Urinary estrogen profile determination in young Finnish vegetarian and omnivorous women

For a long time it has been postulated that diet may influence estrogen metabolism and in this way affect breast cancer risk. In order to investigate possible effects of variations of dietary fiber intake on estrogen metabolism, the urinary estrogen profile (13 estrogens), including the catecholestrogens, was determined in one 72-h summer and one winter sample collected in the midfollicular phase of the menstrual cycle by 11 lactovegetarian and 12 omnivorous young Finnish women. Urinary estrogens were purified by ion-exchange chromatography and the quantitative determination was carried out by capillary gas chromatography-mass spectrometry. Detailed records of the subjects' diet during one 5-day period in summer and one in winter were obtained and dietary fiber intake calculated. The mean difference with regard to intake of total fiber in the two dietary groups was 3 g/day in the summer (not significant) and 5 g/day in the winter (P less than 0.05), the mean (geometric) consumption being 23 and 19 g/day by the vegetarian and omnivorous women, respectively. Within the groups we found seasonal variation in fiber intake only for the omnivorous women. During winter, compared to summer, the omnivorous women consumed significantly less grain (P less than 0.001), vegetable (P less than 0.02) and total fiber (P less than 0.02). The excretion of 13 estrogens was remarkably constant in the omnivoric group but a significant seasonal variation of total and individual catecholestrogens and of estrone was observed in the vegetarians (P less than 0.05-0.005). The quantitatively most important estrogen was 2-hydroxyestrone, followed by estrone, estriol, 2-hydroxyestradiol, 4-hydroxyestrone and estradiol, the three latter being excreted in similar amounts. Between the dietary groups there were no significant differences in excretion of total or individual urinary estrogens in any season or between the mean values for both seasons. However, numerous significant (P less than 0.05-0.01) negative correlations between dietary intake of total or grain fiber/kg body weight and the excretion of individual estrogens were found. These correlations disappeared if the fiber intake was not related to body weight. We conclude that dietary fiber intake significantly affects estrogen metabolism by reducing estrogen excretion in urine and that grain fiber seems to be most important in that respect. One of the mechanisms involved is a partial interruption of the enterohepatic circulation of the estrogens, due to alterations of the intestinal metabolism and reabsorption of these steroids, caused by the fiber.     

Measurement of enterolactone and enterodiol, the first mammalian lignans, using stable isotope dilution and gas chromatography mass spectrometry

Methods are described to extract and measure 2,3-bis(3-hydroxybenzyl)-gamma-butyrolactone (enterolactone) and 2,3-bis(3-hydroxybenzyl)butane-1,4-diol (enterodiol) from physiological fluids. They are based on the use of stable labelled analogues of each compound as internal standards with end point assay being by gas chromatography mass spectrometry. The methods were developed to quantify enterolactone and enterodiol in experiments designed to investigate the significance and source of these compounds in man and animals. Examples of studies on human ovarian blood and investigations of their excretion in urine following dietary manipulation are described.     

Comparison of plasma and urinary phytoestrogens in Japanese and Finnish women by time-resolved fluoroimmunoassay

Time-resolved fluoroimmunoassays (TR-FIA), with europium labeled phytoestrogens as tracers, were developed for the quantitative measurement of genistein, daidzein and enterolactone in plasma and urine for the purpose of screening large populations and studies on possible correlation between the values in biological fluids and the risk of western diseases. The mean values of the three phytoestrogens in plasma as determined by TR-FIA were similar to those obtained by gas chromatography-mass spectrometry (GC-MS). The urinary excretion levels of total individual phytoestrogens were higher than those obtained by GC-MS, with the exception of the daidzein values. However, comparing the assay results obtained by the present method and those obtained by GC-MS, a strong correlation was evident (r = 0.87 - 0.99, p < 0.001). We measured plasma levels of genistein, daidzein and enterolactone in 111 healthy Japanese women The mean and median levels of genistein were 406.8 and 306.3 nmol/l, respectively, and those of daidzein were 118.4 and 76.8 nmol/l, respectively. These levels are higher than those reported for Americans and Western Europeans. Isoflavone intake as calculated from dietary records (genistein: mean, 86.5 mircomol/day and daidzein: mean, 57.4 micromol/day) was correlated with the plasma concentrations observed (genistein: r = 0.287, p < 0.01 and daidzein: r = 0.313, p < 0.01). Plasma enterolactone levels were low in Japanese women (mean, about 10 nmol/l). The levels of urinary excretions of genistein, daidzein were also measured and it was found that, in the majority, the levels ranged between 5-25 and 5-50 micromol/24 h, respectively. In contrast, healthy Finnish women showed very low values of isoflavones (below 10 nmol/l in plasma (n = 87) and below 0.6 micromol/24 h in urine (n = 126) for both compounds) and high levels of enterolactone in both plasma and urine (plasma: mean, 25 nmol/l and urine: majority range, 1-7 micromol/24 h).     

Urinary prostaglandin excretion in pregnancy: the effect of dietary sodium restriction

INTRODUCTION: Dietary sodium restriction results in activation of the renin-angiotensin-aldosterone-system. In the non-pregnant situation renin release in response to a low sodium diet is mediated by prostaglandins. We studied the effect of dietary sodium restriction on urinary prostaglandin metabolism in pregnancy. PATIENTS AND METHODS: In a randomized, longitudinal study the excretion of urinary metabolites of prostacyclin (6-keto-PGF(1 alpha)and 2,3-dinor-6-keto-PGF(1 alpha)) and thromboxane A(2)(TxB(2)and 2,3-dinor-TxB(2)) was determined throughout pregnancy and post partum in 12 women on a low sodium diet and in 12 controls. RESULTS: In pregnancy the excretion of all urinary prostaglandins is increased. The 6-keto-PGF(1 alpha)/ TxB(2)-ratio as well as the 2, 3-dinor-6-keto-PGF(1 alpha)/ 2,3-dinor-TxB(2)-ratio did not significantly change in pregnancy. CONCLUISION Prostacyclin and thromboxane do not seem to play an important role in sodium balance during pregnancy.     

Effect of wheat bran on excretion of radioactively labeled estradiol-17 beta and estrone-glucuronide injected intravenously in male rats.

Urinary and fecal estrogen excretion were studied in male rats fed a non-fiber wheat starch diet (dietary fiber less than 1%; NF group; n = 4), a low-fiber wheat flour diet (dietary fiber 2%; LF group; n = 4) or a high-fiber wheat bran diet (dietary fiber 11.6%; HF group; n = 3). Short-term effects of the experimental diet on estrogen excretion were studied after i.v. injection of 5 microCi (0.185 MBq) of [14C]estradiol-17 beta (E2) into the tail vein of the rats fed the diets for 2 days. After 3 weeks on the experimental diets, the long-term effects were studied after injection of 5 microCi of [14C]E2 and 10 microCi of [3H]estrone-3-glucuronide (E1-gluc). The diet was found to affect estrogen excretion. The short-term effect indicated that rats fed the HF diet excreted a relatively large amount of labeled compounds in the feces during the first day after injection, while rats fed the NF or the LF diets excreted about half that amount over the same period. On the other hand, urinary excretion of labeled compounds was significantly higher in the NF and LF rats. The long-term effect resulted in steeper slopes (P less than 0.05) of the fecal excretion profiles of rats fed the HF diet as compared with rats fed the NF and LF diets, indicating an accelerated fecal excretion of labeled compounds in the HF rats. The kinetic profiles of 14C and 3H radioactivity in blood plasma indicated a fast decrease (t1/2 of less than 2 min) for both [14C]E2 and [3H]E1-gluc. It was concluded that, owing to the short-term effect of wheat bran intake, during the first 24 h after i.v. administration relatively large amounts of radioactively labeled compounds are excreted in feces of rats fed the HF diet. In contrast, excretion is lower in urine of these rats. When the microflora is adapted to the experimental diet the wheat bran diet still results in an accelerated fecal excretion of labeled compounds, which might be attributed to an interruption of the enterohepatic circulation of estrogens. This might result in lowered plasma and/or tissue estrogen levels and hence a decreased exposure of estrogen-sensitive tissue to estrogens, which might decrease risk on mammary (breast) cancer development.     

Antibody-mediated extraction/negative-ion chemical ionization mass spectrometric measurement of thromboxane B2 and 2,3-dinor-thromboxane B2 in human and rat urine

An antibody-mediated extraction method for gas chromatographic-mass spectrometric analysis of thromboxane A2 (TXA2) urinary metabolites is reported. An antibody (Ab) raised against thromboxane B2 (TXB2) (35% cross-reacting with 2,3-dinor-TXB2) was coupled to CNBr-activated Sepharose 4B (Se) and used as stationary phase for simultaneous extraction of both compounds from urine. After addition of deuterium-labeled TXB2 as internal standard, rat or human urine was percolated through a small Ab-Se column. After being washed, the eluate was directly derivatized to the pentafluorobenzyl ester, methyloxime, and trimethylsilyl ether. Quantitation was performed by high-resolution gas chromatography-negative-ion chemical ionization mass spectrometry, monitoring the carboxylate anions. This method was applied to evaluate the urinary excretion of TXB2 and 2,3-dinor-TXB2 in humans and rats. We report on the excretion of 2,3-dinor-TXB2 in the rat. This novel approach to the extraction of urinary thromboxanes is more convenient than currently available methods in terms of simplicity, rapidity, and recovery. This method could be extended to any other prostanoid for which an antibody could be obtained.     

Liquid chromatographic-photodiode array mass spectrometric analysis of dietary phytoestrogens from human urine and blood

Dietary phytoestrogens have been implicated in the prevention of chronic diseases. However, it is uncertain whether the phytoestrogens or the foods associated with phytoestrogens account for the observed effects. We report here a new liquid chromatography photodiode array mass spectrometry (LC-PDA-MS) assay for the determination of nanomolar amounts of the most prominent dietary phytoestrogens (genistein, dihydrogenistein, daidzein, dihydrodaidzein, glycitein, O-desmethylangolensin, hesperetin, naringenin, quercetin, enterodiol, enterolactone) in human plasma or serum and urine. This assay was found to be suitable for the assessment of quercetin exposure in an onion intervention study by measuring urinary quercetin levels. Other successful applications of this assay in clinical and epidemiologic studies validated the developed method and confirmed previous results on the negative association between urinary isoflavone excretion and breast cancer risk.     

Diet and urinary estrogen profile in premenopausal omnivorous and vegetarian women and in premenopausal women with breast cancer

The urinary estrogen profile was studied in the midfollicular phase twice, and diet four times during 1 yr in 10 premenopausal breast cancer (BC) patients consuming an omnivorous normal Finnish diet and in two control groups, one consuming an omnivorous (n = 12) and the other a lactovegetarian (n = 11) diet. Total fat intake in relation to caloric intake was almost identical in all three groups. Only with regard to grain fiber intake did the BC patients differ significantly from both other groups. No differences were found between the groups with regard to urinary excretion of 13 individual estrogens and total estrogens, with the exception of 4-hydroxyestrone (4-OH-E1), which was significantly lower (P less than 0.05) in the BC group than in the vegetarians. A high carbohydrate to protein ratio in the diet had a negative correlation with the excretion of 2-hydroxyestrogens and 2-hydroxyesterone (2-OH-E1) to 4-OH-E1 ratio. The BC group had significantly higher urinary 2-OH-E1 to E1 ratio (P less than 0.05) compared to the vegetarians. The 2-OH-E1 to 4-OH-E1 ratio was highest in the BC group (= 7.1) and differed significantly from that of the omnivores (= 4.3; P less than 0.02) and vegetarians (= 3.6; P less than 0.005). This ratio showed a negative correlation with intake of carbohydrates, starch, total and grain fiber. Urinary excretion of 4-OH-E1 correlated positively with total and grain fiber intake and plasma SHBG. Protein intake correlated positively with urinary 2-methoxy-E1 excretion, and retinol intake positively with catechol estrogen, E1 and E2 excretion. It is concluded that estrogen production and urinary estrogen profile in premenopausal breast cancer patients is normal with the exception of a low 4-OH-E1 excretion and high urinary 2-OH-E1 to 4-OH-E1 ratio. This ratio, which seems to depend on diet, is the only urinary estrogen parameter separating premenopausal BC patients from the control omnivorous and lactovegetarian women.     

Effects of diet and age on oxidative damage products in healthy subjects

Damage of molecules as a consequence of oxidative stress has been implicated in the pathogenesis of chronic diseases related to aging. Diet is a key environmental factor affecting the incidence of many chronic diseases. Antioxidant substances in diet enhance the DNA, lipid and protein protection by increasing the scavenging of free radicals. Products of oxidative damage of DNA (DNA strand breaks with oxidized purines or oxidized pyrimidines), lipids (conjugated dienes of fatty acids) and proteins (carbonyls) in relation to nutrition (vegetarian diet vs. non-vegetarian, traditional mixed diet) were measured in young women aged 20-30 years (46 vegetarians, 48 non-vegetarians) vs. older women aged 60-70 years (33 vegetarians, 34 non-vegetarians). In young subjects, no differences in values of oxidative damage as well as plasma values of antioxidative vitamins (C,beta-carotene) were observed between vegetarian and non-vegetarian groups. In older vegetarian group significantly reduced values of DNA breaks with oxidized purines, DNA breaks with oxidized pyrimidines and lipid peroxidation and on the other hand, significantly increased plasma values of vitamin C and beta-carotene were found compared to the respective non-vegetarian group. Significant age dependences of measured parameters (increase in all oxidative damage products and decrease in plasma vitamin concentrations in older women) were noted only in non-vegetarians. Vegetarian values of older women vs. young women were similar or non-significantly changed. The results suggest that increase of oxidative damage in aging may be prevented by vegetarian nutrition.     

Urinary excretion of 2,3-dinor-thromboxane B2 in man under normal conditions, following drugs and during some pathological conditions

Quantitation of 2,3-dinor-thromboxane B2 (2,3-dinor-TxB2) was performed by gas chromatography-mass spectrometry. Under normal conditions the urinary excretion of 2,3-dinor-TxB2 was relatively constant in the same individual from day to day but during a 24-hour period a somewhat higher excretion rate was found during the first few hours after awakening. A pronounced reduction of the urinary excretion of 2,3-dinor-TxB2 was found after oral administration of 500 mg of aspirin or 50 mg of indomethacin, while 500 mg of paracetamol did not affect the urinary excretion. Increased excretion of 2,3-dinor-TxB2 was found in normal pregnancies and in diseases such as diabetes mellitus and homocysteinuria in comparison to the urinary excretion in normal healthy subjects. We also report one case, where the urinary excretion of 2,3-dinor-TxB2 was increased for a short period following the first symptoms of a myocardial infarction and those data indicate that thromboxane A2 (TxA2) may be of pathophysiological importance in human myocardial infarction. The results strongly indicate that measurements of the urinary excretion of 2,3-dinor-TxB2 should be meaningful as a tool for investigation of the involvement of thromboxane in various pathophysiological processes in vivo in man.     

Dietary phytoestrogens and cancer: in vitro and in vivo studies

Thirty postmenopausal women (11 omnivores, 10 vegetarians and 9 apparently healthy women with surgically removed breast cancer) were investigated with regard to the association of their urinary excretion of estrogens, lignans and isoflavonoids (all diphenols) with plasma sex hormone binding globulin (SHBG). A statistically significant positive correlation between urinary total diphenol excretion and plasma SHBG was found which remained statistically significant after elimination of the confounding effect of body mass determined by body mass index (BMI). Furthermore we found a statistically significant negative correlation between plasma SHBG and urinary excretion of 16α-hydroxyestrone and estriol which also remained significant after eliminating the effect of BMI. Furthermore we observed that enterolactone (Enl) stimulates the synthesis of SHBG by HepG2 liver cancer cells in culture acting synergistically with estradiol and at physiological concentrations. Enl was rapidly conjugated by the liver cells, mainly to its monosulfate. Several lignans and the isoflavonoids daidzein and equol were found to compete with estradiol for binding to the rat uterine type II estrogen binding site (the s.c. bioflavonoid receptor). It is suggested that lignans and isoflavonoids may affect uptake and metabolism of sex hormones by participating in the regulation of plasma SHBG levels and in this way influence their biological activity and that they may inhibit cancer cell growth like some flavonoids by competing with estradiol for the type II estrogen binding sites.     

Dietary phytoestrogens and cancer: in vitro and in vivo studies.

Thirty postmenopausal women (11 omnivores, 10 vegetarians and 9 apparently healthy women with surgically removed breast cancer) were investigated with regard to the association of their urinary excretion of estrogens, lignans and isoflavonoids (all diphenols) with plasma sex hormone binding globulin (SHBG). A statistically significant positive correlation between urinary total diphenol excretion and plasma SHBG was found which remained statistically significant after elimination of the confounding effect of body mass determined by body mass index (BMI). Furthermore we found a statistically significant negative correlation between plasma SHBG and urinary excretion of 16-hydroxyestrone and estriol which also remained significant after eliminating the effect of BMI. Furthermore we observed that enterolactone (Enl) stimulates the synthesis of SHBG by HepG2 liver cancer cells in culture acting synergistically with estradiol and at physiological concentrations. Enl was rapidly conjugated by the liver cells, mainly to its monosulfate. Several lignans and the isoflavonoids daidzein and equol were found to compete with estradiol for binding to the rat uterine type II estrogen binding site (the s.c. bioflavonoid receptor). It is suggested that lignans and isoflavonoids may affect uptake and metabolism of sex hormones by participating in the regulation of plasma SHBG levels and in this way influence their biological activity and that they may inhibit cancer cell growth like some flavonoids by competing with estradiol for the type II estrogen binding sites.     

Vegetarian and Weight‐Loss Diets among Young Adults

Objective: Young adults frequently experiment with vegetarian and weight‐loss diets. Comparisons of their experiences on these two different diets may help in the development of approaches to improve long‐term adherence to weight‐loss regimens. In the current study vegetarian and weight‐loss diets were compared on how long and how strictly they were followed, and reasons why they were initiated and discontinued. Research Methods and Procedures: From 428 college students surveyed, four groups were delineated: 1) 59 participants had been following a vegetarian diet but not a weight‐loss diet (Vegetarian), 2) 117 participants had tried a weight‐loss diet but not a vegetarian diet (Weight Loss), 3) 133 participants had followed both a vegetarian and a weight‐loss diet (Both), and 4) 119 participants had not tried either diet (Neither). Results: Differences were examined by comparing the Vegetarian and Weight‐Loss groups as well as by comparing the two diets within the Both group. Duration of the vegetarian diet was much greater than the weight‐loss diet; most participants in the Vegetarian group (62%) remained on their diet for more than 1 year, whereas the majority of the Weight‐Loss participants (61%) followed their diet for 1 to 3 months. Similar results were found when comparing the two diets within the Both group. How strictly the two diets were followed, however, did not differ. Analyses revealed that reasons for discontinuing a diet varied; participants were more likely to cite boredom as a reason for discontinuing a weight‐loss diet than a vegetarian diet (53% vs. 5% between groups and 30% vs. 10% within the Both group). Discussion: The longer duration of the vegetarian diet relative to the weight‐loss diet warrants further investigation. Results could possibly be applied to behavioral weight‐loss treatment to improve long‐term maintenance.     

Abnormal Excretion of Corticosteroid Sulphates in Patients with Breast Cancer

In a preliminary study, the 24-hour urinary excretion of corticosteroid sulphates and free cortisol have been measured in a group of patients with breast cancer and compared with the excretion of the same compounds in a group of normal women of similar age. Excretion of corticosteroid sulphates in the breast cancer group was found to be markedly raised. In a small number of patients with localized cancer of sites other than the breast the level of corticosteroid sulphate was not raised. If proved metastases were present a noticeable rise was observed.     

Olive oils rich in natural catecholic phenols decrease isoprostane excretion in humans

This study was undertaken to evaluate, in humans, the antioxidant activity of olive oil phenolics, namely hydroxytyrosol and oleuropein aglycone that share an orthodiphenolic (catecholic) structure. Human volunteers were administered olive oil samples containing increasing amounts of an olive oil phenolic extract that was characterized by gas-chromatography/mass spectrometry. The administration of phenol-rich oils was dose-dependently associated with a decreased urinary excretion of 8-iso-PGF(2alpha), a biomarker of oxidative stress. Also, a statistically significant negative correlation between homovanillyl alcohol (HValc, hydroxytyrosol's major metabolite, formed through the COMT system) and F(2)-isoprostanes excretion was found. Thus, the administration of oil samples with increasing, albeit low, concentrations of orthodiphenolic compounds, namely hydroxytyrosol and oleuropein aglycone, results in a dose-dependent reduction in the urinary excretion of 8-iso-PGF(2alpha). The statistically significant negative correlation between 8-iso-PGF(2alpha) and HValc urinary concentrations suggests that this metabolite better reflects the in vivo activities of hydroxytyrosol.     

Studies on anabolic steroids--8. GC/MS characterization of unusual seco acidic metabolites of oxymetholone in human urine.

One of the biotransformation routes of oxymetholone (17 beta-hydroxy-2-hydroxymethylene-17 alpha-methyl-5 alpha-androstan-3-one) in man leads to the formation of 17 beta-hydroxy-17 alpha-methyl-5 alpha-androstan-3-one (mestanolone). To demonstrate that this latter steroid may be formed by decarboxylation of an intermediate metabolite of oxymetholone bearing a 2-carboxylic group, we studied the urinary excretion of oxymetholone acidic metabolites. Five new acidic metabolites are reported here for the first time, among which four are unusual seco steroids resulting from the oxidative cleavage of the A-ring. The most abundant compound is 17 beta-hydroxy-17 alpha-methyl-2,3-seco-5 alpha-androstane-2,3-dioic acid 1, the cumulative excretion of which accounted for 1.52% of the dose. Three other seco diacids were produced in smaller amounts, namely 17 beta-hydroxy-17 alpha-methyl-2,3-seco-5 alpha-androstane-2,4- dicarboxylic acid 3, 17 beta-hydroxy-17 alpha-methyl-1,3-seco-5 alpha-androstane-1,3-dioic acid 4 and 17 beta-hydroxy-17 alpha-methyl-2,4-seco-5 alpha-androstane-2,4-dioic acid 5. The fifth acidic metabolite was identified as 3 alpha, 17 beta-dihydroxy-17 alpha-methyl-5 alpha-androstane-2 beta-carboxylic acid 2. The excretion in urine of these acidic metabolites suggests that the 2-hydroxymethylene group in oxymetholone is readily oxidized to yield the corresponding beta-keto acid which can be (1) decarboxylated to form mestanolone; (2) reduced at C-3 to give compound 2; and (3) further oxidized to afford the unexpected seco diacids 1, 3, 4 and 5. The identity of compounds 1 and 2 was ascertained by GC/MS and 1H and 13C-NMR analysis of reference compounds. The other metabolites were characterized by GC/MS analysis.     

Influence of diet on cystathionine ketimine and lanthionine ketimine content in human urine

A simple HPLC procedure for the routine analyses of Cystathionine ketimine (CK) and Lanthionine ketimine (LK) content in human urine has been developed. The values obtained in morning urine of fifteen healthy subjects (both sexes, 25-45 years old) on a common mixed diet are 330-2480 micrograms/g creatinine (mean 1110) of CK and 100-420 micrograms/g creatinine (mean 200) of LK. Quantitation of the two ketimines in urine of subjects on strictly vegetarian diet indicate that while the excretion of LK is independent of the diet, the excretion of CK is significantly decreased in conditions of vegetarian diet.     

Effects of pressure on the skin exerted by clothing on responses of urinary catecholamines and cortisol,heart rate and nocturnal urinary melatonin in humans

The study investigated how the pressure exerted on the skin by clothing worn while working in the daytime affected the urinary excretion of adrenaline, noradrenaline and cortisol, heart rate, and also melatonin secretion at night. Nine young women (experiment I) and seven young women (experiment II) participated. Participants wore either a 100% cotton jacket (tight clothes, TC) or a 100% cotton T-shirt (loose clothes, LC). Loose-fitting, 100% cotton tank tops and panties were worn as underwear in both the TC and the LC groups. The main results can be summarized as follows: (1) urinary excretion of adrenaline, noradrenaline and cortisol was facilitated, and the amounts of urinary excretion were significantly higher when TC were worn. Heart rate was significantly higher in the TC group; (2) nocturnal urinary melatonin excretion was significantly greater in the TC group. These results are discussed in terms of an enhancement of diurnal sympathetic nervous system activity caused by pressure on the skin produced by tight clothing.     

Phytoestrogens and breast cancer

The role of phytoestrogens and consumption of phytoestrogen-rich foods such as soy containing isoflavones and whole grain products with lignans for the prevention of breast cancer is reviewed. It is concluded that soy-containing diet in adult women is not or only slightly protective with regard to breast cancer, but that it may be beneficial if consumed in early life before puberty or during adolescence supporting results of immigrant and epidemiological studies. No negative effects of soy on breast cancer have been observed. On the other hand, a diet low in lignans, resulting in a low plasma enterolactone concentration, increases risk both in a case-control and a prospective study, but some controversial results have also been obtained. Some of these results may be explained by the fact that the determinants of plasma or urinary enterolactone concentration are very different in different countries. In Scandinavia, the main determinants are whole grain cereal food, vegetables and berries. Whether the protective effect is caused by the phytoestrogens in the diet or whether they are only biomarkers of a healthy diet has not been established.     

Toxicological effects of an organophosphorus pesticide (dimethoate) on urinary collagen metabolites in normal and high protein diets fed female albino rats

The effect of an organophosphorus pesticide (dimethoate) on the urinary excretion of hydroxyproline (total, nondialysable, dialysable and free fractions) and hydroxylysylglycosides, glucosylgalactosyl hydroxylysine and galactosehydroxylysine was investigated in two groups of female albino rats fed with normal and high protein diets. In comparison to controls, dimethoate treated animals were found to excrete significantly decreased amounts of urinary hydroxyproline fractions from 7th day onwards. The excretion of total hydroxylysylglycoside in urine parallels the excretion of hydroxyproline. The urinary output of both glu-gal-hyl and gal-hyl was also appreciably lower from dimethoate treated animals. The normal ratio of glu-gal-hyl and gal-hyl found in the urine of dimethoate treated animals was discussed in light of decreased turn over of collagen in both bone and skin. The effect of dimethoate in rats fed with high protein diet was comparatively less than those fed with normal diet.