The Fe solubility test is a commonly used, easy and relatively cheap in vitro tool for predicting Fe bioavailability in food matrices. However, the outcome of a recent field trial comparing the effect on Fe status of Tanzanian infants of processed V. unprocessed complementary foods (CF), with otherwise the same composition, challenged the validity of this test for predicting Fe bioavailability. In the solubility test, significant more soluble Fe was observed in processed compared with unprocessed foods (mean 18·8 (sem 0·21) V. 4·8 (sem 0·23) %; V<0·001). However, in the field trial, no significant difference in Fe status was seen between processed and unprocessed CF groups after 6 months' follow-up. Therefore, twenty-four samples of these CF (twelve processed and twelve unprocessed batches) were analysed in triplicate for Fe availability using an in vitro digestion–Caco-2 cell culture method and results were compared with solubility results. Significantly more soluble Fe was presented to Caco-2 cells in the processed compared with unprocessed samples (mean 11·5 (sem 1·16) V. 8·5 (sem 2·54) % p=0·028), but proportionally less Fe was taken up by the cells (mean 3·0 (sem 0·40)p. 11·7 (sem 2·22) %; p=0·007). As a net result, absolute Fe uptake was lower (not significantly) in processed compared with unprocessed CF (mean 1·3 (sem 0·16) V. 3·4 (sem 0·83) nmol/mg cell protein; p=0·052). These data clearly demonstrate that the Fe solubility test was not a good indicator of Fe bioavailability in these particular food matrices. In contrast, the results of an in vitro Caco-2 model supported the effects observed in vitro.

The intestine of newborn pigs develops rapidly during the first days postpartum. We investigated if feeding milk replacer (infant formula) as an alternative to colostrum has compromising effects on nutrient digestive function in the neonatal period. Nineteen piglets born at termwere assigned to one of four treatments: (1) newborn controls; (2) natural suckling for 24h; (3) tube-fed formula for 24h; (4) tube-fed porcine colostrum for 24h. All three fed groups showed significant increases in small-intestinal and colonic weights, villous heights and widths, maltase and aminopeptidase A activities, and decreases in dipeptidylpeptidase IV activity, relative to newborn pigs. Following oral boluses of mannitol, lactose or galactose, formula-fed pigs showed significantly reduced plasma levels of mannitol and galactose compared with colostrum-fed pigs. Activity of intestinal inducible NO synthase and plasma levels of cortisol were significantly increased, whereas intestinal constitutive NO synthase and α-tocopherol were decreased in formula-fed pigs compared with colostrum-fed pigs. Although formula-fed pigs only showed minor clinical signs of intestinal dysfunction and showed similar intestinal trophic responses just after birth, as those fed colostrum, lactose digestivecapacity was markedly reduced. We conclude that formula-feeding may exert detrimental effects on intestinal function in neonates. Formula-induced subclinical malfunction of the gut in pigsborn at term was associated with altered NO synthase activity and antioxidative capacity.

To investigate the efficacy of the intake of vinegar for prevention of hyperlipidaemia, we examined the effect of dietary acetic acid, the main component of vinegar, on serum lipid values in rats fed a diet containing 1% (w/w) cholesterol. Animals were allowed free access to a diet containing no cholesterol, a diet containing 1% cholesterol without acetic acid, or a diet containing 1% cholesterol with 0·3% (w/w) acetic acid for 19 d. Then, they were killed after food deprivation for 7 h. Cholesterol feeding increased serum total cholesterol and triacylglycerol levels. Compared with the cholesterol-fed group, the cholesterol and acetic acid-fed group had significantly lower values for serum total cholesterol and triacylglycerols, liver ATP citrate lyase (ATP-CL) activity, and liver 3-hydroxy-3-methylglutaryl-CoA content as well as liver mRNA levels of sterol regulatory element binding protein-1, ATP-CL and fatty acid synthase (P<,0·05). Further, the serum secretin level, liver acyl-CoA oxidase expression, and faecal bile acid content were significantly higher in the cholesterol and acetic acid-fed group than in the cholesterol-fed group (P<0·05). However, acetic acid feeding affected neither the mRNA level nor activity of cholesterol 7a-hydroxylase. In conclusion, dietary acetic acid reduced serum total cholesterol and triacylglycerol: first due to the inhibition of lipogenesis in liver; second due to the increment in faecal bile acid excretion in rats fed a diet containing cholesterol.

The aim of the study was to characterize the time course of the development of high-fat diet-induced hepatic steatosis and its relation to body fat accretion and changes in plasma lipid profile. Female Sprague–Dawley rats were high-fat fed (HF; 42%, kJ) for 1, 2, 4, 6, 12 and 16 weeks and compared to standard fed rats (SD). Data obtained from HF rats were further analysed by classifying the animals into obesity-prone and obesity-resistant. In HF rats, liver lipid content increased rapidly by approximately 200% during the first 2 weeks, decreased almost to baseline levels between weeks 2 and 6, and re-increased by 17% between weeks 6 and 16 (P<0·05). Body weight, body fat accretion, plasma leptin, NEFA and glycerol concentrations were higher in HF than in SD rats (P<0·05). These higher values were established in 2 weeks and the differences between the groups did not further enlarge from weeks 2 to 16. Obesity-prone rats depicted higher body weight and body fat accretion than obesity-resistant and SD rats. Surprisingly, however, liver lipid content was the same in obesity-prone as in obesity-resistant rats as they were both higher than in SD rats (weeks 2 and 16; P<0·05). Our data support the hypothesis that the liver acts as a systemic buffer, largely increasing its lipid content in the early stage of high-fat feeding. Our results also suggest that the development of non-alcoholic hepatic steatosis is more linked to dietary fat ingestion than to body weight gain.

Previous studies have found Kenyan endurance runners to be in negative energy balance during training and prior to competition. The aim of the present study was to assess energy balance in nine elite Kenyan endurance runners during heavy training. Energy intake and expenditure were determined over 7d using weighed dietary intake and doubly labelled water, respectively. Athletes were on average in negative energy balance (mean energy intake 13 241 (SD 1330) kJ/d v. mean energy expenditure 14 611 (SD 1043) kJ/d; P=0·046), although there was no loss in body mass (mean 56·0 (SD 3·4) kg v. 55·7 (SD 3·6) kg; P=0·285). The calculation of underreporting was 13; (range −24 to +9%) and almost entirely accounted for by undereating (9% (range −55 to +39%)) as opposed to a lack of significant underrecording (i.e. total water intake was no different from water loss (mean 4·2 (SD 0·6) l/d v. 4·5 (SD 0·8) l/d; P=0·496)). Fluid intake was modest and consisted mainly of water (0·9 (SD 0·5) l/d) and milky tea (0·9 (SD 0·3) l/d). The diet was high in carbohydrate (67·3 (SD 7·8) %) and sufficient in protein (15·3 (SD 4·0) %) and fat (17·4 (SD 3·9) %). These results confirm previous observations that Kenyan runners are in negative energy balance during periods of intense training. A negative energy balance would result in a reduction in body mass, which, when combined with a high carbohydrate diet, would have the potential in the short term to enhance endurance running performance by reducing the energy cost of running.

Factorial approaches to estimate energy requirements of growing pigs require estimation of maintenance energy requirements. Heat production (HP) during fasting (FHP) may provide an estimate of maintenance energy requirements. Six barrows were used to determine effects of feedinglevel on components of HP, including extrapolated plateau HP following a 24h fast (FHPp). Based on a cross-over design, each pig was exposed to three feeding levels (1·55, 2·05 and 2·54MJ metabolisable energy/kg body weight (BW)0·60 per d) between 30 and 90kg BW. Following a 14d adaptation period, HP wasestimated using indirect calorimetry on pigs housed individually. Dynamics of HP were recordedin pigs for 5d during the fed state and during a subsequent 24h fast. Metabolisable energy intake was partitioned between thermal effect of feeding (HPf), activity HP (HPa), FHPp and energy retention. Feeding level influenced (P<0·05) total HP during the fed state, HPf and activity-free FHPp (609, 644 and 729 (se 31) kJ/kg BW0·60 per d for low, medium and high ME intakes, respectively). The value of FHPp when expressed per kg BW0·60 did not differ (P=0·34) between the three subsequent experimental periods. Feeding level did not (P=0·75) influence HPa. Regression of total HP during the fed state to zero metabolisable energy intake yielded a value of 489 (se 69) kJ/kg BW0·60 per d, which is a lower estimate ofmaintenanceenergy requirement than FHPp. Duration of adaptation of pigs to changes in feeding level and calculation methods should be considered when measuring or estimating FHPp, maintenance energy requirements and diet net energy content.

Evidence from animal studies suggests that conjugated linoleic acid (CLA) modulates plasma and tissue appearance of newly synthesized PUFA. The effects of a 1·2g (0·5% energy) daily intake of the cis-9, trans-11 (c9, t11) isomer of CLA, trans-10,cis-12 (t10, c12) isomer of CLA or olive oil (placebo) on linoleic acid (LA) and linolenic acid (LNA) metabolism in healthy human volunteers was investigated. Fifteen subjects were fed an experimental diet and supplemented with c9,t11-CLA, t10, c12-CLA or placebo for 7d before consuming a tracer dose of U-[13C]La (50%Mg) And U-[13C]Lna (50Mg). Blood Samples Were Taken At 0, 2, 4, 6, 8, 24, 48, 72 and 168%h and analysed using high-precision MS. No differences between the groups in peak plasma [13C]LA (10·3–11·6% of dose), [13C]LNA (2·5–2·9% of dose), [13C]arachidonic acid (0·09–0·12% of dose), [13C]EPA (0·04–0·06% of dose) or [13C]Dha (0c·06–0·10% of dose) were detected. Concentration V. time curves (area under the curve) also showed no significant differences between groups. This suggests that, in healthy human subjects consuming a diet with adequate intake of essential fatty acids, CLA does not affect metabolism of LA or LNA

High-viscosity carboxymethylcellulose (CMC) promotes gastrointestinal disorders, tissue alterations and bacterial overgrowth in pigs. The impact of CMC on intestinal absorptive and secretory physiology is not known. We hypothesised that CMC consumption alters intestinal Na-dependent glucose absorption and stimulates electrogenic chloride secretion. For testing this hypothesis, twenty-four piglets were weaned at 21d of age and pair-fed for 13d a starter diet based on skimmed milk powder and maltodextrin containing cellulose (control) or CMC. Body weight and faecal total aerobe and coliform counts were measured kinetically. At slaughter, digesta were weighed and characterised for viscosity and pH. Gastrointestinal tissues were weighed and sampled for physiology in Ussing chambers, morphometry and enzymology. Glucose absorption tended to be higher (P=0·08) and carbachol-stimulated chloride secretion was lower (P=0·01) with CMC in the small intestine, without changes in the colon. Aerobes were transiently higher at day 7 (P<0·05) but coliform counts remained unchanged (P=0·78) and β-haemolitic Escherichia coli were virtually absent. Stomach and small-intestinal segments were heavier, and viscosity higher with CMC (0·001<P<0·05). The pH in the stomach was higher, and in the caecum and proximal colon lower with CMC (0·001<P<0·05). Jejunal villus area was slightly reduced with CMC (P<0·05) without effects on enzyme activities (P>0·10). In conclusion, CMC supplementation had pro-absorptive effects on the small intestine, possibly due to the absence of pathogenic E. coli in the present study.

Excessive dietary NaCl in association with a paucity of plant foods, major sources of K alkaline salts, is a common feature in Western eating habits which may lead to acid–base disorders and to Ca and Mg wasting. In this context, to evaluate the effects of potato, rich in potassium citrate, on acid–base homeostasis and mineral retention, Wistar rats were fed wheat starch (WS) or cooked potato (CP) diets with a low (0·5 %) or a high (2 %) NaCl content during 3 weeks. The replacement of WS by CP in the diets resulted in a significant urinary alkalinisation (pH from 5·5 to 7·3) parallel to a rise in citrate and K excretion. Urinary Ca and Mg elimination represented respectively 17 and 62% of the daily absorbed mineral in rats fed the high-salt WS diet compared with 5 and 28% in rats fed the high-salt CP diet. The total SCFA concentration in the caecum was 3-fold higher in rats fed the CP diets compared with rats fed the WS diets, and it led to a significant rise in Ca and Mg intestinal absorption (Ca from 39 to 56 %; Mg from 37 to 60 %). The present model of low-grade metabolic acidosis indicates that CP may be effective in alkalinising urine, enhancing citrate excretion and ameliorating Ca and Mg balance.

Alkylresorcinols (AR) are phenolic lipids found in high amounts in wholegrain wheat and rye. They may be important as bioactive components and/or biomarkers of wholegrain wheat and rye intake. AR absorption was studied with pigs during a habitual diet and after a single meal of AR-rich diet. In study 1, four pigs were fed wholegrain rye (RD) and white wheat bread (WD) for 1 week in a cross-over design. Arterial and venous AR concentrations were determined over 540min after feeding on days 5 and 7. In study 2, four pigs were fed a synthetic, starch-based diet for 5d, and arterial and venous AR concentrations were determined over 960min after feeding a single meal of RD. In study 1, plasma AR concentrations after consuming RD peaked at 120min, remained elevated between 120 and 420min, and were re-elevated on refeeding at 480min. In study 2, AR appeared in the plasma after 60min, peaked at 180–240min, and remained elevated after 960min. The apparent elimination half-life was 3·93h, and the maximum plasma concentration was 666 (sem 35) nmol/l. Arterial and venous plasma AR concentrations were similar, suggesting that AR are absorbed via the lymphatic system. AR concentrations in pig plasma increase rapidly after a meal containing AR, and persist in plasma for at least 5d, indicating that AR may be a useful biomarker of wholegrain wheat and rye intake.

An increased consumption of fruits and vegetables (F&V) has been suggested as a way to limit, or even lower, energy and fat intakes. The present study examined the effects of incorporating F&V supplements into the diets of adults who reported consuming <240g (three portions) of F&V per d on energy and fat intakes, and change in body weight, over 8 weeks using a randomised parallel design. Thirty-four males and twenty-eight females (age 42·6 (sd 11·1) years, BMI 23·7 (sd 2·7) kg/m2) were each provided with supplements of 0, 300 or 600g F&V per d. Food, nutrient and energy intakes were measured before, during and at the end of the supplementation period using 7 d weighed records. Mean daily energy intakes were not different among the three groups before (P=0·151) or during the supplementation periods (P=0·407), although changes in energy intakes over the study period tended to be more positive with increasing amounts of F&V supplements (P=0·078). There was no difference in changes of body weights during the study (P=0·242). Carbohydrate (P<0·001), sugar (P<0·001), fibre (P<0·001) and weight of food consumed (P=0·022) increased in the treatment groups. There were no significant differences, or changes, in fat intakes among the three groups. Consumption of mandatory F&V supplements for 8 weeks produced beneficial changes in diet composition, but did not result in lower reported energy or fat intakes, and did not result in loss of body weight.

The present study was to investigate the effects of l-arginine (l-Arg) supplementation on cardiac oxidative stress and the inflammatory response in rats following acute exhaustive exercise on a treadmill. Rats were randomly divided into four groups: sedentary control (SC); SC with l-Arg treatment (SC+Arg); exhaustive exercise (E); exhaustive exercise with l-Arg treatment (E+Arg). Rats in groups SC+Arg and E+Arg received a 2% l-Arg diet. Rats in groups E and E+Arg performed an exhaustive running test on a treadmill at a final speed of 30m/min, 10% grade, at approximately 70–75% VO2max. The results showed a significant increase in cardiac xanthine oxidase (XO) and myeloperoxidase activities and membrane lipid peroxidation endproduct (malondialdehyde; MDA) levels of exercised rats compared with SC rats. The increased cardiac XO activity and MDA levels in exercised rats were significantly decreased in exercised rats supplemented with l-Arg. Myocardial GSSG content increased whereas the GSH:GSSG ratio was depressed in exercised rats compared with SC rats. Cardiac GSSG levels significantly decreased, whereas total glutathione, GSH and the GSH:GSSG ratio increased in exercised rats supplemented with l-Arg compared with exercised rats. The activities of creatinine kinase (CK) and lactate dehydrogenase (LDH), and lactate, uric acid, and nitrite and nitrate levels in the plasma significantly increased in exercised rats compared with SC rats. The activities of plasma CK and LDH were significantly decreased in l-Arg-supplemented plus exercised rats compared with exercised rats. These findings suggest that l-Arg supplementation reduces the oxidative damage and inflammatory response on the myocardium caused by exhaustive exercise in rats.

Elevated plasma homocysteine is a risk factor for atherosclerotic disease. In the present study, we have examined whether the oxidative stress due to a low level of vitamin B6 accelerates the development of homocysteine-induced atherosclerosis in rats. First, the effect of homocysteine thiolactone intake (50mg/kgperd) on vascular integrity, lipid peroxide concentration, endothelial NO synthase (eNOS) expression and biochemical profiles was examined at day 1, day 21 and day 42 (five rats per group). The histochemical staining ofthe rat aorta showed no change at day 1 and day 21, but the subendothelial space was observed to be enlarged in rat aorta at day 42 with exposure to homocysteine thiolactone. Expression of eNOS was observed in rat aorta at day 42, but not at day 1 and day 21. Serum lipid peroxide concentration and biochemical profiles including glucose cholesterol and triacylglycerol showed no change at any day. Second, the effect of homocysteine thiolactone intake in the presence and absence of vitamin B6 on vascular integrity was examined at day 1 and day 14 (five rats per group). Aortic lesions were observed in vitamin B6-deficient rat aorta at day 14 but not in vitamin B6-supplemented rats. The expression of eNOS was also observedin vitamin B6-deficient rat aorta at day 14. Serum lipid concentrations of the vitamin B6-deficient group significantly increased compared with concentrations of the vitamin B6-supplemented group, though serum concentration of homocysteine did not change between both groups. These results suggest that the oxidative stress caused by a low level of vitamin B6 accelerates the development of homocysteine-induced atherosclerosis in rats.

Tomatoes are an important part of the diet. Lycopene, the predominant carotenoid in tomatoes, is hypothesised to mainly mediate the health benefits of tomato products. Anticancer activity of tomato products and lycopene has been suggested by numerous studies. The aim of the present study was to investigate the effect of ingestion of three different tomato-based foodstuffs on plasma contents of lycopene, tocopherols and ascorbic acid. Because isomers of lycopene may have different biological activities, a special interest was to look how the lycopene isomer pattern is changed depending on the matrix of tomato products. Following a 2-week depletion phase volunteers ingested 12·5mg lycopene/d for 4 weeks comprising tomatoes, tomato juice or tomato purée. The basal levels of lycopene in plasma were comparable for all groups and decreased significantly during the 2 weeks of depletion to approximately half of the basal values. Following intervention, plasma lycopene concentration increased significantly. Conversely, supplementation did not significantly affect levels of tocopherols and ascorbic acid in plasma. Regarding isomers of lycopene, the (Z)-lycopene:(all-E)-lycopene plasma isomer ratio was significantly changed during the study for all groups. A remarkable enrichment of the relative contents of (5Z)-lycopene was observed during the depletion period, which supports the hypothesis that lycopene (Z)-isomers are formed within the human body after ingestion of (all-E)-lycopene. After dietary intervention with lycopene-rich products the isomer ratios returned to those observed at the start of the study. Further investigations will clarify the process of isomerisation in more detail.

Twins can be used to investigate the biological basis for observed associations between birth weight and later disease risk, as they experience in utero growth restriction compared with singletons, which can differ in magnitude within twin pairs despite partial or total genetic identity. In the present study, sixty monozygotic and seventy-one dizygotic same-sex twin pairs aged 19–50 years and eighty-nine singleton controls matched for age, gestational age, sex, maternal age and parity were recruited from an obstetric database. Associations between fasting lipid levels and birth weight were assessed by linear regression with adjustment for possible confounding factors. Twins were significantly lighter at birth but were not significantly different in adult height, weight or lipid levels from the singleton controls. There was a significant inverse association between birth weight and both total and LDL-cholesterol levels among singleton controls (−0·53mmol/l per kg (95% CI −0·97, −0·09), P=0·02 and −0·39mmol/l per kg (95% CI −0·76, −0·02), P=0·04, respectively), but there was no significant association between birth weight and lipid levels in either unpaired or within-pair analysis of twins. The results suggest that the in utero growth restriction and early catch-up growth experienced by twins does not increase the risk of an atherogenic lipid profile in adult life.

We have recently shown that meal-induced insulin sensitization (MIS) occurs after feeding and decreases progressively to insignificance after 24h of fasting and is caused by action of a hepatic insulin sensitizing substance (HISS). In order to carry out quantitative studies of MIS, some standardized meal intake is required. Our objective was to establish animal models to be tested in both the conscious and anaesthetized state using intragastric injection of liquid meals in order to quantify MIS. Insulin sensitivity was assessed before and 90min after the meal using the rapid insulin sensitivity test (RIST) which is a transient euglycaemic clamp. Rats tested in the conscious state were instrumented under anaesthesia 6–9d prior to testing with catheters in the carotid artery, jugular vein and stomach. Meals, injected into the stomach, consisted of a liquid mixed meal, sucrose, glucose or water. The glucose sequestration in response to insulin increased by 90% and 61% following the liquid mixed meal (10ml/kg) in conscious and anaesthetized rats, respectively. Glucose, sucrose and water did not effectively activate MIS. MIS was completely reversed in the conscious model by atropine and completely prevented from developing in the anaesthetized model that had previously undergone hepatic denervation. Gastric administration of a liquid mixed meal but not glucose or sucrose is capable of activating MIS for purposes of mechanistic studies and quantification of the MIS process. The feeding signal is mediated by the hepatic parasympathetic nerves.

The present study consisted of two experiments. The first experiment was conducted to determine the effects of lipoic acid (ALA; 200mg/kg) on plasma lipids and insulin sensitivity of whole-body tissue in broilers treated with or without corticosterone (5mg/kg). Chickens received these agents from 2 to 5 weeks of age in a 2×2 factorial arrangement. Thereafter, from 39 to 42d of age, insulin sensitivity was estimated using the euglycaemic and hyperinsulinaemic clamp technique. Experiment 2 examined whether ALA supplementation for 5 weeks (400mg/kg) would alter short-chain acyl-CoA concentration in the liver and in vitro lipolysis of an adipose tissue slice, in relation to noradrenaline (10μm) supplementation. In experiment 1, ALA had no effect on the corticosterone-induced negative growth performance. ALA lowered plasma glucose level (P<0·05) and, in contrast, increased triacylglycerol level (P<0·05). These responses to ALA had, however, no interrelationship with corticosterone. The rate of glucose uptake of whole-body P<0·05) but was not affected by noradrenaline supplementation. This study suggests that ALA stimulates the insulin sensitivity of tissues regardless of corticosterone-dependent metabolism and that the ALA-induced fatty acid metabolism of broilers differs between the liver and adipose tissue.

Rainbow trout has a limited ability to utilize digestible carbohydrates efficiently. Trout feeds generally contain high levels of DHA, a fatty acid known to inhibit a number of glycolytic and lipogenic enzymes in animals. A study was conducted to determine whether carbohydrate utilization by rainbow trout might be affected by dietary DHA level. Two low-carbohydrate (<4% digestible carbohydrate) basal diets were formulated to contain 1 (adequate) or 4 (excess)g/100g DHA diet respectively. The two basal diets were diluted with increasing levels of digestible starch (0%, 10%, 20% and 30%, respectively) to produce eight diets. These diets were fed to fish for 12 weeks at 15°C according to a pair-fed protocol that consisted of feeding the same amount of basal diet but different amounts of starch. Live weight, N and lipid gains, hepatic glycogen and plasma glucose values significantly increased, whereas feed efficiency (gain:feed) significantly decreased, with increasing starch intake (P<0·05). The retention efficiency of N (N gain/digestible N intake) improved with starch supplementation but was not affected by DHA level (P>0·05). Starch increased the activity of glucokinase, pyruvate kinase, glucose 6-phosphate dehydrogenase and fatty acid synthase (P<0·05) but did not affect hexokinase and malic enzyme activity. DHA had no effect on growth but increased plasma glucose and reduced carcass lipid and liver glycogen contents (P<0·05). Glycolytic and lipogenic enzymes were not affected by DHA level, except for pyruvate kinase, which was reduced by increasing DHA level. These results suggest only a marginal effect of dietary DHA on the ability of fish to utilize carbohydrate.

Extra-virgin olive oils (EVOO), high in phenolic compounds with antioxidant properties, could be partly responsible for the lower mortality and incidence of cancer and CVD in the Mediterranean region. The present study aims to measure oxidative DNA damage in healthy human subjects consuming olive oils with different concentrations of natural phenols. A randomised cross-over trial of high-phenol EVOO (high-EVOO; 592mg total phenols/kg) V low-phenol EVOO (low-EVOO; 147mg/kg) was conducted in ten postmenopausal women in Florence. Subjects were asked to substitute all types of fat and oils habitually consumed with the study oil (50g/d) for 8 weeks in each period. Oxidative DNA damage was measured by the comet assay in peripheral blood lymphocytes, collected at each visit during the study period. Urine samples over 24h were collected to measure the excretion of the olive oil phenols. The average of the four measurements of oxidative DNA damage during treatment with high-EVOO was 30% lower than the average during the low-EVOO treatment (p=0·02). Urinary excretion of hydroxytyrosol and its metabolite homovanillyl alcohol were significantly increased in subjects consuming high-EVOO. Despite the small sample size, the present study showed a reduction of DNA damage by consumption of an EVOO rich in phenols, particularly hydroxytyrosol.

The inhibitory effect on human and rat intestinal disaccharidase by the extractive from the leaves ofMorus alba (ELM) containing 0·24% 1-deoxynojirimycin equivalent and its inhibitory activities were investigated by the modified Dahlqvist method. In the presence of 1000-fold diluted ELM solution, the sucrase activity of four human samples was inhibited by 96% and that of maltase and isomaltase by 95 and 99 %, respectively. The activities of trehalase and lactase were inhibited by 44 and 38 %, respectively. The human disaccharidase activities varied from sample to sample because the samples were obtained from different resected regions after surgery. However, the ratio of the inhibitory effect for sucrase, maltase, isomaltase, trehalase and lactase was very similar among the four samples, and also that of resembled rat intestinal disaccharides. The inhibitory constant of the 1-deoxynojirimycin equivalent for sucrase, maltase and isomaltase was 2·1× 10−4, 2·5 × 10−4 and 4·5 10−4μM, respectively, and these inhibitory activities were shown, using rat brush border membrane vesicles, to be competitive. These results demonstrate that digestion is inhibited when an appropriate amount of ELM is orally ingested with sucrose or polysaccharide in man. When ELM was orally administered in a sucrose solution to fasted rats, the elevation in blood glucose was significantly suppressed, depending on the concentration of ELM given. These results suggest that ELM could be used as an ingredient in health foods and in foods that help to prevent diabetes.