intervention centers (n = 338) were included with similar baseline conditions. An analysis for intention-to-treat was done by applying multilevel mixed models fitted by basal values and the health center: the HbA1c adjusted mean difference = -0.09 (95% CI: -0.29-0.10), the DQI-I adjusted mean difference = 0.25 (95% CI: -0.32-0.82), the MEDAS adjusted mean difference = 0.45 (95% CI: 0.01-0.89), moderate/high physical activity OR = 1.09 (95% CI: 0.64-1.86), not living a sedentary lifestyle OR = 0.97 (95% CI: 0.55-1.73), no smoking OR = 0.61 (95% CI: 0.54-1.06), EVA adjusted mean difference = -1.26 (95% CI: -4.98-2.45). Conclusions: No statistically significant changes were found for either glycemic control or physical activity, sedentary lifestyle, smoking and quality of life. The multicomponent individual, group and community interventions only showed a statistically significant improvement in adhering to Mediterranean diet. Such innovative interventions need further research to demonstrate their effectiveness in patients with poor glycemic control.
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Effect of n-3 PUFA on extracellular matrix protein turnover in patients with psoriatic arthritis: a randomized, double-blind, placebo-controlled trial.
Holm Nielsen, S, Sardar, S, Siebuhr, AS, Schlemmer, A, Schmidt, EB, Bay-Jensen, AC, Karsdal, MA, Christensen, JH, Kristensen, S
Rheumatology international. 2021;41(6):1065-1077
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Psoriatic arthritis is a chronic inflammatory condition that causes joint pain and swelling along with red, flaky, and scaly skin. Inflammation affects the extracellular matrix, which comprises proteins and molecules that support cartilage, bone, and soft tissues in joints. A high level of collagen fragments is released into the bloodstream as a result. Fish oils and fish are good sources of n-3 polyunsaturated fatty acids (n-3 PUFA), including eicosapentaenoic acid and docosahexaenoic acid. Inflammation and joint pain have been shown to be reduced by n-3 PUFA in previous studies. This randomised, double-blinded, placebo-controlled study randomly assigned 142 patients with psoriatic arthritis to receive 3g n-3 PUFA (50% EPA and 50% DHA) or 3g of olive oil as the control for 24 weeks. Taking N-3 PUFA supplementation did not affect extracellular matrix turnover in psoriatic arthritis patients. This may be due to the anti-inflammatory properties of olive oil, which was used as a control, and to the short duration of the study. The benefits of using n-3 PUFA as a therapeutic strategy in patients with psoriatic arthritis need to be evaluated in larger, robust long-term studies. Furthermore, the clinical efficacy of n-3 PUFA cannot be distinguished since 75% of the patients took anti-rheumatic drugs. A study like this can provide healthcare professionals with insights into the potential benefits of n-3 PUFAs, which may aid them in making therapeutic decisions.
Abstract
Psoriatic arthritis (PsA) is a chronic inflammatory disease characterized by involvement of skin, axial and peripheral skeleton. An altered balance between extracellular matrix (ECM) formation and breakdown is a key event in PsA, and changes in ECM protein metabolites may provide insight to tissue changes. Dietary fish oils (n-3 PUFA) might affect the inflammation driven tissue turnover. The aim was to evaluate ECM metabolites in patients with PsA compared to healthy individuals and investigate the effects of n-3 PUFA. The 24-week randomized, double-blind, placebo-controlled trial of PUFA included 142 patients with PsA. Fifty-seven healthy individuals were included for comparison. This study is a sub-study investigating biomarkers of tissue remodelling as secondary outcomes. Serum samples at baseline and 24 weeks and healthy individuals were obtained, while a panel of ECM metabolites reflecting bone and soft tissue turnover were measured by ELISAs: PRO-C1, PRO-C3, PRO-C4, C1M, C3M, C4M, CTX-I and Osteocalcin (OC). C1M, PRO-C3, PRO-C4 and C4M was found to be elevated in PsA patients compared to the healthy individuals (from 56 to 792%, all p < 0.0001), where no differences were found for OC, CTX-I, PRO-C1 and C3M. PRO-C3 was increased by 7% in patients receiving n-3 PUFA after 24 weeks compared to baseline levels (p = 0.002). None of the other biomarkers was changed with n-3 PUFA treatment. This indicates that tissue turnover is increased in PsA patients compared to healthy individuals, while n-3 PUFA treatment for 24 weeks did not have an effect on tissue turnover. Trial registration NCT01818804. Registered 27 March 2013-Completed 18 February 2016. https://clinicaltrials.gov/ct2/show/NCT01818804?term=NCT01818804&rank=1.
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The effect of different sources of fish and camelina sativa oil on immune cell and adipose tissue mRNA expression in subjects with abnormal fasting glucose metabolism: a randomized controlled trial.
de Mello, VD, Dahlman, I, Lankinen, M, Kurl, S, Pitkänen, L, Laaksonen, DE, Schwab, US, Erkkilä, AT
Nutrition & diabetes. 2019;9(1):1
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Dietary fish oils, particularly omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in oily fish, nuts and seeds have long been researched and purported to have both anti-inflammatory and glucose-stabilising effects when consumed orally and it is widely believed that in reducing low-grade inflammation and stabilising blood glucose levels, the risk of suffering from type 2 diabetes, heart disease or a stroke is reduced. Lean fish on the other hand has been far less researched with regards to its protective effects. This study was a randomised controlled study designed to assess and compare the protective effects of fish oils and Camelina Sativa oil (CSO - a seed oil containing alpha-linolenic acid) on inflammatory-related genes in subjects with suggestive pre-diabetes. Subjects were allocated to a randomised group and instructed to consume a given amount of either fatty fish, lean fish, camelina oil, or no fish/oil (control group). The study was carried out on 72 participants over a 12-week period. Although no significant change could be seen on inflammatory gene expression for the group consuming fatty fish, there was a modest decrease in inflammatory gene markers in the group consuming lean fish and a significant decrease in the group consuming CSO. Implications from this study suggest that CSO exerts its protective effect by reducing inflammation, therefore possibly decreasing the risk of strokes and cardiovascular episodes. The authors suggest that consuming a variety of fish, especially lean fish 4 times/ week could also play a protective role in cardiovascular health and type 2 diabetes.
Abstract
BACKGROUND/OBJECTIVES Molecular mechanisms linking fish and vegetable oil intakes to their healthy metabolic effects may involve attenuation of inflammation. Our primary aim was to examine in a randomized controlled setting whether diets enriched in fatty fish (FF), lean fish (LF) or ALA-rich camelina sativa oil (CSO) differ in their effects on the mRNA expression response of selected inflammation-related genes in peripheral blood mononuclear cells (PBMCs) and subcutaneous adipose tissue (SAT) in subjects with impaired fasting glucose. SUBJECTS/METHODS Samples from 72 participants randomized to one of the following 12-week intervention groups, FF (n = 19), LF (n = 19), CSO (n = 17) or a control group (n = 17), were available for the PBMC study. For SAT, 39 samples (n = 8, n = 10, n = 9, n = 12, respectively) were available. The mRNA expression was measured at baseline and 12 weeks by TaqMan® Low Density Array. RESULTS In PBMCs, LF decreased ICAM1 mRNA expression (P < 0.05), which was different (P = 0.06, Bonferroni correction) from the observed increase in the FF group (P < 0.05). Also, compared to the control group, LF decreased ICAM1 mRNA expression (P < 0.05). Moreover, the change in ICAM1 mRNA expression correlated positively with the intake of FF (P < 0.05) and negatively with the intake of LF (P < 0.05), independently of study group. A diet enriched in CSO, a rich source of alpha-linolenic acid (ALA), decreased PBMC IFNG mRNA expression (P < 0.01). The intake of CSO in the CSO group, but not the increase in plasma ALA proportions, correlated inversely with the IFNG mRNA expression in PBMCs (P = 0.08). In SAT, when compared with the control group, the effect of FF on decreasing IL1RN mRNA expression was significant (P < 0.03). CONCLUSION We propose that CSO intake may partly exert its benefits through immuno-inflammatory molecular regulation in PBMCs, while modulation of ICAM1 expression, an endothelial/vascular-related gene, may be more dependent on the type of fish consumed.
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Effect of Fish Oil Supplementation on Hepatic and Visceral Fat in Overweight Men: A Randomized Controlled Trial.
Parker, HM, Cohn, JS, O'Connor, HT, Garg, ML, Caterson, ID, George, J, Johnson, NA
Nutrients. 2019;11(2)
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Being overweight increases the risk of the development of metabolic conditions such as non-alcoholic fatty liver disease (NAFLD). Omega-3 polyunsaturated fatty acid (PUFA) supplementation is recommended for prevention of chronic disease, and is thought to reduce liver fat, but there have been few randomised controlled trials that accurately measure liver fat. The aim of this double-blind randomised controlled trial was to assess the effect of 12 weeks of supplementation with omega-3 PUFA from fish oil on liver fat, liver tests, and body composition. Fifty healthy overweight men were given either fish oil (1,728 mg marine triglycerides, of which 588 mg EPA and 412 mg DHA, combined with 200 mg antioxidant, coenzyme Q10) or placebo (capsules containing 2g olive oil) daily for 12 weeks. Participants were assessed at the beginning of the study, and following 6 and 12 weeks of supplementation. At the start of the study, 16 (32%) participants met the criteria for NAFLD (>5.5% liver fat). There were no significant changes in liver fat, liver function or body composition in either of the groups over 12 weeks. When the researchers looked at the results for those participants with NAFLD at the start of the study, there were no significant changes here either. The authors concluded that omega-3 PUFA did not appear to be an effective agent for reducing liver fat in overweight men. The factors determining the health benefits of omega-3 PUFA supplementation on an individual level need to be clarified.
Abstract
Being overweight increases the risk of the development of metabolic conditions such as non-alcoholic fatty liver disease (NAFLD), which is itself an independent predictor of cardiovascular disease. Omega-3 polyunsaturated fatty acid (PUFA) supplementation is recommended for prevention of chronic disease, and is thought to reduce raised liver fat, yet there have been few randomized controlled trials with accurate measurement of liver fat. We assessed the effect of 12 weeks of supplementation with omega-3 PUFA from fish oil versus placebo on quantified liver fat, liver tests, and body composition including visceral adipose tissue (VAT) in a double-blind randomized controlled trial. Fifty apparently healthy overweight men (BMI 25.0⁻29.9 kg/m²; waist > 94 cm) were randomly allocated to consume fish oil (total daily dose: 1728 mg marine triglycerides, of which 588 mg EPA and 412 mg DHA, combined with 200 mg antioxidant, coenzyme Q10) or placebo (olive oil capsules) daily for 12 weeks. Liver fat was assessed using proton magnetic resonance spectroscopy. All outcomes were assessed at baseline and following 6 and 12 weeks of supplementation. Baseline liver fat was 4.6 ± 0.5% (range: 0.6 to 18.2%); 16 (32%) participants met the criteria for NAFLD (>5.5% liver fat). Repeated measures ANOVA revealed no significant time or group × time effect for fish oil versus placebo for liver fat, liver enzymes, anthropometry, or body composition including VAT (p > 0.05 for all), with similar finding for sub-analysis of participants with NAFLD. Omega-3 PUFA did not appear to be an effective agent for reducing liver fat in overweight men. The factors determining the health benefits of omega-3 PUFA supplementation on an individual level need to be clarified.
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Hormonal and metabolic effects of polyunsaturated fatty acids in young women with polycystic ovary syndrome: results from a cross-sectional analysis and a randomized, placebo-controlled, crossover trial.
Phelan, N, O'Connor, A, Kyaw Tun, T, Correia, N, Boran, G, Roche, HM, Gibney, J
The American journal of clinical nutrition. 2011;93(3):652-62
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5-10% of women of reproductive age are thought to be affected by polycystic ovary syndrome (PCOS). Women with PCOS don’t ovulate and have high levels of androgens (‘male’ hormones) such as testosterone. Dietary changes are often recommended for women with PCOS, yet the optimal diet for managing the condition has not been defined. Long-chain polyunsaturated fatty acids (PUFAs), in particular omega-3s, may influence various aspects of metabolic health in ways that are beneficial for women with PCOS. The objectives of this study were to determine the link between PUFAs and hormonal aspects of PCOS, to investigate the effects of omega-3 supplementation, and to support the findings with cellular studies. Participants were given 4 mg of either omega-3 supplementation or an olive oil placebo every day for 6 weeks. There was a 6-week rest period, after which the women crossed over to receive the alternative treatment for a further 6 weeks. Women who had higher levels of circulating androgens at the start of the study tended to have both higher omega-6 levels and omega-6:omega-3 ratios. After taking omega-3 supplements, testosterone levels were significantly reduced, particularly in those women who experienced more substantial falls in the ratio of omega-6:omega-3. Alongside this, the researchers found that ovarian cells sourced from cows increased production of androgens when treated with omega-6, but not omega-3. The authors concluded that supplementation with omega-3 PUFAs improves hormonal balance in women with PCOS.
Abstract
BACKGROUND Polycystic ovary syndrome (PCOS) is characterized by an adverse metabolic profile. Although dietary changes are advocated, optimal nutritional management remains uncertain. Polyunsaturated fatty acids (PUFAs), particularly long-chain (LC) n-3 (omega-3) PUFAs, improve metabolic health, but their therapeutic potential in PCOS is unknown. OBJECTIVES We aimed to determine the associations between plasma PUFAs and metabolic and hormonal aspects of PCOS to investigate the efficacy of LC n-3 PUFA supplementation and to support the findings with mechanistic cellular studies. DESIGN We selected a cross-sectional PCOS cohort (n = 104) and conducted a principal component analysis on plasma fatty acid profiles. Effects of LC n-3 PUFA supplementation on fasting and postprandial metabolic and hormonal markers were determined in PCOS subjects (n = 22) by a randomized, crossover, placebo-controlled intervention. Direct effects of n-6 (omega-6) compared with n-3 PUFAs on steroidogenesis were investigated in primary bovine theca cells. RESULTS Cross-sectional data showed that a greater plasma n-6 PUFA concentration and n-6:n-3 PUFA ratio were associated with higher circulating androgens and that plasma LC n-3 PUFA status was associated with a less atherogenic lipid profile. LC n-3 PUFA supplementation reduced plasma bioavailable testosterone concentrations (P < 0.05), with the greatest reductions in subjects who exhibited greater reductions in plasma n-6:n-3 PUFA ratios. The treatment of bovine theca cells with n-6 rather than with n-3 PUFAs up-regulated androstenedione secretion (P < 0.05). CONCLUSIONS Cross-sectional data suggest that PUFAs modulated hormonal and lipid profiles and that supplementation with LC n-3 PUFAs improves androgenic profiles in PCOS. In bovine theca cells, arachidonic acid modulated androstenedione secretion, which suggests an indirect effect of n-3 PUFAs through the displacement of or increased competition with n-6 PUFAs. This trial was registered at clinicaltrials.gov as NCT01189669.
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Omega-3 supplementation lowers inflammation and anxiety in medical students: a randomized controlled trial.
Kiecolt-Glaser, JK, Belury, MA, Andridge, R, Malarkey, WB, Glaser, R
Brain, behavior, and immunity. 2011;25(8):1725-34
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Dietary intake of both omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) influence inflammation, and observational studies have linked lower omega-3 PUFAs with inflammation and depression. The aim of this trial was to investigate the effects of omega-3 PUFA supplementation on inflammatory cytokine production and symptoms of depression and anxiety. Sixty-eight medical students aged 21 to 29 were enrolled in the study and were randomised to either receive omega-3 PUFA pills or placebo pills that approximated the average fat intake consumed by adults. This study found that students who received omega-3 PUFAs showed a decrease both in inflammatory cytokine production and anxiety symptoms compared with controls. This study provides the first evidence that omega-3 PUFAs may be beneficial for individuals with anxiety.
Abstract
Observational studies have linked lower omega-3 (n-3) polyunsaturated fatty acids (PUFAs) and higher omega-6 (n-6) PUFAs with inflammation and depression, but randomized controlled trial (RCT) data have been mixed. To determine whether n-3 decreases proinflammatory cytokine production and depressive and anxiety symptoms in healthy young adults, this parallel group, placebo-controlled, double-blind 12-week RCT compared n-3 supplementation with placebo. The participants, 68 medical students, provided serial blood samples during lower-stress periods as well as on days before an exam. The students received either n-3 (2.5 g/d, 2085 mg eicosapentaenoic acid and 348 mg docosahexanoic acid) or placebo capsules that mirrored the proportions of fatty acids in the typical American diet. Compared to controls, those students who received n-3 showed a 14% decrease in lipopolysaccharide (LPS) stimulated interleukin 6 (IL-6) production and a 20% reduction in anxiety symptoms, without significant change in depressive symptoms. Individuals differ in absorption and metabolism of n-3 PUFA supplements, as well as in adherence; accordingly, planned secondary analyses that used the plasma n-6:n-3 ratio in place of treatment group showed that decreasing n-6:n-3 ratios led to lower anxiety and reductions in stimulated IL-6 and tumor necrosis factor alpha (TNF-α) production, as well as marginal differences in serum TNF-α. These data suggest that n-3 supplementation can reduce inflammation and anxiety even among healthy young adults. The reduction in anxiety symptoms associated with n-3 supplementation provides the first evidence that n-3 may have potential anxiolytic benefits for individuals without an anxiety disorder diagnosis. ClinicalTrials.gov identifier: NCT00519779.
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Fish consumption and markers of colorectal cancer risk: a multicenter randomized controlled trial.
Pot, GK, Majsak-Newman, G, Geelen, A, Harvey, LJ, Nagengast, FM, Witteman, BJ, van de Meeberg, PC, Timmer, R, Tan, A, Wahab, PJ, et al
The American journal of clinical nutrition. 2009;90(2):354-61
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Colorectal cancer (CC) risk is strongly related to dietary habits, with 65–75% of the incidence of CC attributed to dietary factors. This RCT studied the effects of fish consumption on markers of CC risk. 242 patients, either at high risk of developing CC or with a healthy bowel, were randomly assigned to 3 groups - 2 portions of oily fish per week, 2 portions of lean fish per week, or a control group who received dietary advice only for 6 months. 216 patients completed the trail. No statistically significant effect on CC risk markers was found between the fish groups and controls at 6 months. These results did not support the hypothesis that additional fish consumption over a 6-month period changes the number of colonic precancerous cells. The authors call for further studies to include non-fish eaters to further test their hypothesis.
Abstract
BACKGROUND Diet is a major factor in the etiology of colorectal cancer, with high fish consumption possibly decreasing colorectal cancer risk, as was shown in several observational studies. To date, no intervention trials have examined the possible beneficial effects of fish intake on colorectal cancer risk. OBJECTIVE The objective was to investigate the effects of a 6-mo intervention with oil-rich or lean fish on apoptosis and mitosis within the colonic crypt. DESIGN In a multicenter, randomized, controlled intervention trial, patients with colorectal polyps, inactive ulcerative colitis, or no macroscopic signs of disease were recruited (n = 242) and randomly allocated to receive dietary advice plus either 300 g oil-rich fish (salmon) per week (n = 82), 300 g lean fish (cod) per week (n = 78), or only dietary advice (DA) (n = 82). Apoptosis and mitosis were measured in colonic biopsy samples collected before and after intervention (n = 213). RESULTS The total number of apoptotic cells per crypt did not increase in the salmon or cod group: -0.10 (95% CI: -0.36, 0.16) and -0.06 (95% CI: -0.32, 0.20), respectively, compared with the DA group. The total number of mitotic cells per crypt decreased nonsignificantly in the salmon group (-0.87; 95% CI: -2.41, 0.68) and in the cod group (-1.04; 95% CI: -2.62, 0.53) compared with the DA group. Furthermore, the distribution of mitosis within the crypt did not significantly change in either group. CONCLUSION An increase in the consumption of either oil-rich or lean fish to 2 portions weekly over 6 mo does not markedly change apoptotic and mitotic rates in the colonic mucosa. This trial was registered at www.clinicaltrials.gov as NCT00145015.