0
selected
-
1.
The Influence of n-3PUFA Supplementation on Muscle Strength, Mass, and Function: A Systematic Review and Meta-Analysis.
Santo André, HC, Esteves, GP, Barreto, GHC, Longhini, F, Dolan, E, Benatti, FB
Advances in nutrition (Bethesda, Md.). 2023;14(1):115-127
-
-
-
Free full text
Plain language summary
Omega 3 polyunsaturated fatty acids (n-3PUFA) are long-chain polyunsaturated fatty acids essential to human health. They play a role in cell membrane integrity, immune and inflammation regulation, cognition and neuromuscular function. As the human body cannot make these fatty acids, they need to be obtained through diet or supplementation. Regarding skeletal muscle, recent research showed that n-3PUFAs may increase the uptake of amino acids by increasing the membrane fluidity in the muscle, and by activating pathways that inhibit protein breakdown. This led to the hypothesis that n-3PUFAs may enhance muscle mass gain and strength. This systematic review sought to gather all available evidence about the impact of n-3PUFA supplementation on muscle mass, strength, and function in healthy young and older adults. The review included 14 studies with a total of 1443 participants. The authors found that n-3PUFA supplementation had no significant effect on muscle mass or muscle function in healthy young and older adults, however, a very small but significant positive effect was noted regarding muscle strength. In the discussion section, the authors explain the challenges of their review and how these findings integrate with the current understanding and other research findings. They concluded more research is needed to get a better insight into the effects of n-3PUFA on muscle function and the variants.
Abstract
The effects of omega 3 polyunsaturated fatty acids (n-3PUFA) supplementation on skeletal muscle are currently unclear. The purpose of this systematic review was to synthesize all available evidence regarding the influence of n-3PUFA supplementation on muscle mass, strength, and function in healthy young and older adults. Four databases were searched (Medline, Embase, Cochrane CENTRAL, and SportDiscus). Predefined eligibility criteria were determined according to Population, Intervention, Comparator, Outcomes, and Study Design. Only peer-reviewed studies were included. The Cochrane RoB2 Tool and the NutriGrade approach were used to access risk of bias and certainty in evidence. Effect sizes were calculated using pre-post scores and analyzed using a three-level, random-effects meta-analysis. When sufficient studies were available, subanalyses were performed in the muscle mass, strength, and function outcomes according to participant's age (<60 or ≥60 years), supplementation dosage (<2 or ≥2 g/day), and training intervention ("resistance training" vs. "none or other"). Overall, 14 individual studies were included, total 1443 participants (913 females; 520 males) and 52 outcomes measures. Studies had high overall risk of bias and consideration of all NutriGrade elements resulted in a certainty assessment of moderate meta-evidence for all outcomes. n-3PUFA supplementation had no significant effect on muscle mass (standard mean difference [SMD] = 0.07 [95% CI: -0.02, 0.17], P = 0.11) and muscle function (SMD = 0.03 [95% CI: -0.09, 0.15], P = 0.58), but it showed a very small albeit significant positive effect on muscle strength (SMD = 0.12 [95% CI: 0.006, 0.24], P = 0.04) in participants when compared with placebo. Subgroup analyses showed that age, supplementation dose, or cosupplementation alongside resistance training did not influence these responses. In conclusion, our analyses indicated that n-3PUFA supplementation may lead to very small increases in muscle strength but did not impact muscle mass and function in healthy young and older adults. To our knowledge, this is the first review and meta-analysis investigating whether n-3PUFA supplementation can lead to increases in muscle strength, mass, and function in healthy adults. Registered protocol: doi.org/10.17605/OSF.IO/2FWQT.
-
2.
Acute Flaxseed Intake Reduces Postprandial Glycemia in Subjects with Type 2 Diabetes: A Randomized Crossover Clinical Trial.
Moreira, FD, Reis, CEG, Welker, AF, Gallassi, AD
Nutrients. 2022;14(18)
-
-
-
Free full text
Plain language summary
Glucose levels tend to rise postprandially in patients with type 2 diabetes. Flaxseeds are known to have glycaemic control-improving properties and are rich in dietary fibre, alpha-linolenic acid which is an omega-3 fatty acid and phenolic compounds such as phenolic acids, lignans, flavonoids and tocopherols. Therefore, this randomised cross-over clinical trial evaluated the effects of ground raw golden flaxseeds on postprandial glycaemia induced by the consumption of complex carbohydrates in Type 2 diabetic patients. To assess the 2-hour postprandial glycaemic curve, 19 male Type 2 diabetics were randomly assigned either to consume 15 grams of ground raw gold flaxseeds 15 minutes before eating a standardised balanced breakfast or to consume a standardised balanced breakfast without ground flaxseeds. Compared to men who did not consume ground flaxseeds before their breakfast meal, those who ate 15 grams of ground flaxseed were able to lower their postprandial glucose levels by 24% and reduce their peak glucose levels by 17%. In order to generalise the results for the general population, further robust long-term studies are required to examine the beneficial effects of flaxseed on postprandial glycaemic excursions. This study can, however, assist healthcare professionals in implementing dietary strategies that include flaxseed to manage postprandial blood sugar levels in patients with type 2 diabetes.
Abstract
BACKGROUND Postprandial glycemic excursions are associated with impairment control of diabetes mellitus. Long-term consumption of flaxseed can lower blood glucose levels; however, its effects on the postprandial glycemic response remain unknown. Therefore, this study aimed to evaluate the acute effects of raw flaxseed consumption on the 2 h postprandial glycemic curve in men with type 2 diabetes mellitus (T2DM). METHODS This was a randomized crossover clinical trial. Nineteen men with T2DM were randomly assigned a standardized breakfast without (control) or with a previous intake of 15 g of ground raw golden flaxseed (flax). Glycemia was measured at fasting and postprandial at 15, 30, 45, 60, 90, and 120 min. Palatability markers (visual appeal, smell, and pleasantness of taste) and taste intensity (sweetness, saltiness, bitterness, sourness, and creaminess) were evaluated. RESULTS The peak glucose rise and the 2 h AUC glycemic response reduced in the flax group by 17% (p = 0.001) and 24% (p < 0.001), respectively. The glucose peak time, palatability, and taste parameters did not differ between the two groups. CONCLUSIONS Ingestion of 15 g of ground raw golden flaxseed before breakfast decreases the 2 h postprandial glycemic response in men with T2DM.
-
3.
Effects of camelina oil supplementation on lipid profile and glycemic control: a systematic review and dose‒response meta-analysis of randomized clinical trials.
Jalili, C, Talebi, S, Mehrabani, S, Bagheri, R, Wong, A, Amirian, P, Zarpoosh, M, Ghoreishy, SM, Kermani, MAH, Moradi, S
Lipids in health and disease. 2022;21(1):132
-
-
-
Free full text
Plain language summary
Research indicates that alpha-linolenic acid (ALA) can reduce the risk of cardiovascular disease by improving blood lipids, blood pressure, and haemostatic factors, among others. Camelina oil, considered a good source of ALA compared to other edible oils, is one of the richest dietary sources of omega-3 fatty acids, with a polyunsaturated fatty acid content over 50%. The aim of this study was to determine the effectiveness of camelina oil supplementation (COS) on lipid profiles and glycaemic control in human studies. This study is a systematic review and meta-analysis of seven randomised controlled trials with a total of 428 individuals (202 participants in the COS group and 226 in the control group). Results did not show any affects of COS on lipid profile and glycaemic indices compared with placebo intake. However, subgroup analysis showed that COS for more than 8 weeks and at a dose lower than 30g/d could decrease total cholesterol. Authors conclude that COS may be a beneficial nonpharmacological strategy for the improvement of this lipid marker. However, further studies are required to confirm the findings of this study.
Abstract
BACKGROUND This systematic review and dose-response meta-analysis of published randomized controlled trials (RCTs) was conducted to determine the effectiveness of camelina oil supplementation (COS) on lipid profiles and glycemic indices. METHODS Relevant RCTs were selected by searching the ISI Web of Science, PubMed, and Scopus databases up to July 1, 2022. RTCs with an intervention duration of less than 2 weeks, without a placebo group, and those that used COS in combination with another supplement were excluded. Weighted mean differences and 95% confidence intervals were pooled by applying a random-effects model, while validated methods examined sensitivity analyses, heterogeneity, and publication bias. RESULTS Seven eligible RCTs, including 428 individuals, were selected. The pooled analysis revealed that COS significantly improved total cholesterol in studies lasting more than 8 weeks and utilizing dosages lower than 30 g/d compared to the placebo group. The results of fractional polynomial modeling indicated that there were nonlinear dose-response relations between the dose of COS and absolute mean differences in low-density cholesterol, high-density cholesterol, and total cholesterol, but not triglycerides. It appears that the greatest effect of COS oil occurs at the dosage of 20 g/day. CONCLUSION The present meta-analysis indicates that COS may reduce cardiovascular disease risk by improving lipid profile markers. Based on the results of this study, COS at dosages lower than 30 g/d may be a beneficial nonpharmacological strategy for lipid control. Further RCTs with longer COS durations are warranted to expand on these results.
-
4.
Alpha-Linolenic and Linoleic Fatty Acids in the Vegan Diet: Do They Require Dietary Reference Intake/Adequate Intake Special Consideration?
Burns-Whitmore, B, Froyen, E, Heskey, C, Parker, T, San Pablo, G
Nutrients. 2019;11(10)
-
-
-
Free full text
Plain language summary
Fish and seafood are good sources of long-chain omega-3 fatty acids, like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A vegan diet does not include animal-sourced foods and is therefore void of EPA and DHA, unless algae-derived omega-3 supplements are consumed. Thus, vegans rely on the body's own production of long-chain fatty acids from plant-derived alpha-linolenic acid (ALA). However, adequate conversion can have several limitations. Vegan diets are generally rich in linoleic acid (LA), an omega-6 fatty acid, which in high levels can impede the conversion of ALA to EPA and DHA. Furthermore, the efficiency of conversion is influenced by gender, age or health conditions like obesity. This review sought to discuss whether vegans require special dietary recommendations for fatty acids and what these suggestions could be. Most studies assessing biological indicators of fatty acid status showed that vegans had lower levels of EPA and DHA compared to omnivores. Thus, the authors concluded that special consideration should be given to ALA and LA intake in vegan diets. In the absence of a set recommendation for a fatty acid ratio, a ratio of 4:1 (omega-6:omega-3) was proposed for vegans and omnivores. A reduction in LA and an increased intake of ALA of 2.2–4.4 g/day (or 1.1 g/day/1000 Kcals) was suggested to achieve such. This article is a useful guide when considering adequate fatty acid balance and omega-3 conversion for individuals following a vegan diet.
Abstract
Good sources of the long-chain n-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) include cold-water fish and seafood; however, vegan diets (VGNs) do not include animal-origin foods. Typically, US omnivores obtain enough dietary EPA and DHA, but unless VGNs consume algal n-3 supplements, they rely on endogenous production of long-chain fatty acids. VGN diets have several possible concerns: (1) VGNs have high intakes of linoleic acid (LA) as compared to omnivore/non-vegetarian diets. (2) High intakes of LA competitively interfere with the endogenous conversion of alpha-linolenic acid (ALA) to EPA and DHA. (3) High somatic levels of LA/low ALA indicate a decreased ALA conversion to EPA and DHA. (4) Some, not all VGNs meet the Dietary Reference Intake Adequate Intake (DRI-AI) for dietary ALA and (5) VGN diets are high in fiber, which possibly interferes with fat absorption. Consequently, health professionals and Registered Dietitians/Registered Dietitian Nutritionists working with VGNs need specific essential fatty acid diet guidelines. The purpose of this review was: (1) to suggest that VGNs have a DRI-AI Special Consideration requirement for ALA and LA based on VGN dietary and biochemical indicators of status and (2) to provide suggestions to ensure that VGNs receive adequate intakes of LA and ALA.
-
5.
Omega-3 polyunsaturated fatty acids and vegetarian diets.
Saunders, AV, Davis, BC, Garg, ML
The Medical journal of Australia. 2013;199(S4):S22-6
-
-
-
Plain language summary
Even though vegetarians may have a lower overall risk of common chronic disease, they may still be at a disadvantage where essential fatty acids (EFAs) intake is concerned. The main aim of this study was to review EFA intake and status of vegetarians in order to assess whether current intakes in this population are sufficient to achieve and maintain optimal health. A secondary aim is to explore the potential benefits of adding supplemental sources of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). This review shows that: - although vegetarians consume minimal EPA and DHA, their plasma levels of omega-3 polyunsaturated fatty acids are typically low but stable. - there are no official separate recommendations for intake of fatty acids by vegetarians. - improving EFA status in individuals who are vegetarians might offer further protection. - there may be advantages to adding DHA and possibly EPA supplements derived from microalgae, particularly for people with increased needs (e.g., pregnant and lactating women) or reduced conversion ability (e.g., people with diabetes, metabolic syndrome or hypertension, and older people). Authors conclude that there is no convincing evidence that vegetarians or vegans experience adverse effects as a result of a low dietary intake of EPA and DHA.
Abstract
While intakes of the omega-3 fatty acid α-linolenic acid (ALA) are similar in vegetarians and non-vegetarians, intakes of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are low in vegetarians and virtually absent in vegans. Plasma, blood and tissue levels of EPA and DHA are lower in vegetarians than in non-vegetarians, although the clinical significance of this is unknown. Vegetarians do not exhibit clinical signs of DHA deficiency, but further research is required to ascertain whether levels observed in vegetarians are sufficient to support optimal health. ALA is endogenously converted to EPA and DHA, but the process is slow and inefficient and is affected by genetics, sex, age and dietary composition. Vegetarians can take practical steps to optimise conversion of ALA to EPA and DHA, including reducing intake of linoleic acid. There are no official separate recommendations for intake of fatty acids by vegetarians. However, we suggest that vegetarians double the current adequate intake of ALA if no direct sources of EPA and DHA are consumed. Vegetarians with increased needs or reduced conversion ability may receive some advantage from DHA and EPA supplements derived from microalgae. A supplement of 200-300 mg/day of DHA and EPA is suggested for those with increased needs, such as pregnant and lactating women, and those with reduced conversion ability, such as older people or those who have chronic disease (eg, diabetes).
-
6.
Primary prevention of cardiovascular disease with a Mediterranean diet.
Estruch, R, Ros, E, Salas-Salvadó, J, Covas, MI, Corella, D, Arós, F, Gómez-Gracia, E, Ruiz-Gutiérrez, V, Fiol, M, Lapetra, J, et al
The New England journal of medicine. 2013;368(14):1279-90
-
-
-
Free full text
-
Plain language summary
The traditional Mediterranean diet has been shown to have cardiovascular protective effects based on previous observational cohort studies and a secondary prevention trial. While the mechanism for the beneficial effects of this diet have not been established, small trials have suggested that it fosters favourable changes in the pathways involved in cardio-metabolic disease. The aim of this randomised trial was to test the efficacy of two variations of the Mediterranean diet on reducing the incidence of cardiovascular events. These diets included Mediterranean diet supplemented with extra-virgin olive oil or mixed nuts, and a control diet (advised to reduce dietary fat). The study included 7,447 participants aged 55-80 and participants were followed for an average of 4.8 years. Both groups showed good adherence to the diets. The findings of this study showed that among persons at high cardiovascular risk, both variations of the Mediterranean diet resulted to a significant risk reduction of cardiovascular events, notably stroke. Based on this study, the authors’ conclusions support the benefits of the Mediterranean diet for the primary prevention of cardiovascular disease.
Abstract
BACKGROUND Observational cohort studies and a secondary prevention trial have shown an inverse association between adherence to the Mediterranean diet and cardiovascular risk. We conducted a randomized trial of this diet pattern for the primary prevention of cardiovascular events. METHODS In a multicenter trial in Spain, we randomly assigned participants who were at high cardiovascular risk, but with no cardiovascular disease at enrollment, to one of three diets: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control diet (advice to reduce dietary fat). Participants received quarterly individual and group educational sessions and, depending on group assignment, free provision of extra-virgin olive oil, mixed nuts, or small nonfood gifts. The primary end point was the rate of major cardiovascular events (myocardial infarction, stroke, or death from cardiovascular causes). On the basis of the results of an interim analysis, the trial was stopped after a median follow-up of 4.8 years. RESULTS A total of 7447 persons were enrolled (age range, 55 to 80 years); 57% were women. The two Mediterranean-diet groups had good adherence to the intervention, according to self-reported intake and biomarker analyses. A primary end-point event occurred in 288 participants. The multivariable-adjusted hazard ratios were 0.70 (95% confidence interval [CI], 0.54 to 0.92) and 0.72 (95% CI, 0.54 to 0.96) for the group assigned to a Mediterranean diet with extra-virgin olive oil (96 events) and the group assigned to a Mediterranean diet with nuts (83 events), respectively, versus the control group (109 events). No diet-related adverse effects were reported. CONCLUSIONS Among persons at high cardiovascular risk, a Mediterranean diet supplemented with extra-virgin olive oil or nuts reduced the incidence of major cardiovascular events. (Funded by the Spanish government's Instituto de Salud Carlos III and others; Controlled-Trials.com number, ISRCTN35739639.).