Fish consumption, blood docosahexaenoic acid and chronic diseases in Chinese rural populations

The Possible Mechanism of Physiological Adaptation to the Low-Se Diet and Its Health Risk in the Traditional Endemic Areas of Keshan Diseases

Selenium is an essential trace element for humans and animals. As with oxygen and sulfur, etc., it belongs to the sixth main group of the periodic table of elements. Therefore, the corresponding amino acids, such as selenocysteine (Sec), serine (Ser), and cysteine (Cys), have similar spatial structure, physical, and chemical properties. In this review, we focus on the neglected but key role of serine in a possible mechanism of the physiological adaptation to Se-deficiency in human beings with an adequate intake of dietary protein: the insertion of Cys in place of Sec during the translation of selenoproteins dependent on the Sec insertion sequence element in the 3'UTR of mRNA at the UGA codon through a novel serine-dependent pathway for the de novo synthesis of the Cys-tRNA^[Ser]Sec, similar to Sec-tRNA^[Ser]Sec. We also discuss the important roles of serine in the metabolism of selenium directly or indirectly via GSH, and the maintenance of selenium homostasis regulated through the methylation modification of Sec-tRNA^[Ser]Sec at the position 34U by SAM. Finally, we propose a hypothesis to explain why Keshan disease has gradually disappeared in China and predict the potential health risk of the human body in the physiological adaptation state of low selenium based on the results of animal experiments.

Nutritional Status of Selenium and Its Association with Diet and Indoor Air Pollution among Pregnant Women in a Rural Area of Northern China

The nutritional status of selenium (Se) in pregnant women in rural areas of northern China and its association with diet and indoor air pollution are rarely reported. We recruited 273 pregnant women in early or middle term in Shanxi and Hebei province and detected their fasting blood selenium. Demographic characteristics, food habits, and indoor air pollution exposure were collected with a questionnaire. Multivariate logistic regression models were used to estimate the adjusted odds ratios (AORs) and their 95% confidence intervals for the factors and relatively low blood levels of Se (below the lower quartile). The median (interquartile range [IQR]) blood concentration of Se was 117.35 (103.90, 129.23) μg/L. The rate of Se deficiency was 4.8%, and the rate of overnutrition was 23.8%. The AORs for the risk for relatively low blood levels of Se were 2.26 (1.15, 4.44) for consuming less beef and pork/mutton; 0.39 (0.19, 0.80) for a lower frequency of vinegar consumption; and 1.41 (0.76, 2.60) and 1.18 (0.59, 2.36) for passive smoking and indoor coal pollution, respectively. In conclusion, the nutritional status of Se in pregnant women in a rural area of northern China was acceptable; diet was the main determinant; no conclusive association was found between indoor air pollution and Se nutritional status.

Blood n-3 fatty acid levels and total and cause-specific mortality from 17 prospective studies

The health effects of omega-3 fatty acids have been controversial. Here we report the results of a de novo pooled analysis conducted with data from 17 prospective cohort studies examining the associations between blood omega-3 fatty acid levels and risk for all-cause mortality. Over a median of 16 years of follow-up, 15,720 deaths occurred among 42,466 individuals. We found that, after multivariable adjustment for relevant risk factors, risk for death from all causes was significantly lower (by 15-18%, at least p < 0.003) in the highest vs the lowest quintile for circulating long chain (20-22 carbon) omega-3 fatty acids (eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids). Similar relationships were seen for death from cardiovascular disease, cancer and other causes. No associations were seen with the 18-carbon omega-3, alpha-linolenic acid. These findings suggest that higher circulating levels of marine n-3 PUFA are associated with a lower risk of premature death.

NMR assignment of the in vivo daphnia magna metabolome

Daphnia (freshwater fleas) are among the most widely used organisms in regulatory aquatic toxicology/ecology, while their recent listing as an NIH model organism is stimulating research for understanding human diseases and processes.

Docosahexaenoic Acid in Neural Signaling Systems

Docosahexaenoic acid has been conserved in neural signalling systems in the cephalopods, fish, amphibian, reptiles, birds, mammals, primates and humans. This extreme conservation, despite wide genomic changes over 500 million years, testifies to a uniqueness of this molecule in the brain. The brain selectively incorporates docosahexaenoic acid and its rate of incorporation into the developing brain has been shown to be greater than ten times more efficient than its synthesis from the omega 3 fatty acids of land plant origin. Data has now been published demonstrating a significant influence of dietary omega 3 fatty acids on neural gene expression. As docosahexaenoic acid is the only omega 3 fatty acid in the brain, it is likely that it is the ligand involved. The selective uptake, requirement for function and stimulation of gene expression would have conferred an advantage to a primate which separated from the chimpanzees in the forests and woodlands and sought a different ecological niche. In view of the paucity of docosahexaenoic acid in the land food chain it is likely that the advantage would have been gained from a lacustrine or marine coastal habitat with access to food rich in docosahexaenoic acid and the accessory micronutrients, such as iodine, zinc, copper, manganese and selenium, of importance in brain development and protection against peroxidation. Land agricultural development has, in recent time, come to dominate the human food chain. The decline in use and availability of aquatic resources is not considered important by Langdon (2006) as he considers the resource was not needed for human evolution and can be replaced from the terrestrial food chain. This notion is not supported by the biochemistry nor the molecular biology. He misses the point that the shoreline hypothesis is not just dependent on docosahexaenoic acid but also on the other accessory nutrients specifically required by the brain. Moreover he neglects the basic principle of Darwinian evolution. The well documented greater efficiency of preformed docosahexaenoic acid for brain incorporation during development would have conferred a distinct survival advantage over those without it. All terrestrial mammals lost brain capacity in relation to advancing increase in body size. The rise in mental ill health and brain disorders, to replace all other costs in the European list of burdens of ill health, (Andlin Sobocki et al., 2005) raises interesting questions as to its association with the reduced availability and consumption of marine and fresh water products. The threat posed by the continued rise in brain disorders also raises questions of importance to present and future food and agricultural policies.

Protective effects of ectoine on heat-stressed Daphnia magna

Ectoine (ECT) is an amino acid produced and accumulated by halophilic bacteria in stressful conditions in order to prevent the loss of water from the cell. There is a lack of knowledge on the effects of ECT in heat-stressed aquatic animals. The purpose of our study was to determine the influence of ECT on Daphnia magna subjected to heat stress with two temperature gradients: 1 and 0.1 °C/min in the range of 23–42 °C. Time to immobilisation, survival during recovery, swimming performance, heart rate, thoracic limb movement and the levels of heat shock protein 70 kDa 1A (HSP70 1A), catalase (CAT) and nitric oxide species (NOx) were determined in ECT-exposed and unexposed daphnids; we showed protective effects of ECT on Daphnia magna subjected to heat stress. Time to immobilisation of daphnids exposed to ECT was longer when compared to the unexposed animals. Also, survival rate during the recovery of daphnids previously treated with ECT was higher. ECT significantly attenuated a rapid increase of mean swimming velocity which was elevated in the unexposed daphnids. Moreover, we observed elevation of thoracic limb movement and modulation of heart rate in ECT-exposed animals. HSP70 1A and CAT levels were reduced in the presence of ECT. On the other hand, NOx level was slightly elevated in both ECT-treated and unexposed daphnids, however slightly higher NOx level was found in ECT-treated animals. We conclude that the exposure to ectoine has thermoprotective effects on Daphnia magna, however their mechanisms are not associated with the induction of HSP70 1A.

Prostatic and dietary omega-3 fatty acids and prostate cancer progression during active surveillance

The association between omega-3 (ω-3) fatty acids and prostate cancer has been widely studied. However, little is known about the impact of prostate tissue fatty acid content on prostate cancer progression. We hypothesized that compared with the estimated dietary ω-3 fatty acids intake and the ω-3 fatty acids levels measured in red blood cells (RBC), the prostate tissue ω-3 fatty acid content is more strongly related to prostate cancer progression. We present the initial observations from baseline data of a phase II clinical trial conducted in a cohort of 48 untreated men affected with low-risk prostate cancer, managed under active surveillance. These men underwent a first repeat biopsy session within 6 months after the initial diagnosis of low-risk prostate cancer, at which time 29% of the men had progressed from a Gleason score of 6 to a Gleason score of 7. At the first repeat biopsy session, fatty acid levels were assessed with a food-frequency questionnaire, and determined in the RBC and in the prostate tissue biopsy. We found that eicosapentaenoic acid (EPA) was associated with a reduced risk of prostate cancer progression when measured directly in the prostate tissue. Thus, this initial interim study analysis suggests that prostate tissue ω-3 fatty acids, especially EPA, may be protective against prostate cancer progression in men with low-risk prostate cancer.

Obesity-associated oxidative stress: strategies finalized to improve redox state

Obesity represents a major risk factor for a plethora of severe diseases, including diabetes, cardiovascular disease, non-alcoholic fatty liver disease, and cancer. It is often accompanied by an increased risk of mortality and, in the case of non-fatal health problems, the quality of life is impaired because of associated conditions, including sleep apnea, respiratory problems, osteoarthritis, and infertility. Recent evidence suggests that oxidative stress may be the mechanistic link between obesity and related complications. In obese patients, antioxidant defenses are lower than normal weight counterparts and their levels inversely correlate with central adiposity; obesity is also characterized by enhanced levels of reactive oxygen or nitrogen species. Inadequacy of antioxidant defenses probably relies on different factors: obese individuals may have a lower intake of antioxidant- and phytochemical-rich foods, such as fruits, vegetables, and legumes; otherwise, consumption of antioxidant nutrients is normal, but obese individuals may have an increased utilization of these molecules, likewise to that reported in diabetic patients and smokers. Also inadequate physical activity may account for a decreased antioxidant state. In this review, we describe current concepts in the meaning of obesity as a state of chronic oxidative stress and the potential interventions to improve redox balance.

Characterization of allergens isolated from the freshwater fish blunt snout bream (Megalobrama amblycephala)

Fish are an important source of dietary protein for humans throughout the world. However, they are recognized as one of the most common food allergens and pose a serious health problem in countries where fish consumption is high. Many marine fish allergens have been extensively studied, but relatively little is known about freshwater fish allergens. This study identified two main allergens from blunt snout bream (Megalobrama amblycephala), a freshwater fish widely consumed in China. Sera from 11 patients with convincing clinical history of blunt snout bream allergy were utilized in IgE immunoblot analysis to identify prominent allergens. Several blunt snout bream proteins revealed specific binding to serum IgE, with the 47 and 41 kDa proteins being the most immunodominant among them. Two-dimensional gel electrophoresis (2D SDS-PAGE) enabled resolution of the 47 and 41 kDa proteins into several protein spots with distinct isoelectric points. 2D SDS-PAGE along with IgE immunoblot analysis further confirmed the strong reactivity of these protein spots with the pooled sera from blunt snout bream-sensitive patients. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis of the peptides generated by trypsin digestion of the different spots corresponding to the 47 and 41 kDa proteins indicated that these spots were isoforms of enolase and muscle creatine kinase, respectively. The potential allergenicity of these proteins was further verified by an bioinformatics approach using the full-length and 80 amino acid sliding window FASTA searches, which revealed a significant amino acid sequence homology between blunt snout bream allergens and several known inhaled and crustacean allergens.

Purification and characterization of parvalbumins, the major allergens in red stingray (Dasyatis akajei)

Fish has received increasing attention because it induces IgE-mediated food allergy. Parvalbumin (PV) represents the major allergen of fish, and IgE cross-reactivity to PV in various teleost fish species has been shown, while little information is available about allergens in elasmobranch fish. In this study, two PV isoforms (named as PV-I and PV-II) from red stingray (Dasyatis akajei) were purified to homogeneity by a series of procedures including ammonium sulfate precipitation and column chromatographies of DEAE-Sepharose and Sephacryl S-200. Purified PVs revealed a single band on tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular masses of PV-I and PV-II were 12.29 and 11.95 kDa, respectively, as determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Western blot using antifrog PV monoclonal antibody (PARV-19) showed positive reactions to the two proteins, confirming that they were PVs, although their immunological reactivities were weaker than those of PV from silver carp. The N-terminal amino acid sequence of PV-I was determined, and comparison with PVs from other fish species showed low homology between teleost and elasmobranch fish. The isoelectric points of PV-I and PV-II were 5.4 and 5.0, respectively, as determined by two-dimensional electrophoresis (2-DE), suggesting that both isoforms belong to the α-group. IgE immunoblotting analysis showed that sera from fish-allergic patients reacted to both PV-I and PV-II from red stingray. Thermal stability revealed that PV-I easily formed oligomers than PV-II, which might contribute to the maintenance of its allerginicity during heat processing.

Increased selenium intake in elderly high fish consumers may account for health benefits previously ascribed to omega-3 fatty acids

OBJECTIVE

To examine relationships between fish consumption and plasma selenium (Se) and red blood-cell fatty acid (RBC FA) profile in aged subjects. We hypothesised that the importance of Se has been underestimated when interpreting the beneficial effect of fish consumption on health.

DESIGN

Cross-sectional analysis of data from a prospective cohort study.

SETTING

The EVA study in Nantes, France (1991-2002).

SUBJECTS

200 subjects aged > or = 69 y with information on RBC FAs, plasma Se and completed food frequency questionnaires.

METHODS

We examined correlations between the most abundant FAs, Se and number of fish meals per week. Linear regression models were used.

RESULTS

Plasma Se was negatively correlated with RBC omega6 poly-unsaturated FA (PUFAs) and positively with omega3 PUFAs. Plasma Se, RBC omega3 PUFAs, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) increased with fish consumption. Conversely, levels of omega6 PUFAs were lower in the highest fish consumption group. All associations between plasma Se and fish consumption remained significant when adjusting for omega6 PUFAs alone or additionally for age, sex, education, diabetes, hypertension, dyslipidemia, cardiovascular diseases, and broad food categories (meat, eggs, dairy products, cereals, fruit and vegetable). Associations between omega3 PUFAs and fish also remained significant in the same model independently of Se. In linear regression models adjusted for demographic indicators, fish consumption explained only 2.6% of the variance in RBC omega3 FAs (6.2% for omega6) but as much as 15% of the variance in plasma selenium.

CONCLUSIONS

The observed health benefits of fish consumption in the elderly could be related not only to the increase in omega3 FA intake but also to other nutrients such as selenium. It is important to consider this observation when interpreting associations between fish consumption and health status in the elderly, particularly with regard to brain function.

Zooplankton chitobiase activity as an endpoint of pharmaceutical effect

Numerous human and veterinary pharmaceuticals are constantly entering surface waters, despite little understanding of their potential impacts on aquatic ecosystems. To address this concern, an attempt to create a simple, reproducible, inexpensive, and sublethal toxicity bioassay for freshwater zooplankton was initiated. The approach was centered on characterizing the response of a zooplankton enzyme, chitobiase, to the presence of a toxicant. The aim of the present research was to develop a reproducible laboratory-based assay for Daphnia magna chitobiase activity and to screen four commonly prescribed pharmaceuticals using that assay. The four pharmaceuticals tested for potential effects on D. magna chitobiase activity were atorvastatin, lovastatin, fluoxetine, and sertraline. We were able to detect exposure-associated differences in chitobiase activity at concentrations of 0.1 mug/L fluoxetine after 24 and 72 hours of exposure. Differences were also detected for the other compounds. The response of chitobiase was found to be promising as an assay to measure sublethal effects in D. magna and perhaps other zooplankton species.

Do aggregates of multiple questions better capture overall fish consumption than summary questions?

Objective

To compare intake estimates, validity and reliability of two summary questions to measure fish consumption with information from a detailed semi-quantitative food-frequency questionnaire (FFQ) on fish consumption.

Design

Population-based, cross-sectional study. Participants completed an FFQ and provided blood samples for erythrocyte membrane eicosapentaenoic acid (EPA) analysis. Aggregate measures of consumption of fresh/frozen/canned fish (fresh fish) and smoked/salted/dried fish (preserved fish) were generated from the FFQ and were compared with responses to the summary questions regarding intakes of similar items. Both methods were tested for validity, using correlation and linear regression techniques with EPA, and retest reliability.

Setting

Perth metropolitan area, Western Australia.

Subjects

One hundred and nine healthy volunteers of both sexes, aged 21–75 years.

Results

The summary fresh fish measure underestimated frequency and grams per week given by the aggregate question by about 50%, while estimates from the summary preserved fish measure were approximately three times that of the aggregate measure. Multiple linear regression analysis suggested that the aggregates accounted for more of the variation in EPA levels, but the difference was minimal. Intra-class correlations confirmed that both methods were reliable.

Conclusions

Our study indicates that extensive questioning results in different absolute intakes of fish compared with brief questioning, but does not add any information if ranking individuals according to overall consumption of fish.

Tissue n-3 and n-6 fatty acids and risk for coronary heart disease events

BACKGROUND

Tissue proportions of long chain n-6 [especially arachidonic acid (AA)] and n-3 fatty acids [FA; eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) acids], or some ratio of these may be markers of risk for coronary heart disease (CHD). The purpose of this paper is to evaluate the published associations between risk for CHD events and tissue n-3 and n-6 FA composition.

METHODS

Case-control or prospective cohort data sets examining the risk for CHD endpoints as a function of tissue FA composition were identified. Effect sizes were computed for case versus control comparisons using standard meta-analytic methods.

RESULTS

Twenty-five studies were included, 18 examining the FA composition of phospholipid-rich and 7 of triglyceride-rich samples. DHA, with or without EPA, was significantly lower in cases than controls in all studies combined, in those with fatal endpoints, in those with prospective designs, and in both tissue types. The only setting where increased AA was associated with case status was in adipose tissue. The AA/EPA ratio in phospholipid-rich samples did not distinguish cases from controls. Lower linoleic acid content was associated with increased risk for non-fatal events.

CONCLUSIONS

The long-chain n-3 FA, especially DHA, were consistently and significantly reduced in patients experiencing CHD events. These findings add further support to the view that long-chain n-3 FA are cardioprotective.

A valid semiquantitative food frequency questionnaire to measure fish consumption

OBJECTIVE

To validate a detailed semiquantitative food frequency questionnaire designed to measure habitual fish and seafood consumption.

DESIGN

Cross-sectional validation study using an independent biomarker of fish consumption.

SETTING

Perth metropolitan area, Western Australia.

SUBJECTS

Ninety-one healthy volunteers of both sexes aged 21-75 years.

METHODS

Participants completed the questionnaire and provided a fasting blood sample for erythrocyte membrane omega-3 fatty acid (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) analysis. The questionnaire was then validated by linear regression analysis of EPA and DHA levels on categories of fish and seafood and overall consumption, adjusted for age, sex, smoking status, body mass index (BMI) and alcohol intake.

RESULTS

Regression coefficients were statistically significant for most fish and seafood items with both EPA and DHA. The strongest association was observed between oily fish and EPA, whereas no significant association was observed between lean fish and omega-3 fatty acids. Variation in omega-3 fatty acids was best accounted for by a model containing variables representing different categories of fish and seafood consumption (R (2) 0.484), rather than a single variable representing overall fish and seafood consumption (R (2) 0.313).

CONCLUSIONS

This study confirms that the varying content of omega-3 fatty acids in foods are reflected in omega-3 biomarkers, and that the questionnaire is a valid measure of fish consumption that enables differentiation between cooking and processing methods and oily versus lean fish intake.

Is B vitamins deficiency associated with prevalence of Alzheimer's disease in Cuban elderly?

Alzheimer's disease (AD), is a major public health problem among the elderly in industrialized countries and a growing problem in developing countries. In Cuba, 14,6% of the population is older than 60 years. The AD prevalence in Cuba lies between 5,13-7,14%. Several studies have shown the relationship between the low nutritional status of B vitamins, hyperhomocysteinaemia with loss of neuro-cognitive function and AD. In studies during the epidemic neuropathy that affected Cuba between 1992-1993, B vitamins deficiency and smoking habits were strongly associated with the epidemic. Some studies in healthy adults and elderly after this epidemic have shown a sub-clinical deficiency of some B vitamins and a high prevalence of infection by Helicobacter pylori. The possibility that B vitamin deficiencies could be an additional risk factor for the high prevalence of the AD in Cuba is discussed.

Physiological and reproductive effects of beta adrenergic receptor antagonists in Daphnia magna

Although pharmaceuticals are increasingly found in surface waters, environmental levels of many of these compounds are not acutely toxic to model test organisms. Prior to conducting appropriate ecological risk assessments of pharmaceuticals, the mode of action-based biomarkers needs to be developed for non-target species. To evaluate toxicity of the beta-adrenergic blockers propranolol and metoprolol on non-target biota, we assessed standard ecotoxicological endpoints after 9 days of subchronic exposure in a transgenerational study with Daphnia magna. On day 9 of exposure, the lowest observed effects concentration (LOEC) for growth were 0.44 mg L(-1) for propranolol and 12 mg L(-1) for metoprolol. Total fecundity LOECs for the 9-day exposure were 0.11 mg L(-1) and 6 mg L(-1) for propranolol and metoprolol, respectively. In addition to typical ecotoxicological endpoints, we evaluated the utility of employing the physiological biomarkers of heart rate and metabolic rate following subchronic and acute exposures to propranolol and metoprolol. Propranolol and metoprolol LOECs for heart rate were 0.055 mg L(-1) and 3.1 mg L(-1), significantly lower than the LOECs for growth and reproduction. At these concentrations, heart rate was significantly lower than the control values for both compounds. Daphnia magna endpoint sensitivity to chronic propranolol and metoprolol exposure was mortality < growth < fecundity < heart rate. Second generation D. magna were less sensitive to both compounds. Responses of the physiological biomarkers heart rate and metabolic activity suggest that propranolol and metoprolol exerts sublethal toxicity to D. magna at lower concentrations than observed in the classical endpoints.

Effect of frozen period on the chemical, microbiological and sensory quality of frozen Tilapia fish (Sarotherodun galiaenus)

The study was designed to investigate the effect of duration of frozen storage on the chemical, microbiological and sensory profile of Tilapia fish (Sarotherodun galiaenus) collected from a research pond of the Agricultural Development Project, Akure, Nigeria, subjected to sixty days of frozen storage and analyzed at intervals of ten days. Protein content (%) ranges from 43.70 +/- 1.17-60.65 +/- 2.40. Protein decreases with increasing duration of frozen storage with the fresh samples (not frozen) having the highest protein content (60.65 +/- 2.40) while the least (43.70 +/- 1.17) was recorded for fish samples that were frozen for sixty days. Similar results were obtained for the fat content (%) where the highest fat content (9.72 +/- 0.25) was recorded for the fresh samples and the least value was recorded for those stored for sixty days. Ash content (%) and moisture content (%) do not show any significant change during storage. Mineral composition (Fe, Ca, Mg, P and Zn in mg/100g) and iodine content (microg/100g) of the samples showed a slight change with respect to duration of storage. pH values ranges between 5.20-6.90 while the total coliform count range was between 3.0 x 10(3)-7.5 x 10(6) with increasing values, as the duration of storage increases. Sensory evaluation of the fish samples on storage revealed that quality of the fish samples with respect to taste decreases with increasing duration of storage with the best quality (texture, odor and color) when freshly prepared; and that better quality during storage is obtainable during the first ten days of storage. These, by implication simply mean that fish should be stored for a short period of time to retain the taste, and provide both the protein and fat at optimal level.

Suicide attempt and n-3 fatty acid levels in red blood cells: a case control study in China

BACKGROUND

Epidemiologic studies show that low fish intake is a risk factor of suicidality; however, there are no case-control studies investigating suicide attempt risk and tissue n-3 fatty acid levels.

METHODS

We recruited 100 suicide-attempt cases and another 100 control patients injured by accidents who were admitted to three hospitals affiliated with Dalian Medical University in Dalian, China. Case and control subjects were matched for age, gender, and smoking status. Those who were inebriated at the time of hospitalization were excluded. Blood was sampled immediately after admission to a hospital. Washed red blood cells (RBCs) were obtained, and the fatty acid composition of the total RBC phospholipid fraction was analyzed by gas chromatography.

RESULTS

Eicosapentaenoic acid (EPA) levels in RBC in the case subjects were significantly lower than those of the control subjects (.74 +/-.52% vs. 1.06 +/-.62%, p <.0001). When the highest and lowest quartiles of EPA in RBC were compared, the odds ratios of suicide attempt was.12 in the highest quartile (95% confidence interval:.04-.36, p for trend =.0001) after adjustment for possible confounding factors

CONCLUSIONS

Our findings suggest that low n-3 fatty acid levels in tissues were a risk factor of suicide attempt. Further studies including intervention with fish oil are warranted.