Seasonal changes in markers of oxidative damage to lipids and DNA; correlations with seasonal variation in diet

Intake of Fruits, Vegetables, and Sugar-Sweetened Beverages among a Sample of Children in Rural Northern Ontario, Canada

There is evidence to suggest that dietary intake of children differs by rural/urban place of residence: rural children may have a higher intake of foods high in fat and sugar than those living in urban environments. The aim of this study was to examine the intake of fruits and vegetables (FV) and the frequency of sugar-sweetened beverage (SSB) consumption, among a sample of rural children in Northern Ontario, Canada, in two different seasons. Sociodemographic factors and children's FV and SSB intake were measured using two repeated cross-sectional surveys, and seasonal information was based on the month of data collection. Logistic regressions were used to examine the odds of children eating five or more FVs, and the odds of 'frequently or always' consuming SSBs. During the fall, children reported eating five or more FV more often, when compared to winter (53.9% vs. 48.3%). In the fall, 25.8% of children reported 'frequently or always' drinking SSB, compared with 16.9% in winter. Indigenous children were less likely to eat five or more FV (OR 0.34 (95% CI 0.12-0.95)) in the fall when compared to non-Indigenous children. Findings indicate that intake of FV among rural students in this region is low, and the frequency of SSB is high, when compared with national recommendations.

Diet and Maternal Obesity Are Associated with Increased Oxidative Stress in Newborns: A Cross-Sectional Study

Overweight and obesity have become a world-health public problem, mainly for developing countries. Both health conditions have a higher prevalence among women of childbearing age. Physiopathology, overweight and obesity are characterized by a chronic oxidative stress status, which has deleterious effects on mothers and children. Hence, we determine whether the qualities of diet during pregnancy and maternal pregestational body mass index (BMI) are associated with increased oxidative stress markers in mothers and newborns. Two hundred forty-two (242) mother-newborn pairs were classified according to their pregestational BMI. Information on food intake was collected using a food frequency questionnaire in the third trimester of pregnancy. Levels of Malondialdehyde (MDA) and Nitric Oxide (NO) were measured in plasma from mothers at the end of the third trimester of pregnancy and from cord blood at birth. MDA and NO levels in mother–newborn pairs with maternal pregestational overweight or obesity were higher than in mother–newborn pairs with pregestational normal weight. For women (and newborns) who had a higher intake of fruit and vegetables, the levels of NO and MDA were lower. Lastly, women with pregestational obesity had lower fruit and vegetable intake during pregnancy and higher levels of oxidative stress and in their newborns.

Exploring Pathways of Socioeconomic Inequity in Vegetable Expenditure Among Consumers Participating in a Grocery Loyalty Program in Quebec, Canada, 2015-2017

Vegetable consumption remains consistently low despite supportive policy and investments across the world. Vegetables are available in great variety, ranging in their processing level, availability, cost, and arguably, nutritional value. A retrospective longitudinal study was conducted in Quebec, Canada to explore pathways of socioeconomic inequity in vegetable expenditure. Data was obtained for consumers who participated in a grocery loyalty program from 2015 to 2017 and linked to the 2016 Canadian census. Vegetable expenditure share (%) was examined as a fraction of the overall food basket and segmented by processing level. Panel random effects and tobit models were used overall and to estimate the stratified analysis by median income split. Consumers allocated 8.35% of their total food expenditure to vegetables, which was mostly allocated to non-processed fresh (6.88%). Vegetable expenditure share was the highest in early winter and lowest in late summer. In the stratified analysis, the low-income group exhibited less seasonal variation, allocated less to fresh vegetables, and spent more on canned and frozen compared to the high-income group. Measures of socioeconomic status were all significant drivers of overall vegetable consumption. Consumers with high post-secondary education in the low-income group spent 2% more on vegetables than those with low education. The complexity of observed expenditure patterns points to a need for more specific vegetable consumption guidelines that include provisions by processing level. Implications for education, marketing, intersectional policies, and the role of government are discussed. Governments can scale present efforts and catalyze health-promoting investments across local, state, national, and global food systems.

Different Seasonal Variations of Potassium in Hemodialysis Patients with High Longitudinal Potassium Levels: A Multicenter Cohort Study Using DialysisNet

PURPOSE

To determine seasonal variations in serum potassium levels among hemodialysis patients.

MATERIALS AND METHODS

This was a multicenter cohort study of patients whounderwent hemodialysis and were registered in DialysisNet at our four associated general hospitals between January and December 2016. Month-to-month potassium variability was quantified as SD/√{n/(n-1)}, and a non-hierarchical method was used to cluster groups according to potassium trajectories. Seasonal variations in potassium levels were analyzed using a cosinor analysis.

RESULTS

The analysis was performed on 279 patients with a mean potassium level of 5.08±0.58 mmol/L. After clustering, 52.3% (n=146) of patients were included in the moderate group (K⁺, 4.6±0.4 mmol/L) and 47.7% (n=133) in the high group (K⁺, 5.6±0.4 mmol/L). The mean potassium level peaked in January in the moderate group (4.83±0.74 mmol/L) and in August in the high group (5.51±0.70 mmol/L). In the high potassium group, potassium levels were significantly higher in summer than in autumn (p<0.001) and spring (p=0.007). Month-to-month potassium variability was greater in the high group than in the moderate group (0.59±0.19 mmol/L vs. 0.52±0.21 mmol/L, respectively, p=0.012). Compared to patients in the first quartile of potassium variability (≤0.395 mmol/L), those with higher variability (2nd-4th quartiles) were 2.8-4.2 fold more likely to be in the high potassium group.

CONCLUSION

Different seasonal patterns of serum potassium were identified in the moderate and high potassium groups, with potassium levels being significantly higher in the summer season in the high potassium group and in winter for the moderate potassium group.

Human AP-endonuclease (Ape1) activity on telomeric G4 structures is modulated by acetylatable lysine residues in the N-terminal sequence

Loss of telomeres stability is a hallmark of cancer cells. Exposed telomeres are prone to aberrant end-joining reactions leading to chromosomal fusions and translocations. Human telomeres contain repeated TTAGGG elements, in which the 3' exposed strand may adopt a G-quadruplex (G4) structure. The guanine-rich regions of telomeres are hotspots for oxidation forming 8-oxoguanine, a lesion that is handled by the base excision repair (BER) pathway. One key player of this pathway is Ape1, the main human endonuclease processing abasic sites. Recent evidences showed an important role for Ape1 in telomeric physiology, but the molecular details regulating Ape1 enzymatic activities on G4-telomeric sequences are lacking. Through a combination of in vitro assays, we demonstrate that Ape1 can bind and process different G4 structures and that this interaction involves specific acetylatable lysine residues (i.e. K^27/31/32/35) present in the unstructured N-terminal sequence of the protein. The cleavage of an abasic site located in a G4 structure by Ape1 depends on the DNA conformation or the position of the lesion and on electrostatic interactions between the protein and the nucleic acids. Moreover, Ape1 mutants mimicking the acetylated protein display increased cleavage activity for abasic sites. We found that nucleophosmin (NPM1), which binds the N-terminal sequence of Ape1, plays a role in modulating telomere length and Ape1 activity at abasic G4 structures. Thus, the Ape1 N-terminal sequence is an important relay site for regulating the enzyme's activity on G4-telomeric sequences, and specific acetylatable lysine residues constitute key regulatory sites of Ape1 enzymatic activity dynamics at telomeres.

Effect of seasonal changes on nutritional status and biochemical parameters in Turkish older adults

BACKGROUND/OBJECTIVES

Available data suggest that seasonal changes may influence the nutritional status and overall health of elderly individuals. Therefore, this study was conducted to investigate the effects of seasonal changes and related factors on energy and nutrient intake of older adults.

SUBJECTS/METHODS

Individuals aged 65 years or over were prospectively enrolled in this single-center study (male: 11, female: 20). Data were collected between May 2013 and February 2014 during winter, spring, summer and autumn. Food consumption and biochemical parameters were taken during each season to assess the seasonal nutrition status of the elderly. Upon analysis of biochemical parameters (retinol, vitamin D and vitamin C), an high-performance liquid chromatography device was utilized whereas an Immulite 2000 device was utilized during analysis of serum folic acid and parathyroid hormone.

RESULTS

Fruit, fat, egg and bread consumption varied seasonally in males and females (P < 0.05). During winter, daily energy intake was found to be greater than in other seasons in males (557 kcal) and females (330 kcal) (P < 0.05). Additionally, carbohydrates, vegetable protein, n-3 fatty acid and sodium intake increased in winter, while the n-6/n-3 ratio increased in summer among males (P < 0.05). Dietary fiber and sodium intake in winter, vitamin C, iron and zinc intake in spring, and cholesterol, retinol, vitamin D and niacin intake in autumn were found to be higher in females when compared to other seasons (P < 0.05). Serum parathyroid hormone level was higher in winter, and vitamin D level was higher in autumn in both genders (P < 0.05). In males, blood folic acid level was higher in winter, while vitamin C level was higher in females, and there was no seasonal variation in retinol concentration (P < 0.05).

CONCLUSION

Food consumption and biochemical parameters showed significant seasonal variations in older adults. It is not clear if nutrition plans in older adults will benefit from consideration of seasonal changes in eating habits.

The effect of ambient temperature on diabetes mortality in China: A multi-city time series study

Few multi-city studies have been conducted to investigate the acute health effects of low and high temperatures on diabetes mortality worldwide. We aimed to examine effects of ambient temperatures on city-/gender-/age-/education-specific diabetes mortality in nine Chinese cities using a two-stage analysis. Distributed lag non-linear model was first applied to estimate the city-specific non-linear and delayed effects of temperatures on diabetes mortality. Pooled effects of temperatures on diabetes mortality were then obtained using meta-analysis, based on restricted maximum likelihood. We found that heat effects were generally acute and followed by a period of mortality displacement, while cold effects could last for over two weeks. The pooled relative risks of extreme high (99th percentile of temperature) and high temperature (90th percentile of temperature) were 1.29 (95%CI: 1.11-1.47) and 1.11 (1.03-1.19) over lag 0-21 days, compared with the 75th percentile of temperature. In contrast, the pooled relative risks over lag 0-21 days were 1.44 (1.25-1.66) for extreme low (1st percentile of temperature) and 1.20 (1.12-1.30) for low temperature (10th percentile of temperature), compared to 25th percentile of temperature. The estimate of heat effects was relatively higher among females than that among males, with opposite trend for cold effects, and the estimates of heat and cold effects were particularly higher among the elderly and those with low education, although the differences between these subgroups were not statistically significant (P>0.05). These findings have important public health implications for protecting diabetes patients from adverse ambient temperatures.

Patterns of fruit and vegetable availability and price competitiveness across four seasons are different in local food outlets and supermarkets

OBJECTIVE

To explore the effect of seasonality on fruit and vegetable availability and prices across three outlet types (farmers' markets, roadside stands and conventional supermarkets).

DESIGN

Cross-sectional survey of geographically clustered supermarkets, farmers' markets and roadside stands. Enumerators recorded the availability and lowest price for eleven fruits and eighteen vegetables in each season of 2011.

SETTING

Price data were collected at retail outlets located in central and eastern North Carolina.

SUBJECTS

The sample consisted of thirty-three supermarkets, thirty-four farmers' markets and twenty-three roadside stands.

RESULTS

Outside the local harvest season, the availability of many fruits and vegetables was substantially lower at farmers' markets and roadside stands compared with supermarkets. Given sufficient availability, some items were significantly cheaper (P<0·05) at direct retail outlets in the peak season (e.g. cantaloupe cost 36·0 % less at roadside stands than supermarkets), while others were significantly more expensive (e.g. carrots cost 137·9 % more at farmers' markets than supermarkets). Although small samples limited statistical power in many non-peak comparisons, these results also showed some differences by item: two-thirds of fruits were cheaper at one or both direct outlets in the spring and autumn, whereas five of eighteen vegetables cost more at direct retail year-round.

CONCLUSIONS

Commonly consumed fruits and vegetables were more widely available at supermarkets in central and eastern North Carolina than at direct retail outlets, in each season. Contingent on item availability, price competitiveness of the direct retail outlets varied by fruit and vegetable. For many items, the outlets compete on price in more than one season.

Pollution biomonitoring in the Bizerte lagoon (Tunisia), using combined chemical and biomarker analyses in grass goby, Zosterisessor ophiocephalus (Teleostei, Gobiidae)

In this study, biological responses and contaminant levels in biological tissues were investigated in grass goby fish specimens (Zosterisessor ophiocephalus) collected from five stations in a moderately polluted ecosystem, namely the Bizerte lagoon on the north coast of Tunisia. The following biomarkers were measured: muscular acetylcholinesterase (AChE), hepatic ethoxyresorufin-O-deethylase (EROD), glutathione-S-transferase (GST), catalase (CAT), lipoperoxidation (TBARS), condition factor (CF), and hepatosomatic index (HSI). These measurements were taken in parallel with the content of Organochlorine pesticides (OCPs), Polychlorinated biphenyls (PCBs), Polycyclic aromatic hydrocarbons (PAHs) and trace metals (As, Cr, Cu, Mn, Pb, V, Zn, Ag, Cd, Co and Ni) in muscle tissue. Total PAH concentrations ranged from 20.09 ± 0.68 to 105.77 ± 42.58 ng g(-1) dw, PCB from 33.19 ± 6.25 to 126.28 ± 7.37 ng g(-1) dw, OCP from 11.26 ± 1.62 to 19.17 ± 2.06 ng g(-1) dw, and metals from 107.83 ± 1.83 to 187.21 ± 2.00 mg/kg dw. The highest levels of pollutants and biomarkers were observed at station S1, located in the Bizerte channel. Elevated EROD, GST and CAT activities, as well as TBARS levels in liver were positively correlated with tissue contaminant levels at station S1. Significant negative correlations were also found between hexachlorobenzene (HCB) and dichlorodiphenyltrichloroethane (DDTs) body burden with AChE activity in muscle at station S2. The integration of biological responses and contaminant tissue content indicated that certain areas of the Bizerte lagoon, notably station S1, are significantly impacted by various human activities, which likely represent a threat for aquatic wildlife. On the basis of these results, and due to its ecological characteristics, the grass goby appears a suitable indicator species for pollution biomonitoring in coastal marine areas along the Mediterranean Sea.

Extremely cold and hot temperatures increase the risk of diabetes mortality in metropolitan areas of two Chinese cities

BACKGROUND

Numerous studies have reported the association between ambient temperature and mortality. However, few studies have focused on the effects of extreme temperatures on diabetes mortality, particularly in China. The objective of the present study was to assess the effects of extremely cold and hot temperatures on diabetes mortality in urban areas of Harbin and Chongqing in China to provide scientific evidence for public health policy implementation to respond to challenges in diabetes mortality because of extreme temperature events.

METHODS

A double threshold B-spline distributed lag non-linear model (DLNM) was used to investigate the effects of extremely cold and hot temperatures on diabetes mortality from lag 0 to 30 days, after controlling for potential confounders including air pollutants. The unit risk, which is the elevated cumulative risk of diabetes mortality caused by each 1 °C change in extremely cold and hot temperatures during certain lag days, was estimated for extreme cold and heat using simple regression analysis.

RESULTS

Significant associations between both extreme hot and cold temperatures and diabetes mortality were observed in Harbin and Chongqing for different lag lengths. In Harbin, the extreme cold effects on diabetes mortality were delayed by three days and lasted for six days (lag 3-8), with the highest risk (RR 95% CI: 1.223,1.054-1.418 for -23 °C) at lag 5. The hot effects were delayed one day and lasted for three days (lag 1-3), with the peak RR (1.343: 1.080-1.670 for 37 °C) at lag 2. In Chongqing, the cold effects on diabetes mortality were delayed by seven days and lasted for four days (lag 7-10), with the highest risk (1.201: 1.006-1.434 for 4 °C) at lag 7. The hot effects peaked (1.811: 1.083-3.027 for 41 °C) at lag 0 and lasted for 2 days (lag 0-1). The unit risk for cold and hot effects was 12.9% (95% CI: 2.5-33.7%) and 16.5% (95% CI: 3.8-39.1%) in Harbin and 12.5% (95% CI: -4.7 to 47.5%) and 19.7% (95% CI: 3.9-48.5%) in Chongqing, respectively.

CONCLUSIONS

The results indicate that both extremely cold and hot temperatures increase diabetes mortality in different manners in Harbin and Chongqing. Diabetes education programs should include information on either managing or combating the effects of extreme hot and cold weather.

The influence of chronological period of data collection on differences in reported dietary intake among school-aged children surveyed in 39 countries

OBJECTIVE

To examine whether dietary intake reported by school-aged children relates to the chronological period of data collection.

DESIGN

Cross-sectional surveys in 39 countries in different monthly periods of the 2009-2010 school year.

SETTINGS

Questionnaires were completed in schools anonymously.

PARTICIPANTS

Children from 39 countries, aged 11, 13, and 15 years (n = 209,320).

MAIN OUTCOME MEASURES

Daily consumption of fruits, vegetables, sweets, and soft drinks, derived from a food frequency questionnaire.

ANALYSIS

Multivariate logistic regression (applied for 3 countries); 2-level random intercept logistic regression (applied for 36 countries).

RESULTS

Monthly variations in food intake among students from Canada, England, and Norway, where data collection took place almost all months of the school year, revealed significantly lower daily consumption of food items in January to February. A 2-level random intercept logistic regression model for 36 countries, where questionnaires were administered in relatively shorter periods, indicated the lowest likelihood of fruit and soft drink consumption when the data were collected in March to April (β = -0.30; P = .006, compared with October to December) and in January to February (β = -0.65; P = .018, compared with May to June), respectively.

CONCLUSIONS AND IMPLICATIONS

The chronological period of data collection must be considered when comparing children's reported food consumption, but this effect is small relative to cross-national variations in dietary patterns.

Excess winter mortality and cold temperatures in a subtropical city, Guangzhou, China

BACKGROUND

A significant increase in mortality was observed during cold winters in many temperate regions. However, there is a lack of evidence from tropical and subtropical regions, and the influence of ambient temperatures on seasonal variation of mortality was not well documented.

METHODS

This study included 213,737 registered deaths from January 2003 to December 2011 in Guangzhou, a subtropical city in Southern China. Excess winter mortality was calculated by the excess percentage of monthly mortality in winters over that of non-winter months. A generalized linear model with a quasi-Poisson distribution was applied to analyze the association between monthly mean temperature and mortality, after controlling for other meteorological measures and air pollution.

RESULTS

The mortality rate in the winter was 26% higher than the average rate in other seasons. On average, there were 1,848 excess winter deaths annually, with around half (52%) from cardiovascular diseases and a quarter (24%) from respiratory diseases. Excess winter mortality was higher in the elderly, females and those with low education level than the young, males and those with high education level, respectively. A much larger winter increase was observed in out-of-hospital mortality compared to in-hospital mortality (45% vs. 17%). We found a significant negative correlation of annual excess winter mortality with average winter temperature (rs=-0.738, P=0.037), but not with air pollution levels. A 1 °C decrease in monthly mean temperature was associated with an increase of 1.38% (95% CI:0.34%-2.40%) and 0.88% (95% CI:0.11%-1.64%) in monthly mortality at lags of 0-1 month, respectively.

CONCLUSION

Similar to temperate regions, a subtropical city Guangzhou showed a clear seasonal pattern in mortality, with a sharper spike in winter. Our results highlight the role of cold temperature on the winter mortality even in warm climate. Precautionary measures should be strengthened to mitigate cold-related mortality for people living in warm climate.

Biochemical and bioaccumulation approaches for investigating marine pollution using Mediterranean rainbow wrasse, Coris julis (Linneaus 1798)

A multibiomarkers approach was used in order to estimate and monitor marine pollution. Coris julis (Linneaus, 1758) was chosen as a sentinel organism, and the specimens were collected from three well-known sites along the Ionic coast of Sicily: the protected marine area (P.M.A) "Cyclop's Islands" of Acitrezza (CT), used as a control site, Riposto (CT), and the industrial site of Augusta (SR). Abiotic levels of contaminants were also detected. High levels of biotic and abiotic accumulation were found at the industrial site in which the presence of genotoxic and oxidative damage were also evidenced, measured by Micronuclei, Alkaline and Fpg-modified Comet assays. The protein expression analysis showed metallothioneins (MTs) as good tissue-specific markers of metal accumulation. Their levels were significantly higher in muscle than in liver tissue for all the sampling sites, with a positive correlation among tissue levels and the degree of pollution at the sites. Conversely, heat shock proteins 70 (HSP70) expression was higher in Augusta and Riposto than in the control site, but no significant difference was found between the examined tissues among all sites.

Changing blood lead levels and DNA damage (comet assay) among immigrant women in Taiwan

BACKGROUND

International marriage has had a rapid growth in recent years in Taiwan. However, little is known about the blood lead levels and DNA damage levels among immigrant women from resource-limited countries.

OBJECTIVE

This study (a) explored differences between immigrant women and native women in demographic characteristics, blood lead levels, and DNA damage levels, and (b) identified risk factors that are associated with blood lead concentrations and DNA damage levels after immigration.

METHODS

We used a structured questionnaire to collect data on socio-demographic status from (a) 71 immigrant women who had resettled in 2006 in Taichung, Taiwan and (b) 83 native women who live in the same area. Each study participant provided blood samples for lead and metal measurements, complete blood count examination, and the comet assay to measure degree of DNA damage.

RESULTS

Immigrant women had higher mean blood lead concentration (2.23+/-1.63 vs. 1.63+/-1.00 microg/dl; p=0.04) and lower mean blood zinc level (6.22+/-2.22 vs. 6.89+/-2.44 mg/l; p=0.07) than native women. Resettlement time was a determinant to decrease blood lead and DNA damage levels among immigrants in Taiwan. Multiple linear regression analysis confirmed a statistically significant association between blood lead level and DNA damage, while zinc had a protective effect.

CONCLUSIONS

Public health agencies should focus on primary prevention and providing screening programs for this vulnerable population. An immigrant women's cohort should been established to follow-up and improve for elevated lead exposure families.

Antioxidant supplementation reduces inter-individual variation in markers of oxidative damage

The aim of this study was to examine the effect of antioxidant supplementation on oxidative damage and chromosome stability in middle-aged men, smokers and non-smokers. A total of 124 men aged 48+/-6 years from Bratislava and from the rural population near Bratislava were investigated; 64 men (22 smokers and 42 non-smokers) were supplemented for 12 weeks with antioxidants, while 60 (25 smokers and 35 non-smokers) were given placebo. The daily antioxidant supplementation consisted of vitamin C (100 mg), vitamin E (100 mg), ss-carotene (6 mg), and selenium (50 microg). Samples of blood were taken on two occasions: At the beginning and at the end of the supplementation trial. Concentrations of dietary antioxidants, ferric reducing ability, malondialdehyde as an indicator of lipid peroxidation in plasma, micronuclei and chromosome aberrations in lymphocytes were measured. Antioxidant supplementation significantly increased the levels of vitamin C, ss-carotene, a-tocopherol and selenium in plasma. The overall antioxidant status of plasma measured as ferric reducing ability of plasma (FRAP) increased significantly (p<0.001) after antioxidant supplementation as well. The increase in antioxidant parameters after supplementation were consistently more pronounced in non-smokers than in smokers. There was a significant decrease of malondialdehyde concentration in the non-smokers, while in smokers the decrease of malondialdehyde concentration was not significant. Antioxidant supplementation did not affect the proportion of lymphocytes with micronuclei or the total number of micronuclei; however, there was a significant positive correlation (p<0.001) between the malondialdehyde concentration at the beginning of the supplementation trial and the difference in number of cells with micronuclei before and after the supplementation. The percent of cells with chromosome aberrations decreased significantly after antioxidant supplementation in smokers. These results indicate that a combined antioxidant supplementation (a) is effective even at very moderate doses; (b) significantly diminishes oxidative damage to lipids when it is high initially; and (c) is effective in decreasing chromosomal instability in lymphocytes of middle-aged men.

Seasonal variation in fruit and vegetable consumption in a rural agricultural community

BACKGROUND

Seasonal variation in fruit and vegetable consumption has been documented in a limited number of previous investigations and is important for the design of epidemiologic investigations and in the evaluation of intervention programs.

OBJECTIVE

This study investigates fruit and vegetable consumption behaviors among Hispanic farmworkers and non-farmworkers in a rural agricultural community.

DESIGN

A larger study recruited 101 farmworker families and 100 non-farmworker families from the Yakima Valley in Washington State between December 2004 and October 2005. All families were Hispanic. An in-person administered questionnaire collected information on consumption of locally grown fruits and vegetables and sources of obtaining fruits and vegetables. Data on dietary intake asked whether or not the respondent had consumed a given fruit or vegetable in the past month. Data were collected longitudinally, coinciding with three agricultural seasons: thinning (summer), harvest (fall), and nonspray (winter).

STATISTICAL ANALYSES PERFORMED

Generalized estimating equations were used to test for statistical significance between proportions of the population who consumed a given fruit or vegetable across agricultural seasons. Multivariable logistic regression was performed and corresponding odds ratios and 95% confidence intervals are reported.

RESULTS

The proportion of respondents who ate apples, pears, plums, peaches, apricots, peppers, corn, and cucumbers was highest in the fall harvest season, whereas the proportions of those who ate cherries and asparagus were highest in the summer thinning season. Compared to non-farmworkers, a higher proportion of farmworkers reported having eaten peaches, apricots, cherries, green beans, carrots, peppers, corn, pumpkin, squash, and onions, in the past month.

CONCLUSIONS

Epidemiologic investigations and public health interventions that examine the consumption of fruits and vegetables should consider seasonal variation in consumption patterns, especially in agricultural communities.

Exposures to airborne particulate matter and adverse perinatal outcomes: a biologically plausible mechanistic framework for exploring potential

This article has three objectives: to describe the biologically plausible mechanistic pathways by which exposure to particulate matter (PM) may lead to adverse perinatal outcomes of low birth weight (LBW), intrauterine growth retardation (IUGR), and preterm delivery (PTD); review evidence showing that nutrition affects biologic pathways; and explain mechanisms by which nutrition may modify the impact of PM exposure on perinatal outcomes. We propose an interdisciplinary framework that brings together maternal and infant nutrition, air pollution exposure assessment, and cardiopulmonary and perinatal epidemiology. Five possible biologic mechanisms have been put forth in the emerging environmental sciences literature and provide corollaries for the proposed framework. The literature indicates that the effects of PM on LBW, PTD, and IUGR may manifest through the cardiovascular mechanisms of oxidative stress, inflammation, coagulation, endothelial function, and hemodynamic responses. PM exposure studies relating mechanistic pathways to perinatal outcomes should consider the likelihood that biologic responses and adverse birth outcomes may be derived from both PM and non-PM sources. We present strategies for empirically testing the proposed model and developing future research efforts.

An update of the general health status in the indigenous populations of Malaysia

OBJECTIVES

Health scenarios are constantly evolving, particularly in developing countries but little is known regarding the health status of indigenous groups in Malaysia. This study aims to elucidate the current health status in four indigenous populations in the country, who by and large been left out of mainstream healthcare developments.

METHODS

Participants were recruited from the Temuan, Jehai, Kensiu and Bidayuh indigenous groups throughout Peninsula Malaysia and Sarawak. Health parameters including body mass index (BMI), blood pressure, casual blood glucose and, total cholesterol levels were measured using established methods. Malondialdehyde (MDA) and ferric-reducing antioxidant power (FRAP) levels were measured to assess oxidative stress status. Blood films were screened for evidence of microbial or parasitic infections and leukocyte differential counting was performed.

RESULTS

The Temuan and Bidayuh who are more urbanized, had significantly higher mean body weight, BMI, total cholesterol (p<0.05) and higher prevalence of obesity and hypercholesterolemia. Low cholesterol levels, elevated eosinophil counts and increased total IgE, indicative of immune responses to infection or allergy, were recorded in the rural Kensiu and Jehai. The Kensiu had higher levels of FRAP and lower levels of MDA, whereas the reverse was found in the Temuan. This suggests reduced oxidative stress in the Kensiu compared to the Temuan. Expected correlations between FRAP and MDA levels with age, were evident in Jehai.

CONCLUSIONS

Our findings reflect a shifting health burden and an epidemiological transition, particularly in the Temuan and Bidayuh. These changes could be attributed to dietary habits, lifestyles and socio-economic factors brought about by urbanization.

The relationship between micronuclei in human lymphocytes and selected micronutrients in vegetarians and non-vegetarians

A vegetarian diet results in higher intake of vitamins and micronutrients, which - although providing antioxidant defence - may lead to deficiency in other micronutrients involved in DNA metabolism and stability (such as vitamins belonging to the B group). The principal difference among various vegetarian diets is the extent to which animal products are avoided. We have performed a pilot study to determine the relationship between the micronucleus frequency in lymphocytes and diet, and we compared the levels of Vitamins C and E, beta-carotene, B(12), folic acid, homocysteine and total antioxidant capacity in healthy vegetarians and non-vegetarians. The vegetarian group, consisting of 24 volunteers (13 women and 11 men), were matched for age and sex with 24 volunteers (12 women and 12 men) with a traditional dietary habit. Among the vegetarians were 13 lacto-ovo-vegetarians with average duration of vegetarian diet 10.8 years (ranging from 5 to 26 years) and 11 lacto-vegetarians with average duration of vegetarian diet 8.2 years (ranging from 3 to 15 years). Homocysteine, Vitamins C and E and beta-carotene levels in plasma were assayed by HPLC, and serum folate and Vitamin B(12) were determined with Elecsys Immunoassay tests. The total antioxidant capacity of plasma was estimated by measuring the ferric-reducing activity in a spectrophotometric assay. Micronuclei were measured in cytokinesis-blocked lymphocytes. Vegetarians had significantly higher levels of Vitamin C and beta-carotene (but not Vitamin E) in plasma compared with non-vegetarians (P<0.001). There were no significant differences in serum levels of folic acid and Vitamin B(12) between the monitored groups. Levels of folic acid in vegetarians correlated with length of vegetarianism (r=0.62, P=0.001, N=24). Vegetarians had elevated levels of homocysteine compared with non-vegetarians (P=0.007), as did vegetarian women compared with non-vegetarian women (P=0.031). We did not find any differences in total antioxidant capacity or in micronucleus frequency between the groups. Micronuclei correlated with age (r=0.62, P<0.001, N=48), women having higher frequencies than men. Multifactorial regression analysis showed significant effects of age, sex and total antioxidant capacity on micronucleus frequency (N=48, P<0.001).

Exposures to airborne particulate matter and adverse perinatal outcomes: a biologically plausible mechanistic framework for exploring potential effect modification by nutrition

OBJECTIVES

The specific objectives are threefold: to describe the biologically plausible mechanistic pathways by which exposure to particulate matter (PM) may lead to the adverse perinatal outcomes of low birth weight (LBW), intrauterine growth retardation (IUGR), and preterm delivery (PTD); review the evidence showing that nutrition affects the biologic pathways; and explain the mechanisms by which nutrition may modify the impact of PM exposure on perinatal outcomes.

METHODS

We propose an interdisciplinary conceptual framework that brings together maternal and infant nutrition, air pollution exposure assessment, and cardiopulmonary and perinatal epidemiology. Five possible albeit not exclusive biologic mechanisms have been put forth in the emerging environmental sciences literature and provide corollaries for the proposed framework.

CONCLUSIONS

Protecting the environmental health of mothers and infants remains a top global priority. The existing literature indicates that the effects of PM on LBW, PTD, and IUGR may manifest through the cardiovascular mechanisms of oxidative stress, inflammation, coagulation, endothelial function, and hemodynamic responses. PM exposure studies relating mechanistic pathways to perinatal outcomes should consider the likelihood that biologic responses and adverse birth outcomes may be derived from both PM and non-PM sources (e.g., nutrition). In the concluding section, we present strategies for empirically testing the proposed model and developing future research efforts.

DNA damage, oxidative mutagen sensitivity, and repair of oxidative DNA damage in nonmelanoma skin cancer patients

Nonmelanoma skin cancer (NMSC) is the most frequent type of cancer in humans. Exposure to UV radiation is a major risk factor for NMSC, and oxidative DNA damage, caused either by UV radiation itself or by other agents, may be involved in its induction. Increased sensitivity to oxidative damage and an altered DNA repair capacity (DRC) increase the risk of many types of cancer; however, sensitivity to oxidizing agents has not been evaluated for NMSC, and results regarding DRC in NMSC are inconclusive. In the present study, we evaluated DNA damage and repair in leukocytes from 41 NMSC patients and 45 controls. The Comet assay was used to measure basal and H(2)O(2)-induced DNA damage, as well as the DRC, while the cytokinesis-block micronucleus assay was used to measure the basal level of chromosome damage. Although basal DNA damage was higher for the controls than for the patients, this finding was mainly due to sampling more controls in the summer, which was associated with longer comet tails. In contrast, H(2)O(2)-induced DNA damage was significantly higher in cases than in controls, and this parameter was not influenced by the season of the year. The DRC for the H(2)O(2)-induced damage was similar for cases and controls and unrelated to seasonality. Finally, the frequency of binucleated lymphocytes with micronuclei was similar for cases and controls. The results of this study indicate that NMSC patients are distinguished from controls by an increased sensitivity to oxidative DNA damage.

Seasonal variations of DNA damage in human lymphocytes: correlation with different environmental variables

Several types of DNA damage, including DNA breaks and DNA base oxidation, display a seasonal trend. In the present work, a sample of 79 healthy subjects living in the city of Florence, Italy, was used to analyse this effect. Three possible causative agents were taken into consideration: solar radiation, air temperature and air ozone level. DNA damage was measured in isolated human lymphocytes at different times during the year and the observed damage was correlated with the levels of these three agents in the days preceding blood sampling. Three time windows were chosen: 3, 7 and 30 days before blood sampling. DNA strand breaks and the oxidized purinic bases cleaved by the formamidopyrimidine glycosylase (FPG sites) were measured by means of the comet assay. The results of multivariate regression analysis showed a positive correlation between lymphocyte DNA damage and air temperature, and a less strong correlation with global solar radiation and air ozone levels.

Diet and biomarkers of oxidative damage in women previously treated for breast cancer

This study sought to evaluate the relationship between dietary intake of fat, polyunsaturated fat, saturated fat, arachidonic acid, and selected dietary antioxidants and levels of oxidative damage as measured by urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-epi-prostaglandin F2alpha (8-iso-PGF2alpha) in women previously treated for breast cancer. Two hundred two study subjects participating in the Women's Healthy Eating and Living (WHEL) study were included in this ancillary study. Dietary intakes and concentrations of urinary 8-OHdG and 8-iso-PGF2alpha were measured at baseline and 12 mo in the 179 women included in the analytical cohort. Study subjects demonstrated a significant reduction in dietary total, polyunsaturated, and saturated fat intake and a significant increase in vitamins E and C and beta-carotene intake from baseline to 12 mo. Linear mixed-models analysis using baseline and Year 1 data indicated that vitamin E intake was inversely associated with both 8-OHdG and 8-iso-PGF2alpha. 8-Iso-PGF2alpha is increased with increased body mass index (BMI) and polyunsaturated fatty acid (PUFA) intake, indicating an increase in lipid peroxidation with greater BMI and higher PUFA intake. 8-OHdG was inversely related to age but positively related to arachidonic acid, indicating an increase in DNA damage with higher intake of arachidonic acid (meat). The results of this nested case-controlled study provide potential mechanisms by which a high fruit and vegetable, low-fat diet might reduce the recurrence rate of or early-stage breast cancer.

Antioxidant intervention as a route to cancer prevention

The notion of cancer prevention through antioxidant intervention arises from the fact that fruits and vegetables contain antioxidants and are linked to low cancer rates in those who consume them. Protection against DNA damage by plant food products can be demonstrated in vitro. However, particular care is needed when measuring the damage, since oxidation readily occurs during sample preparation, creating a serious artefact. In the case of DNA oxidation, estimates of background levels in human cells range over 3 orders of magnitude, depending on the method used. Using validated, reliable biomarker assays for DNA oxidation, it is possible to demonstrate a decrease in oxidative damage after supplementation with isolated antioxidants or whole plant foods in humans. In contrast, in several large-scale interventions with disease or death as the endpoint, supplementation with beta-carotene resulted in no effect or an increase in cancer incidence. It is certainly true that we do not yet fully understand the role of phytochemicals as antioxidants, or as modulators of other processes related to carcinogenesis and its prevention.

Assays for oxidative stress and antioxidant status: applications to research into the biological effectiveness of polyphenols

Oxidative stress is a factor in many human diseases, as either cause or effect. A convenient biomarker of oxidative stress is the extent of oxidation of bases in DNA (although measures of lipid or protein oxidation may be equally informative). 8-Oxo-7,8-dihydroguanine or the corresponding nucleoside is most often measured, either chromatographically (gas chromatography-mass spectrometry, HPLC with electrochemical detection, or HPLC-tandem mass spectrometry) or enzymically, with the use of the enzyme formamidopyrimidine DNA glycosylase to convert 8-oxo-7,8-dihydroguanine to DNA breaks, which are detected with alkaline elution, alkaline unwinding, or the comet assay. Estimates of background levels of 8-oxo-7,8-dihydroguanine in normal human cells vary 1000-fold, depending on the technique used. Gas chromatography-mass spectrometry is particularly prone to oxidation of samples during derivatization, whereas HPLC suffers from this artifact to a lesser degree. In a recent interlaboratory study that measured the same samples of human cells, median values obtained with HPLC with electrochemical detection and with formamidopyrimidine DNA glycosylase differed by approximately 10-fold. There are still questions regarding the actual level of damage, but it is probably approximately one 8-oxo-7,8-dihydroguanine residue per 10(6) guanines. Assays for antioxidant protection against oxidative damage generally depend on measurements of decreases in a marker of oxidation. Potential dietary antioxidants can be screened with in vitro antioxidant assays or tested in cell culture systems. The best test, however, is in humans. The total antioxidant capacity of plasma is generally insensitive to dietary supplementation with antioxidants or antioxidant-rich foods. An increase in the resistance of lymphocyte DNA to oxidation in vitro is commonly seen, however, and a decrease in endogenous oxidation of DNA may be detected, especially after prolonged supplementation.

Nutrition and carcinogenesis

Traditional views of nutritional carcinogenesis depend on the identification of exogenous carcinogens as major risk factors. As our understanding evolves, it is clear that the pattern of events involves not only exogenous carcinogens, but also metabolic processes and endogenous and exogenous anticarcinogens. The process is modulated by the immune system, and genetics plays a significant role. New monitoring methods provide much-needed tools for providing proof of involvement of various factors at the level of human populations.