Synergistic interaction of cigarette smoking and alcohol drinking with serum carotenoid concentrations: findings from a middle-aged Japanese population

Japanese carotenoid database with α- and β-carotene, β-cryptoxanthin, lutein, zeaxanthin, lycopene, and fucoxanthin and intake in adult women

Carotenoid intake is associated with low mortality and cancer risks; data on non-provitamin carotenoid intake is limited especially in Asians. We aimed to estimate carotenoid intake in Japanese adult women. Carotenoid content database comprises 196 food items, including 39 fruits, 87 vegetables and mushrooms, and 11 seaweeds, and was established using data from the literature and analyses of foods available in Japan. We surveyed the intake of these foods in Japanese women aged 21-56 years (n=109). Total intake of 7 carotenoids (mean±SD [range]) was 7,450±3,840 (1,160-21,300) μg/day; α-carotene, β-carotene, β-cryptoxanthin, lutein, zeaxanthin, lycopene, and fucoxanthin represented 4.3%, 23%, 3.4%, 15%, 2.0%, 39%, and 13% of total intake, respectively. Lutein intake was 1,132±686 (294-3,490) μg/day; its best sources were spinach, cucumber, chicken egg, green onion, and Chinese chives, representing 51% of total intake. Lutein can be obtained from a variety of sources. Thus, lutein intake levels did not vary widely among individuals and very few individuals consumed insufficient levels of lutein. Intake of zeaxanthin, lycopene, and fucoxanthin was 149±93 (2-479), 2,890±2,970 (0-17,100), and 980±1,230 (0-5,660) μg/day, respectively. Their intake required rich sources including chicken egg for zeaxanthin (52%); tomato products for lycopene (98%), and wakame seaweed for fucoxanthin (76%). The carotenoid content database including all food items consumed in Japan will be helpful for further investigations on carotenoid intake and its health benefits.

α-Carotene: a valuable carotenoid in biological and medical research

α-Carotene, one of the C₄₀ carotenes, is a natural lipid-soluble terpene. The chemical structure of α-carotene is based on the unsaturated polyene chain skeleton, with an ε-ring and a β-ring on each side of the skeleton. α-Carotene is widely found in dietary fruits and vegetables, and the concentration depends on the plant species. In addition, processing methods and storage conditions used in the food and medical industries can alter the concentration of α-carotene in raw materials. This review of α-carotene summarizes the major studies on chemical structure, source, extraction, detection, biosynthesis, processing effect, bioactivity, medicine, and biotechnology. Whether α-carotene supplementation or a diet rich in fruits and vegetables has a positive effect on the prevention of cancer, cardiovascular disease, and other diseases is the focus of this study. © 2022 Society of Chemical Industry.

Fingertip-Measured Skin Carotenoids and Advanced Glycation End Product Levels in Glaucoma

Carotenoids have antioxidant properties, and the accumulation of advanced glycation end products (AGEs) is associated with reactive oxygen species production; they have attracted attention as factors predictive of the onset and progression in glaucoma. Fingertip measurement is applicable for carotenoids and AGEs due to its noninvasiveness and simplicity. The study included 663 eyes of 663 Japanese subjects (357 males, 306 females). The mean age was 69.9 years with a standard deviation of 11.0. The study population comprised participants with primary open-angle glaucoma (PG) (n = 358), exfoliation glaucoma (EG) (n = 168), and controls (n = 137). Multivariate models suggested that lower skin carotenoid (SC) levels were associated with male gender (standard β = −0.14), AGE scores (−0.24), and a history of intraocular surgery (−0.22). Higher SC levels were associated with higher vegetable intake scores (0.21 for score 3) and diabetes (0.10). However, no association was seen between SCs and glaucoma type. AGEs levels were negatively associated with carotenoid scores (−0.25), PG (−0.15), and smoking habits (−0.26) and positively correlated with EG (0.14). SCs and AGEs were negatively correlated in the single regression analysis (r = −0.20, p < 0.0001). In conclusion, higher levels of AGEs may be candidates for systemic biomarkers of glaucoma associated with the exfoliation syndrome. SC levels can reflect self-reported daily vegetable intake.

Serum Lutein and Zeaxanthin Are Inversely Associated with High-Sensitivity C-Reactive Protein in Non-Smokers: The Mikkabi Study

Recent randomized controlled trials have demonstrated a protective association between carotenoids and inflammation; however, the basis of this association on lifestyle factors remains unclear. This study aimed to clarify the associations between carotenoids and inflammatory markers stratified by lifestyle factors, using baseline data from the Mikkabi Study. Serum carotenoid and high-sensitivity C-reactive protein (hs-CRP) levels were measured. Multivariable adjusted odds ratios (ORs) for a high hs-CRP level (≥2.0 mg/dL) were obtained using logistic regression analysis. The data of 882 individuals were analyzed; 11.7% had high hs-CRP levels. The highest tertile of lutein (OR: 0.44; 95% confidence interval [CI]: 0.25–0.76), zeaxanthin (OR: 0.36; 95% CI: 0.21–0.64), total carotenoid (OR: 0.57; 95% CI: 0.32–0.9997), and oxygenated carotenoid concentration (OR: 0.50; 95% CI: 0.28–0.90), with the lowest tertile as reference, was inversely associated with a high hs-CRP level. The interaction between lutein, but not other carotenoids, and current smoking was significant. The inverse association between lutein and a high hs-CRP level was significant in non-smokers (OR: 0.41; 95% CI: 0.22–0.76) but not in smokers. These results further support the anti-inflammatory effect of carotenoids; nevertheless, further studies should clarify the interaction of smoking with the association between lutein and inflammation.

Prevention of NAFLD/NASH by Astaxanthin and β-Cryptoxanthin

Metabolic disorders, such as lipid accumulation, insulin resistance, and inflammation, have been implicated in the pathogenesis of NAFLD/NASH. Both innate and recruited immune cells mediate the development of insulin resistance and NASH. Oxidative stress is also pivotal for the progression of NASH. Astaxanthin is a natural carotenoid mainly derived from microorganisms and marine organisms. Due to its special chemical structure, astaxanthin has strong antioxidant activity. β-Cryptoxanthin is a xanthophyll carotenoid specifically found in the Satsuma mandarin. β-Cryptoxanthin is readily absorbed and relatively abundant in human plasma, together with α-carotene, β-carotene, lycopene, lutein, and zeaxanthin. Considering the unique chemical properties of astaxanthin and β-cryptoxanthin and the complex pathogenic mechanism of NASH, astaxanthin and β-cryptoxanthin are regarded as a considerable compound for the prevention and treatment of NASH. This chapter comprehensively describes the mechanism of the application for astaxanthin and β-cryptoxanthin on the prevention and treatment of NASH from the aspects, including antioxidative stress, inhibition of inflammation and promotion of M2 macrophage polarization, improvement of mitochondrial oxidative respiration, amelioration of insulin resistance, and suppression of fibrosis.

Fruit and Vegetable Intake and Stomach Cancer among Male Adults: A Case-Control Study in Northern Viet Nam

OBJECTIVE

This study investigated the association between fruit and vegetable intake and stomach cancer, with considering the impacts of Helicobacter pylori (H. pylori) infection and tobacco smoking.

METHODS

A case-control study featuring 80 male incident stomach-cancer cases and 146 male controls was conducted in a general hospital in Viet Nam. A semi-quantitative food frequency and demographic lifestyle questionnaire were used; and venous blood samples were collected to determine H. pylori status by IgG ELISA. The respective associations between fruit and vegetable intake and stomach cancer were examined using unconditional logistic regression analysis with adjustments for possible cofactors.

RESULTS

Fruit intake and stomach cancer showed a weak inverse association when this became non-significant after adjusting for H. pylori infection (OR = 0.50, 95%CI: 0.22-1.12, p trend = 0.094). Stratifying by H. pylori status returned a negative trend for fruit intake and stomach cancer among H. pylori-negative participants (OR = 0.21, 95%CI: 0.06-0.69, p trend = 0.010), but no significant interaction for H. pylori-positive participants (OR = 0.76, 95%CI: 0.21-2.68, p trend = 0.670). Vegetable intake and stomach cancer showed no association, regardless of H. pylori status. Compared to ever-smokers with low intake, never-smokers with high vegetable (OR = 0.25, 95% CI: 0.06-0.95) and fruit intake (OR = 0.20, 95%CI: 0.06-0.65) showed the lowest odds of stomach cancer.

CONCLUSIONS

Fruit, but not vegetable, intake showed a weak inverse association with stomach cancer. H. pylori infection and tobacco-smoking status may influence the protective effects of fruit and vegetable intake on stomach cancer.
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The effect of β-carotene on the mortality of male smokers is modified by smoking and by vitamins C and E: evidence against a uniform effect of nutrient

A previous analysis of the Alpha-Tocopherol Beta-Carotene (ATBC) Study on male smokers found that β-carotene supplementation increased the risk of pneumonia 4-fold in those who started smoking at the age of ≥21 years and smoked ≥21 cigarettes/d (a subgroup of 7 % of the study population). The present study hypothesised that β-carotene increases mortality in the same subgroup. The ATBC Study (1985–1993) recruited 29 133 Finnish male smokers (≥5 cigarettes/d) aged 50–69 years. Cox regression models were constructed to estimate the effect of β-carotene supplementation in subgroups. β-Carotene increased mortality (risk ratio 1·56; 95 % CI 1·06, 2·3) in those who started to smoke at ≥21 years and smoked ≥21 cigarettes/d. Within this subgroup, there was strong evidence of further heterogeneity. The effect of β-carotene supplementation was further modified by dietary vitamin C intake, fruit and vegetable intake (P = 0·0004), and by vitamin E supplementation (P = 0·011). Thus, harm from β-carotene was not uniform within the study population. Interactions between β-carotene and vitamins C and E were seen only within a subgroup of 7 % of the ATBC participants, and therefore should not be extrapolated to the general population. Heterogeneity of the β-carotene effect on mortality challenges the validity of previous meta-analyses that have pooled many diverse antioxidants for one single estimate of effect using the assumption that a single estimate equally applies to all antioxidants and all people. Trial registration: ClinicalTrials.gov NCT00342992.

Health Benefits of Carotenoids: A Role of Carotenoids in the Prevention of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases with a prevalence of ~25% worldwide. NAFLD includes simple hepatic steatosis, non-alcoholic steatohepatitis, fibrosis, and cirrhosis, which can further progress to hepatocellular carcinoma. Therefore, effective strategies for the prevention of NAFLD are needed. The pathogenesis of NAFLD is complicated due to diverse injury insults, such as fat accumulation, oxidative stress, inflammation, lipotoxicity, and apoptosis, which may act synergistically. Studies have shown that carotenoids, a natural group of isoprenoid pigments, prevent the development of NAFLD by exerting antioxidant, lipid-lowering, anti-inflammatory, anti-fibrotic, and insulin-sensitizing properties. This review summarizes the protective action of carotenoids, with primary focuses on astaxanthin, lycopene, β-carotene, β-cryptoxanthin, lutein, fucoxanthin, and crocetin, against the development and progression of NAFLD.

Safety Evaluation and Plasma Carotenoid Accumulation in Healthy Adult Subjects after 12 Weeks of Paprika Oleoresin Supplementation

Paprika oleoresin is obtained by solvent extraction from Capsicum annuum L. fruits and contains multiple carotenoids, such as capsanthin, β-carotene, zeaxanthin, and β-cryptoxanthin, which are considered protective against various diseases. Herein, we investigated the effect of paprika oleoresin supplementation on plasma carotenoid accumulation and evaluated the safety of the oleoresin. We used a double-blinded, placebo-controlled comparative clinical study design and tested the effects of varying doses in healthy adult subjects. In total, 33 subjects were randomly divided into three groups to take capsules containing 0, 20, or 100 mg of paprika oleoresin daily for 12 consecutive weeks. Plasma carotenoid concentrations were measured at 0, 4, 8, and 12 weeks, and the safety of paprika oleoresin capsules was investigated using analyses of blood biochemistry, hematology, and urine contents. In these experiments, β-cryptoxanthin and zeaxanthin dose-dependently accumulated in plasma within the dose range of the study over 12 consecutive weeks of paprika oleoresin supplementation. Moreover, β-cryptoxanthin accumulated to higher levels than the other paprika oleoresin carotenoids. In contrast, capsanthin was not detected in plasma before or during the 12-week treatment period. Finally, no adverse events were associated with intake of paprika oleoresin (20 and 100 mg/day) in safety evaluations. Paprika oleoresin is a suitable source of carotenoids, especially β-cryptoxanthin.

Association between Dietary Carotenoid Intake and Bone Mineral Density in Korean Adults Aged 30-75 Years Using Data from the Fourth and Fifth Korean National Health and Nutrition Examination Surveys (2008-2011)

Age-related bone loss is a major public health problem. This cross-sectional study examined the association between the dietary intake of carotenoids and bone mineral density (BMD). Data from 8022 subjects (3763 males and 4259 females) aged 30–75 years included in the Korean National Health and Nutrition Examination Survey (2008–2011) were analyzed. BMD was measured by dual-energy X-ray absorptiometry. Intake of carotenoids was estimated using 24-h dietary recall. In multiple linear analysis, after adjusting for covariates, lutein + zeaxanthin and β-cryptoxanthin intake was positively associated with total hip BMD in males and premenopausal women respectively, while β-carotene intake was positively correlated with femoral neck, total hip, and whole-body BMD in postmenopausal women. Postmenopausal women in the highest quintile of daily β-carotene intake, showed a lower risk of osteopenia at the lumbar spine (odds ratio (OR): 0.35, 95% CI: 0.16–0.79, P for trend = 0.009) than those in the lowest quintile, after adjusting for covariates. Daily β-cryptoxanthin intake was significantly associated with a lower risk of osteopenia at the total hip (OR per 1 mg/day increase: 0.76; 95% CI: 0.59–0.97), and lumbar spine (OR per 1 mg/day increase: 0.79; 95% CI: 0.70–0.89) in postmenopausal women. These results suggest that the dietary intake of β-carotene and β-cryptoxanthin may have a positive effect on bone health.

A Possible Indicator of Oxidative Damage in Smokers: (13Z)-Lycopene?

In vitro, the gaseous phase of cigarette smoke is known to induce both isomerization and degradation of dietary carotenoids, such as β-carotene and lycopene. However, the effects of cigarette smoke on the composition of circulating lycopene in vivo are not well understood. In this study, we examined the lycopene profiles of plasma from non-smokers and smokers. No oxidative intermediates of lycopene that have been observed previously in vitro were detected in the plasma, but evidence of isomerization of the carotenoid was seen. Four geometric forms of lycopene were detected in the plasma of both smokers and non-smokers, namely the (5Z), (9Z), (13Z) and (all-E) forms. The relative amounts of these isomers differed between the two cohorts and there was a significant difference (p < 0.05) between smokers and non-smokers for the ratio of total-Z:all-E lycopene, and in the relative amounts of (13Z) and (all-E)-lycopene. The ratio of (all-E):(13Z)-lycopene was 0.84:1.00 in smokers compared to 1.04:1.00 in non-smokers. In smokers, the (13Z)-isomer was generated in preference to the more thermodynamically stable (5Z) and (9Z)-isomers. This mirrors the scenario seen in vitro, in which the formation of (13Z)-lycopene was the main isomer that accompanied the depletion of (all-E) lycopene, when exposed to cigarette smoke. The results suggest that the relative amount of (13Z)-lycopene could be used as an indicator of oxidative damage to lycopene in vivo.

High Vitamin C Intake with High Serum β-Cryptoxanthin Associated with Lower Risk for Osteoporosis in Post-Menopausal Japanese Female Subjects: Mikkabi Cohort Study

Recent epidemiological studies show that antioxidant vitamins and carotenoids might be beneficial to the maintenance of bone health. Recently, we found that serum carotenoids were inversely associated with the risk of developing osteoporosis in post-menopausal Japanese female subjects. However, little is known about the vitamin alone and/or the combination of the vitamin and carotenoid with the risk of osteoporosis. The objective of this study was to investigate longitudinally whether antioxidant vitamins and their combination with carotenoids are associated with the risk of developing of osteoporosis. We conducted a follow-up study on 187 post-menopausal female subjects from the Mikkabi prospective cohort study. Those who participated in previous bone mineral density (BMD) surveys and completed four years of follow-up were examined longitudinally. During a four-year follow-up, fifteen of the post-menopausal female subjects developed new-onset osteoporosis. After adjustment for confounders, the odds ratios (OR) for osteoporosis in the highest tertiles of vitamins C and E and retinol intakes against the lowest tertiles were 0.15 (95% confidence interval (CI): 0.02-0.99), 0.50 (CI: 0.08-3.23), and 1.49 (CI: 0.36-6.22), respectively. Furthermore, a significantly lower odds ratio was observed in the higher vitamin C intake group (169-625 mg/d) with higher serum β-cryptoxanthin (1.88-10.53 μM) against the lower vitamin C intake group (47-168 mg/d) with lower serum β-cryptoxanthin (0.24-1.84 μM) used for the reference group (p<0.05). The combination of β-cryptoxanthin and vitamin C is inversely associated with the risk of developing osteoporosis in post-menopausal Japanese female subjects.

Nonalcoholic Fatty Liver Disease and Insulin Resistance: New Insights and Potential New Treatments

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver disorders worldwide. It is associated with clinical states such as obesity, insulin resistance, and type 2 diabetes, and covers a wide range of liver changes, ranging from simple steatosis to non-alcoholic steatohepatitis (NASH), liver cirrhosis, and hepatocellular carcinoma. Metabolic disorders, such as lipid accumulation, insulin resistance, and inflammation, have been implicated in the pathogenesis of NAFLD, but the underlying mechanisms, including those that drive disease progression, are not fully understood. Both innate and recruited immune cells mediate the development of insulin resistance and NASH. Therefore, modifying the polarization of resident and recruited macrophage/Kupffer cells is expected to lead to new therapeutic strategies in NAFLD. Oxidative stress is also pivotal for the progression of NASH, which has generated interest in carotenoids as potent micronutrient antioxidants in the treatment of NAFLD. In addition to their antioxidative function, carotenoids regulate macrophage/Kupffer cell polarization and thereby prevent NASH progression. In this review, we summarize the molecular mechanisms involved in the pathogenesis of NAFLD, including macrophage/Kupffer cell polarization, and disturbed hepatic function in NAFLD. We also discuss dietary antioxidants, such as β-cryptoxanthin and astaxanthin, that may be effective in the prevention or treatment of NAFLD.

[β-Cryptoxanthin and the risk for lifestyle-related disease: findings from recent nutritional epidemiologic studies]

  Antioxidant micronutrients, such as vitamins and carotenoids, exist in abundance in fruits and vegetables and have been known to contribute to the body's defense against reactive oxygen species. Numerous recent epidemiologic studies have demonstrated that a high dietary consumption of fruit and vegetables rich in carotenoids or with high serum carotenoid concentrations results in lower risks of certain cancers, diabetes, and cardiovascular disease. These epidemiologic studies have suggested that antioxidant carotenoids may have a protective effect against several lifestyle-related diseases. β-Cryptoxanthin is a carotenoid pigment found in Japanese mandarin (Citrus unshiu MARC.) fruit, which is mainly produced in Japan. Our nutritional epidemiologic survey, the Mikkabi Study, utilized data derived from health examinations of inhabitants performed in the town of Mikkabi in Shizuoka, Japan. In this survey, we measured serum β-cryptoxanthin as a specific biomarker to estimate the consumption of Japanese mandarin fruit. From the cross-sectional analyses from the Mikkabi Study, we found inverse associations of serum β-cryptoxanthin with the risks for atherosclerosis, insulin resistance, liver dysfunction, metabolic syndrome, low bone mineral density, and oxidative stress. In this review, recent epidemiologic studies about the associations between serum β-cryptoxanthin with the risk for several lifestyle-related diseases were reviewed.

Serum β-cryptoxanthin and β-carotene derived from Satsuma mandarin and brachial-ankle pulse wave velocity: The Mikkabi cohort study

BACKGROUND AND AIMS

Findings of observational studies suggest cardioprotective effects of antioxidant vitamins and carotenoids. However, recent meta-analyses failed to show the beneficial effects of supplemental intake of antioxidants on cardiovascular disease (CVD). We aimed to assess the association between CVD risk and β-cryptoxanthin in Japan, where Satsuma mandarin, a major source of β-cryptoxanthin, is widely consumed.

METHODS AND RESULTS

This was part of the Mikkabi cohort study. Surveys were conducted at baseline, in 2003 and 2005, and on follow-up in 2006, 2009, and 2013. We examined brachial-ankle pulse wave velocity (baPWV) with a high cut-off value set at 18.3 m s(-1). Hazard ratios (HR) and 95% confidence intervals for high baPWV were estimated using a Cox proportional hazards model with adjustment for potential confounders. A total of 635 participants with baPWV of less than 18.3 m s(-1) at baseline were included in the analysis. During the follow-up period of 57,921 person-months, 99 subjects developed high baPWV. After multivariate adjustment, the HR for high baPWV in the highest tertile compared with the lowest tertile was significantly low for β-cryptoxanthin, β-carotene, and total carotenoids. Serum concentrations of β-cryptoxanthin and β-carotene were higher in people who ate Satsuma mandarin frequently. Compared with <1/d intake of Satsuma mandarin, 3-4/d was associated with a low risk of high PWV.

CONCLUSION

This study indicated that β-cryptoxanthin and β-carotene derived from Satsuma mandarin are candidate micronutrients for preventing arteriosclerosis development. Further longitudinal and interventional studies will be required to validate the effect on CVD.

Novel Action of Carotenoids on Non-Alcoholic Fatty Liver Disease: Macrophage Polarization and Liver Homeostasis

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. It is characterized by a wide spectrum of hepatic changes, which may progress to non-alcoholic steatohepatitis (NASH) and cirrhosis. NAFLD is considered a hepatic manifestation of metabolic syndrome; however, mechanisms underlying the onset and progression of NAFLD are still unclear. Resident and recruited macrophages are key players in the homeostatic function of the liver and in the progression of NAFLD to NASH. Progress has been made in understanding the molecular mechanisms underlying the polarized activation of macrophages. New NAFLD therapies will likely involve modification of macrophage polarization by restraining M1 activation or driving M2 activation. Carotenoids are potent antioxidants and anti-inflammatory micronutrients that have been used to prevent and treat NAFLD. In addition to their antioxidative action, carotenoids can regulate macrophage polarization and thereby halt the progression of NASH. In this review, we summarize the molecular mechanisms of macrophage polarization and the function of liver macrophages/Kupffer cells in NAFLD. From our review, we propose that dietary carotenoids, such as β-cryptoxanthin and astaxanthin, be used to prevent or treat NAFLD through the regulation of macrophage polarization and liver homeostasis.

High serum carotenoids are associated with lower risk for developing elevated serum alanine aminotransferase among Japanese subjects: the Mikkabi cohort study

Many recent studies have shown that antioxidant vitamins and/or carotenoids may reduce liver disease, but this association has not been well established with thorough longitudinal cohort studies. The objective of this study was to longitudinally investigate whether serum carotenoids at baseline are associated with the risk of developing elevated serum alanine aminotransferase (ALT) among Japanese subjects. We conducted a follow-up study of 1073 males and females aged between 30 and 79 years at baseline from the Mikkabi prospective cohort study. Those who participated in the baseline study and completed follow-up surveys were examined longitudinally. Exclusions included excessive alcohol consumption (≥60 g alcohol/d), hepatitis B and C and having a history of medication use for liver disease. A cohort of 213 males and 574 females free of elevated serum ALT (>30 IU/ml) at baseline was studied. Over a mean follow-up period of 7·4 (sd 3·1) years, thirty-one males and forty-nine females developed new elevated serum ALT. After adjustments for confounders, the hazard ratios for elevated serum ALT in the highest tertiles of basal serum β-carotene, β-cryptoxanthin and total provitamin A carotenoids against the lowest tertiles were 0·43 (95 % CI 0·22, 0·81), 0·51 (CI 0·27, 0·94) and 0·52 (CI 0·28, 0·97), respectively. For α-carotene and lycopene, borderline reduced risks were also observed; however, these were not significant. Our results further support the hypothesis that antioxidant carotenoids, especially provitamin A carotenoids, might help prevent earlier pathogenesis of non-alcoholic liver disease in Japanese subjects.

Association between Smoking Status and Food and Nutrient Consumption in Japanese: a Large-Scale Cross-Sectional Study

BACKGROUND

In Japan, in comparison with the rest of the world the death rate of lung cancer is low although the smoking rate is relatively high. This is the so-called "Japanese smoking paradox". A healthy diet is proposed to attenuate the risk without quitting smoking. We here examined the relationships between smoking status (SS) and the consumption of food and nutrient in Japan.

MATERIALS AND METHODS

Totals of 5,587 men and 2,718 women were divided into three (non-smokers, smokers and heavy smokers) and two (non-smokers and smokers) groups, respectively, according to pack-year, which represents the amount of smoking over a long period. Food and nutrient consumption was estimated with a validated food frequency questionnaire. Using general linear models, food and nutrient consumption was estimated for each group in men and women, separately.

RESULTS

In men, SS was positively related to consumption of rice, 3 alcoholic beverages, carbohydrate, alcohol and other 8 foods/nutrients (p<0.05 for all) and negatively to those of protein animal, fat, fatty acids, dietary fiber, isoflavones and 36 other foods/nutrients (p<0.05 for all). In women, SS was positively associated with intake of 13 foods/nutrients, while being negatively associated with those of rice, energy, dietary fiber, and 14 other foods/nutrients (p<0.05 for all).

CONCLUSIONS

Our results support lower intake of vegetables and fruits rich in antioxidants, which are thought as preventive factors for many diseases, in smokers.

High serum carotenoids associated with lower risk for the metabolic syndrome and its components among Japanese subjects: Mikkabi cohort study

Recent epidemiological studies show the association of carotenoids with the metabolic syndrome (MetS), but thorough longitudinal cohort studies regarding this association have not been well conducted. The objective of this study was to investigate longitudinally whether serum carotenoids are associated with the risk of developing the MetS and its components in Japanese subjects. We conducted a follow-up study on 1073 men and women aged 30-79 years at the baseline from the Mikkabi prospective cohort study. Those who participated in the baseline and completed follow-up surveys were examined longitudinally. Over the 10-year period, 910 subjects (295 men and 615 women) took part in the follow-up survey at least once. Over a mean follow-up period of 7·8 (sd 2·9) years, thirty-six men and thirty-one women developed new MetS. After adjustments for confounders, the hazard ratio (HR) for the MetS in the highest tertile of serum β-carotene against the lowest tertile was 0·47 (95 % CI 0·23, 0·95). On the other hand, significantly lower risks for dyslipidaemia were observed in the highest tertiles of serum α- and β-carotene and β-cryptoxanthin (HR 0·66; 95 % CI 0·46, 0·96; HR, 0·54; 95 % CI 0·37, 0·79; and HR 0·66; 95 % CI 0·44, 0·99, respectively). Other significant associations between the risks for obesity, high blood pressure and hyperglycaemia with serum carotenoids were not observed. Our results further support the hypothesis that eating a diet rich in carotenoids might help prevent the development of the MetS and its complications in Japanese subjects.

High-serum carotenoids associated with lower risk for developing type 2 diabetes among Japanese subjects: Mikkabi cohort study

OBJECTIVE

Recent epidemiological studies show the association of antioxidant carotenoids with type 2 diabetes, but thorough longitudinal cohort studies regarding this association have not been well conducted. The objective of this study was to investigate longitudinally whether serum carotenoids are associated with the risk for developing type 2 diabetes among Japanese subjects.

RESEARCH DESIGN AND METHODS

We conducted a follow-up study on 1073 males and females aged 30-79 years at the baseline from the Mikkabi prospective cohort study. Those who participated in the baseline and completed follow-up surveys were examined longitudinally. Over the 10-year period, 910 subjects (295 males and 615 females) took part in the follow-up survey at least one time. A cohort of 264 males and 600 females free of diabetes at baseline was studied.

RESULTS

Over a mean follow-up period of 7.8 years (SD=2.9), 22 males and 33 females developed new type 2 diabetes. After adjustments for confounders, the HRs for type 2 diabetes in the highest tertiles of serum α-carotene, β-cryptoxanthin, and total provitamin A carotenoids against the lowest tertiles were 0.35 (95% CI 0.15 to 0.82), 0.43 (CI 0.20 to 0.92) and 0.41 (CI 0.19 to 0.90), respectively. For β-carotene and zeaxanthin, borderline reduced risks were also observed, but these were not significant.

CONCLUSIONS

Our results further support the hypothesis that eating a diet rich in carotenoids, especially provitamin A carotenoids, might help prevent the development of type 2 diabetes in Japanese patients.

TRIAL REGISTRATION NUMBER

NIFT-2013001.

Comparison of bioavailability between β-cryptoxanthin and β-carotene and tissue distribution in its intact form in rats

The bioavailability of two intact carotenoids in several tissues of β-cryptoxanthin- and β-carotene-fed rats (20 mg/kg of diet) was investigated. Although metabolites of provitamin A are not included in our study, β-cryptoxanthin was found at higher concentrations in majority of the tissues. The results show that the bioavailability of intact β-cryptoxanthin seemed to be higher than that of β-carotene.

High serum carotenoids associated with lower risk for bone loss and osteoporosis in post-menopausal Japanese female subjects: prospective cohort study

Introduction

Recent epidemiological studies show that high intakes of carotenoids might be useful to maintain bone health, but little is known about the association of serum carotenoids with change of bone mineral density (BMD). The objective of this study was to investigate longitudinally whether serum carotenoids are associated with bone loss.

Methods

We conducted a follow-up on 146 male and 99 pre- and 212 post-menopausal female subjects from the Mikkabi study. Those who participated in previous BMD surveys and completed four years of follow-up were examined longitudinally.

Results

During a 4-year follow-up, 15 of the post-menopausal female subjects developed new-onset osteoporosis. In contrast, none of the male and pre-menopausal female subjects did. In male and pre-menopausal female subjects, the six serum carotenoids at the baseline were not associated with bone loss. On the other hand, in post-menopausal female subjects, the 4-year bone loss of radius was inversely associated with the serum carotenoid concentrations, especially in β-carotene. After adjustments for confounders, the odds ratios (OR) for osteoporosis in the highest tertiles of serum β-carotene and β-cryptoxanthin against the lowest tertiles were 0.24 (95% confidence interval 0.05–1.21) and 0.07 (CI: 0.01–0.88), respectively. Serum β-cryptoxanthin was also inversely associated with the risk for osteopenia and/or osteoporosis (P for trend, 0.037). In addition, our retrospective analysis revealed that subjects who developed osteoporosis and/or osteopenia during the survey period had significantly lower serum concentrations of β-cryptoxanthin and β-carotene at the baseline than those in the normal group.

Conclusions

Antioxidant carotenoids, especially β-cryptoxanthin and β-carotene, are inversely associated with the change of radial BMD in post-menopausal female subjects.

Beta-cryptoxanthin, plentiful in Japanese mandarin orange, prevents age-related cognitive dysfunction and oxidative damage in senescence-accelerated mouse brain

Increased oxidative stress is known to accelerate age-related pathologies. Beta-cryptoxanthin (β-CRX, (3R)-β,β-caroten-3-ol) is a potent antioxidant that is highly rich in Satsuma mandarin orange (mandarin), which is the most popular fruit in Japan. We investigated the antioxidative and anti-aging effects of β-CRX and mandarin using senescence-accelerated mice (SAMP10), which were characterized by a short lifespan, high generation of superoxide anions in the brain and poor learning ability with aging. β-CRX (0.5-5.0 µg/ml) or mandarin juice (3.8-38.0%) was added to drinking water of SAMP10 one to 12 months of age. β-CRX was dose-dependently incorporated into the cerebral cortex and the contents were similar to the concentration of β-CRX in the human frontal lobe. These mice also had higher learning ability. The level of DNA oxidative damage was significantly lower in the cerebral cortex of mice that ingested β-CRX and mandarin than control mice. In addition, the mice that ingested β-CRX (>1.5 µg/ml) and mandarin (>11.3%) exhibited a higher survival when 12 month-old, the presenile age of SAMP10, than control mice. These results suggest that β-CRX is incorporated into the brain and has an important antioxidative role and anti-aging effect.

Frequency of citrus fruit intake is associated with the incidence of cardiovascular disease: the Jichi Medical School cohort study

Background

It has been reported that fruit intake protects against cardiovascular disease (CVD). However, most of the relevant studies were conducted in Western countries, and only a few investigated Japanese populations. The present cohort study assessed the effect of citrus fruit intake on the incidence of CVD and its subtypes in a Japanese population.

Methods

A baseline examination consisting of physical and blood examinations and a self-administered questionnaire was conducted during the period from April 1992 through July 1995. Dietary habits were assessed using a food frequency questionnaire that was divided into 5 categories. Citrus fruit was examined separately due to its frequent consumption by the general Japanese population. Using the Cox proportional hazards model, data from 10 623 participants (4147 men, 6476 women) who had no history of CVD or carcinoma were analyzed to assess the association between frequency of citrus fruit intake and CVD incidence.

Results

Frequent intake of citrus fruit was associated with a lower incidence of CVD: the hazard ratio for almost daily intake versus infrequent intake of citrus fruit was 0.57 (95% confidence interval: 0.33–1.01, P for trend = 0.04) in men and 0.51 (0.29–0.88, P for trend = 0.02) in women. Frequent intake of citrus fruit was also associated with lower incidences of both all stroke and cerebral infarction, but not hemorrhagic stroke or myocardial infarction.

Conclusions

Frequent intake of citrus fruit may reduce the incidence of CVD, especially cerebral infarction, in men and women.

Dietary patterns of antioxidant vitamin and carotenoid intake associated with bone mineral density: findings from post-menopausal Japanese female subjects

Recent studies show that antioxidants may reduce the risk of osteoporosis. This study showed the associations of bone mineral density with dietary patterns of antioxidant vitamins and carotenoids. The findings suggest the combination of vitamin C and β-cryptoxanthin intakes might provide benefit to bone health in post-menopausal Japanese female subjects.

INTRODUCTION

Recent epidemiological studies show antioxidants may reduce the risk of osteoporosis, but little is known about the dietary patterns of antioxidant vitamin and carotenoid intakes and their relation with bone mineral density (BMD).

METHODS

A total of 293 post-menopausal female subjects who had received health examinations in the town of Mikkabi, Shizuoka Prefecture, Japan, participated in the study. Radial BMD was measured using dual-energy X-ray absorptiometry. Dietary intakes of antioxidant vitamins and carotenoids were assessed by using a validated food-frequency questionnaire. Dietary patterns were identified on a selected set of antioxidants through principal component factor analysis.

RESULTS

Three dietary patterns were identified. The "retinol" pattern, characterized by notably high intakes of preformed retinol, zeaxanthin, and vitamin E, was positively associated with the risk for low BMD. In contrast, the "β-cryptoxanthin" pattern, characterized by notably high intakes of β-cryptoxanthin and vitamin C, was negatively associated with low BMD. The odds ratios for low BMD in the highest tertiles of dietary intakes of preformed retinol, vitamin C, and β-cryptoxanthin against the lowest tertiles were 3.22 [95% confidence interval (CI), 1.38-7.51], 0.25 (CI, 0.10-0.66), and 0.40 (CI, 0.17-0.92), respectively, after adjustments for confounders. However, negative associations of vitamin C and β-cryptoxanthin with low BMD were not significant after further adjustment for intake of β-cryptoxanthin or vitamin C, respectively. Higher intakes of both vitamin C and β-cryptoxanthin were significantly associated with low BMD (P < 0.05).

CONCLUSIONS

The combination of vitamin C and β-cryptoxanthin may be associated with radial BMD in post-menopausal Japanese female subjects.

Fruit and vegetable consumption and risk of distal gastric cancer in the Shanghai Women's and Men's Health studies

Results from case-control and cohort studies of the association between fruit and vegetable consumption and gastric cancer risk have been inconsistent. Cases for the current study consisted of incident distal gastric cancers identified between 1996 and 2007 among members of the Shanghai Women's Health Study (n = 206) and the Shanghai Men's Health Study (n = 132). Intakes of fruits, vegetables, and select micronutrients were assessed on the basis of validated food frequency questionnaires. Multivariate-adjusted hazards ratios and 95% confidence intervals were calculated by Cox proportional hazards regression. For women, no associations were found between gastric cancer risk and the highest intake of fruits (hazard ratio (HR) = 1.02, 95% confidence interval (CI): 0.68, 1.54; P(trend) = 0.87) or vegetables (HR = 0.89, 95% CI: 0.60, 1.31; P(trend) = 0.32). For men, increased fruit intake was associated with decreased risk of distal gastric cancer (for the highest quartile of intake, HR = 0.50, 95% CI: 0.29, 0.84; P(trend) = 0.004), but no association was seen with increased intake of vegetables (HR = 1.00, 95% CI: 0.59, 1.68; P(trend) = 0.87). The inverse association with fruit intake for men was more evident among ever smokers (P(trend) = 0.001) than never smokers (P(trend) = 0.67). No associations between dietary intakes of select antioxidant micronutrients were seen for men or women. Fruit intake is inversely associated with distal gastric cancer risk among men in Shanghai, China.

Case-crossover and case-time-control designs in birth defects epidemiology

The case-crossover and the case-time-control designs can be used to evaluate the effect of intermittent exposures on the risk of acute events. To explore how birth defects epidemiology could benefit from these approaches, the authors compared them with a traditional case-control study design that evaluated the association between use of folic acid antagonists during the second and third pregnancy months and the risk of cardiovascular defects. Among 3,870 cases and 8,387 control infants in the Slone Epidemiology Center Birth Defects Study (1976-1998), the odds ratio was 2.3 (95% confidence interval (CI): 1.4, 3.9). The case-crossover approach compared folic acid antagonist use between the 2-month embryologically sensitive period (case window) and the 2 months preceding the last menstrual period (control window) among mothers of case infants (odds ratio = 1.0, 95% CI: 0.5, 2.0). Although it controls between-person confounding and avoids issues of control selection, this design may be biased by time trends of exposure prevalence during pregnancy. The case-time-control design, which adjusts for exposure time trends under certain assumptions, yielded an odds ratio of 2.9 (95% CI: 1.2, 7.2), but it requires controls. In the presence of gestational time trends of exposure, the new designs do not offer clear advantages over the case-control design.