The association between razor clam consumption and memory in the CoASTAL Cohort.

This study represents a preliminary effort to examine the possible impacts of chronic, low level Domoic Acid (DA) exposure on memory in the CoASTAL cohort. Five hundred thirteen men and women representing three Native American Tribes were studied with standard measures of cognition and razor clam consumption (a known vector of DA exposure) over a four year period. In addition, a pilot metric of DA concentration exposure was used which took into consideration average DA concentration levels in source beaches as well as consumption. Based upon GEE analysis, controlling for age, sex, race, year, education level, tribe, and employment status, findings indicated that high razor clam consumers (15 or more per month) had isolated decrements on some measures of memory (p=.02 to .03), with other cognitive functions unaffected. The relatively lower memory scores were still within normal limits, thus not clinically significant. The pilot DA exposure metric had no association with any aspect of cognition or behavior. There is a possible association between long term, low level exposure to DA through heavy razor clam consumption and memory. The availability of a reliable biological marker for human exposure to DA is needed.

Communities advancing the studies of Tribal nations across their lifespan: Design, methods, and baseline of the CoASTAL cohort.

The CoASTAL cohort represents the first community cohort assembled to study a HAB related illness. It is comprised of three Native American tribes in the Pacific NW for the purpose of studying the health impacts of chronic, low level domoic acid (DA) exposure through razor clam consumption. This cohort is at risk of domoic acid (DA) toxicity by virtue of their geographic location (access to beaches with a history of elevated DA levels in razor clams) and the cultural and traditional significance of razor clams in their diet. In this prospective, longitudinal study, Wave 1 of the cohort is comprised of 678 members across the lifespan with both sexes represented within child, adult and geriatric age groups. All participants are followed annually with standard measures of medical and social history; neuropsychological functions, psychological status, and dietary exposure. DA concentration levels are measured at both public and reservation beaches where razor clams are sourced and multiple metrics have been piloted to further determine exposure. Baseline data indicates that all cognitive and psychological functions are within normal limits. In addition there is considerable variability in razor clam exposure. Therefore, the CoASTAL cohort offers a unique opportunity to investigate the potential health effects of chronic, low level exposure to DA over time.

Assessment of sodium channel mutations in Makah Tribal members of the U.S. Pacific Northwest as a potential mechanism of resistance to paralytic shellfish poisoning.

The Makah Tribe of Neah Bay, Washington, has historically relied on the subsistence harvest of coastal seafood, including shellfish, which remains an important cultural and ceremonial resource. Tribal legend describes visitors from other tribes that died from eating shellfish collected on Makah lands. These deaths were believed to be caused by paralytic shellfish poisoning, a human illness caused by ingestion of shellfish contaminated with saxitoxins, which are produced by toxin-producing marine dinoflagellates on which the shellfish feed. These paralytic shellfish toxins include saxitoxin, a potent Na+ channel antagonist that binds to the pore region of voltage gated Na+ channels. Amino acid mutations in the Na+ channel pore have been demonstrated to confer resistance to saxitoxin in softshell clam populations exposed to paralytic shellfish toxins present in their environment. Because of the notion of resistance to paralytic shellfish toxins, we aimed to determine if a resistance strategy was possible in humans with historical exposure to toxins in shellfish. We collected, extracted and purified DNA from buccal swabs of 83 volunteer Makah tribal members and sequenced the skeletal muscle Na+ channel (Nav1.4) at nine loci to characterize potential mutations in the relevant saxitoxin binding regions. No mutations of these specific regions were identified after comparison to a reference sequence. This study suggests that any resistance of Makah Tribal members to saxitoxin is not a function of Nav1.4 modification but may be due to mutations in neuronal or cardiac sodium channels or some other mechanism unrelated to sodium channel function.

Perception of risk for Domoic Acid related health problems: A Cross-cultural study.

Risk perception is a complex process that refers to the way people approach, think about and interpret risks in their environment. An important element of risk perception is that it is culturally situated. Since HAB's can present a health risk in many places around the world, looking at cultural parameters for understanding and interpreting risks are important. This study examined how two different groups of people perceive the potential health risks of low level exposure to domoic acid (DA) through razor clam consumption. The risk perceptions of Washington State, USA coastal dwelling Native American nations (NA) were compared to that of a community sample of recreational razor clam harvesters (CRH). Overall, the findings support the hypothesis that cultural and community specific contexts impact the perception of risk of a DA related illness. Specifically, the NA sample was distinguished by worrying more about ocean pollution, attributing DA risks to climate change, expressing concerns about the potential impact of DA on future generations, and feeling better informed than the CRH group. The CRH group were more likely to attribute the DA problem to anthropogenic or industrial causes; and view the risk of health problems as lower than that associated with smoking, high cholesterol, anxiety or depression, alcoholism, high blood pressure or obesity. The CRH group was also more likely to turn to the media for DA related information. Both groups trust the decisions of state and tribe health and natural resources officials and demonstrated a complex pattern of findings that involved gender. It was recommended that risk communication and outreach activities are designed to take into consideration factors that specifically apply to each cultural community.

Dietary Assessment of domoic acid Exposure: What can be learned from traditional methods and new applications for a technology assisted device.

Three Tribal Nations in the Pacific Northwest United States comprise the members of the CoASTAL cohort. These populations may be at risk for neurobehavioral impairment, i.e., amnesic shellfish poisoning, from shellfish consumption as a result of repeated, low-level domoic acid (DA) exposure present in local clams. Previous work with this cohort confirmed a high proportion of clam consumers with varying levels of potential exposure over time. Since clams are an episodically consumed food, traditional dietary records do not fully capture exposure. Frequency questionnaires can capture accumulated doses over time and this data can be used to examine dose-response relationships with periodic studies of memory and learning. However, frequency questionnaires cannot be used to assess consumption and memory response in real time. To address this shortcoming, a modified technology assisted dietary assessment (TADA) iPod application was developed to capture images of the clam meal, sourcing data, and associated memory functioning within 24 hours and seven days after consumption. This methodology was piloted with razor clam meals consumed by members from the CoASTAL cohort. Preliminary findings suggest that the TADA iPod application is potentially useful in collecting real-time data with respect to razor clam consumption, as well as one day and seven day memory outcome data. This technology holds promise for addressing the challenges of other HAB related dietary exposure outcome studies.

Gene Expression Patterns in Peripheral Blood Leukocytes in Patients with Recurrent Ciguatera Fish Poisoning: Preliminary Studies.

Ciguatera fish poisoning (ciguatera) is a common clinical syndrome in areas where there is dependence on tropical reef fish for food. A subset of patients develops recurrent and, in some instances, chronic symptoms, which may result in substantial disability. To identify possible biomarkers for recurrent/chronic disease, and to explore correlations with immune gene expression, peripheral blood leukocyte gene expression in 10 ciguatera patients (7 recurrent, 3 acute) from the U.S. Virgin Islands, and 5 unexposed Florida controls were evaluated. Significant differences in gene expression were noted when comparing ciguatera patients and controls; however, it was not possible to differentiate between patients with acute and recurrent disease, possibly due to the small sample sizes involved.

The association between razor clam consumption and memory in the CoASTAL cohort.

This study represents a preliminary effort to examine the potential impacts of chronic, low level domoic acid (DA) exposure on memory in the CoASTAL cohort over the first four years of data collection (Wave 1). Five hundred and thirteen adult men and women representing three Native American Tribes were studied annually with standard measures of cognition and razor clam consumption (a known vector of DA exposure) over a four-year period. In addition, a pilot metric of DA concentration exposure was used which took into consideration average DA concentration levels in source beaches, as well as the amount consumed. Based upon generalized estimating equations (GEE) analysis, controlling for age, sex, race, year, education level, tribe, and employment status, findings indicated that high razor clam consumers (15 or more per month) had isolated decrements on some measures of memory (p=0.02-0.03), with other cognitive functions unaffected. The relatively lower memory scores were still within normal limits, and were thus not clinically significant. The pilot DA exposure metric had no association with any other aspect of cognition or behavior. There is a possible association between long-term, low-level exposure to DA through heavy razor clam consumption and memory functioning.

Gene expression patterns in peripheral blood leukocytes in patients with recurrent ciguatera fish poisoning: Preliminary studies.

Ciguatera fish poisoning (ciguatera) is a common clinical syndrome in areas where there is dependence on tropical reef fish for food. A subset of patients develops recurrent and, in some instances, chronic symptoms, which may result in substantial disability. To identify possible biomarkers for recurrent/chronic disease, and to explore correlations with immune gene expression, peripheral blood leukocyte gene expression in 10 ciguatera patients (7 recurrent and 3 acute) from the U.S. Virgin Islands, and 5 unexposed Florida controls were evaluated. Significant differences in gene expression were noted when comparing ciguatera patients and controls; however, it was not possible to differentiate between patients with acute and recurrent disease, possibly due to the small sample sizes involved.

Assessment of sodium channel mutations in Makah tribal members of the U.S. Pacific Northwest as a potential mechanism of resistance to paralytic shellfish poisoning.

The Makah Tribe of Neah Bay, Washington, has historically relied on the subsistence harvest of coastal seafood, including shellfish, which remains an important cultural and ceremonial resource. Tribal legend describes visitors from other tribes that died from eating shellfish collected on Makah lands. These deaths were believed to be caused by paralytic shellfish poisoning, a human illness caused by ingestion of shellfish contaminated with saxitoxins, which are produced by toxin-producing marine dinoflagellates on which the shellfish feed. These paralytic shellfish toxins include saxitoxin, a potent Na+ channel antagonist that binds to the pore region of voltage gated Na+ channels. Amino acid mutations in the Na+ channel pore have been demonstrated to confer resistance to saxitoxin in softshell clam populations exposed to paralytic shellfish toxins present in their environment. Because of the notion of resistance to paralytic shellfish toxins, the study aimed to determine if a resistance strategy was possible in humans with historical exposure to toxins in shellfish. We collected, extracted and purified DNA from buccal swabs of 83 volunteer Makah tribal members and sequenced the skeletal muscle Na+ channel (Nav1.4) at nine loci to characterize potential mutations in the relevant saxitoxin binding regions. No mutations of these specific regions were identified after comparison to a reference sequence. This study suggests that any resistance of Makah tribal members to saxitoxin, if present, is not a function of Nav1.4 modification, but may be due to mutations in neuronal or cardiac sodium channels, or some other mechanism unrelated to sodium channel function.

Perception of risk for domoic acid related health problems: A cross-cultural study.

Risk perception is a complex process that refers to the way people approach, think about, and interpret risks in their environment. An important element of risk perception is that it is culturally situated. Since HABs can present a health risk in many places around the world, looking at cultural parameters for understanding and interpreting risks is important. This study examined how two different groups of people perceive the potential health risks of low-level exposure to domoic acid (DA) through razor clam consumption. The risk perceptions of Washington State, USA coastal dwelling Native American nations (NA) were compared to that of a community sample of recreational razor clam harvesters (CRH). Overall, the findings support the hypothesis that cultural and community specific contexts impact the perception of risk of a DA related illness. Specifically, the NA sample was distinguished from the CRH group in particular, by their worries about ocean pollution, attribution of DA risks to climate change, concerns about the potential impact of DA on future generations, and feeling of being better informed than the CRH group. The CRH group was more likely to attribute the DA problem to anthropogenic or industrial causes and view the risk of health problems from DA as lower than those associated with smoking, high cholesterol, anxiety or depression, alcoholism, high blood pressure or obesity. The CRH group was also more likely to turn to the media for DA-related information. Both groups trusted the decisions of state and tribe health and natural resources officials, and demonstrated a complex pattern of findings that involved gender. In summary, risk communication and outreach activities should be designed to take into consideration the specific factors that are unique to each cultural community.

Dietary assessment of domoic acid exposure: What can be learned from traditional methods and new applications for a technology assisted device.

Three Tribal Nations in the Pacific Northwest United States comprise the members of the CoASTAL cohort. These populations may be at risk for neurobehavioral impairment, i.e., amnesic shellfish poisoning, from shellfish consumption resulting in repeated, low-level domoic acid (DA) exposure. Previous work with this cohort confirmed a high proportion of clam consumers with varying levels of potential exposure over time. Since clams are an episodically consumed food, traditional dietary records do not fully capture exposure. Frequency questionnaires can capture accumulated doses over time and this data can be used to examine dose-response relationships with periodic studies of memory and learning. However, frequency questionnaires cannot be used to assess consumption and memory response in real time. To address this shortcoming, a modified technology assisted dietary assessment (TADA) iPod application was developed to capture images of the clam meal, sourcing data, and associated memory functioning within 24h and seven days after consumption. This methodology was piloted with razor clam meals consumed by members from the CoASTAL cohort. Preliminary findings suggest that the TADA iPod application is potentially useful in collecting real-time data with respect to razor clam consumption, as well as one day and seven day memory outcome data. This technology holds promise for addressing the challenges of other HAB related dietary exposure outcome studies.

Communities advancing the studies of Tribal nations across their lifespan: Design, methods, and baseline of the CoASTAL cohort.

The CoASTAL cohort represents the first community cohort assembled to study a HAB-related illness. It is comprised of three Native American tribes in the Pacific NW for the purpose of studying the health impacts of chronic, low level domoic acid (DA) exposure through razor clam consumption. This cohort is at risk of DA toxicity by virtue of their geographic location (access to beaches with a history of elevated DA levels in razor clams) and the cultural and traditional significance of razor clams in their diet. In this prospective, longitudinal study, Wave 1 of the cohort was comprised of 678 members across the human lifespan, with both sexes represented within child, adult, and geriatric age groups. All participants were followed annually with standard measures of medical and social history; neuropsychological functions, psychological status, and dietary exposure. DA concentrations were measured at both public and reservation beaches where razor clams are acquired. Multiple metrics were piloted to further determine exposure. Baseline data indicated that all cognitive and psychological functions were within normal limits. In addition, there was considerable variability in razor clam exposure. Therefore, the CoASTAL cohort offers a unique opportunity to investigate the potential health effects of chronic, low level exposure to DA over time.

Dietary patterns are associated with dietary recommendations but have limited relationship to BMI in the Communities Advancing the Studies of Tribal Nations Across the Lifespan (CoASTAL) cohort.

OBJECTIVE: Traditional food systems in indigenous groups have historically had health-promoting benefits. The objectives of the present study were to determine if a traditional dietary pattern of Pacific Northwest Tribal Nations (PNwT) could be derived using reduced rank regression and if the pattern would be associated with lower BMI and current Dietary Reference Intakes. DESIGN: The baseline data from the Communities Advancing the Studies of Tribal Nations Across the Lifespan (CoASTAL) cohort were used to derive dietary patterns for the total sample and those with plausibly reported energy intakes. SETTING: Pacific Northwest Coast of Washington State, USA. SUBJECTS: Adult PNwT members of the CoASTAL cohort with laboratory-measured weight and height and up to 4 d of dietary records (n 418). RESULTS: A traditional dietary pattern did not evolve from the analysis. Moderate consumption of a sweet drinks dietary pattern was associated with lower BMI while higher consumption of a vegetarian-based dietary pattern was associated with higher BMI. The highest consumers of the vegetarian-based dietary pattern were almost six times more likely to meet the recommendations for dietary fibre. CONCLUSIONS: Distinct dietary patterns were found. Further exploration is needed to confirm whether the lack of finding a traditional pattern is due to methodology or the loss of a traditional dietary pattern among this population. Longitudinal assessment of the CoASTAL cohort's dietary patterns needs to continue.

The early psychological impacts of the Deepwater Horizon oil spill on Florida and Alabama communities.

BACKGROUND: Although public concern has focused on the environmental impact of the Deepwater Horizon oil spill, the public health impact on a broad range of coastal communities is minimally known. OBJECTIVE: We sought to determine the acute level of distress (depression, anxiety), mechanisms of adjustment (coping, resilience), and perceived risk in a community indirectly impacted by the oil spill and to identify the extent to which economic loss may explain these factors. METHODS: Using a community-based participatory model, we performed standardized assessments of psychological distress (mood, anxiety), coping, resilience, neurocognition, and perceived risk on residents of fishing communities who were indirectly impacted (n = 71, Franklin County, Florida) or directly exposed (n = 23, Baldwin County, Alabama) to coastal oil. We also compared findings for participants who reported income stability (n = 47) versus spill-related income loss (n = 47). RESULTS: We found no significant differences between community groups in terms of psychological distress, adjustment, neurocognition, or environmental worry. Residents of both communities displayed clinically significant depression and anxiety. Relative to those with stable incomes, participants with spill-related income loss had significantly worse scores on tension/anxiety, depression, fatigue, confusion, and total mood disturbance scales; had higher rates of depression; were less resilient; and were more likely to use behavioral disengagement as a coping strategy. CONCLUSIONS: Current estimates of human health impacts associated with the oil spill may underestimate the psychological impact in Gulf Coast communities that did not experience direct exposure to oil. Income loss after the spill may have a greater psychological health impact than the presence of oil on the immediately adjacent shoreline.

Estimated nutrient intakes from food generally do not meet dietary reference intakes among adult members of Pacific Northwest tribal nations.

Diet is influential in the etiology of chronic diseases in many populations including Native Americans. The objective of this report is to present the first comprehensive dietary survey, to our knowledge, of a representative sample of nonpregnant adults from Pacific Northwest tribal nations participating in the Communities Advancing the Studies of Tribal Nations Across the Lifespan (CoASTAL) cohort. Only participants who completed 1-4 d of dietary records and had weights and heights measured in the laboratory were eligible for this analysis (n = 418). Mean nutrient intakes were stratified by gender for the total sample, those with plausibly reported energy intakes (rEI), and those with implausibly rEI. Estimates of nutrient intakes were compared with Dietary Reference Intakes (DRI). Nutrient estimates from NHANES 2001-2002 were used as a reference. Among both men and women, total fat contributed 34-37% of energy intake and saturated fat contributed 11-12% of energy intake. Daily cholesterol intakes ranged from 262 to 442 mg. A majority of men and women were not meeting recommendations for vitamins A, C, and E, magnesium, and sodium. For a majority of the nutrients examined, plausibility resulted in higher mean estimates. The CoASTAL cohort nutrient profile is similar to NHANES 2001-2002, with a majority of DRI recommendations not being met. Adequate dietary intake information may be more important for this population, because Native Americans experience a disproportionate burden for diseases.

Evaluation of dietary assessment tools used to assess the diet of adults participating in the Communities Advancing the Studies of Tribal Nations Across the Lifespan cohort.

BACKGROUND: Accurate assessment of dietary intake is essential for researchers and public health practitioners to make advancements in public health. This is especially important in Native Americans who display disease prevalence rates that are dramatically higher than the general US population. OBJECTIVE: To evaluate three dietary assessment tools: dietary records, a food frequency questionnaire (FFQ), and a shellfish assessment survey among Native American adults from the Communities Advancing the Studies of Tribal Nations Across the Lifespan (CoASTAL) cohort. DESIGN: The CoASTAL cohort was composed of randomly selected individuals from three tribal registries of Pacific Northwest Tribal Nations. This cross-sectional study used data from the baseline of CoASTAL and was restricted to the non-pregnant adults (aged 18 years or older) who completed the shellfish assessment survey (n=500), an FFQ (n=518), dietary records (n=444), weight measures (n=493), and height measures (n=496). Paired t tests, Pearson correlation coefficients, and percent agreement were used to evaluate the dietary records and the FFQ with and without accounting for plausibility of reported energy intake (rEI). Sensitivity and specificity as well as Spearman correlation coefficients were used to evaluate the shellfish assessment survey and the FFQ compared to dietary records. RESULTS: Statistically significant correlations between the FFQ and dietary records for selected nutrients were not the same by sex. Accounting for plausibility of rEI for the dietary records and the FFQ improved the strength of the correlations for percent energy from protein, energy from carbohydrate, and calcium for both men and women. In addition, the association between rEI (dietary records and FFQ) and weight became significant when the sample was limited to plausible rEI. The shellfish assessment survey was found to similarly assess shellfish consumption in comparison to the FFQ. CONCLUSIONS: These results support the benefit of multiple measures of diet, including regional and culturally specific surveys, especially among Native Americans. Accounting for plausibility of rEI may ensure more accurate estimations of dietary intakes.