Fish consumption and omega-3 polyunsaturated fatty acids from diet are positively associated with cognitive function in older adults even in the presence of exposure to lead, cadmium, selenium, and methylmercury: a cross-sectional study using NHANES 2011-2014 data.

BACKGROUND: Long-chain omega-3 polyunsaturated fatty acids (ω-3 PUFAs) are reported to be beneficial for cognition, but limited consumption of some fish is recommended due to high concentrations of heavy metals and persistent organics. OBJECTIVE: We aimed to determine whether dietary ω-3 PUFAs from fish consumption are associated with higher cognitive scores in older adults and explored the associations of mixtures of ω-3 PUFAs and blood concentrations of lead, cadmium, selenium, and methylmercury on cognitive performance. METHODS: We conducted a cross-sectional study with data from the NHANES 2011-2014, assessing cognitive scores of immediate recall, delayed recall, and executive function in adults ≥60 y (n = 3123). We performed multivariate linear regressions and mixture models utilizing the quantile-based g-computation method to identify associations between monthly fish consumption or dietary ω-3 PUFAs with blood concentrations of lead, cadmium, methyl mercury, and selenium on cognitive scores. RESULTS: Fish consumption had significant positive associations with all 3 cognitive scores, whereas dietary ω-3 PUFAs were only significantly associated with the Digit Symbol Substitution Test (DSST) scores. Mixture analysis showed significant positive associations with DSST scores for fish consumption (ß: 0.88; 95% CI: 0.48, 1.29) and dietary ω-3 PUFAs (ß: 0.41; 95% CI: 0.03, 0.78) with positive component weights for fish consumption, dietary ω-3 PUFAs, and blood selenium and negative component weight for blood cadmium concentrations. CONCLUSIONS: Our findings support dietary recommendations for older adults to consume fish to maintain cognitive function, likely due to biomolecular actions of ω-3 PUFAs that increase neuronal membrane fluidity, have antioxidation activity, and restore cell damage. The combination of selenium and fish consumption or ω-3 PUFAs was associated with reduced decline in cognitive scores and less negative associations from exposures to lead, cadmium, and mercury compounds.

Risk-benefit of consuming Lake Erie fish.

BACKGROUND: Consumption of fish is promoted as a healthy way to obtain essential fatty acids (EFA) in the diet, yet the risk of ingesting harmful contaminants remains a concern. A recent study concluded that the risk-benefit of consuming fish from the North American Laurentian Great Lakes, which sustain important commercial and recreational fisheries, is currently unclear. We report the fatty acid (FA) content in skin-off fillets of fifteen fish species from Lake Erie and assess whether recommended dietary requirements for two EFA (EPA and DHA) can be met by safely consuming Lake Erie fishes, as an example of a risk-benefit analysis. METHODS: A total of 146 samples were analyzed for FA and contaminant content. A simulated fish consumption advisory (maximum recommended number of meals per month, up to 32) was calculated for each sample, and used to calculate the maximum amount of EPA+DHA that would be consumed if the consumption advisory was followed. RESULTS: All fifteen species had nutritionally desirable PUFA:SAFA (>0.4) and n-3:n-6 (>1). Large, fatty species had the highest EPA+DHA content, but had the most restrictive consumption advisories due to high PCB concentrations. To minimize contaminant exposure while maximizing EPA+DHA intake, consumers should consider small lake whitefish and lake trout, small panfish species, and/or walleye. However, very few species had an EPA+DHA content sufficient to safely meet the highest dietary guidelines while following advisories. CONCLUSIONS: Consumption of certain Lake Erie fish, an important recreational and commercial fishery, within the limits of our simulated fish consumption advisories, can be a good supplemental source of beneficial n-3 long chain PUFA.

Organochlorine and metal contaminants in traditional foods from St. Lawrence Island, Alaska.

Marine mammals (bowhead whale, walrus, and various seals) constitute the major component of the diet of the Yupik people of St. Lawrence Island, Alaska. St. Lawrence Island residents have higher serum concentrations of polychlorinated biphenyls (PCB) than in the general U.S. population. In order to determine potential sources, traditional food samples were collected from 2004 to 2009 and analyzed for PCBs, three chlorinated pesticides, and seven heavy metals (mercury, copper, zinc, arsenic, selenium, cadmium, and lead). Concentrations of PCB in rendered oils (193-421 ppb) and blubber (73-317 ppb) from all marine mammal samples were at levels that trigger advisories for severely restricted consumption, using U.S. Environmental Protection Agency (EPA) fish consumption advisories. Concentrations of pesticides were lower, but were still elevated. The highest PCB concentrations were found in polar bear (445 ppb) and the lowest in reindeer adipose tissue (2 ppb). Marine mammal and polar bear meat in general have PCB concentrations that were 1-5% of those in rendered oils or adipose tissue. PCB concentrations in organs were higher than meat. Concentrations of metals in oils and meats from all species were relatively low, but increased levels of mercury, cadmium, copper, and zinc were present in some liver and kidney samples. Mercury and arsenic were found in lipid-rich samples, indicating organometals. These results show that the source of the elevated concentrations of these contaminants in the Yupik population is primarily from consumption of marine mammal blubber and rendered oils.

Depleted uranium contamination by inhalation exposure and its detection after approximately 20 years: implications for human health assessment.

Inhaled depleted uranium (DU) aerosols are recognised as a distinct human health hazard and DU has been suggested to be responsible in part for illness in both military and civilian populations that may have been exposed. This study aimed to develop and use a testing procedure capable of detecting an individual's historic milligram-quantity aerosol exposure to DU up to 20 years after the event. This method was applied to individuals associated with or living proximal to a DU munitions plant in Colonie New York that were likely to have had a significant DU aerosol inhalation exposure, in order to improve DU-exposure screening reliability and gain insight into the residence time of DU in humans. We show using sensitive mass spectrometric techniques that when exposure to aerosol has been unambiguous and in sufficient quantity, urinary excretion of DU can be detected more than 20 years after primary DU inhalation contamination ceased, even when DU constitutes only approximately 1% of the total excreted uranium. It seems reasonable to conclude that a chronically DU-exposed population exists within the contamination 'footprint' of the munitions plant in Colonie, New York. The method allows even a modest DU exposure to be identified where other less sensitive methods would have failed entirely. This should allow better assessment of historical exposure incidence than currently exists.

Effects of polycyclic aromatic hydrocarbon-containing oil mixtures on generation of reactive oxygen species and cell viability in MCF-7 breast cancer cells.

Clarified slurry oil (CSO), and two crude oil samples, Belridge heavy crude oil (BHCO) and Lost Hills light crude oil (LHLCO), were examined for their ability to generate reactive oxygen species (ROS) in MCF-7 cells. Intracellular ROS and cell viability were determined in a flow cytometer using dihydroxyrhodamine 123 and propidium iodide, respectively. In experiments with short-term exposure, single-cell suspensions were loaded with the fluorescent probes and then treated with the oil samples (1 or 10 ppm). Measurements were made at 5, 15, 30, 60, and 90 min after addition of oil samples. In experiments with longer term exposure, preconfluent cell cultures were treated with oil samples for 6, 12, or 24 h prior to preparing single-cell suspensions. Both short-term and longer term treatment with oil samples resulted in elevated generation of reactive oxygen species (ROS). Cell cultures also were treated with benzo[a]pyrene, a polycyclic aromatic hydrocarbon detected in all three oil samples. Treatment with benzo[a]pyrene produced a significant increase in levels of ROS. The present findings suggest that oil samples with higher concentrations of polycyclic aromatic hydrocarbons may exert adverse effects on human mammary epithelial tissue through induction of oxidative stress.