Do dietary and supplementary intakes of antioxidants differ with smoking status?

Sources of Variation in Food-Related Metabolites during Pregnancy

The extent to which variation in food-related metabolites are attributable to non-dietary factors remains unclear, which may explain inconsistent food-metabolite associations observed in population studies. This study examined the association between non-dietary factors and the serum concentrations of food-related biomarkers and quantified the amount of variability in metabolite concentrations explained by non-dietary factors. Pregnant women (n = 600) from two Canadian birth cohorts completed a validated semi-quantitative food frequency questionnaire, and serum metabolites were measured by multisegment injection-capillary electrophoresis-mass spectrometry. Hierarchical linear modelling and principal component partial R-square (PC-PR2) were used for data analysis. For proline betaine and DHA (mainly exogenous), citrus foods and fish/fish oil intake, respectively, explained the highest proportion of variability relative to non-dietary factors. The unique contribution of dietary factors was similar (15:0, 17:0, hippuric acid, TMAO) or lower (14:0, tryptophan betaine, 3-methylhistidine, carnitine) compared to non-dietary factors (i.e., ethnicity, maternal age, gestational age, pre-pregnancy BMI, physical activity, and smoking) for metabolites that can either be produced endogenously, biotransformed by gut microbiota, and/or derived from multiple food sources. The results emphasize the importance of adjusting for non-dietary factors in future analyses to improve the accuracy and precision of the measures of food intake and their associations with health and disease.

Factors Affecting Vitamin C Status and Prevalence of Deficiency: A Global Health Perspective

A recent review of global vitamin C status has indicated a high prevalence of deficiency, particularly in low- and middle-income countries, as well as in specific subgroups within high-income countries. Here, we provide a narrative review of potential factors influencing vitamin C status globally. The in vivo status of vitamin C is primarily affected by dietary intake and supplement use, with those who supplement having a higher mean status and a lower prevalence of deficiency. Dietary intake can be influenced by cultural aspects such as traditional cooking practices and staple foods, with many staple foods, such as grains, contributing negligible vitamin C to the diet. Environmental factors can also affect vitamin C intake and status; these include geographic region, season, and climate, as well as pollution, the latter partly due to enhanced oxidative stress. Demographic factors such as sex, age, and race are known to affect vitamin C status, as do socioeconomic factors such as deprivation, education and social class, and institutionalization. Various health aspects can affect vitamin C status; these include body weight, pregnancy and lactation, genetic variants, smoking, and disease states, including severe infections as well as various noncommunicable diseases such as cardiovascular disease and cancer. Some of these factors have changed over time; therefore, we also explore if vitamin C status has shown temporal changes. Overall, there are numerous factors that can affect vitamin C status to different extents in various regions of the world. Many of these factors are not taken into consideration during the setting of global dietary intake recommendations for vitamin C.

Total Antioxidant Capacity and Pancreatic Cancer Incidence and Mortality in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

BACKGROUND

Total antioxidant capacity (TAC) reflects an individual's overall antioxidant intake. We sought to clarify whether higher TAC is associated with lower risks of pancreatic cancer incidence and mortality in the U.S. general population.

METHODS

A total of 96,018 American adults were identified from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. A ferric-reducing ability of plasma score was used to reflect an individual's TAC intake from diet and/or supplements. Cox regression was used to calculate hazard ratios (HR) for pancreatic cancer incidence, and competing risk regression was used to calculate subdistribution HRs for pancreatic cancer mortality. Restricted cubic spline regression was used to test nonlinearity.

RESULTS

A total of 393 pancreatic cancer cases and 353 pancreatic cancer-related deaths were documented. Total (diet + supplements) TAC was found to be inversely associated with pancreatic cancer incidence (HR _{quartile 4 vs. quartile 1} = 0.53; 95% confidence interval, 0.39-0.72; P _trend = 0.0002) and mortality (subdistribution HR _{quartile 4 vs. quartile 1} = 0.52; 95% confidence interval 0.38-0.72; P _trend = 0.0003) in a nonlinear dose-response manner (all P _nonlinearity < 0.01). Similar results were observed for dietary TAC. No association of supplemental TAC with pancreatic cancer incidence and mortality was found.

CONCLUSIONS

In the U.S. general population, dietary but not supplemental TAC level is inversely associated with risks of pancreatic cancer incidence and mortality in a nonlinear dose-response pattern.

IMPACT

This is the first prospective study indicating that a diet rich in antioxidants may be beneficial in decreasing pancreatic cancer incidence and mortality.

Smokers report lower intake of key nutrients than nonsmokers, yet both fall short of meeting recommended intakes

Smoking is a major risk factor in the development of preventable disease which may be due to a poorer diet and the reduced nutrient intake of smokers. Our objective was to compare and evaluate the reported intake of current smokers with that of nonsmokers among participants of a study evaluating stress and smoking. We hypothesized (1) that overall energy and nutrient intake would be reduced in smokers compared with nonsmokers and (2) that smokers would have increased noncompliance with Dietary Reference Intakes (DRIs). Men and women (smokers n=138, nonsmokers n=46) completed a 3-day diet record at baseline. Mean energy and nutrient intakes were stratified by smoking status and compared with DRI levels. The mean body mass index was 28.3±0.5kg/m2 for smokers and 27.2±1.0kg/m2 for nonsmokers. Compared with nonsmokers, the smokers reported lower intakes of energy, total polyunsaturated fatty acids, linolenic acid, docosahexaenoic acid, total sugars, calcium, iron, magnesium, phosphorus, potassium, vitamin C, riboflavin, niacin, pantothenic acid, vitamin B6, folate, vitamin A, and vitamin E. Smokers reported reduced compliance with the DRIs for iron, phosphorus, vitamin C, riboflavin, and folate compared with nonsmokers. Unlike other evaluations of smokers vs nonsmokers, we observed no difference in body weight between groups. Smokers and nonsmokers alike reported dietary intakes lower than the DRIs for many nutrients. However, the reported nutrient intake of the smokers was substantially lower than nonsmokers for key nutrients, and they were more likely to not comply with the DRIs for essential nutrients, placing them at increased risk of chronic disease.

Protective Effects of Selenium, N-Acetylcysteine and Vitamin E Against Acute Ethanol Intoxication in Rats

The aim of this study was to determine possible protective influences of selenium (Se), N-acetylcysteine (NAC), and vitamin E (Vit E) against acute ethanol (EtOH) intoxication. Thirty-six rats were divided into six groups: I (control), II (EtOH), III (EtOH + Se), IV (EtOH + Vit E), V (EtOH + NAC), and VI (EtOH + mix). Except group I, EtOH was given the other pretreated (groups III, IV, V, and VI) and untreated groups (group II). Compared with the EtOH group, serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, creatine kinase, and creatine kinase-MB levels were significantly decreased in all pretreated groups, whereas slightly diminished amylase and lipase were observed. Compared with the control group, a remarkably lower total antioxidant status (TAS), but higher total oxidant status (TOS), and oxidative stress index (OSI) were seen in brain, liver, and kidney tissues. The values of these parameters were less affected from EtOH-exposed brain tissue of EtOH + NAC and liver of EtOH + mix groups. Both significant decrease of catalase activity and marked increases of adenosine deaminase and myeloperoxidase were determined only in liver tissue of the EtOH group. Activities of these enzymes were restored in almost all pretreated groups. Moreover, an increase of xanthine oxidase activity was prevented in brain tissue of pretreated groups. In histopathological examination of the liver, hydropic degeneration, sinusoidal dilatation, mononuclear cell infiltration, and marked congestion, which were seen in the EtOH group, were prevented in all pretreated groups. Relative protection against acute EtOH toxicity, in both single and combined pretreatments of Se, NAC, and Vit E supplementation, was probably through antioxidant and free radical-neutralizing effects of foregoing materials.

Fruit and vegetable intake as a moderator of the association between depressive symptoms and cigarette smoking

BACKGROUND

Studies have consistently reported associations among depression, cigarette smoking, and fruit and vegetable intake (FVI). This study evaluated FVI as a moderator of the association between depressive symptoms and smoking.

METHODS

The authors analyzed data from the National Longitudinal Survey of Youth 1979: Child and Young Adult. The study sample was adults aged 19-33 years at baseline in the year 2004 from the Young Adult Survey portion. Moderation analyses were performed using the Johnson-Neyman technique to assess whether baseline FVI moderated the association between depressive symptoms and smoking status cross-sectionally and as a predictor of smoking cessation longitudinally at 4-year follow-up.

RESULTS

Cross-sectionally, at lower levels of FVI (<4.9 times/day), there was a significant association between smoking and depressive symptoms (P < .05), but not at higher levels of FVI (≥4.9 times/day; P > .05). Longitudinally, there was an inverse association between depressive symptoms and quitting smoking at FVI <1.2 times/day (P < .05), but there was not a significant association at FVI ≥1.2 times/day (P ≥ .05).

CONCLUSIONS

FVI moderated the association between depressive symptoms and cigarette smoking cross-sectionally and longitudinally. The cross-sectional findings might be partially explained by the longitudinal findings paired with prior research; there might be fewer smokers with high FVI because depressive symptoms are removed as an impediment to cessation. Further experimental research is warranted to test the efficacy of increased FVI as an adjunct to smoking cessation, with a possible mechanism of action being reduced depressive symptoms during quit attempts.

Anthocyanin-rich extract from Hibiscus sabdariffa calyx counteracts UVC-caused impairments in rats

CONTEXT

Ultraviolet radiation (UV) was reported to cause oxidative stress. Hibiscus sabdariffa L. (Malvaceae) calyx is commonly used in traditional Asian and African medicines and possesses strong antioxidant capacity due to its anthocyanin (ANTH) content.

OBJECTIVE

This study researched the possible protective role of Hibiscus sabdariffa calyx extract (HSCE) in UVC exposure of rats.

MATERIAL AND METHODS

Levels of serum enzymes, renal function tests, and some oxidant/antioxidant biomarkers of skin, lens, and retina tissues were monitored. Rats were exposed to UVC 4 h daily for 40 d and simultaneously received HSCE containing 2.5, 5, and 10 mg doses of ANTH in drinking water.

RESULTS

Significant (p < 0.05) increases in the levels of serum aminotransferases, lactate dehydrogenase, urea, creatinine, and uric acid were noted after UVC exposure. In skin, lens, and retina tissues, total oxidant status, oxidative stress index, lipid peroxidation, and protein oxidation escalated markedly (p < 0.05) whereas total antioxidant status, reduced glutathione, and superoxide dismutase decreased dramatically (p < 0.05) related to UVC. Co-administration of HSCE with each ANTH dose significantly (p < 0.05) reversed aforementioned parameters (except total oxidant status) almost in all tissues. The LD50 of HSCE in rats was determined to be above 5000 mg/kg.

DISCUSSION AND CONCLUSION

Our data revealed that HSCE has a remarkable potential to counteract UVC-caused impairments, probably through its antioxidant and free radical-defusing effects. Therefore, HSCE could be useful against some cutaneous and ocular diseases in which UV and oxidative stress have a role in the etiopathogenesis.

Complement c3 is inversely associated with habitual intake of provitamin A but not with dietary fat, fatty acids, or vitamin E in middle-aged to older white adults and positively associated with intake of retinol in middle-aged to older white women

Complement factor 3 (C3) has been identified as a novel risk factor for obesity-associated cardiometabolic diseases. Data in the literature suggest that C3 concentrations may be influenced by diet. Therefore, we investigated the associations of intake of total fat, specific fatty acids, and fat-soluble vitamin E (and individual tocopherols) and vitamin A (and its dietary precursors) with circulating C3. In a white cohort [Cohort on Diabetes and Atherosclerosis Maastricht (CODAM); n = 501; 59.4 ± 7.1 y; 61% men], associations of habitual nutrient intake (assessed by a food-frequency questionnaire) with circulating C3 were evaluated by using cross-sectional multiple linear regression analyses. Adjustments were first performed for age, sex, glucose metabolism status (i.e., impaired glucose metabolism or type 2 diabetes), and energy intake and subsequently for BMI, waist circumference, alcohol intake, smoking behavior, and season of blood collection. No associations with C3 were observed for total dietary fat intake or intake of specific fatty acids [saturated, monounsaturated, polyunsaturated, n-6 (ω-6), and n-3 (ω- 3) fatty acids], vitamin E, or individual tocopherols. We observed an inverse association with intake of provitamin A carotenoids α-carotene (in μg/d; regression coefficient β = -0.075; 95% CI: -0.140, -0.010; P = 0.025) and β-carotene (in μg/d; β = -0.021; 95% CI: -0.044, 0.002; P = 0.068) with C3 (in mg/L). In contrast, and only in women, dietary retinol intake (in μg/d) was positively associated with C3 (β = 0.116; 95% CI: 0.014, 0.218; P = 0.026; n = 196). In conclusion, these data suggest that fasting concentrations of C3 may, in a complex manner, be modifiable by variation in dietary provitamin A carotenoids and/or retinol content of the usual diet but most likely not by variations in fat composition and vitamin E content.

Do smoking and fruit and vegetable intake mediate the association between socio-economic status and plasma carotenoids?

BACKGROUND

The aim was to study whether the association between educational attainment and antioxidant status is mediated by smoking and fruit and vegetable intake.

METHODS

Cross-sectional analyses of the Oslo Youth Study 2006 wave were carried out. Information about education, smoking habits and diet was collected by questionnaire for 261 subjects (142 women and 119 men aged 38-42 years). Blood samples, height and weight measurements were taken by the participants' General Practitioner. Blood were analysed for plasma carotenoids. Linear regression analyses were used to examine whether smoking and fruit and vegetable intake mediate the association between education and plasma carotenoids.

RESULTS

Educational level was positively associated with β-cryptoxanthin, α-carotene and lutein/zeaxanthin, but not with total carotenoids, β-carotene or lycopene. Education was negatively associated with smoking and positively associated with fruit and vegetable intake. Smoking was negatively associated with β-cryptoxanthin, and fruit and vegetable intake was positively associated with β-cryptoxanthin (adjusted for educational level). Moreover, cigarette consumption mediated the association between education and β-cryptoxanthin by 37%, while fruit and vegetable intake mediated this association by 18%. The total mediation effect was 55%.

CONCLUSION

Smoking seemed to be more important as a mediator between education and plasma levels of β-cryptoxanthin than the intake of fruit and vegetables, but more studies are needed to establish the relative importance of smoking and diet as mediators of the association between education and antioxidant status.

Beneficial influence of topical extra virgin olive oil application on an experimental model of penile fracture in rats

Penile fracture (PF) is known as a traumatic rupture of the tunica albuginea of corpus cavernosum. In this study, we aimed to investigate the healing influence of topical extra virgin olive oil (EVOO) on PF through evaluating levels of some oxidative stress biomarkers for the first time. Histopathological evaluation was also realized. A total of 18 male Sprague-Dawley albino rats were divided into three groups of six rats each as control group, in PF (alone) group, and PF + EVOO group. Experimental PF was formed via incising from the proximal dorsal side of the penis in the rats of all groups except control. While in PF (alone) group, fracture was formed and the incision was primarily closed, in PF + EVOO group in addition to foregoing processes, EVOO was also administrated topically twice a day for 3 weeks. At the end of the experiment, all rats were killed and penectomy was carried out. While malondialdehyde, myeloperoxidase, lipid hyroperoxide, and total oxidant status significantly (p < 0.05) increased, reduced glutathione and total free sulfhydryl groups markedly (p < 0.05) decreased in PF (alone) group when compared with PF + EVOO group. Levels of these parameters were reversed to nearly normal values by topical EVOO application. Protection by EVOO is further substantiated via the improved histological findings in PF + EVOO group as against degenerative changes in the rats of PF (alone) group. Our data revealed that EVOO has protective effect in penile cavernosal tissue through probably its antioxidant, free radical defusing, anti-inflammatory, and antimicrobial effects.

Non-invasive assessment of β-carotene levels in the skin of Colombian adults

INTRODUCTION

Carotenoid pigments have antioxidant properties beneficial for human health. Use of resonance Raman spectroscopy (RRS) as a reliable method for measuring carotenoid levels in tissues such as dermis has been suggested. However, data about the variability and reproducibility of this technique should be collected before it can be used.

OBJECTIVE

To assess reproducibility of RRS for detection of total β-carotene levels in the skin of Colombian adults.

DESIGN

Forty-eight healthy men and 30 healthy women with various pigmentation levels were enrolled into the study. Measurements by RRS were performed in the palmar region and medial and lateral aspects of the arms. Odds ratio and 95% confidence intervals were calculated, adjusting for confounding factors: body mass index, waist circumference, percent body fat, age, race, smoking, and sex. Reproducibility of the technique was estimated using intraclass correlation coefficient (ICC).

RESULTS

Mean β-carotene levels were 29.9 ± 11.9 in men and 30.6 ± 8.6 in women (P=.787). No differences or significant associations were found of β-carotene levels with confounding factors assessed by sex. ICCs were 0.89 in the palmar region, 0.85 in the medial aspect of arm, and 0.82 in the external aspect of arm.

CONCLUSION

RRS spectroscopy is a reliable method for non-invasive measurement of β-carotene levels in skin, and may be used as an important biomarker of antioxidant status in nutritional and health studies in humans.

Subacute effect of cigarette smoke exposure in rats: protection by pot marigold (Calendula officinalis L.) extract

This study was carried out to determine the preventive effect of Calendula officinalis L. (pot marigold) on rats exposed to cigarette smoke (CS). Rats were divided into three groups as control, CS and CS + pot marigold (PM). The rats in the CS and CS + PM groups were subjected to CS for 1 h twice a day for 23 days. PM (100 mg/kg body weight) was given to rats in the CS + PM group by gavage, 1 h before each administration period. While malondialdehyde, protein carbonyl contents and reduced glutathione level of the CS group increased, their levels diminished by PM administration. In addition, glutathione peroxidase (GPx), superoxide dismutase activities and β-carotene, vitamins A and C levels decreased in the CS group compared to control, however activities of these enzymes and concentration of vitamins were elevated by PM supplementation. This investigation showed that administration of PM supplied relative protection against subacute CS-induced cell injury.

Dietary patterns and their associations with health behaviours in Korea

OBJECTIVE

Dietary habits, including dietary patterns, have been associated with the risk of chronic diseases, including cancer. The objective of the present study was to evaluate Korean dietary patterns as assessed by using an FFQ and associations of dietary patterns with lifestyle risk factors.

DESIGN

Dietary patterns were analysed by factor analysis using a sixteen-group FFQ. The associations between dietary patterns and lifestyle risk factors were investigated by logistic regression analysis.

SETTING

The National Cancer Center in South Korea.

SUBJECTS

The study population included 11 440 participants aged ≥ 30 years who were recruited between 2002 and 2007.

RESULTS

Compared with the lowest quartile intake of each dietary pattern, current smoking was positively associated with the Western pattern (OR = 1·55 for the highest quartile, 95 % CI 1·27, 1·88; P < 0·001) and the traditional pattern (OR = 1·34, 95 % CI 1·11, 1·62; P = 0·002) in men, but was inversely associated with the healthy pattern in both genders (P < 0·001) and the traditional pattern (OR = 0·52, 95 % CI 0·36, 0·75; P = 0·001) in women. Alcohol consumption was positively associated with all patterns in both genders, while no association was observed with the healthy pattern in women. Physical activity and dietary supplement use were positively associated with all patterns in both genders, with the exception of physical activity in women, which showed an inverse association with the traditional pattern.

CONCLUSIONS

Dietary patterns are strongly associated with health behaviours. The possible confounding effect of other risk behaviours should be appropriately considered when conducting nutritional epidemiological studies.

Factors contributing to gender differences in serum retinol and alpha-tocopherol in infertile couples

Oxidative stress is detrimental to fertility potential. Retinol and alpha-tocopherol are natural antioxidants that inhibit lipid peroxidation and protect against cell damage induced by oxidative stress. This study evaluated whether gender-related differences in antioxidant status exist among couples with infertility and, if so, to evaluate relevant factors that may contribute to such differences. Retinol and alpha-tocopherol in the sera of 40 couples and in the semen of 40 men were measured using high performance liquid chromatography. Serum retinol and alpha-tocopherol in women were significantly higher than in men (both P < 0.001). There was an inverse relationship between body mass index and serum retinol and alpha-tocopherol in both men and women. Heavy smokers (>or=20 cigarettes/day), compared with nonsmokers, had lower serum concentrations of retinol and alpha-tocopherol. Serum concentrations of retinol and alpha-tocopherol in men with normal sperm parameters were significantly higher than in those with oligozoospermia and asthenozoospermia (both P < 0.001). Lower serum retinol and alpha-tocopherol in men compared with their female partners could be related to their older age, higher body mass index and smoking habits. Low concentrations of these natural antioxidants were associated with abnormal semen parameters in men and anovulation in women.

Lack of cholesterol awareness among physicians who smoke

Cigarette use is a known risk factor for the development of coronary artery disease (CAD) as it adversely affects HDL cholesterol levels and promotes thrombogenesis. Smoking may also be associated with behavioral characteristics that potentiate the risk of CAD. A lack of cholesterol knowledge would indicate an aversion to a prevention-oriented lifestyle. Thus, our goal was to determine the association between tobacco use and knowledge of self-reported cholesterol among male physicians. Using the 1982 and follow-up questionnaires from the physician health study, we report the changes in the frequencies of awareness of self-reported total cholesterol and cardiovascular risk factors among the 22,067 participants. We classified physicians as being aware of their cholesterol if they reported a cholesterol level and unaware if the question was left unanswered. In 1997, 207 physicians were excluded, as the recorded cholesterol was not interpretable, leaving 21,860 for our follow up analyses. Using unadjusted logistic models, we determined the odds ratios (OR) and 95% confidence intervals (CI) of not reporting a cholesterol level in either 1982 or 1997 for each specified risk factor. We then evaluated whether the lack of cholesterol awareness at both time points was associated with the use of tobacco throughout the study. After 14-years of follow up, cholesterol awareness increased from 35.9 to 58.6 percent. During this period, the frequency of hypertension and hyperlipidemia treatment increased (13.5 to 40.5% and 0.57% to 19.6% respectively), as did the diagnosis of diabetes (2.40 to 7.79%). Behavioral characteristics such as a sedentary lifestyle and obesity also increased (27.8 to 42% and 43.5 to 53.5%, respectively), however the proportion of current smokers deceased from 11.1 to 4.05%. The percentages of individuals being unaware of their cholesterol decreased in all risk factor groups. However, individuals were likely to be unaware of their cholesterol at both time points if they were current smokers (1982 OR 1.44, CI 1.4–1.7; 1997 OR 1.71, CI 1.48–1.97), past smokers (1982 OR 1.12, CI 1.05–1.18; 1997 OR 1.13, CI 1.06–1.20), overweight (BMI 25 kg/m2) or sedentary. In addition, physicians who never quit smoking were likely to be unaware of their cholesterol throughout the study (OR 1.42, CI 1.21–1.67). Cholesterol awareness in general and among those with CAD risk factors improved after 14-years of follow-up. However, the likelihood of being unaware was greater among smokers at both time points. Therefore, smokers do not appear to take advantage of other preventive strategies that would minimize their risk of developing CAD.

Smoking status in relation to serum folate and dietary vitamin intake

OBJECTIVE

Cigarette smoke itself is an abundant source of free radicals and a major cause of oxidative stress, to which plasma antioxidants function as a vital protective and counterbalancing mechanism. The objective of this study was to investigate into the relationship between smoking status and serum and dietary micronutrient concentrations.

DESIGN

Cross-sectional study SUBJECTS - SETTING: 502 farmers from the Valley of Messara in Crete were randomly selected and examined. Complete three-day and 24-hr recall questionnaires were collected along with anthropometrical, physical activity and clinical data from all participating subjects.

RESULTS

After adjusting for age, gender and number of fasting days adhered to per year, current smokers were found to have a lower dietary intake of vitamin C (112.1 mg vs. 136.4 mg, p = 0.03), fibre (16.6 g vs. 19.1 g, p = 0.006) and fruits and vegetables (339 g vs. 412 g, p = 0.014), while dietary vitamin B1 intake was found to be higher (1.7 mg vs. 1.4 mg, p = 0.02) in comparison to non/ex smokers. Dietary intake of meat, folate and vitami A, E, B2, B6 and B12 did not differ between the groups. Controlling age, gender, fasting days and dietary micronutrient intake, serum folate levels were found to be lower among smokers (geometric mean 15.3 nmol/L vs. 17.7 nmol/L, p = 0.023), while serum iron and vitamin B12 levels were not affected by smoking status.

CONCLUSION

Current smoking status affects dietary nutrient intake as well as plasma folate levels. The above coherence between antioxidant depletion and reduced antioxidant intake may predispose smokers to the premature development of tobacco related mortality and morbidity.

Consumption of fruit and vegetables and risk of lung cancer: a case-control study in Galicia, Spain

OBJECTIVE

We analyzed the effect of fruit and vegetable intake on lung cancer risk in a population in northwest Spain.

METHODS

We analyzed data from a hospital-based case-control study including 295 histologically confirmed cases and 322 controls. Controls were patients attending the hospital for minor surgery. There was a minimum age limit of 35 y and sampling was carried out on a sex-frequency basis.

RESULTS

After adjustment for sex, age, tobacco use, and occupation, no protective effect of overall consumption of fruit was present (odds ratio 1.49, 95% confidence interval 0.81-2.73). Green leafy vegetables conferred a protective effect (odds ratio 0.50, 95% confidence interval 0.30-0.83).

CONCLUSION

These findings indicate that green leafy vegetables, rather than fruit, might have a genuine protective effect against lung cancer.

Dietary patterns associated with vitamin/mineral supplement use and smoking among women of the E3N-EPIC cohort

BACKGROUND/OBJECTIVES

An understanding of the relationships between dietary habits and supplement use or smoking is useful for aetiological studies and surveillance purposes. The objective of this study is to describe dietary patterns associated with vitamin/mineral supplement use and smoking habits in French women.

METHODS

Scores for dietary patterns were obtained by factor analysis in 64,252 women from the French E3N-EPIC cohort. The association with supplement and tobacco use was investigated by logistic regression analysis.

RESULTS

We identified three dietary patterns: 'processed meat/starchy foods' (fast foods, processed meat, rice/pasta/semolina and cakes and few vegetables); 'fruit/vegetables' (fruits, vegetables, seafood, vegetable oils and yoghurt); and 'alcohol/meat products' (alcohol, meat and meat products, and coffee, and few fruits and soup). Supplement use was positively associated with the fruit/vegetables pattern (multivariate OR for quartile 4 versus 1 (OR(4))=1.55, 95% confidence interval: 1.47-1.63), and inversely associated with the processed meat/starchy foods (OR(4)=0.84; 0.80-0.89) and alcohol/meat products (OR(4)=0.69; 0.66-0.73) patterns (P trend for all associations <0.0001). As compared with never smoking, current smoking was inversely associated with the fruit/vegetables pattern (OR(4)=0.85; 0.78-0.92), while former smoking was positively associated with the fruit/vegetables pattern (OR(4)=1.32; 1.25-1.40); both current and former smoking were inversely associated with the processed meat/starchy foods pattern (OR(4)=0.57; 0.53-0.62 and 0.64; 0.60-0.67, respectively); whereas current and former smoking were both strongly positively associated with the alcohol/meat products pattern (OR(4)=5.78; 5.26-6.36 and 2.03; 1.91-2.15, respectively); P trend for all associations was <0.001.

CONCLUSIONS

Supplement use and smoking are strongly associated with dietary patterns.

The prevalence of inflammatory periodontitis is negatively associated with serum antioxidant concentrations

Chronic periodontitis is an inflammatory disease that affects the supporting tissues of the teeth. It is initiated by specific bacteria within the plaque biofilm and progresses due to an abnormal inflammatory-immune response to those bacteria. Periodontitis is the major cause of tooth loss and is also significantly associated with an increased risk of stroke, type-2 diabetes and atheromatous heart disease. Oxidative stress is reported in periodontitis both locally and peripherally (serum), providing potential mechanistic links between periodontitis and systemic inflammatory diseases. It is therefore important to examine serum antioxidant concentrations in periodontal health/disease, both at an individual species and total antioxidant (TAOC) level. To determine whether serum antioxidant concentrations were associated with altered relative risk for periodontitis, we used multiple logistic regression for dual case definitions (both mild and severe disease) of periodontitis in an analysis of 11,480 NHANES III adult participants (>20 y of age). Serum concentrations of vitamin C, bilirubin, and TAOC were inversely associated with periodontitis, the association being stronger in severe disease. Vitamin C and TAOC remained protective in never-smokers. Higher serum antioxidant concentrations were associated with lower odds ratios for severe periodontitis of 0.53 (CI, 0.42,0.68) for vitamin C, 0.65 (0.49,0.93) for bilirubin, and 0.63 (0.47,0.85) for TAOC. In the subpopulation of never-smokers, the protective effect was more pronounced: 0.38 (0.26,0.63, vitamin C) and 0.55 (0.33,0.93, TAOC). Increased serum antioxidant concentrations are associated with a reduced relative risk of periodontitis even in never-smokers.

Plasma levels of six carotenoids in nine European countries: report from the European Prospective Investigation into Cancer and Nutrition (EPIC)

Background:

In addition to their possible direct biological effects, plasma carotenoids can be used as biochemical markers of fruit and vegetable consumption for identifying diet–disease associations in epidemiological studies. Few studies have compared levels of these carotenoids between countries in Europe.

Objective:

Our aim was to assess the variability of plasma carotenoid levels within the cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC).

Methods:

Plasma levels of six carotenoids – α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein and zeaxanthin – were measured cross-sectionally in 3043 study subjects from 16 regions in nine European countries. We investigated the relative influence of gender, season, age, body mass index (BMI), alcohol intake and smoking status on plasma levels of the carotenoids.

Results:

Mean plasma level of the sum of the six carotenoids varied twofold between regions (1.35μmoll−1for men in Malmö, Sweden vs. 2.79μmoll−1for men in Ragusa/Naples, Italy; 1.61μmoll−1for women in The Netherlands vs. 3.52μmoll−1in Ragusa/Naples, Italy). Mean levels of individual carotenoids varied up to fourfold (α-carotene: 0.06μmoll−1for men in Murcia, Spain vs. 0.25μmoll−1for vegetarian men living in the UK). In multivariate regression analyses, region was the most important predictor of total plasma carotenoid level (partialR2=27.3%), followed by BMI (partialR2=5.2%), gender (partialR2=2.7%) and smoking status (partialR2=2.8%). Females had higher total carotenoid levels than males across Europe.

Conclusions:

Plasma levels of carotenoids vary substantially between 16 different regions in Italy, Greece, Spain, France, Germany, the UK, Sweden, Denmark and The Netherlands. Compared with region of residence, the other demographic and lifestyle factors and laboratory measurements have limited predictive value for plasma carotenoid levels in Europe.

The inhibitory effect of vitamin E on cigarette smoke-induced oxidative damage to the rat urothelium: can it prevent transitional cell carcinoma?

INTRODUCTION

We aimed to detect reactive oxygen species (ROS) and assess subsequent carcinogenesis in terms of cellular proliferation in the bladder and kidney epithelial tissues of rats exposed to cigarette smoke (CS), and to investigate the changes following vitamin E treatment.

MATERIALS AND METHODS

Twenty-four male Sprague-Dawley rats were divided into 3 groups: group 1 was kept intact; group 2 was subjected to CS exposure for 8 weeks, and group 3 received intraperitoneal vitamin E injections (200 mg/kg/week) for 8 weeks in addition to CS exposure. Histological examination and Ki67 antigen expression measurements were made from bladder and renal pelvic tissue sections. Luminol-amplified chemiluminescence was used to measure ROS levels. All results were compared using a one-way ANOVA test.

RESULTS

In CS-exposed rats, light microscopy of renal and bladder tissues revealed nonspecific epithelial changes; however, Ki67 expression was significantly increased in bladder tissues compared to other groups (17.5 +/- 4.7, 35 +/- 2.9 and 18.7 +/- 5.1% in groups 1, 2 and 3, respectively, p < 0.05). Chemiluminescence levels in bladder and renal tissues were also significantly higher in the CS-exposed animals (78.1 +/- 11.4, 148 +/- 13.3, 97.8 +/- 6.1 rlu/mg for the bladder, and 99.8 +/- 12.2, 176.1 +/- 27.9, 67.1 +/- 9 rlu/mg, for renal pelvic tissues, respectively, p < 0.05).

CONCLUSIONS

Vitamin E can alleviate CS-induced oxidative damage in rat bladder and kidney epithelium suggesting a potential role for vitamin E in the prevention of CS-mediated carcinogenesis.

Monitoring micronutrients in cigarette smokers

Smoking is associated with oxidative stress and increased risks of many chronic diseases that both shorten life and impair its quality. Low concentrations of several micronutrients, especially the antioxidants vitamin C and beta-carotene, are also associated with smoking, and there has been much interest in determining whether deficiencies in micronutrients are involved etiologically in smoking-related diseases. The objective of this review was to bring together reports on dietary intakes, biochemical indicators of micronutrient status, and results of some intervention studies on micronutrients where authors had compared outcomes in smokers and non-smokers. The micronutrients discussed are vitamins A, E, and C; the carotenoids; some of the B-vitamin group; and the minerals selenium, zinc, copper, and iron. The data were then examined to determine whether effects on the biochemical markers of micronutrient status were due to differences in dietary intakes between smokers and non-smokers or to the consequences of inflammatory changes caused by the oxidative stress of smoking. It was concluded that although smoking is associated with reduced dietary intake of vitamin C and carotenoid-containing foods, inflammatory changes increase turnover of these micronutrients so that blood concentrations are still lower in smokers than non-smokers even when there is control for dietary differences. In the case of vitamin E, there is some evidence for increased turnover of this nutrient in smokers, but this has little to no influence on blood concentrations, and there are no differences in dietary intake of vitamin E between smokers and non-smokers. Serum concentrations of vitamin A, folate, and vitamin B12 and B6 markers do not appear to be influenced by smoking, although there is some influence of dietary intake on concentrations of these nutrients in the body. In the case of the minerals examined, the main effects on biochemical markers of mineral status were attributed to inflammation and were therefore greater in heavy or long-term smokers. Serum concentrations of selenium and erythrocyte GPx activity were lower in smokers. Erythrocyte CuZn-SOD activity and serum ceruloplasmin concentrations were elevated, while serum zinc concentrations were depressed only in heavy smokers. Lastly, smoking appears to affect iron homeostasis mainly by changing hemoglobin concentrations, which were in general increased. Serum iron, TfR, and ferritin were mostly unaffected by smoking, except in pregnancy where there is evidence of increased erythropoiesis causing lower saturation of plasma transferrin and some evidence of lowering of iron stores.

Effect of bacoside A on brain antioxidant status in cigarette smoke exposed rats

Free radicals mediated oxidative stress has been implicated in the pathogenesis of smoking-related diseases and antioxidant nutrients are reported to prevent the oxidative damage induced by smoking. Therefore, the present study was conducted to evaluate the antioxidant role of bacoside A (triterpenoid saponin isolated from Bacopa monniera) against chronic cigarette smoking induced oxidative damage in rat brain. Adult male albino rats were exposed to cigarette smoke for a period of 12 weeks and simultaneously administered with bacoside A (10 mg/kg b.w./day, p.o.). Antioxidant status of the brain was assessed from the levels of reduced glutathione, vitamin C, vitamin E, and vitamin A and the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. The levels of copper, iron, zinc and selenium in brain and serum ceruloplasmin activity were also measured. Oxidative stress was evident from the diminished levels of both enzymatic and non-enzymatic antioxidants. Alterations in the levels of trace elements with accumulation of copper and iron, and depletion of zinc and selenium were also observed. Bacoside A administration improved the antioxidant status and maintained the levels of trace elements. These results suggest that chronic cigarette smoke exposure enhances oxidative stress, thereby disturbing the tissue defense system and bacoside A protects the brain from the oxidative damage through its antioxidant potential.

A cross-sectional analysis demonstrated the healthy volunteer effect in smokers

OBJECTIVE

This cross-sectional descriptive analysis sought to determine if a healthy volunteer effect can be demonstrated among smokers selected to participate in a dietary intervention trial.

STUDY DESIGN AND SETTING

Body mass index (BMI), body fat, physical activity, dietary intake, and plasma concentration of antioxidant nutrients and carotenoids were assessed cross-sectionally, at the time of enrollment into a dietary intervention trial, among 136 adult smokers.

RESULTS

Mean BMI was below national age- and gender-specific averages as was prevalence of overweight and obesity. Physical activity was reported to average 15.4 h/wk. Compared with other sample populations of smokers, our smokers reported lower total fat and cholesterol intakes, higher vitamin C and beta-carotene intakes, and generally equal vitamin E intakes. Plasma ascorbic acid, alpha-tocopherol, alpha- and beta-carotene, and beta-cryptoxanthin concentrations were higher than those of smokers surveyed by NHANES III.

CONCLUSION

These findings suggest that a "healthy volunteer effect" can be described among adult smokers. Future dietary intervention trials among smokers should cautiously estimate sample size because smokers electing to participate may report healthier dietary patterns than other smokers. Screening criteria regarding baseline micronutrient status of smokers should be evaluated given that intervention effects may be dependent on overall health status.

Correlates of active and passive smoking in the California Teachers Study cohort

OBJECTIVES

These analyses were designed to describe characteristics associated with active and passive smoking in a large cohort of women in order to identify possible confounders of the relationship between smoking exposures and breast cancer risk.

METHODS

Analyses were based on 1995 data collected from the California Teachers Study (CTS) and were restricted to those with complete and usable tobacco data (n = 128,174). Age-adjusted and race-adjusted odds ratios (OR) were generated by unconditional logistic regression.

RESULTS

Compared with never smokers, both current and former smokers experienced menarche at an earlier age. Current and former smokers also were more likely than their never smoking counterparts to be nulliparous. Among parous women, current, but not former smokers were less likely than never smokers to have had their first child at an older age. Similarly, among never smokers, those exposed to household passive smoking experienced menarche at an earlier age, were more likely to be nulliparous, and among parous women, were less likely to have had their first child at an older age than never smokers not exposed to passive smoking. Greater alcohol consumption was strongly associated with both active and passive smoking exposures. Compared with never smokers, current smokers were less likely to take antioxidant supplements, whereas former smokers were more likely to take antioxidant supplements. Among never smokers, antioxidant use did not differ depending on passive smoking exposure. A number of other dietary correlates of active and passive smoking were identified.

CONCLUSIONS

We identified a number of reproductive and dietary correlates to smoking exposures that underscore the need to adjust for such factors in an analysis of smoking and breast cancer and potentially other disease entities. Furthermore, these findings may suggest potential mechanisms underlying an association between breast cancer and smoking.

Geographical, seasonal and gender differences in folate status among Chinese adults

Low blood folate concentrations have been associated with cardiovascular disease, neural tube defects and selected cancers, but little is known about folate status in Chinese adults. In a cross-sectional study we measured the plasma and red blood cell folate concentrations in 2422 Chinese men and women aged 35 to 64 y, living in the North and South of China, who provided blood samples either in March or September of 2001. The geometric mean concentrations of plasma and red blood cell folate were lower among Northerners than Southerners (adjusted geometric means, 8.4 and 502, and 16.7 and 811 nmol/L, respectively) controlling for age, gender, season (spring and fall), area (urban and rural), BMI, multivitamin use, alcohol intake and current smoking status. We estimated that approximately 40% of the Northerners and approximately 6% of the Southerners had plasma folate concentrations lower than the 6.8 nmol/L (3 microg/L), and approximately 30% of the Northerners and approximately 4% of the Southerners had red blood cell folate concentrations lower than the 363 nmol/L (160 microg/L), levels used to define folate deficiency. Within each region, men had lower plasma folate concentrations than women (6.9 versus 9.8 nmol/L in the North, and 14.5 versus 19.6 nmol/L in the South). In men, current smokers had a higher risk of folate deficiency compared with nonsmokers [adjusted odds ratios, 1.9 (95% CI, 1.4-2.6) for plasma folate deficiency and 2.5 (95% CI, 1.7-3.6) for red blood cell folate deficiency (P < 0.001)]. Our findings suggest that a large proportion of Chinese adults have a low folate status, especially those living in northern China where 60% of the men are plasma folate deficient in the spring. Further studies are needed to elucidate the factors that influence folate concentrations among middle-aged Chinese and to evaluate possible intervention strategies.

Dietary intake in male and female smokers, ex-smokers, and never smokers: the INTERMAP study

This report examines dietary intakes in smokers, ex-smokers, and never smokers in INTERMAP. The 4680 participants aged 40-59 years-from 17 population samples in four countries (China, Japan, UK, USA)-provided four 24-h recalls to assess nutrient intakes and two 24-h urine collections to assess excretion of urea, sodium (Na), potassium (K), etc. Compared to never smokers, current smokers generally consumed more energy from alcohol and saturated fats (SFA), less energy from vegetable protein and carbohydrates, less dietary fibre, vitamin E, beta carotene, vitamin C, thiamine, riboflavin, folate, vitamin B6, calcium, iron, phosphorus, magnesium (Mg), and K per 1000 kcal, excreted less K and urea (marker of dietary protein), had a lower ratio of polyunsaturated fat (PFA) to SFA intake, higher Keys dietary lipid score, and higher dietary and urinary Na/K. There were few differences between smokers and never smokers for total energy intake, energy from total and animal protein, monounsaturated fats, PFA, omega 3 and omega 6 PFA, dietary cholesterol, total vitamin A, retinol, vitamin D, vitamin B12, and urinary and dietary Na. Compared to ex-smokers, smokers generally consumed less energy from vegetable protein, omega 3 PFA, carbohydrates, less dietary fibre, beta carotene, vitamin E, vitamin C, thiamine, riboflavin, folate, vitamin B6, iron, phosphorus, Mg, had lower PFA/SFA, and excreted less urea and K. In conclusion, INTERMAP results are consistent with other reports indicating that smokers have less healthful diets than nonsmokers. Public health interventions in smokers should focus not only on helping them to quit smoking but also on improving their diets to further reduce cancer and cardiovascular disease risks.

Green vegetable drink consumption protects peripheral lymphocytes DNA damage in Korean smokers

Smoking increases indices of free radical-mediated damage of DNA which are potential underlying processes in the pathogenesis of many diseases. In this study, we evaluated whether 8 weeks of green vegetable drink (Angelica keiskei based juice) supplementation to smokers can be protective against lymphocytic DNA damage. Twenty smokers were given 240 ml of commercially available green vegetable drink every day for 8 weeks. The DNA damage was determined using single cell gel electrophoresis (COMET assay) and the damage was quantified by measuring tail length (TL), tail moment (TM), and percent DNA in tail. Eight weeks of green vegetable drink consumption resulted in a significant in lymphocytes DNA damage in all three measurements; TL, TM and % DNA in tail. These results support the hypothesis that green vegetable drink exerts a cancer-protective effect via a decrease in oxidative damage to DNA in humans.

Effect of orange juice intake on vitamin C concentrations and biomarkers of antioxidant status in humans

BACKGROUND

Consumption of fruit and vegetables is associated with improved health and a decreased prevalence of chronic degenerative processes.

OBJECTIVES

The objectives were to assess the bioavailability of vitamin C from orange juice and its influence on plasma vitamin C and 8-epi-prostaglandin F(2 alpha) (8-epi-PGF(2 alpha)) concentrations in a healthy human population.

DESIGN

Six men and 6 women consumed 500 mL commercial fresh-squeezed orange juice/d for 14 d, corresponding to an intake of 250 mg ascorbic acid/d. On the first day of the study, the subjects drank the juice in one dose (dose-response study), and on days 2-14 they consumed 250 mL in the morning and 250 mL in the afternoon. Blood was collected every hour for 6 h on the first day and again on days 7 and 14.

RESULTS

Baseline plasma vitamin C concentrations were significantly higher (P = 0.03) among the women than among the men (56.4 +/- 4.4 compared with 44.3 +/- 3.5 micromol/L). In the dose-response study, the maximum increase in plasma vitamin C occurred 3 h postdose in both the men and the women. Vitamin C concentrations remained significantly higher on days 7 and 14 than at baseline. Baseline concentrations of 8-epi-PGF(2 alpha) were significantly higher (P = 0.03) among the men than among the women (249.6 +/- 25.4 compared with 177.7 +/- 6.2 pg/mL) but decreased significantly (P = 0.04) by day 14 of the intervention. A significant inverse correlation was observed between vitamin C and 8-epi-PGF(2 alpha) (r = -0.791, P = 0.0022). Among smokers, baseline vitamin C was lower and 8-epi-PGF(2 alpha) higher than among nonsmokers.

CONCLUSIONS

Drinking orange juice (500 mL/d) increases plasma concentrations of vitamin C and reduces concentrations of 8-epi-PGF(2 alpha) in humans. These effects were significantly more pronounced in smokers.

A population-based case-control study on fruit and vegetable intake and lung cancer: a paradox effect?

A population-based case-control study was carried out in Northwest Spain to analyze the effect of fruit and vegetable intake on the appearance of lung cancer. A non-significant protective association was found for overall consumption of leafy green and other vegetables, with consumption once a day or more vs. less than once a week yielding odds ratios of 0.63 [95% confidence interval (CI) = 0.24-1.63] for leafy green vegetables and 0.64 (95% CI = 0.30-1.36) for other vegetables. A significant protective association was found for potato consumption. No protective associations were recorded for fruit, whether overall or singly; instead, fruit consumption once a day or more vs. less than once a week registered a risk of 2.16 (95% CI = 1.02-4.58). Although the possibility that this effect may be due to a phenomenon of reverse causation cannot be ruled out, these results could support other reports and hypotheses which indicate that the protective effect of fruit might not be as pronounced as generally thought.

Dietary vitamin C intake is inversely related to cough and wheeze in young smokers

We aimed to investigate whether dietary vitamin C intake, an important antioxidant, is inversely related to self-reported respiratory symptoms in young adults of a community. A random sample of 4300 subjects, aged 20-44 years, living in Bergen, Norway, received a postal questionnaire on respiratory symptoms; 80% responded. Vitamin C intake (mg per week) was estimated from a food-frequency questionnaire asking how often the subject, during the last year, had consumed units of orange juice, oranges, potatoes, carrots and tomatoes. Significant differences in the intake of vitamin C were observed across smoking categories with current smokers having the lowest intake, while there was no variation by gender, age or occupational dust exposure. Dietary vitamin C intake was in univariate analyses inversely related to "morning cough", "chronic cough", "wheeze" and "wheeze ever". After adjusting for gender, age, body mass index, "occupational exposure" pack-years as well as having and stratified on smoking habits in multiple logistic regression analyses, the relationship between dietary vitamin C intake and "cough" and "wheeze" tended to be associated to smoking. The odds ratio (OR) for "morning cough" was 0.68 (95% CI: 0.35-0.95), "chronic cough" OR 0.69 (95% CI: 0.47-1.04) and "wheeze ever" OR 0.75 (95% CI: 0.56-1.01) in current-smokers with dietary vitamin C intake in the upper (> or =395 mg/ week) vs. the lower (<209 mg/week) tertile. The OR for "wheeze" was 0.56 (95% CI: 0.35-0.88) in ex-smokers. The magnitude ofthese effects remained after excluding subjects with supplementary vitamin C intake (n=199) from the statistical analyses. Among young Norwegian adults, having a low prevalence of asthma and high prevalences of smoking-related respiratory symptoms, dietary vitamin C intake may act as an antioxidant and thereby reduce cough and wheeze in smokers having high oxidant stress.

Smoking and exposure to environmental tobacco smoke decrease some plasma antioxidants and increase gamma-tocopherol in vivo after adjustment for dietary antioxidant intakes

BACKGROUND

Free radicals in cigarette smoke may cause oxidative damage to macromolecules, contributing to cardiovascular diseases and cancer. Decreased plasma antioxidant concentrations may indicate cigarette smoke-related oxidative stress.

OBJECTIVE

We compared the effects on plasma antioxidant concentrations in cotinine-confirmed active and passive smokers with those in nonsmokers, independent of differences in dietary intakes and other covariates.

DESIGN

Plasma samples from 83 smokers, 40 passive smokers, and 36 nonsmokers were analyzed for total ascorbic acid, alpha- and gamma-tocopherols, 5 carotenoids, retinol, and cotinine. Groups were compared by using analysis of variance with adjustment for sex, age, race, body mass index, alcohol intake, triacylglycerol concentration, fruit and vegetable intakes, and dietary antioxidants.

RESULTS

After adjustment for dietary antioxidant intakes and other covariates, smokers and passive smokers had significantly lower plasma beta-carotene concentrations than did nonsmokers (0.15, 0.17, and 0.24 micro mol/L, respectively) and significantly higher gamma-tocopherol concentrations (7.8, 7.8, and 6.5 micro mol/L, respectively). Smokers had significantly lower plasma ascorbic acid and beta-cryptoxanthin concentrations than did nonsmokers and passive smokers (ascorbic acid: 43.6, 54.5, and 54.6 micro mol/L, respectively; beta-cryptoxanthin: 0.12, 0.16, and 0.16 micro mol/L, respectively) and significantly lower concentrations of lutein and zeaxanthin than did nonsmokers (0.33 compared with 0.41 micro mol/L). The P values for all the differences described above were < 0.05. No significant differences in plasma concentrations of alpha-tocopherol, alpha-carotene, total carotenoids, lycopene, or retinol were observed.

CONCLUSIONS

These results indicate that cigarette smokers and nonsmokers exposed to cigarette smoke have a significantly lower plasma antioxidant status than do unexposed nonsmokers, independent of differences in dietary antioxidant intakes. Further research is required to explain why plasma gamma-tocopherol concentrations were significantly higher in smokers and passive smokers than in nonsmokers.

Epidemiology of lung cancer

In the United States, lung cancer remains the leading cause of cancer death in both men and women even though an extensive list of risk factors has been well-characterized. Far and away the most important cause of lung cancer is exposure to tobacco smoke through active or passive smoking. The reductions in smoking prevalence in men that occurred in the late 1960s through the 1980s will continue to drive the lung cancer mortality rates downward in men during the first portion of this century. This favorable trend will not persist unless further reductions in smoking prevalence are achieved.

The influence of cigarette smoking on circulating concentrations of antioxidant micronutrients

Cigarette smoke is a significant source of oxidative stress, one potential mechanism for its untoward health effects. The antioxidant defense system is partly comprised of antioxidant micronutrients, making it important to understand the relationship between cigarette smoking and circulating concentrations of antioxidant micronutrients. A synthesis of the literature shows that compared with nonsmokers, on average, active smokers have greater than 25% lower circulating concentrations of ascorbic acid, alpha-carotene, beta-carotene, and cryptoxanthin. The differences in blood concentrations of these micronutrients in former smokers is intermediate between never and current smokers, but average circulating concentrations of alpha-carotene, beta-carotene, and cryptoxanthin were 16-22% lower in former smokers compared with never smokers. Differences in dietary habits between smokers and nonsmokers could potentially account for these associations. Dietary micronutrient intake is associated with blood micronutrient concentrations. Furthermore, patterns of micronutrient consumption by smoking status mimic the pattern of associations observed for blood concentrations. For example, when pooled across studies intake of vitamin C was 16% lower in current smokers and 2% lower in former smokers than in never smokers; the corresponding figures for beta-carotene were 17 and 4%, respectively. Despite the strong potential for confounding, the differences observed between current smokers and nonsmokers seem to be due to an acute effect of smoking based on results of studies of smoking and antioxidant micronutrient concentrations that have either adjusted for dietary antioxidant micronutrient intake and other potential confounding factors or documented short term changes in circulating antioxidant micronutrient concentrations in smokers before and after smoking cigarettes. The associations observed with active smoking also appear to hold true for passive smoking, implying that even low-dose exposures to tobacco smoke can result in lowered circulating antioxidant micronutrient concentrations. Smoking was more weakly associated with circulating concentrations of vitamin E and the nonprovitamin A carotenoids lutein/zeaxanthin and lycopene. The combined evidence supports the conclusion that cigarette smoking is independently associated with lowered circulating concentrations of ascorbic acid and provitamin A carotenoids. These associations have implications for the design and interpretation of epidemiologic studies of antioxidant micronutrients in relation to health and disease. To the extent that these micronutrients are associated with health and longevity, this evidence documents yet another deleterious consequence of cigarette smoking on human health.

Lifestyle factors affecting fruit and vegetable consumption in the UK Women's Cohort Study

The UK Women's Cohort Study (UKWCS) was originally set up to look at morbidity and mortality data on subjects with a wide range of dietary intakes including vegans, lacto-ovo vegetarians, non-red meat eaters and red meat eaters. The aim of the present study was to investigate factors that affect fruit and vegetable consumption within this particular cohort of women. Females of ages 35-69 years, taking part in the UK Women's Cohort Study (N=35 367), provided health and lifestyle information including a 217-item food frequency questionnaire. In multiple logistic regression, the strongest predictors of a higher reported level of fruit and vegetable consumption were being a vegetarian or vegan, taking vitamin or mineral supplements, being married, educated to A-level or degree level and belonging to a higher socio-economic group. Conversely, smokers were found to be only half as likely as non-smokers to be high fruit and vegetable consumers. These lifestyle distinctions among three levels of reported fruit and vegetable consumption are relevant to the future targeting of health promotion strategies.

Health impact of "reduced yield" cigarettes: a critical assessment of the epidemiological evidence

Cigarettes with lower machine measured "tar" and nicotine yields have been marketed as "safer" than high tar products over the last four decades, but there is conflicting evidence about the impact of these products on the disease burden caused by smoking. This paper critically examines the epidemiological evidence relevant to the health consequences of "reduced yield" cigarettes. Some epidemiological studies have found attenuated risk of lung cancer but not other diseases, among people who smoke "reduced yield" cigarettes compared to smokers of unfiltered, high yield products. These studies probably overestimate the magnitude of any association with lung cancer by over adjusting for the number of cigarettes smoked per day (one aspect of compensatory smoking), and by not fully considering other differences between smokers of "high yield" and "low yield" cigarettes. Selected cohort studies in the USA and UK show that lung cancer risk continued to increase among older smokers from the 1950s to the 1980s, despite the widespread adoption of lower yield cigarettes. The change to filter tip products did not prevent a progressive increase in lung cancer risk among male smokers who began smoking during and after the second world war compared to the first world war era smokers. National trends in vital statistics data show declining lung cancer death rates in young adults, especially males, in many countries, but the extent to which this is attributable to "reduced yield" cigarettes remains unclear. No studies have adequately assessed whether health claims used to market "reduced yield" cigarettes delay cessation among smokers who might otherwise quit, or increase initiation among non-smokers. There is no convincing evidence that past changes in cigarette design have resulted in an important health benefit to either smokers or the whole population. Tobacco control policies should not allow changes in cigarette design to subvert or distract from interventions proven to reduce the prevalence, intensity, and duration of smoking.

Diet and lung cancer: a new approach

Lung cancer is one of major public health problems facing the world today, owing to the high incidence of the disease and its poor prognosis. Although the principal cause of lung cancer is tobacco use, smokers find it extremely difficult to quit the habit. Hence, there is a need to take action targeted at other risk factors for this disease. One such factor is diet, which is known to be able to raise or lower the risk of lung cancer. This paper seeks to complement other reviews in the field and to shed more light both on the influence that dietary factors may have upon the occurrence of this neoplasm and on the causes of this possible effect.

Influence of Increased Fruit and Vegetable Intake on Plasma and Lipoprotein Carotenoids and LDL Oxidation in Smokers and Nonsmokers

Background: Epidemiological studies suggest a cardioprotective role for carotenoid-rich foods. Smokers have a high risk of cardiovascular disease and low dietary intake and plasma concentrations of carotenoids. The aim of this study was to determine the carotenoid response of smokers and nonsmokers to increased intake of 300–400 g of vegetables and its effect on LDL oxidation.

Methods: After a depletion period of 8 days, 34 healthy females (18 nonsmokers, 16 smokers) were supplemented with β-carotene- and lutein-rich (green) and lycopene-rich (red) vegetable foods, each for 7 days.

Results: Baseline concentrations (mean ± SD) of plasma β-carotene (0.203 ± 0.28 μmol/L vs 0.412 ± 0.34 μmol/L; P &lt;0.005) and lutein (0.180 ± 0.10 vs 0.242 ± 0.11 μmol/L; P &lt;0.05) but not lycopene (0.296 ± 0.10 vs 0.319 ± 0.33 μmol/L) were significantly lower in smokers compared with nonsmokers. After supplementation, the change (supplementation minus depletion) in plasma β-carotene (0.152 ± 0.43 vs 0.363 ± 0.29 μmol/L in smokers vs nonsmokers; P = 0.002) and LDL lutein (0.015 ± 0.03 vs 0.029 ± 0.03 μmol/mmol cholesterol; P = 0.01) was significantly lower in smokers than nonsmokers. Green-vegetable supplementation had no effect on the resistance of LDL to oxidation (lag-phase) in either group. After red-vegetable supplementation, plasma and LDL lycopene concentrations were increased in both groups, but only nonsmokers showed a significant increase in the lag-phase (44.9 ± 9.5 min at baseline, 41.4 ± 6.5 min after depletion, and 49.0 ± 8.9 min after supplementation; P &lt;0.01) compared with depletion.

Conclusions: In this short-term intervention study, a dietary intake of &gt;40 mg/day of lycopene by a group of nonsmoking individuals significantly reduced the susceptibility of LDL to oxidation, whereas an equivalent increase in lycopene by a group of smokers showed no such effect.

Clustering of lifestyle behaviors: the relationship between cigarette smoking, alcohol consumption, and dietary intake

PURPOSE

To examine relationships between cigarette smoking, alcohol use, and dietary intake.

DESIGN

Respondents to the U.S. Department of Agriculture's Continuing Survey of Food Intakes by Individuals, a nationwide probability sample conducted from January 1994 through January 1997 (n = 23,602; response rate = 80%), were selected. Adults ages 19 years and older were grouped according to their smoking and drinking habits. Selected demographic variables, food group servings, food energy, and densities of selected nutrients were compared.

SETTING

In-home interviews were conducted in the 50 states and the District of Columbia.

SUBJECTS

The selected sample (n = 6745) included 3229 nonsmokers, 1701 former smokers, and 1808 current smokers, and 2284 abstainers, 2713 occasional drinkers, 1000 moderate drinkers, and 748 liberal drinkers.

MEASURES

Responses to standard questionnaires were examined by Student's t-test, chi 2, one-way analysis of variance, and univariate and multivariate analyses of covariance.

RESULTS

Men were more likely than women to be current smokers and liberal drinkers (64% vs. 40% and 62% vs. 38%). For both, the use of cigarettes and alcohol was closely related. An additive relationship was observed between smoking/drinking classification and lower food group servings and nutrient intakes. Although cigarette and alcohol use may have been underreported, these findings support previous ones showing poor food choices along with lower nutrient intakes as smoking and drinking increase.

CONCLUSIONS

Smoking and drinking habits may alter individuals' food selections and nutrient intakes. Future interventions for health promotion may achieve greater success by targeting multiple risk factors simultaneously or sequentially.

Differences and trends in antioxidant dietary intake in smokers and non-smokers, 1980-1992: the Minnesota Heart Survey

PURPOSE

Differences and secular trends in dietary antioxidant vitamin intake (vitamins E, C, and beta-carotene) in current non-smokers, light smokers, and heavy smokers were examined as part of the Minnesota Heart Survey.

METHODS

Three cross-sectional surveys were conducted in adults ages 25-74 years in 1980-82 (N = 1682), 1985-87 (N = 2326), and 1990-92 (N = 2487). Dietary information was obtained from a 24-hour dietary recall. Smoking was assessed through self-report. Intakes were adjusted for age, energy intake, body mass index, education level, and exercise level (vitamins E, C and beta-carotene).

RESULTS

Antioxidant vitamin intakes were significantly higher in non-smokers than in light (1-20 cig/day) and heavy smokers (>20 cig/day) when all three survey periods were combined. In men, mean vitamin E intake was 9.2 mg, 8.6 mg, and 7.8 mg for non-smokers, light smokers, and heavy smokers, respectively. Results were similar in men for beta-carotene (non-smokers 1408 microg, light smokers 1287 microg, and heavy smokers 1064 microg), and vitamin C (non-smokers 81 mg, light smokers 67 mg, and heavy smokers 56 mg). Women had results of similar magnitude and direction. From 1980-92, secular trends in men showed non-significant increases from 1980-82 to 1990-92 in beta-carotene (+6.1%), while decreases were observed in vitamins E (-1.1%) and C (-2.6%). In contrast, women had large decreases in all antioxidant vitamin intakes: vitamin E (-13%), vitamin C (-18.6%), and beta-carotene (-16.2%).

CONCLUSIONS

Light and heavy smokers had a significantly lower overall mean dietary antioxidant vitamin intake than non-smokers. Over the decade, antioxidant dietary intake remained relatively stable in men and decreased in women in Minneapolis-St. Paul, despite improvements in access to antioxidant rich fruits and vegetables.

Smoking characteristics, antioxidant vitamins, and carotid artery wall thickness among life-long smokers

We studied the associations between the common carotid-intima-media thickness (IMT), as a marker of atherosclerosis, and smoking characteristics and antioxidant vitamins among 158 male life-long cardiovascular disease (CVD)-free smokers. An "increased" carotid IMT was defined as the upper 25%. The prevalence of increased IMT was 2.5 times (odds ratio (OR) = 2.5; 95% CI: 1.1, 5.6) higher among smokers inhaling smoke deeply into the lungs than among moderate and non-inhalers. This association decreased when adjusted for other CVD risk factors. Smokers with an increased carotid IMT did not differ significantly in mean antioxidant vitamin intake and status with the remaining group. However, classical CVD risk factors contributed importantly to increased carotid IMT. In our study, depth of inhalation was the only smoking characteristic associated with carotid IMT although attenuated after adjustment for traditional risk factors for CVD. Furthermore, in these life-long smokers not using any vitamin supplements, no associations were found for antioxidant vitamins.

The effect of vitamin E and vitamin C supplementation on LDL oxidizability and neutrophil respiratory burst in young smokers

OBJECTIVE

The purpose of this study was to determine the effect of vitamin E and/or vitamin C supplementation on low-density lipoprotein (LDL) oxidizability and neutrophil (PMN) superoxide anion production in young smokers.

METHODS

Thirty smokers with a <5 pack-year history were randomly assigned to take placebo; vitamin C (1 g/day); vitamin E (400 IU/day), or both vitamins in a double-blind fashion. Subjects took the supplements for 8 weeks. At weeks 0 and 8, blood was collected for isolation of LDL and PMN, and for antioxidant vitamin analysis. LDL was oxidized with a copper (Cu) catalyst, and oxidation was measured by formation of conjugated dienes over a 5-hour time course. Lag times and maximum oxidation rates were calculated from the time course data. PMN superoxide anion release was assessed by respiratory burst after stimulation with phorbol ester and opsonized zymosan, and their ability to oxidize autologous LDL following treatment with the above stimuli was measured with the conjugated diene assay.

RESULTS

Subjects who received vitamin E alone had a significant increase in the lag phase of Cu-catalyzed LDL oxidation (week 0, 118+/-31 min vs. week 8, 193+/-80 min, mean +/- SD, p < 0.05), whereas the vitamin C and placebo groups had no changes in LDL oxidation kinetics. The group receiving both vitamins E and C had a significant reduction in oxidation rate (week 0. 7.4+/-2.3 vs. week 8, 5.1+/-2.1, p < 0.05). There were no significant changes for any group in PMN superoxide anion production or PMN LDL oxidation after stimulation with either phorbol ester or opsonized zymosan. Plasma and LDL vitamin E concentrations were significantly increased in both groups that received vitamin E. The subjects who received vitamin C alone had no significant change in plasma vitamin C concentrations; however, when data were pooled from both groups who received vitamin C, the increases were significant.

CONCLUSION

Vitamin E supplementation of young smokers was effective in reducing Cu-catalyzed LDL oxidizability; however, vitamin E and/or C supplementation showed few significant effects on the more physiologically relevant PMN function. This casts doubt on the ability of antioxidant supplementation to reduce oxidative stress in smokers in vivo. Therefore, smoking cessation remains the only means by which young smokers can prevent premature coronary heart disease.

Antioxidant intakes and smoking status: data from the continuing survey of food intakes by individuals 1994-1996

BACKGROUND

Cigarette smoking is a major risk factor for several chronic oxidative diseases that can be ameliorated by antioxidants.

OBJECTIVES

This study identified the typical dietary intakes and the major food group contributors of the antioxidants beta-carotene, vitamin C, and vitamin E by smoking status.

DESIGN

The 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII) provided the current sample (n = 6749), who were categorized as non- (n = 3231), former (n = 1684), and current (n = 1834) smokers. In the CSFII, individuals' food intakes were estimated with two 24-h dietary recalls. Data were analyzed by using a chi-square test with a simultaneous Fisher's z test, analysis of variance with Scheffe's test, multivariate analysis of covariance, and analysis of covariance with Bonferroni adjustment for multiple comparisons.

RESULTS

The sample consisted of 3707 men and 3042 women. Current smokers tended to be younger with less education and lower incomes than nonsmokers and former smokers. The average body mass index (in kg/m(2)) of current smokers was 25.8, the lowest of the 3 groups. Current smokers had the lowest dietary antioxidant intake. Fatty foods such as luncheon meats, condiments and salad dressings, and ground beef contributed more to the antioxidant intakes of current smokers than to those of the other 2 groups, whereas fruit and vegetables contributed less. Current smokers consumed the fewest numbers of servings of all nutrient-bearing groups in the food guide pyramid, except the meat group.

CONCLUSION

Future interventions should target the clustering of cigarette smoking and other unhealthy lifestyle habits, eg, an imprudent diet.

Ascorbate is depleted by smoking and repleted by moderate supplementation: a study in male smokers and nonsmokers with matched dietary antioxidant intakes

BACKGROUND

Lack of reliable dietary data has hampered the ability to effectively distinguish between effects of smoking and diet on plasma antioxidant status. As confirmed by analyses of comprehensive food-frequency questionnaires, the total dietary intakes of fruit and vegetables and of dietary antioxidants were not significantly different between the study groups in the present study, thereby enabling isolation of the effect of smoking.

OBJECTIVE

Our objective was to investigate the effect of smoking on plasma antioxidant status by measuring ascorbic acid, alpha-tocopherol, gamma-tocopherol, beta-carotene, and lycopene, and subsequently, to test the effect of a 3-mo dietary supplementation with a moderate-dose vitamin cocktail.

DESIGN

In a double-blind, placebo-controlled design, the effect of a vitamin cocktail containing 272 mg vitamin C, 31 mg all-rac-alpha-tocopheryl acetate, and 400 microg folic acid on plasma antioxidants was determined in a population of smokers (n = 37) and nonsmokers (n = 38). The population was selected for a low intake of fruit and vegetables and recruited from the San Francisco Bay area.

RESULTS

Only ascorbic acid was significantly depleted by smoking per se (P < 0.01). After the 3-mo supplementation period, ascorbic acid was efficiently repleted in smokers (P < 0.001). Plasma alpha-tocopherol and the ratio of alpha- to gamma-tocopherol increased significantly in both supplemented groups (P < 0.05).

CONCLUSIONS

Our data suggest that previous reports of lower concentrations of plasma vitamin E and carotenoids in smokers than in nonsmokers may primarily have been caused by differences in dietary habits between study groups. Plasma ascorbic acid was depleted by smoking and repleted by moderate supplementation.

Nutrient intakes during pregnancy: the influence of smoking status and age

STUDY OBJECTIVE

To examine the relation of antioxidant and other nutrient intakes in pregnancy to smoking and sociodemographic variables.

DESIGN

Cohort study.

SETTING

St Mary's Maternity Hospital, Portsmouth.

PARTICIPANTS

Pregnant nulliparous women, with no existing complications of pregnancy, were recruited from antenatal booking clinics. A total of 774 women completed seven day food diaries, and supplied detailed data on their use of nutrient supplements.

MAIN RESULTS

Smokers had lower intakes of most micronutrients. After adjustment for the confounding effects of maternal age, height, and education, only vitamin C and carotenoid intakes remained significantly depressed. Age was strongly and significantly associated with the intake of most nutrients, including antioxidants, and this association was independent of other maternal factors. Antioxidant intake was therefore lowest in young women who smoked: for example smokers under 24 years had a mean vitamin C intake of 57 mg (SD 35) compared with 106 mg (SD 52) for non-smokers aged 28 and over (difference 49 mg, 95% CI 39, 59). The corresponding intakes of carotenoid equivalents were 1335 micrograms (SD 982) and 2093 micrograms (SD 1283) (difference 758 micrograms, 95% CI 496, 1020).

CONCLUSIONS

The study has identified, for the first time, young pregnant women as a group at particular risk of low micronutrient intake. The health implications of poor nutrition now need to be evaluated, particularly for those women who smoke.