The relation between single/double or repeated tea catechin ingestions and plasma antioxidant activity in humans.

OBJECTIVE: The purpose of this study was to investigate the effects of single/double or repeated intake of a normal amount of tea catechin on plasma catechin concentrations and antioxidant activity in young women. DESIGN: First, after an overnight fast, five healthy subjects were given water or single/double dose(s) of tea polyphenol extract (164 mg tea catechins containing 61% epigallocatechin gallate in 190 ml water). Blood samples were taken before and 30, 60 and 180 min after the ingestion. Second, 16 healthy subjects ingested the tea polyphenol extract three times a day at mealtimes for 7 days followed by withdrawal of tea polyphenol extract for 7 days. Blood samples were taken before and after ingestion, and 7 days after the withdrawal of tea catechin. Subjects were prohibited from drinking any beverages containing polyphenols or antioxidant supplements during the study period. Catechin and other antioxidant concentrations in the plasma were measured, and changes in antioxidant activity were evaluated by ferric reducing ability of plasma assay. RESULTS: Single/double ingestion of tea polyphenol extract did not cause an increase in the antioxidant activity. There was no also change in antioxidant activity after the ingestion of tea polyphenol extract for 7 days. Plasma-free epigallocatechin gallate concentration remained at the pre-study level; however, the plasma FRAP value decreased significantly at 7 days after the withdrawal of tea polyphenol extract. Decreases in endogenous antioxidants in the plasma, including vitamin C and bilirubin, were also observed 7 days after withdrawal of tea polyphenol. CONCLUSIONS: The results suggest that continuous daily intake of tea catechins affects the concentrations of endogenous antioxidants in the plasma and has the potential to maintain total antioxidant activity.

Enhanced oxidative damage induced by total body irradiation in mice fed a low protein diet.

PURPOSE: To examine the influence of the level of dietary protein on oxidative damage to lipid and protein in the liver and on chromosomal damage in the bone marrow after total body irradiation (TBI). MATERIALS AND METHODS: Male mice were fed a low (7%), basal (20%) or high (33%) protein diet for 3 weeks, and then received TBI at a dose of 0, 0.5 or 1 Gy. Chromosomal damage in the bone marrow was evaluated by determining the proportion of micronucleated reticulocytes in peripheral blood. Oxidative damage in the liver and plasma, and chromosomal damage in the bone marrow were evaluated on day 2 after TBI. RESULTS: The levels of lipid peroxides and protein carbonyls in the liver, lipid peroxides in the plasma, and chromosomal damage in the bone marrow, did not differ among the groups that did not receive TBI. However, the oxidative damage to lipid and protein in the liver, and the level of lipid peroxides in the plasma were increased by TBI only in the low protein group. Chromosomal damage in the bone marrow was increased by TBI in a dose-dependent manner, and the damage was consistently higher in the low protein group than in the basal and high protein groups. In the low protein group, a greater decrease of the relative spleen weight by TBI was also observed. The concentrations of antioxidants (vitamin C, E and GSH) in the liver were lower, and the concentration of non-heme iron in the liver was higher in the low protein group than in the basal and high protein groups. The TBI-induced increase in the level of plasma iron was greater in the low protein group. CONCLUSIONS: Mice fed a low protein diet became susceptible to TBI-induced oxidative damage, and a decrease in antioxidants and an increase in iron are involved in the mechanism of this susceptibility.

[Comparison of photometric, electrochemical and post-column fluorescence detection for the determination of flavonoids by HPLC].

For the analysis of flavonoids by HPLC, we compared three different detection methods, namely UV, electrochemical detection and post-column chelation with aluminum followed by fluorescence detection. Ten flavonoids were used: apigenin, myricetin, luteorin, taxifolin, quercetin-3-O-sulfate, kaempferol, isorhamnetin, isoquercitrin, quercetin and rutin. Nine flavonoids except apigenin were efficiently detected by the electrochemical method with a detection limit of 0.025-0.05 pmol. Flavonols having free 3-hydroxyl and 4-keto oxygen formed a fluorescent complex by post-column chelation and were detected by the fluorescence method. The detection limit of the fluorescence method was 0.05-0.5 pmol. Nine flavonoids except taxifolin were detected by the UV method (absorbance at 370 nm), but the detection level was poor (5-10 pmol). Flavonols added to human plasma were recovered by solid phase extraction, and were analyzed using the three detection methods. Most of the flavonols were efficiently detected by the electrochemical and fluorescence methods, and the detection limits were similar to those of standard samples.

Different onsets of oxidative damage to DNA and lipids in bone marrow and liver in rats given total body irradiation.

We examined time-dependent changes in antioxidant vitamins and oxidative damage to DNA and lipids in the bone marrow, liver, and plasma of rats given total body irradiation (TBI) with X-rays at 3 Gy. The oxidative damage to DNA and lipids was evaluated by measuring increases of 8-hydroxydeoxyguanosine (8OHdG) in DNA and 4-hydroxy-2-nonenal (HNE), respectively. After the TBI, marked increases in 8OHdG and HNE were detected at 3 to 5 h in the bone marrow, while gradual increases in these parameters were detected after a few days in the liver. These changes in 8OHdG and HNE were well correlated within each tissue. In the bone marrow, levels of both vitamin C and vitamin E were decreased by the TBI; however, the changes in vitamin C were earlier and greater than those in vitamin E. In the liver, the level of vitamin C did not decrease, but that of vitamin E decreased due to the TBI. Changes in HNE, vitamin C, and vitamin E in the plasma were similar to those in the liver. Within each tissue, the time of decrease in antioxidants was almost the same as that of the increase in oxidative damage. An increase in total iron due to the TBI was also detected in these tissues. In particular, the total iron in the bone marrow was markedly increased at a few hours after the TBI, with a slight increase in transferrin and no increase in ferritin. Exposure studies performed on cells or isolated DNA showed that an increase in 8OHdG was detected immediately after irradiation at more than 100 Gy in bone marrow cells and at less than 10 Gy in isolated DNA, suggesting that an increase in 8OHdG is undetectable even in bone marrow immediately after the TBI at 3 Gy. These results indicate that the onset of oxidative damage to DNA and lipids was delayed after TBI at 3 Gy, that it was quite different in the bone marrow and the liver, and that an increase in iron and decrease in antioxidant vitamins were involved in the mechanism of oxidative damage.

Docosahexaenoic acid supplementation-increased oxidative damage in bone marrow DNA in aged rats and its relation to antioxidant vitamins.

We compared the influence of docosahexaenoic acid (DHA) supplementation on oxidative DNA damage in bone marrow between young and aged rats. As a marker of oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OHdG) in DNA was analyzed. Young (5-week-old) and aged (100-week-old) female Wistar rats were given DHA (300mg/kg body weight/day) or vehicle (control) orally for 12 weeks. The 8-OHdG in the bone marrow in the aged DHA group was significantly higher than that in the other groups. Vitamin E concentrations, however, did not differ among the groups regardless of the DHA supplementation. Vitamin C (ascorbic acid) concentrations in the aged control group were approximately 1/2 those in the young control group. The concentrations of vitamin C tended to be higher in the young DHA group and lower in the aged DHA group when compared to their respective control groups. Changes in the concentrations of vitamin C and vitamin E in plasma were similar to those in the bone marrow. The activity of hepatic l-gulono- gamma -lactone oxidase, an enzyme responsible for vitamin C synthesis, corresponded well to the concentrations of vitamin C in the bone marrow and the plasma. These results suggest that in aged rats, but not young rats, excess supplementation of DHA induces oxidative DNA damage in bone marrow and that the decrease in vitamin C synthesis in aged rats is involved in the mechanisms of DNA damage.

Analytical method of measuring tea catechins in human plasma by solid-phase extraction and HPLC with electrochemical detection.

We developed an analytical method for measuring tea catechins in plasma by solid-phase extraction (SPE), followed by HPLC with a coulometric electrochemical detector. The plasma was mixed with an equal volume of acetonitrile to precipitate protein, and catechins in the resulting supernatant were extracted by SPE, using a C18 cartridge. To correct the extraction efficiency, ethyl gallate was simultaneously added with acetonitrile as an internal standard. Plasma samples were treated in microtubes, and evaporation and SPE were performed by the use of a vacuum centrifuge and vacuum manifold for SPE. The use of these instruments allowed the handling of a large number of samples simultaneously. In this method, (-)-epicatechin (EC), (-)-epicatechin-3-O-gallate (ECg), (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-O-gallate (EGCg), and ethyl gallate could be detected as a single peak with high sensitivity. For an analysis of the conjugated form of catechins, plasma samples were treated with glucuronidase and sulfatase. Type H-2 beta-glucuronidase effectively digested the conjugated forms, and the enzyme also converted EGCg and ECg to their nongallated form. When the concentrations of catechins in plasma were analyzed in subjects who took a single dose of catechin liquid, the concentration of free EGCg in plasma reached a maximum of 300 nM at 1 h after intake; those of the other free form of catechins increased only slightly after the intake. The concentration of total catechins (free+conjugated forms) in plasma increased up to 2 h after the intake.

Influence of one bout of vigorous exercise on ascorbic acid in plasma and oxidative damage to DNA in blood cells and muscle in untrained rats.

We investigated the influence of a single exhaustive bout of downhill running on oxidative damage to DNA and changes of antioxidant vitamin concentrations in rats. Plasma vitamin E levels were unchanged up to 48 hr postexercise. However, plasma ascorbic acid (AA) levels increased after the exercise, then decreased thereafter. This increase corresponded to a marked decrease in AA concentration in the adrenal glands. The activity of hepatic l-gulono-gamma-lactone oxidase, which catalyzes AA synthesis, was unaltered after the exercise. The weight of the adrenal glands was significantly increased 24 hr postexercise. These results indicate that the change in the plasma AA concentration after vigorous exercise was due mainly to the release of AA from the adrenal glands. The plasma creatine phosphokinase (CPK) activity and white blood cell (WBC) count increased 3 to 6 hr postexercise. Over this same period, a marker of oxidative DNA damage, 8-hydroxydeoxyguanosine in DNA, increased in the WBC, but not in the foreleg muscle. Lipid peroxide and vitamin E levels were also unchanged in the foreleg muscle. There was a positive correlation between CPK activity in the plasma and DNA damage in the WBC, suggesting that the DNA damage in the WBC was closely related with muscle damage due to exercise.

[Impact of health practices on changes in the physical and mental well-being of older adults].

Previous studies on young and middle-aged adults have demonstrated a correlation between certain personal health practices and reduced mortality. However, we have little knowledge to what extent the findings can be generalized to older adults. Our purpose was to investigate the impact of health practices on subsequent changes in the physical and mental well-being of the elderly. We used longitudinal data of a national representative sample of 2,200 older adults aged 60 and over at baseline. This six-year prospective study examined the associations of six items related to personal health habits--cigarette smoking, alcohol consumption, physical exercise, eating breakfast, hours of sleep, and relative weight--with subsequent health status change. Not smoking was the only health practice that achieved a statistically significant relationship with the reduction of future mortality risk. Obesity (20% or more overweight) was a risk factor for the subsequent impairment in activities of daily living. Those who reported a high frequency of exercise and sleeping 7 or 8 hours per night at baseline were less likely to show decreases in their levels of mental well-being. These results suggest that not smoking, weight control, physical exercise, and sleep patterns may have an important role in maintaining physical and mental well-being in older adults.

[Effect of retirement on mental health and social well-being among elderly Japanese].

Based on a longitudinal study of a national representative sample aged 60 and over, we examined the impact of retirement on mental health and social well-being among elderly Japanese. From the baseline interviewees, we selected 178 study subjects who were full-time workers employed at least five days per week for at least six hours per day. At a follow-up survey three years after baseline, 34 had retired from their jobs and the rest still continued working. Mental health was rated from an aspect of depression, using a short form of the Center for Epidemiologic Studies Depression Scale. Social well-being was measured by two indicators: the degree of social participation and the frequency of meeting friends or neighbors. Multiple regression analyses were used to investigate the effect of retirement on mental health and social well-being, controlling for baseline health characteristics. Results showed there was no significant effect of retirement on either mental health or the degree of social participation. On the frequency of social contacts with friends or neighbors, however, the retirement x sex x age interaction contributed a significant effect. Early retirement among elderly men tended to decrease the frequency of social contrasts. This finding suggests that an extra-workplace social relationship should be recommended especially to middle-aged working men to prevent them from falling into social isolation after retirement.

[Development of research on self-rated health in the United States].

The development of research on self-rated health in the United States was reviewed to elucidate the background of the research. The earliest studies utilized medical and objective health data to assess self-rated health. A lack of convenient and exact health measurements in the gerontological research field motivated the development of these early studies. These studies indicated that self-rated health could not serve as a substitute for physicians' ratings. On the other hand, studies of the relationship between psychosocial indices and self-rated health demonstrated that self-rated health was valid as a single measure of overall health, being related to physical, mental and social aspects of well-being. Recent epidemiological investigations have shown that self-rated health is a significant predictor of mortality and changes in activities of daily living. Most of these research studies on self-rated health utilized elderly populations for subjects.

[A study on stressful life events of workers in Japan].

The experience rates of eighteen life events of Japanese workers were surveyed and the strength of each of the events was evaluated by a self-reported questionnaire. The fifteen professions surveyed included construction, transport, mailing, chemical production, banking, newspaper, TV services, commercial publishing, advertising, teaching and civil service. The number of workers who answered was 18,657 males and 4,443 females, aged 20 to 59 years. The male workers were divided and analysed in six job groups: clerical workers (n = 5,866), professionals (n = 3,696), blue collar day workers (n = 1,623), blue collar night or shift workers (n = 3,191), drivers (n = 1,663) and construction workers (n = 2,466). They were divided into groups and compared according to job, sex and five different age groups. The highest experience rate in each of the life events such as family trouble for both sexes, death of a family member, financial trouble and anxiety, death of a close friend, dissatisfactory transport to workplace or job, respectively. Comparing the experience rates between males and females we found no significant difference for five items. However, other items had higher experience rates for males than for females with the exception of family trouble. In regard to the age characteristics of each of the life events, as the age increased the experience rates of health-related life events such as the death of a spouse, child, family member or close friend and one's own illness or injury became higher. In contrast, the experience rates of items such as moving to a worse residence and failure in a school or training program became lower as the age increased for both sexes. Among job groups, construction workers had the highest experience rates of most life events except for the item of dissatisfactory transport to the workplace or job. Among other job groups, drivers had higher experience rates in the following four items: re-employment, death of spouse, divorce and financial trouble and anxiety. Blue collar day workers had higher rates for failure in school or training program and family trouble. The blue collar night or shift workers had higher rates for failure in school or training program and dissatisfactory transport to the workplace or job. The mean values of strength in six life events: re-employment, death of a family member, death of a close friend, serious physical illness, dissatisfactory transport to the workplace or job and family trouble were stronger in females than in males.(ABSTRACT TRUNCATED AT 400 WORDS)

[Health conditions among fishermen living in the Minamata disease prevalent area].

More than thirty years have elapsed since the major outbreak of Minamata disease. The purpose of this study is to examine the current health conditions among fishermen living along the coastal area of Yatsushiro Sea which received high exposure to methylmercury contamination. From 1988 to 1990 an interview survey was conducted on a random sample of 215 fishermen in two adjoining areas classified as contaminated: Minamata City of Kumamoto Prefecture and Izumi City of Kagoshima Prefecture. Completed responses were collected from 181 (129 males and 52 females). Health conditions were measured by four indicators: activities of daily living, presence of chronic diseases, subjective symptoms, and depressive symptoms. The associations between each health indicator and estimated intake levels of fish and/or shellfish during the heavy contamination period were examined. Residents in areas designated as contaminated can be categorized into three groups: 1) persons who are officially recognized as patients with Minamata disease, 2) persons applying for recognition as having Minamata disease but who have not been officially recognized, and 3) persons who have not applied for official recognition. In the analysis this recognition-related status was used as one of the controlling factors. Findings may be summarized as follows: 1. In both areas, a significant relationship was observed between subjective symptoms and estimated fish intake levels after controlling for sex and age. Judging from subjective symptoms, it appeared that the health level of recognized patients was lowest among the three recognition-related groups; and the health level of non-recognized persons was lower than that of the non-applicants. 2. Among Minamata City fishermen, the significant effect of fish intake levels on subjective symptoms disappeared after controlling for sex, age and recognition-related status. On the other hand, among Izumi City fishermen, a significant relationship between subjective symptoms and fish intake levels still remained by the same analysis. 3. The mental health level of the non-recognized as well as of recognized patients was comparatively lower than that of the non-applicant. However, within the limits of this study, the association between mental health and fish intake levels was not clear.

[Mental health and its related factors among middle-aged male workers: an eighteen-month follow-up study].

Based on a longitudinal questionnaire survey of 11,121 subjects (males aged 30-59, engaged in various occupations and firms), this study examined the relationships of the baseline psychosocial work environment and personal health practices to mental disorders which occurred during an 18-month follow-up period. The onset of mental disorders during the follow-up period was assumed to be the time when the subject reported to have received medical treatment for the first time due to mental disorder. The psychosocial factors of the work environment were conceptually constructed from two aspects of working conditions and occupational stress. Working conditions were assessed by actual working hours, frequencies of late night work (10 p.m.-5 a.m.), and role in the organization. Occupational stress was measured by psychological work overload and job characteristics (job demands, decision latitude). Various factors associated with positive health behavior were examined through an index based on six variables, that is, supper time, exercise, smoking, alcohol consumption, sleep and weight. Multiple logistic analysis showed that both psychological work overload and late night work have a significant independent effect on the onset of mental disorders after controlling for other variables.

[Mental health, work environment, and health practices among middle-aged male workers].

A study was made on the cross-sectional relationship of the psychosocial work environment and personal health practices to mental health level among 15,639 male subjects aged 30-59 engaged in various kinds of occupations and firms. Mental health level was dichotomized by self-reported mental disorders. The psychosocial factors of work environment were conceptually constructed from the aspects of working conditions and occupational stress. Working conditions were assessed by work overload, work shifts and role in the organization. Occupational stress was measured by psychological work load and job characteristics (job demands and decision latitude). Various factors associated with positive health behavior--an index based on six parameters such as supper time, physical exercise, smoking, alcohol consumption, sleep, and weight--were examined. The prevalence of self-reported mental disorders was 17.5 per 1,000 population. Multiple logistic analysis showed that both psychological work load and health practice index have a significant independent effect on mental health levels after controlling for age and marital status. Limitations of the present study indicate a need for future longitudinal studies.

[Four-year follow-up study of self-rated health and life satisfaction among caregivers].

Changes in self-rated health and life satisfaction among caregivers of elderly and factors associated with the changes during a four year were investigated. The sample in the baseline survey consisted of persons randomly selected from recipients of welfare allowances for disabled elderly in two communities in Tokyo. A total of 152 persons were identified as living at home at the time of the first survey and 94 persons were surveyed. In a follow-up survey after a 4-year interval, 73 persons were followed. The main results were as follows: 1. Of the 73 original caregivers, 28 persons continued to give care, and 45 stopped caregiving activities. 2. Among those persons who had been cared for by the 45 caregivers who reported stopping care giving activities, 41 had died and 4 were placed in nursing homes or hospitals. Of the elderly who had died, 60% had been admitted to hospitals, with deterioration of the elderly persons' health being the biggest reason for hospitalization. 3. No significant changes in either self-rated health or life satisfaction were seen after the 4-year interval in those caregivers who continued giving care. Persons who terminated caregiving had an increase in self-rated health in comparison with the original survey. 4. Where self-rated health declined among those continuing giving care, the decrease was related to decrease of cognitive ability of the elderly. A decrease of cognitive ability of the elderly, and also low social support and negative perception regarding caring for the elderly at the baseline survey, was associated with reduction in life satisfaction. 5. Among 45 subjects who terminated caregiving, persons who had low economic backgrounds at baseline, had low improvement of life satisfaction. Persons who did not have jobs had increase in self-rated health.