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Carotenoids are important bioactive substances in breast milk, the profile of which is seldom studied. This study aimed to explore the profile of carotenoids in breast milk and maternal/cord plasma of healthy mother–neonate pairs in Shanghai, China, and their correlation with dietary intake. Maternal blood, umbilical cord blood and breast milk samples from five lactation stages (colostrum, transitional milk and early-, mid- and late-term mature milk) were collected. Carotenoid levels were analysed by HPLC. Carotenoid levels in breast milk changed as lactation progressed (P < 0·001). β -Carotene was the primary carotenoid in colostrum. Lutein accounted for approximately 50 % of total carotenoids in transitional milk, mature milk and cord blood. Positive correlations were observed between five carotenoids in umbilical cord blood and maternal blood (P all < 0·001). β -Carotene levels were also correlated between maternal plasma and three stages of breast milk (r = 0·605, P < 0·001; r = 0·456, P = 0·011, r = 0·446; P = 0·013, respectively). Dietary carotenoid intakes of lactating mothers also differed across lactation stages, although no correlation with breast milk concentrations was found. These findings suggest the importance of exploring the transport mechanism of carotenoids between mothers and infants and help guide the development of formulas for Chinese infants as well as the nutritional diets of lactating mothers. [ABSTRACT FROM AUTHOR]

Background and Objectives: Genetic and dietary factors are important contributors to the development of dental fluorosis (DF). This study investigated the association between DF and dietary carotenoids, and explored whether the association was modified by polymorphisms of the antioxidant enzyme superoxide dismutase 2 (SOD2 rs11968525) in Guizhou, China.Methods and Study Design: A cross-sectional study with a total of 899 adults aged 18-75 years were enrolled in the study. Face-to-face interviews were conducted to assess dietary habits using a validated 75 item food frequency questionnaire (FFQ). Sociodemographic and lifestyle information, and blood and urine samples were also collected. Genotypes were evaluated using TaqMan single nucleotide polymorphism (SNP) Genotyping Assay.Results: There were significant dose-dependent inverse associations of the prevalence of DF with intake of α-carotene, β-carotene, lutein/zeaxanthin, lycopene and total carotenoids (p-trend ranged from <0.001-0.004). The odds ratios (ORs) and 95% confidence intervals (CIs) of DF comparing the highest against lowest quartile were 0.56 (0.35, 0.92) for α-carotene, 0.53 (0.35, 0.81) for β-carotene, 0.44 (0.27, 0.74) for lycopene, 0.35 (0.21, 0.58) for lutein/zeaxanthin in combination and 0.42 (0.25, 0.69) for total carotenoids (all p-trend<0.005). Intake of β-cryptoxanthin was not found to be related to DF. The inverse association of DF with dietary intake of α-carotene and β-carotene was more evident in individuals with the AG+AA genotype (p-interaction<0.05).Conclusions: Higher dietary carotenoids were associated with a lower occurrence of DF, polymorphisms in SOD2 (rs 11968525) modified the associations between dietary intake of carotene and DF. These findings provide evidence for precision prevention of fluorosis. [ABSTRACT FROM AUTHOR]

Most previous studies have examined the associations between carotenoids and anthropometrics with cross-sectional designs. Few studies have investigated the associations between serum carotenoids and fat mass and fat distribution (general vs central type). This study aimed to explore the associations of serum carotenoids with body fat and fat distribution in Chinese adults. Cross-sectional and longitudinal analyses of a prospective, community-based cohort were performed. There were 4,048 participants aged 40 to 75 years recruited in the Guangzhou Nutrition and Health Study from 2008 to 2013. Serum carotenoids were assessed at baseline. Anthropometrics, fat mass (FM), and percentage FM (%FM) over the total body, trunk, limbs, and android and gynoid regions were obtained by dual-energy x-ray absorptiometry for 3,002 participants between 2011 and 2013 and for 2,537 participants after 3.1 years. Cross-sectional and longitudinal analyses were performed to compare the mean differences in adiposity indices among the quartiles of carotenoids. Covariance analyses showed significant inverse associations between serum total carotenoid levels and adiposity indices cross-sectionally (all P trends<0.05). The percentage mean differences in quartile 4 (vs 1) in FM and %FM were much more pronounced in the trunk (–15.4% and –7.74%) and android area (–16.6% and –8.59%) than those in the limbs (–8.31% and –4.51%) and gynoid area (–7.76% and –2.71%) (all P <0.001). Longitudinal results revealed that higher total carotenoids were associated with significantly lower 3-year increases in body mass index (calculated as kg/m2); waist circumference; waist-to-hip ratio; body FM in the limbs and android and gynoid area; and %FM in total body, trunk, and limbs (all P trends<0.05). Regarding individual carotenoids, β-carotene tended to have the most notable beneficial associations with the majority of fat indices, especially for cross-sectional analyses. Serum carotenoid concentrations are inversely associated with body fat, especially in the abdominal region, in Chinese adults. [ABSTRACT FROM AUTHOR]

This study aimed to determine whether increased carotenoids intake was associated with reduced risk of gestational diabetes mellitus (GDM). We performed a cross-sectional analysis using data from Tongji Maternal and Child Health Cohort study. The dietary carotenoids intake of 1978 pregnant women was assessed using a researcher-administered FFQ before undertaking an oral glucose tolerance test at 24–28 weeks. Multivariate logistic and linear regression analyses were used to obtain the effect estimates. Participants in the highest quartile of lycopene intake showed a lower risk of GDM (OR 0·50; 95 % CI 0·29, 0·86; P for trend = 0·007) compared with those in the lowest quartile; each 1 mg increase in lycopene consumption was associated with a 5 % (95 % CI 0·91, 0·99; P for trend = 0·020) decrease in GDM risk. No significant association was found between α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin intake and GDM risk. Multiple linear regression analysis suggested an inverse association between lycopene intake and fasting blood glucose (FBG) (P for trend < 0·001); each 1 mg increase in lycopene intake was associated with 0·005 (95 % CI 0·002, 0·007; P for trend < 0·001) mmol/l decrease in FBG. Interaction analysis indicated consistent effect on each age or pre-BMI subgroup; however, a stronger protective effect of lycopene intake against GDM was observed among primigravid women (OR 0·20; 95 % CI 0·07, 0·55 in the highest v. the lowest quartile of intake; P for interaction = 0·036). In conclusion, dietary lycopene intake was mainly assumed via reducing FBG to decrease GDM risk, and the protection was relatively increased among primigravid women. [ABSTRACT FROM AUTHOR]

Previous epidemiological studies have revealed the anti-cancer effect of dietary circulating carotenoids. However, the protective role of specific individual circulating carotenoids has not been elucidated. The purpose of this study was to examine whether serum carotenoids, including α-carotene, β-carotene, β-cryptoxanthin, lycopene and lutein/zeaxanthin, could lower the risk for breast cancer among Chinese women. A total of 521 women with breast cancer and age-matched controls (5-year interval) were selected from three teaching hospitals in Guangzhou, China. Concentrations of α-carotene, β-carotene, β-cryptoxanthin, lycopene and lutein/zeaxanthin were measured using HPLC. Unconditional logistic regression models were used to calculate OR and 95 % CI using quartiles defined in the control subjects. Significant inverse associations were observed between serum α-carotene, β-carotene, lycopene, lutein/zeaxanthin and the risk for breast cancer. The multivariate OR for the highest quartile of serum concentration compared with the lowest quartile were 0·44 (95 % CI 0·30, 0·65) for α-carotene, 0·27 (95 % CI 0·18, 0·40) for β-carotene, 0·41 (95 % CI 0·28, 0·61) for lycopene and 0·26 (95 % CI 0·17, 0·38) for lutein/zeaxanthin. However, no significant association was found between serum β-cryptoxanthin and the risk for breast cancer. Stratified analysis by menopausal status and oestrogen receptor (ER)/progesterone receptor (PR) showed that serum α-carotene, β-carotene, lycopene and lutein/zeaxanthin were inversely associated with breast cancer risk among premenopausal women and among all subtypes of ER or PR status. The results suggest a protective role of α-carotene, β-carotene, lycopene and lutein/zeaxanthin, but not β-cryptoxanthin, in breast cancer risk. [ABSTRACT FROM AUTHOR]

Purpose: The associations between specific carotenoid intake and colorectal cancer risk remain inconsistent. The aim of this study was to examine the association between specific dietary carotenoid intake with colorectal cancer risk in Chinese adults. Method: From July 2010 to October 2013, 845 eligible colorectal cancer cases and 845 frequency-matched controls (age and sex) completed in-person interviews. A validated food frequency questionnaire was used to estimate dietary intake. Multivariate logistical regression models were used to calculate the odds ratio (OR) and 95 % confidence intervals (95 % CIs) of colorectal cancer risk after adjusting for various confounders. Results: A strong inverse association was found between β-cryptoxanthin intake and colorectal cancer risk. Compared with the lowest quartile, the highest quartile intake showed a risk reduction of 77 % (OR 0.23, 95 % CI 0.17-0.33, P < 0.01) after adjustment for various confounding variables. The inverse associations were also observed for α-carotene (OR 0.50, 95 % CI 0.37-0.68, P < 0.01), β-carotene (OR 0.67, 95 % CI 0.49-0.91, P < 0.01), and lycopene (OR 0.51, 95 % CI 0.37-0.70, P < 0.01). There was no statistically significant association between lutein/zeaxanthin intake and colorectal cancer risk. These findings were consistent across cancer site, sources of controls, and smoking status. The inverse associations between dietary α-carotene, β-cryptoxanthin, and lycopene intake and colorectal cancer risk were found in both males and females, while inverse associations between β-carotene intake and colorectal cancer risk were only observed in males. Conclusions: Consumption of α-carotene, β-carotene, β-cryptoxanthin, and lycopene was inversely associated with colorectal cancer risk. No significant association was found between lutein/zeaxanthin intake and colorectal cancer risk. [ABSTRACT FROM AUTHOR]

Background: Observational studies have been inconsistent regarding the association between blood antioxidants or vitamins and risk of age-related cataract. Objective: We performed a meta-analysis to determine whether an association exists between blood levels of antioxidants or vitamins and age-related cataract in observational studies. Design: We searched PubMed, EMBASE, and the Web of Science for relevant studies from inception to October 2012. Study-specific risk estimates were combined by using a random-effects model. Results: A total of 13 studies with 18,999 participants were involved in this meta-analysis. A pooled estimate showed vitamin E (OR: 0.75; 95% CI: 0.58, 0.96), a-carotene (OR: 0.72; 95% CI: 0.59, 0.88), lutein (OR: 0.75; 95% CI: 0.65, 0.87), and zeaxanthin (OR: 0.70; 95% CI: 0.60, 0.82) were inversely associated with age-related cataract. Vitamins A (OR: 0.69; 95% CI: 0.58, 0.83) and C (OR: 0.67; 95% CI: 0.57, 0.78) were inversely associated with age-related cataract in Asian populations but not in Western populations. β-Carotene (OR: 0.90; 95% CI: 0.78, 1.05), lycopene (OR: 0.86; 95% CI: 0.65, 1.15), and β-cryptoxanthin (OR: 0.83; 95% CI: 0.68, 1.02) had no significant association with risk of cataract. Conclusions: This meta-analysis provides additional evidence supporting the view that blood levels of certain antioxidants are inversely associated with risk of age-related cataract. However, the role of antioxidant or vitamin supplement intake in preventing cataract should be further investigated in interventional studies. [ABSTRACT FROM AUTHOR]

The article reports a study which was conducted to compare the vitamin A value of β-carotene in golden rice (GR) and in spinach with that of pure β -carotene in oil when consumed by children. The study revealed that the beta-carotene in GR is as effective as pure beta-carotene in oil and better than that in spinach at providing vitamin A to children. GR may be as useful as a source of preformed vitamin A from vitamin A capsules, eggs, or milk.

Background and Objectives: Genetic and dietary factors are important contributors to the development of dental fluorosis (DF). This study investigated the association between DF and dietary carotenoids, and explored whether the association was modified by polymorphisms of the antioxidant enzyme superoxide dismutase 2 (SOD2 rs11968525) in Guizhou, China., Methods and Study Design: A cross-sectional study with a total of 899 adults aged 18-75 years were enrolled in the study. Face-to-face interviews were conducted to assess dietary habits using a validated 75 item food frequency questionnaire (FFQ). Sociodemographic and lifestyle information, and blood and urine samples were also collected. Genotypes were evaluated using TaqMan single nucleotide polymorphism (SNP) Genotyping Assay., Results: There were significant dose-dependent inverse associations of the prevalence of DF with intake of α-carotene, β-carotene, lutein/zeaxanthin, lycopene and total carotenoids (p-trend ranged from <0.001-0.004). The odds ratios (ORs) and 95% confidence intervals (CIs) of DF comparing the highest against lowest quartile were 0.56 (0.35, 0.92) for α-carotene, 0.53 (0.35, 0.81) for β-carotene, 0.44 (0.27, 0.74) for lycopene, 0.35 (0.21, 0.58) for lutein/zeaxanthin in combination and 0.42 (0.25, 0.69) for total carotenoids (all p-trend<0.005). Intake of β-cryptoxanthin was not found to be related to DF. The inverse association of DF with dietary intake of α-carotene and β-carotene was more evident in individuals with the AG+AA genotype (p-interaction<0.05)., Conclusions: Higher dietary carotenoids were associated with a lower occurrence of DF, polymorphisms in SOD2 (rs 11968525) modified the associations between dietary intake of carotene and DF. These findings provide evidence for precision prevention of fluorosis.

Carotenoids are increasingly being implicated to have an important role in brain and eye development. This study aimed to quantify the content and profile of carotenoids in human breast milk, maternal plasma and neonatal umbilical cord plasma in Chengdu, an urban area in Southwest China. In this study, fifty-four healthy mothers were enrolled. Maternal blood, umbilical cord blood, colostrum, transitional milk and mature milk were collected. Concentrations of carotenoids (lutein, zeaxanthin, β-cryptoxanthin, β-carotene and lycopene) were analysed by HPLC. We found that carotenoid concentrations decreased from colostrum to mature milk. Hydrocarbon carotenoids with weaker polarity decreased more than the polar carotenoids. Lycopene concentrations dropped by 99 %, β-carotene by 92 %, β-cryptoxanthin by 83 %, lutein by 32 % and zeaxanthin by 22 %. Lycopene and β-carotene accounted for 70 % of the total carotenoids in colostrum, and lutein predominated amongst carotenoids in transitional milk and mature milk (51-55 %). Carotenoid concentrations in maternal plasma were much higher than that in cord plasma. Lutein predominated in cord plasma. The concentrations of all carotenoids in maternal plasma were correlated with those of cord plasma and human milk. These results are consistent with selective transport mechanisms in the mammary gland related to the polarity of carotenoids, and each carotenoid has its own implications, which may have different priorities in the early life development of infants. These findings may help guide dietary recommendations for carotenoid inclusion in infant formulas.

Background: Epidemiological studies examining the association between β-carotene intake and risk of fracture have reported inconsistent findings. We conducted a meta-analysis to investigate the association between β-carotene intake and risk of fracture., Methods: We systematically searched PubMed, EMBASE and Cochrane library databases for relevant articles that were published until December 2019. We also identified studies from reference lists of articles identified from the clinical databases. The frequentist and Bayesian random-effects model was used to synthesize data., Results: Nine studies with a total of 190,545 men and women, with an average age of 59.8 years, were included in this meta-analysis. For β-carotene intake (1.76-14.30 mg/day), the pooled risk ratio (RR) of any fracture was 0.67 (95% Credible Interval (CrI): 0.51-0.82; heterogeneity: P = 0.66, I 2  = 0.00%) and 0.63 (95%CrI: 0.44-0. 82) for hip fracture. By study design, the pooled RRs were 0.55 (95% CrI: 0.14-0.96) for case-control studies and 0.82 (95% CrI: 0.58-0.99) for cohort studies. By geographic region, the pooled RRs were 0.58 (95% CrI: 0.28-0.89), 0.86 (95% CrI: 0.35-0.1.37), and 0.91(95% CrI: 0.75-1.00) for studies conducted in China, the United States, and Europe, respectively. By sex, the pooled RRs were 0.88 (95% CrI: 0.73-0.99) for males and 0.76 (95% CrI, 0.44-1.07) for females. There was a 95% probability that β-carotene intake reduces risk of hip fracture and any type of fracture by more than 20%., Conclusions: The present meta-analysis suggests that β-carotene intake was inversely associated with fracture risk, which was consistently observed for case-control and cohort studies. Randomized controlled trials are warranted to confirm this relationship.

In order to discover the relationship between dietary nutrients intake and risk of lung cancer 1:1 matched case-control study on 156 recent histologiclly diagnosed primary lung cancer patients and 156 patients with respiratory tumour and other related diseases as controls, was conducted in Wuhan. All cases and controls were asked to participate in the nutritional assessment program and a food frequency questionnaire containing 64 food items was filled in. The findings showed that there was a statistically significant difference between dietary intake of beta-carotene between the two groups (2877.13 +/- 393.43 vs. 3445 +/- 430.98 micrograms/day). Having controled the confounding factor of cigarette smoking, a significant linear trend for lower dietary carotene intake toward higher lung cancer risk was observed.

Screening examinations were conducted at a Chinese community health fair in Houston, Texas, to identify individuals with oral leukoplakia for a chemoprevention trial of oral-cavity squamous cell carcinoma. All 161 volunteer participants were interviewed regarding age, smoking habits, and betel-nut and alcohol use. The screening included an examination of the oral cavity, oropharynx, and neck. One participant had a 1-mm area of oral leukoplakia on the right lateral surface of the oral tongue. Eighteen participants had other head and neck abnormalities. Only 12 participants (7.5%) were active smokers, and eight (5%) reported a prior history of smoking. One participant reported prior betel-nut use. The mean age was 55 years. The authors conclude that a venue such as this has a low yield for screening and recruitment of high-risk individuals for chemoprevention of oral-cavity squamous cell carcinoma, that generally health-conscious individuals attend health fairs, and that only a small percentage volunteer for oral screening.

In Linxian China, the esophageal/gastric cardia cancer mortality rates are among the highest in the world. There is suspicion that the population's chronic deficiencies of multiple micronutrients are etiologically involved. We conducted two randomized, placebo-controlled nutrition intervention trials to test the effects of vitamin and mineral supplements in lowering the rates of esophageal/gastric cancer. In the first trial, the dysplasia trial, 3318 adults with a cytological diagnosis of esophageal dysplasia received daily supplementation with 26 vitamins and minerals in doses typically 2-3 times the United States Recommended Daily Allowances, or placebos, for 6 years. The second trial, the general population trial, involved 29,584 adults and used a one-half replicate of a 2(4) factorial experimental design which tested the effects of four combinations of nutrients: A, retinol and zinc; B, riboflavin and niacin; C, vitamin C and molybdenum; and D, beta-carotene, vitamin E, and selenium. Doses for these daily supplements ranged from 1 to 2 times the United States Recommended Daily Allowances, and the different vitamin/mineral combinations or placebos were taken for a period of 5.25 years. As part of the general population trial, and end-of-intervention endoscopy survey was carried out in a small (1.3%) sample of subjects to see if supplementation affected the prevalence of dysplasia and early cancer. Herein we review the methods of these trials and the results of the endoscopic survey. Fifteen esophageal and 16 gastric cancers were identified in endoscopic biopsies from the 391 subjects evaluated from two villages, and nearly all were asymptomatic. No significant reductions in the prevalence of esophageal or gastric dysplasia or cancer were seen with any of the four supplement groups. However, the prevalence of gastric cancer among participants receiving retinol and zinc was 62% lower than those not receiving those supplements (P = 0.09), while participants receiving beta-carotene, vitamin E, and selenium had a 42% reduction in esophageal cancer prevalence (0.34). We have reported separately that cancer mortality over the entire 5.25-year period was significantly reduced among those receiving beta-carotene, vitamin E, and selenium. The findings from the overall trial and the endoscopic sample offer a hopeful sign and should encourage additional studies with these agents in larger numbers of subjects.

Serum levels of retinol, beta-carotene, ascorbic acid, alpha-tocopherol, selenium, ferritin, copper, and zinc were assayed for approximately 600 adults aged 35 to 64 with pre-cancerous gastric lesions in an area of China with one of the world's highest rates of stomach cancer. Previous studies have shown that the cancers generally are preceded by chronic atropic gastritis (CAG), intestinal metaplasia (IM) and dysplasia. Concentrations of beta-carotene and ascorbic acid were significantly lower among individuals with IM than among those whose most severe lesion was superficial gastritis or CAG. The associations with IM for these nutrients were strong and independent. In combination, the odds of CAG progressing to IM were only 1/6 as high among those with upper tertile levels of beta-carotene and ascorbic acid as among those with lower tertile levels of both nutrients. The serum levels of beta-carotene and ascorbic acid were similar for individuals having IM with or without accompanying dysplasia. Risk of IM was also somewhat increased among those with low serum ferritin, but no significant effects were observed in multivariate analyses for the other nutrients assayed. The findings point to a major influence of specific nutrient deficits in the mechanisms of gastric carcinogenesis in this high-risk area.

A 1:2 matched case-control study was conducted in Wuhan area with conditional logistic regression model to study the relationship between occurrence of primary lung cancer and serum levels of beta-carotene. The results showed the lower the serum levels of beta-carotene, the higher the risk of lung cancer. It suggested the increase of serum beta-carotene with dietary intake could lower the risk of lung cancer.

A randomized nutrition intervention trial was conducted among 29,584 adult residents of Linxian, China, to examine the effects of vitamin/mineral supplementation on the occurrence of esophageal/gastric cardia cancer in this high-risk population. A fractional factorial study design allowed evaluations of four different combinations of nutrients: (A) retinol and zinc; (B) riboflavin and niacin; (C) vitamin C and molybdenum; and (D) beta-carotene, vitamin E, and selenium. During the 5.25-year intervention, significant reductions in total mortality, total cancer mortality, and stomach cancer mortality occurred among those receiving beta-carotene, vitamin E, and selenium. At the end of intervention, an endoscopic survey was carried out in a sample of subjects to see if the nutritional supplements had affected the prevalence of clinically silent precancerous lesions and early invasive cancers of the esophagus or stomach. Endoscopy was performed on 391 individuals from two study villages. The prevalences of esophageal and gastric dysplasia and cancer were compared by nutrient factor. Cancer or dysplasia was diagnosed in 15% of the participants. No statistically significant reductions in the prevalence of esophageal or gastric dysplasia or cancer were seen for any of the four vitamin/mineral combinations. The greatest reduction in risk (odds ratio, 0.38; P = 0.09) was seen for the effect of retinol and zinc on the prevalence of gastric cancer. Although no significant protective effects were seen in this endoscopic survey, there was a suggestion that supplementation with retinol and zinc may protect against the development of gastric neoplasia in this high-risk population. Additional studies with larger numbers of endpoints will be needed to further evaluate this possibility.

To examine whether vitamin/mineral supplementation may lower mortality and incidence from human cancer and mortality from other diseases as well as to provide the scientific basis and feasible approach for human cancer prevention and control, between 1982-1991 scientists from China and USA conducted two randomized, double-blind, and placebo-controlled nutrition intervention trials in Linxian, China, where the esophageal/gastric cardia cancer mortality rates are among the highest in the world and there is suspicion that the population's chronic deficiencies of multiple nutrients are etiologically involved. In the first trial, the Dysplasia Trial, 3,318 individuals with a cytologic diagnosis of esophageal dysplasia received daily 26 vitamin/mineral supplements or placebos for 6 years; The second trial, the General Population Trial, involved 29,584 individuals and used an one-half replicate of a 2(4) fractional factorial design which randomized to 8 groups for testing the effects of daily supplementation of 4 different vitamin/mineral combinations and placebo for a period of 5 1/4 years. Compliance assessed by monthly pill counts and quarterly monitoring of biochemical assays indicated that the participant compliance was excellent. As endpoints of the trials, incident cancers and deaths were identified through all medical facilities in local areas, supplemented by special endoscopy and cytology examinations, and confirmed by 3-level review groups. A total of 323 deaths occurred during 6 year period among participants in the dysplasia trial, and 2,127 deaths from the general population trial during 5 1/4 years. Besides, an eye examination, which included detailed lens evaluations, was included in the extensive re-examination protocol to ascertain whether use of the supplements had affected the risk of developing age-related cataracts among participants in the two trials. Results from Dysplasia Trial indicated that after 6 years of daily supplementation with multiple vitamins and minerals, total mortality among those in the active treatment group was slightly (9%) lower than in the placebo group; and deaths of esophageal cancer also declined by 17%, as well as a sizeable reduction in cerebrovascular disease mortality (near 40%) was seen, though none was statistically significant. However, intervention had decreased prevalence of eye nuclear cataract (43%) (P < 0.01). The findings from the General Population Trial provide support for the hypothesis that intake of specific micronutrients may inhibit cancer development. Significant reduction of total mortality (9%), cancer mortality (13%), gastric cancer mortality (20%), and mortality of the other cancers (19%) occurred among those receiving beta-carotene/vitamin E/selenium supplementation (P < 0.05). Patterns of cancer incidence, based on 1307 cases, generally resembled those for cancer mortality.(ABSTRACT TRUNCATED AT 400 WORDS)

Stomach cancer mortality data were compared with dietary and biochemical data from 65 Chinese counties to provide clues to reasons for the marked geographic variation of stomach cancer mortality rates in China. Sex-specific correlation and multivariate regression analyses showed significant positive associations with consumption of salted vegetables and eggs, prevalence of antibodies to Helicobacter pylori, and levels of plasma albumin; and significant negative associations with intake of green vegetables and levels of plasma selenium and beta-carotene. Limitations of ecological data preclude causal inferences, but these findings suggest factors that may contribute to making stomach cancer the leading cause of cancer death in China and other countries.

A retinol (15 mg), riboflavin (200 mg) and zinc (50 mg) supplement or a placebo (D-mannitol) was given to 610 Chinese farmers weekly for 13.5 months. Riboflavin, retinol, beta-carotene, tocopherol and zinc status were measured in all subjects at the start and end of the intervention and in a subsample at 2 months. Plasma vitamin C, haemoglobin and haematocrits were measured on other subsamples at the end of the supplementation period. At the start vitamin A, zinc and riboflavin status were poor. Plasma retinol and zinc concentrations were higher in men than women but the opposite was observed with respect to beta-carotene. There was no difference between the sexes for tocopherol and riboflavin. Tocopherol:cholesterol ratios suggested vitamin E status was good and vitamin C status also appeared adequate. The supplement increased plasma retinol throughout the whole period but riboflavin status improved only over the first 2 months and then remained constant. Plasma zinc increased in both treatment and placebo groups by approximately 15 to 20 per cent in men and women. Mean concentrations of retinol and tocopherol and beta-carotene (in women only) increased by approximately 20 per cent in the placebo group. It is argued that seasonal factors and/or the placebo may have been responsible for the increase in retinol and beta-carotene in the placebo group. The lack of an increase in beta-carotene in the men may have been due to their higher retinol requirements. Lastly, the increase in retinol may have been responsible for the increase in tocopherol and zinc in plasma since these nutrients increased in those whose plasma retinol increased, irrespective of treatment.

Plasma levels of nutrients in 196 individuals were assayed as part of a study of the feasibility of a nutrition intervention trial in Linxian, a county in North Central China with exceptionally high rates of esophageal cancer. High-performance liquid chromatography analyses of samples collected in April 1983 showed low (relative to United States standards) base-line levels for retinol, alpha-tocopherol, and beta- and alpha-carotene. Repeat sampling in August 1983 revealed significantly increased plasma levels of retinol and alpha-tocopherol among those who had in the interim received daily supplementation with multivitamin pills containing the Recommended Dietary Allowance levels of those nutrients but not among those without supplementation. Levels of carotenes, which were not included in the pills, tended to increase regardless of supplementation, consistent with seasonal variations in availability of carotenoid-containing foods. Atomic absorption spectrophotometry analyses showed essentially normal levels of copper and zinc in plasma. Neither was affected by vitamin supplementation (the pills did not contain minerals) nor seasonal variation. The data are generally consistent with prior biochemical surveys in indicating marginal or low status of several nutrients in Linxian and in showing that supplementation with vitamins can effectively raise blood nutrient levels.