Marine n-3 fatty acids and CVD: new insights from recent follow-up studies and clinical supplementation trials

Fatty Acid Content of Four Salmonid Fish Consumed by Indigenous Peoples from the Yamal-Nenets Autonomous Okrug (Northwestern Siberia, Russia)

We assayed fatty acids in the flesh of Arctic cisco Coregonus autumnalis (adult and juvenile), least cisco Coregonus sardinella, muksun Coregonus muksun, and Arctic charr Salvelinus alpinus inhabiting water bodies of the Gydan Peninsula, Siberia, Russia. The highest concentrations of total and polyunsaturated fatty acids (PUFAs) were found in Arctic charr (27.8 and 9.5 mg g−1) and adult Arctic cisco (20.2 and 7.6 mg g−1), while the lowest concentrations occurred in juvenile Arctic cisco (7.5 and 3.6 mg g−1). Multivariate analyses divided all studied fish into five distinct groups with the highest similarity between least cisco and muksun and the highest dissimilarity between juvenile Arctic cisco and Arctic charr. Coregonid fish from the study area had a higher content of docosahexaenoic and eicosapentaenoic acids than their conspecifics from subarctic and temperate habitats. The flesh of the studied fish is a source of a healthy diet for humans. Taking into account that all the studied fish are components of the traditional diet of indigenous peoples in northwestern Siberia, our data may be useful not only for local consumers and anglers but also for stakeholders focused on food policy and food security in the area.

Long-chain monounsaturated fatty acids improve endothelial function with altering microbial flora

Fish oil-derived long-chain monounsaturated fatty acids (LCMUFAs) with a carbon chain length longer than 18 units ameliorate cardiovascular risk in mice. In this study, we investigated whether LCMUFAs could improve endothelial functions in mice and humans. In a double-blind, randomized, placebo-controlled, parallel-group, multi-center study, healthy subjects were randomly assigned to either an LCMUFA oil (saury oil) or a control oil (olive and tuna oils) group. Sixty subjects were enrolled and administrated each oil for 4 weeks. For the animal study, ApoE^-/- mice were fed a Western diet supplemented with 3% of either gadoleic acid (C20:1) or cetoleic acid (C22:1) for 12 weeks. Participants from the LCMUFA group showed improvements in endothelial function and a lower trimethylamine-N-oxide level, which is a predictor of coronary artery disease. C20:1 and C22:1 oils significantly improved atherosclerotic lesions and plasma levels of several inflammatory cytokines, including IL-6 and TNF-α. These beneficial effects were consistent with an improvement in the gut microbiota environment, as evident from the decreased ratio of Firmicutes and/ or Bacteroidetes, increase in the abundance of Akkermansia, and upregulation of short-chain fatty acid (SCFA)-induced glucagon-like peptide-1 (GLP-1) expression and serum GLP-1 level. These data suggest that LCMUFAs alter the microbiota environment that stimulate the production of SCFAs, resulting in the induction of GLP-1 secretion. Fish oil-derived long-chain monounsaturated fatty acids might thus help to protect against cardiovascular disease.

Marine n-3 fatty acid consumption in a Norwegian renal transplant cohort: Comparison of a food frequency questionnaire with plasma phospholipid marine n-3 levels

Background

High levels of plasma marine n-3 fatty acids (n-3FAs) are associated with improved patient and graft survival in renal transplant recipients (RTRs). The aim of this study was to evaluate the utility of a new food frequency questionnaire (FFQ) to estimate marine n-3FA consumption in future epidemiological research.

Methods

We developed an FFQ with a simple design of 10 questions to assess intake of marine sources of n-3FAs. RTRs included in the recent ORENTRA trial (n = 132) completed the study FFQ at the baseline visit eight weeks after engraftment and at the end of study visit one year post-transplant. We measured the reference biomarker plasma phospholipid (PL) marine n-3FA levels by gas chromatography at the same time points to evaluate association and degree of agreement between FFQ based marine n-3FA consumption estimates and the biomarker.

Results

The median plasma PL marine n-3FA level was 6.0 weight percentage (wt)% (interquartile range [IQR] 4.7 to 7.3) at baseline and 6.3 wt% (IQR 4.8 to 7.4) at end of study. Median FFQ based marine n-3FA consumption estimates were 22.8 g/month (IQR 13.0 to 34.0) at baseline and 20.3 g/month (IQR 14.5 to 32.3) at end of study. FFQ based marine n-3FA consumption estimates showed a moderate correlation with plasma PL marine n-3FA levels at baseline (Spearman’s correlation coefficient r_s = 0.43, p<0.001) and a stronger correlation at end of study (r_s = 0.62, p<0.001). Bland Altman plots showed a reasonable degree of agreement between the two methods at both time points.

Conclusions

Marine n-3FA consumption estimates based on the FFQ showed a moderate correlation with the reference biomarker plasma PL marine n-3FA levels. The FFQ might be useful in epidemiological studies where resources are limited.

Covid-19 and the Subsequent Lockdown Modified Dietary Habits of Almost Half the Population in an Italian Sample

The Covid-19 pandemic led to lockdowns in several parts of the world and, hence, changed some daily habits, including social interactions, the ability to perform sports, and-possibly-diet. The Italian government established and promulgated lockdown policies on 9 March 2020. We aim at assessing the effects of Covid-19-induced confinement policies on self-reported food consumption of self-selected Italians by means of a questionnaire that was created and diffused by the Internet. Nearly half, i.e., 49.6% of responders did not substantially modify their diet during the lockdown; however, 46.1% of them reported that they were eating more during confinement, and 19.5% gained weight. In particular, we report an increase in "comfort food" consumption, notably chocolate, ice-cream, and desserts (42.5%) and salty snacks (23.5%). In addition, 42.7% percent of this cohort attributed this increase to higher anxiety levels. Related to this, 36.8% of responders reported a decrease in alcohol consumption, even though 10.1% of them reported an increase. Interestingly, 21.2% of responders increased their consumption of fresh fruit and vegetables. Only 33.5% of those who declared decreased consumption attributed this change of diet to lower availability and ease of purchasing such items. Equally interesting, over half of responders, i.e., 56.2%, admitted that fruit and vegetables did not appeal to them while in lockdown. Purchases of ready-made meals were reduced by nearly 50%. Future large-scale similar studies should be undertaken worldwide and will help public health authorities shape their reactions to future, unavoidable pandemics.