Effect of dietary alpha-linolenic acid on thrombotic risk factors in vegetarian men. Plasma lipids and lipoproteins in vegetarians and controls. A low-fat vegan diet and a conventional diabetes diet in the treatment of type 2 diabetes: a randomized, controlled, 74-wk clinical trial. The influence of maternal vegetarian diet on essential fatty acid status of the newborn. The effects of very low fat diets enriched with fish or kangaroo meat on cold-induced vasoconstriction and platelet function. Long-term effect of a plant-based diet on magnesium status during pregnancy A vegetarian diet rich in soybean products compromises iron status in young students. Some problems with Cochrane reviews of diet and chronic disease The lipid-lowering effect of ezetimibe in pure vegetarians Published, JLR Papers in Press, September 11, 2006. Randomization to plant-based dietary approaches leads to larger short-term improvements in Dietary Inflammatory Index scores and macronutrient intake compared with diets that contain meat. Paleolithic nutrition improves plasma lipid concentrations of hypercholesterolemic adults to a greater extent than traditional heart-healthy dietary recommendations. Cardiovascular disease risk factors in free-living men: comparison of two prudent diets, one based on lactoovovegetarianism and the other allowing lean meat. Effects of workplace-based dietary and/or physical activity interventions for weight management targeting healthcare professionals: a systematic review of randomised controlled trials Folate status during pregnancy in women is improved by long-term high vegetable intake compared with the average western diet. Effectiveness of a low-fat vegetarian diet in altering serum lipids in healthy premenopausal women. Serum fatty acid, lipid profile and dietary intake of Hong Kong Chinese omnivores and vegetarians Biochemical and neurohormonal responses to the introduction of a lacto-ovovegetarian diet Vegetarian diet, change in dietary patterns, and diabetes risk: a prospective study Ambulatory blood pressure and heart rate responses to vegetarian meals
BACKGROUND Vegetarians have lower platelet and plasma concentrations of n-3 polyunsaturated fatty acids ( PUFAs ) than do omnivores . We recently showed that male vegetarians have higher platelet aggregability than do omnivores . OBJECTIVE We investigated whether male vegetarians ( n = 17 ) who consumed an increased amount of dietary alpha-linolenic acid ( ALA )  showed any changes in their tissue profile of PUFAs , plasma thromboxane concentrations , platelet aggregability , or hemostatic factors . DESIGN During the study , all subjects maintained their habitual vegetarian diets except that a proportion of dietary fat was replaced with vegetable oils and margarines that were provided . Initially , all subjects consumed a low-ALA diet ( containing safflower oil and safflower oil-based margarine ) for 14 d ; they then consumed either a moderate-ALA diet ( containing canola oil and canola oil-based margarine ) or a high-ALA diet ( containing linseed oil and linseed oil-based margarine ) for 28 d. Blood sample s were collected at day 0 ( baseline ) , day 14 , and day 42 . RESULTS Eicosapentaenoic acid , docosapentaenoic acid , total n-3 PUFAs , and the ratio of n-3 to n-6 PUFAs were significantly increased ( P < 0.05 ) , whereas the ratio of arachidonic acid to eicosapentaenoic acid was decreased ( P < 0.05 ) , in platelet phospholipids , plasma phospholipids , and triacylglycerols after either the moderate-ALA or high-ALA diet compared with the low-ALA diet . No significant differences were observed in thrombotic risk factors . CONCLUSION ALA from vegetable oils ( canola and linseed ) has a beneficial effect on n-3 PUFA concentrations of platelet phospholipids and plasma lipids in vegetarian males The possible effect of diet on plasma lipids was investigated in a group of vegetarians . Seventy-three men and 43 women who had adhered to a vegetarian diet for an average of three years were studied in the fasting state and compared with a r and omly selected group of controls matched for age and sex . Mean cholesterol levels in milligrams per deciliter for vegetarians and controls , respectively , were 126 and 184 ; low-density lipoprotein , 73 and 118 ; very-low-density lipoprotein , 11.8 and 17.2 ; high-density lipoproteins , 42 and 49 ; and mean triglyceride levels 59 and 86 . Mean weight and subscapular skinfold thicknesses were 58 kg and 6 mm for vegetarians and 73 kg and 17 mm for controls . Similar differences in lipid levels were found between subgroups of 42 vegetarians and controls with identical mean weights . Multiple regression analyses showed that consumption of dairy foods and eggs , but not body weight , was associated with the lipoprotein and cholesterol findings BACKGROUND Low-fat vegetarian and vegan diets are associated with weight loss , increased insulin sensitivity , and improved cardiovascular health . OBJECTIVE We compared the effects of a low-fat vegan diet and conventional diabetes diet recommendations on glycemia , weight , and plasma lipids . DESIGN Free-living individuals with type 2 diabetes were r and omly assigned to a low-fat vegan diet ( n = 49 ) or a diet following 2003 American Diabetes Association guidelines ( conventional , n = 50 ) for 74 wk . Glycated hemoglobin ( Hb A(1c ) ) and plasma lipids were assessed at weeks 0 , 11 , 22 , 35 , 48 , 61 , and 74 . Weight was measured at weeks 0 , 22 , and 74 . RESULTS Weight loss was significant within each diet group but not significantly different between groups ( -4.4 kg in the vegan group and -3.0 kg in the conventional diet group , P = 0.25 ) and related significantly to Hb A(1c ) changes ( r = 0.50 , P = 0.001 ) . Hb A(1c ) changes from baseline to 74 wk or last available values were -0.34 and -0.14 for vegan and conventional diets , respectively ( P = 0.43 ) . Hb A(1c ) changes from baseline to last available value or last value before any medication adjustment were -0.40 and 0.01 for vegan and conventional diets , respectively ( P = 0.03 ) . In analyses before alterations in lipid-lowering medications , total cholesterol decreased by 20.4 and 6.8 mg/dL in the vegan and conventional diet groups , respectively ( P = 0.01 ) ; LDL cholesterol decreased by 13.5 and 3.4 mg/dL in the vegan and conventional groups , respectively ( P = 0.03 ) . CONCLUSIONS Both diets were associated with sustained reductions in weight and plasma lipid concentrations . In an analysis controlling for medication changes , a low-fat vegan diet appeared to improve glycemia and plasma lipids more than did conventional diabetes diet recommendations . Whether the observed differences provide clinical benefit for the macro- or microvascular complications of diabetes remains to be established . This trial was registered at clinical trials.gov as NCT00276939 OBJECTIVES To evaluate whether a  maternal vegetarian diet influences the essential fatty acid status of the newborn and whether this is related to outcome of pregnancy . DESIGN  Dietary intake  and the fatty acid composition of plasma phospholipids were determined in 24 South Asian vegetarian and 24 white omnivore non-pregnant premenopausal women r and omly selected from the general population of North London . Umbilical cords and cord blood were collected at delivery from 48 South Asian vegetarian women and 98 white omnivores from the same catchment area along with details of antenatal history and the outcome of pregnancy . The fatty acid composition of the cord arteries and that of cord plasma phospholipids were analysed in a subset of 32 pairs of subjects , who were matched for maternal age , gestational age , parity and sex of infant . RESULTS Intakes of linoleic acid  ( 18:2n-6 ) expressed as proportion of the dietary energy and the ratio of linoleic to alpha-linolenic acid ( 18:3n-3 ) were higher in the vegetarian women , and eicosapentaenoic acid ( EPA , 20:5n-3 ) and docosahexaenoic acid ( DHA , 22:6n-3 ) were absent from their diets . The proportion of linoleic acid , as well as the absolute concentration , was greater and those of EPA and DHA were lower in plasma phospholipids , plasma free fatty acid and total plasma lipids of the vegetarians compared with the white subjects . The proportion of DHA was lower ( P > 0.001 ) but that of docosapentaenoic acid ( 22:5n-6 ) was greater ( P < 0.001 ) in cord those from the omnivores . The ratio of 20:3n-9/20:4n-6 was elevated in cord artery but not in cord plasma phospholipids in both groups . Early onset of labour and the duration of gestation was 5.6 days shorter . Birth weight , head circumference and length were lower in the infants born to South Asian vegetarians even after adjusting for maternal height , duration of gestation , parity , gender of infants and smoking habits . Multivariate analysis did not reveal any relationship between the proportions of DHA in plasma or cord artery phospholipids and the birthweight or head circumference of the infants . CONCLUSION This study demonstrates that vegetarians give birth to infants with less DHA in their plasma and cord artery phospholipids but this did not appear to be independently related to the outcome of pregnancy Eighteen healthy volunteers consumed very low fat diets ( less than 7 % of daily energy ) enriched with different sources of long chain ( C20 and C22 ) polyunsaturated fatty acids ( PUFA ) . Three diets provided 500 g/day of fish caught in the tropical waters of Australia ( rich in arachidonic acid and docosahexaenoic acid ) , fish caught in the southern waters of Australia ( rich in docosahexaenoic acid ) , or kangaroo meat ( rich in linoleic and arachidonic acids ) . The fourth diet was vegetarian , similarly low in fat but containing no 20- and 22-carbon PUFA . An increase in the percentage of a particular C20 or C22 PUFA in the plasma phospholipid fraction in subjects consuming these low fat diets corresponded to the dietary PUFA composition . This study examined the effect of dietary modification of the level of arachidonic acid in plasma phospholipids on both traditional measures of platelet function and on cold-induced vasoconstriction . The cold pressor response , measured by venous occlusion plethysmography , was depressed in diets which elevated the levels of arachidonic acid in plasma lipids ( kangaroo and tropical fish ) , enhanced after subjects consumed a diet which increased the levels of docosahexaenoic acid and eicosapentaenoic acid ( southern fish diet ) , and was unchanged by the low fat vegetarian diet . There was no effect on bleeding time or platelet responsiveness Objective : To compare dietary magnesium intake and magnesium concentrations in serum , red blood cells ( RBC ) and urine during pregnancy of women habitually following a long-term plant-based diet and of women following an average Western ( control ) diet .  Design : Prospect i ve study during pregnancy . Setting : Giessen , Germany . Subjects : Healthy pregnant women ( n=108 ) in their 9–12th , 20–22nd and 36–38th gestational week habitually following a plant-based diet for more than 3 y or an average Western diet .  The vegetarians were subdivided into ovo-lacto vegetarians ( n=27 ) and low-meat eaters ( n=43 ) . Results : Significant higher dietary magnesium intakes were observed in pregnant women consuming  a plant-based diet ( 508±14 mg/day for ovo – lacto vegetarians , P<0.001 and 504±11 mg/day for low-meat eaters , P<0.001 ) than in pregnant women consuming a control diet ( 412±9 mg/day ) . Serum magnesium concentrations were similar in all diet groups whereas RBC magnesium was slightly higher in low-meat eaters than in controls ( P=0.058 ) . Urinary magnesium excretion was higher in ovo-lacto vegetarians ( P=0.023 ) , followed by low-meat eaters ( P=0.017 ) when compared to the control group . During the third trimester of pregnancy , the frequency and the occurrence of calf cramps was lower in the plant-based diet group than in the control group ( P=0.004 and 0.008 ) . Conclusions : Owing to a higher dietary magnesium intake confirmed by higher urinary magnesium excretion , habitual plant-based diets result in a slightly improved magnesium status during pregnancy and reduce the frequency of calf cramps during the third trimester of pregnancy compared to an average Western diet . Therefore , plant-based diets during pregnancy can be recommended with regard to magnesium supply The iron status of young Chinese Buddhist vegetarians ( 23 men and 32 women ) and nonvegetarian students ( 20 men and 39 women from a medical college ) was investigated by dietary assessment of iron intake and hematological measurement of biochemical indices including hemoglobin , plasma iron , transferrin , transferrin saturation and plasma ferritin . A characteristic of the vegetarian diet in this study was the replacement of meat by soybean products . Results of the dietary assessment showed that the average iron density of the diets ranged from 1.9 to 2.2 mg/MJ , with no difference between the vegetarian and nonvegetarian diets . Daily iron intake was similar in both vegetarian and nonvegetarian men . However ,  iron intake was significantly higher in female vegetarians than nonvegetarians , averaging 104 and 78 % of the RDA , respectively . Results of blood analysis showed that , for both sexes , the median plasma ferritin concentration of the vegetarians ( male 47 micrograms/L and female 12 micrograms/L ) was about half the level of the nonvegetarians ( male 91 micrograms/L and female 27 micrograms/L ) . Occurrence and risk of iron deficiency are more prevalent in vegetarians . Correlation between plasma ferritin concentration and years of vegetarian practice in vegetarian men was marginally significant ( r = -0.38 , P = 0.077 ) . We conclude that a vegetarian diet that is rich in soybean products and restricted in animal foods is limited in bioavailable iron and is not adequate for maintaining iron balance in men and women The sum of evidence -based nutrition has to be more than a Cochrane-type meta- analysis of r and omised controlled trials ( RCTs ) . Most of the evidence base in nutrition is observational , especially cohort studies . RCTs of diet change through to disease outcome are uncommon and the change has usually been addition or removal of only a single food component . Trials with whole diets through to disease outcome are rare and dietary changes made by individuals are unlikely to be an exact copy of the prescription . It is hard to even imagine a trial in which half ( r and omised ) of a large group of middle-aged people agree to avoid vegetables for 5 y and be followed up to see who will develop cancer . Most of the USA 's health cl aims , permitted by the Food and Drug Administration , are not supported by RCTs . But where controlled trials of nutritional change and disease outcome have been achieved , they must be review ed very carefully . Two Cochrane review s on diet and cardiovascular disease ( CVD ) , published in the widely read British Medical Journal ( BMJ ) , were criticised after their publication and the conclusions have not been subsequently adopted by expert committees . The first of these review s was ‘ Dietary fat and prevention of CVD : a systematic review ’ . The second was ‘ Systematic review of long term effects of advice to reduce dietary salt in adults ’ . A critique of these two Cochrane review s is presented here as a contribution to our discussion of the potential of Cochrane methodology to the reliability of knowledge about diet and disease Results of previous studies have shown that ezetimibe ( 10 mg/day ) reduces LDL cholesterol in patients with mild hypercholesterolemia on a normal-cholesterol diet ( dietary intake of 200–500 mg/day ) by 16–22 % . However , the LDL cholesterol-lowering effect of ezetimibe in subjects with an extremely low dietary cholesterol intake ( vegetarians ) has not been studied . We conducted a r and omized , double-blind , placebo-controlled , two-phase crossover study in 18 healthy pure vegetarians to assess the effect of ezetimibe ( 10 mg/day ) on plasma lipids , cholesterol absorption , and its synthesis . Treatment periods lasted 2 weeks each , with an intervening 2 week washout period . Fractional cholesterol absorption was determined using the continuous dual stable isotope feeding method . Mean dietary cholesterol intake in the pure vegetarians was extremely low and averaged 29.4 ± 16.8 and 31.4 ± 14.4 mg/day during the placebo and ezetimibe administration phases , respectively . Fractional cholesterol absorption during the placebo phase was 48.2 ± 8.2 % and was decreased by 58 % during ezetimibe treatment to 20.2 ± 6.2 % ( P < 0.001 ) . This change in intestinal cholesterol absorption was followed by a significant reduction in LDL cholesterol of 17.3 % . In individuals with extremely low dietary cholesterol intake , treatment with ezetimibe ( 10 mg/day ) leads to a significant reduction of cholesterol absorption and a clinical ly relevant decrease of plasma LDL cholesterol , comparable to that of subjects with a normal dietary cholesterol intake . Thus , the lipid-lowering effect of ezetimibe is mediated mainly through a reduction of the absorption of endogenous ( biliary ) cholesterol Studies have examined nutrient differences among people following different plant-based diets . However , all of these studies have been observational . The aim of the present study was to examine differences in nutrient intake and Dietary Inflammatory Index ( DII ) scores among overweight and obese ( body mass index 25.0 - 49.9 kg/m(2 ) ) adults r and omized to receive dietary instruction on a vegan ( n = 12 ) , vegetarian ( n = 13 ) , pescovegetarian ( n = 13 ) , semivegetarian ( n = 13 ) , or omnivorous ( n = 12 ) diet during a 6-month r and omized controlled trial . Nutrient intake , nutrient adequacy , and DII score were assessed via two 24-hour dietary recalls ( Automated Self-Administered 24-Hour Dietary Recall ) at baseline and at 2 and 6 months . Differences in nutrient intake and the DII were examined using general linear models with follow-up tests at each time point . We hypothesized that individuals r and omized to the vegan diet would have lower DII scores and greater improvements in fiber , carbohydrate , fat , saturated fat , and cholesterol at both 2 and 6 months as compared with the other 4 diets . Participants r and omized to the vegan diet had significantly greater changes in most macronutrients at both time points , including fat and saturated fat , as well as cholesterol and , at 2 months , fiber , as compared with most of the other diet groups ( Ps < .05 ) . Vegan , vegetarian , and pescovegetarian participants all saw significant improvements in the DII score as compared with semivegetarian participants at 2 months ( Ps < .05 ) with no differences at 6 months . Given the greater impact on macronutrients and the DII during the short term , finding ways to provide support for adoption and maintenance of plant-based dietary approaches , such as vegan and vegetarian diets , should be given consideration Recent research suggests that traditional grain-based heart-healthy diet recommendations , which replace dietary saturated fat with carbohydrate and reduce total fat intake , may result in unfavorable plasma lipid ratios , with reduced high-density lipoprotein ( HDL ) and an elevation of low-density lipoprotein ( LDL ) and triacylglycerols ( TG ) . The current study tested the hypothesis that a grain-free Paleolithic diet would induce weight loss and improve plasma total cholesterol , HDL , LDL , and TG concentrations in nondiabetic adults with hyperlipidemia to a greater extent than a grain-based heart-healthy diet , based on the recommendations of the American Heart Association . Twenty volunteers ( 10 male and 10 female ) aged 40 to 62 years were selected based on diagnosis of hypercholesterolemia . Volunteers were not taking any cholesterol-lowering medications and adhered to a traditional heart-healthy diet for 4 months , followed by a Paleolithic diet for 4 months . Regression analysis was used to determine whether change in body weight contributed to observed changes in plasma lipid concentrations . Differences in dietary intakes and plasma lipid measures were assessed using repeated- measures analysis of variance . Four months of Paleolithic nutrition significantly lowered ( P < .001 ) mean total cholesterol , LDL , and TG and increased ( P < .001 ) HDL , independent of changes in body weight , relative to both baseline and the traditional heart-healthy diet . Paleolithic nutrition offers promising potential for nutritional management of hyperlipidemia in adults whose lipid profiles have not improved after following more traditional heart-healthy dietary recommendations In general , vegetarians have lower serum lipids and blood pressures than omnivores have . We tested the blood pressure and serum lipid lowering effects of two fat-modified diets differing primarily in their source of protein . Twenty-six men were r and omized in an incomplete block design to two of three diets : a high-fat diet , a fat-modified lactoovovegetarian diet ( LOV ) and a diet in which 60 % of plant protein in the LOV was replaced with lean meat ( LM ) . Compared with the high-fat diet both prudent diets significantly lowered blood pressure , serum total cholesterol ( TC ) , and LDL cholesterol but significantly increased serum triglycerides . The LOV diet had a significantly greater cholesterol-lowering effect than did the LM diet ( 10 % vs 5 % decrease ) but blood pressure reductions were similar . The partial substitution of lean meat for plant protein in a fat-modified diet did not negate the overall cardiovascular-risk lowering of the lactoovovegetarian diet Background The prevalence of overweight and obesity is high amongst healthcare professionals and there is growing interest in delivering weight loss interventions in the workplace . We conducted a systematic review to ( i ) examine the effectiveness of workplace-based diet and /or physical activity interventions aim ed at healthcare professionals and to ( ii ) identify and describe key components of effective interventions . Seven electronic data bases were systematic ally search ed . Results Thirteen r and omised controlled trials met the inclusion criteria , of which seven had data available for meta- analysis . Where meta- analysis was possible , studies were grouped according to length of follow-up ( < 12 months and ≥12 months ) and behavioural target ( diet only , physical activity only or diet and physical activity ) , with outcome data pooled using a weighted r and om effects model . Nine studies reported statistically significant ( between-group ) differences . Four studies reported being informed by a behaviour change theory . Meta- analysis of all trials reporting weight data demonstrated healthcare professionals allocated to dietary and physical activity interventions lost significantly more body weight ( −3.95 Kg , [ 95 % CI −4.96 to- 2.95 Kg ] ) than controls up to 12 months follow up . Conclusions Workplace diet and /or physical activity interventions targeting healthcare professionals are limited in number and are heterogeneous . To improve the evidence base , we recommend additional evaluations of theory-based interventions and adequate reporting of intervention content The effect of increasing dietary folate on folate status during pregnancy is controversial . The aim of this study was to compare folate intake and folate status during pregnancy of women with high long-term vegetable intake and those eating an average Western diet .  In a prospect i ve study that included 109 participants , pregnant women adhering to a predominant vegetarian diet with high vegetable intake for 8 + /- 0.5 y with subgroups of ovo-lacto vegetarians ( n = 27 ) and low meat eaters ( n = 43 ) and women eating an average Western diet ( control group , n = 39 ) were compared with regard to dietary intake and plasma and red blood cell ( RBC ) folate concentrations during wk 9 - 12 , 20 - 22 and 36 - 38 of gestation . Plasma and RBC folate concentrations were highest in ovo-lacto vegetarians , followed by low meat eaters and lowest in the controls . Ovo-lacto vegetarians and low meat eaters showed a lower risk for folate deficiency , with RBC folate concentrations of < 320 nmol/L result ing in odds ratios of 0.10 ( 95 % confidence interval , 0.01 - 0.56 ) and 0.52 ( 95 % confidence interval , 0.20 - 1.34 ) , respectively . In ovo-lacto vegetarians , the RBC folate concentration was positively related to the intake of vitamin B-12 ( r = 0.51 , P : < 0.0001 ) . The results of the study suggest that long-term high vegetable intake favorably affects plasma folate as well as RBC folate concentrations throughout pregnancy and reduces the risk of folate deficiency if an adequate vitamin B-12 supply is ensured Few controlled trials have studied cholesterol-lowering diets in premenopausal women . None has examined the cholesterol-lowering effect of a low-fat vegetarian diet , which , in other population groups , leads to marked reductions in serum cholesterol concentrations and , in combination with other life-style changes , a regression of atherosclerosis . We tested the hypothesis that a low-fat , vegetarian diet significantly reduces serum total and low-density lipoprotein ( LDL ) cholesterol concentrations in premenopausal women . In a crossover design , 35 women , aged 22 to 48 , followed a low-fat vegetarian diet deriving approximately 10 % of energy from fat for 2 menstrual cycles . For 2 additional cycles , they followed their customary diet while also taking a " supplement " ( placebo ) pill .  Serum lipid concentrations were assessed at baseline and during each intervention phase . Mean serum LDL , high-density lipoprotein ( HDL ) , and total cholesterol concentrations decreased 16 . 9 % , 16.5 % , and 13.2 % , respectively , from baseline to the intervention diet phase ( p<0.001 ) , whereas mean serum triacylglycerol concentration increased 18.7 % ( p<0.01 ) . LDL/HDL ratio remained unchanged . Thus , in healthy premenopausal women , a low-fat vegetarian diet led to rapid and sizable reductions in serum total , LDL , and HDL cholesterol concentrations Objective : To examine the serum fatty acid and lipid profiles and dietary intake of  Hong Kong Chinese omnivores and vegetarians  with respect to cardiovascular health . Design : R and om population survey stratified by age and sex . Subjects : One-hundred and ninety-four omnivore subjects ( 81 men , 113 women ) age 25–70 y , and 60 ovo-lacto-vegetarian adults ( 15 men , 45 women ) age 30–55 y. Measurements : Nutrient quantitation was by a food frequency method . Serum fatty acids were analysed by  gas chromatography , and serum lipid  by st and ard laboratory methods . Results : Compared with omnivores , vegetarians had higher serum concentrations of polyunsaturated ( PUFA ) and monosaturated fatty acids ( MUFA ) , and lower saturated fatty acids ( SFA ) , long chain omega-3 and trans fatty acids ( TFA ) . They also had lower serum cholesterol and higher apoA-I concentrations , but the LDL/HDL ratio was not different . The ratio of polyunsaturated to saturated fatty acids intake was higher in vegetarians . Compared with results from population s with higher incidences of coronary heart disease , while lower myristic and palmitic acid concentrations and higher eicosapentaneoic ( EPA ) and docosahexanoic acid ( DHA ) may partly account for the difference in incidence , linoleic acid concentration was higher . Although the Chinese vegetarian diet may be beneficial for heart health in that antioxidant and fibre intakes are higher and saturated fat lower , the low EPA and DHA due to omission from dietary source and suppressed formation by high linoleic acid level , and the presence of TFA in the diet , may exert an opposite effect . Conclusion : There are some favourable features in the serum fatty acid profile in the Hong Kong Chinese population with respect to cardiovascular health , but the consumption of TFA is of concern . The Chinese vegetarian diet also contains some adverse features . Sponsorship : This study is partly sponsored by the Hong Kong Health Services Research Grant . European Journal Of Clinical Nutrition ( 2000 ) 24 , Objective : To assess the mechanisms of the blood pressure-lowering effect of a vegetarian diet in the early and later stages of dietary intervention Design : After 2 weeks without intervention ( baseline ) , 20 normotensive men were matched for age and body mass index and r and omly allocated to an omnivorous ( control ) or a lacto-ovovegetarian diet for 6 weeks in a parallel trial Methods : Ambulatory blood pressures were recorded between 0800 and 1700 h on alternate days during the first week of intervention , twice in the second week and weekly thereafter . Blood sample s collected after a st and ard breakfast were analysed for plasma noradrenaline , adrenaline , atrial natriuretic peptide ( ANP ) , renin , aldosterone , glucose and insulin . Factor and multiple regression analyses were used to assess the association among neurohormonal factors , blood pressures and diet . Results were analysed for the first week of the diet and for the entire 6 weeks Results : Ambulatory blood pressures at work were lower on the vegetarian diet than in the controls . This blood pressure decrease was associated with a factor representing lower plasma catecholamine and renin activity levels throughout the study , and a factor representing reduced plasma glucose and insulin levels in week 1 of intervention only . Plasma ANP levels were significantly higher during week 1 of the vegetarian diet Conclusions : A blood pressure lowering effect of a vegetarian diet during normal working activity was shown . Using factors derived from the biochemical variables , results were in keeping with the hypothesis that these effects may be mediated by reduced sympatho-adrenal activity consequent to altered glucose and insulin h and ling . An early increase in plasma ANP may contribute to the blood pressure Background / objectives Vegetarian diets are inversely associated with diabetes in Westerners but their impact on Asians — whose pathophysiology differ from Westerners — is unknown . We aim to investigate the association between a vegetarian diet , change in dietary patterns and diabetes risk in a Taiwanese Buddhist population . Methods We prospect ively followed 2918 non-smoking , non-alcohol drinking Buddhists free of diabetes , cancer , and cardiovascular diseases at baseline , for a median of 5 years , with 183 incident diabetes cases confirmed .  Diet was assessed through a vali date d food frequency question naire at baseline and a simple question naire during follow-ups .  Incident cases of diabetes were ascertained through follow-up question naires , fasting glucose and HbA1C . Stratified Cox Proportional Hazards Regression was used to assess the effect of diets on risk of diabetes . Results Consistent vegetarian diet was associated with 35 % lower hazards ( HR : 0.65 , 95 % CI : 0.46 , 0.92 ) , while converting from a nonvegetarian to a vegetarian pattern was associated with 53 % lower hazards ( HR : 0.47 , 95 % CI : 0.30 , 0.71 ) for diabetes , comparing with nonvegetarians while adjusting for age , gender , education , physical activity , family history of diabetes , follow-up methods , use of lipid-lowering medications , and baseline BMI . Conclusion Vegetarian diet and converting to vegetarian diet may protect against diabetes independent of BMI among Taiwanese Objectives : To determine the effects of a vegetarian diet on daytime ambulatory ( Accutracker ) blood pressures and heart rates , and to relate these to the estimated peak in plasma glucose to determine whether low-glycaemic-index diets reduce sympathetic activity in response to differences in postpr and ial glucose and insulin . Design : The subjects were matched for age and body mass index and r and omly assigned to one of two parallel diet groups . Setting : Clinical . Participants : Twenty-one normotensive non-vegetarian male hospital workers volunteered for the study and 20 completed it . Intervention : After 2 weeks of baseline measurement the subjects followed an omnivorous or a lacto-ovovegetarian diet for 6 weeks . Main outcome measures : Daytime ambulatory blood pressures and heart rate , and postbreakfast catecholamines , insulin and glucose . Results : Ambulatory systolic blood pressure and heart rates were lower in the vegetarian group during the working day . The prepr and ial rise in diastolic pressure was attenuated on the vegetarian diet . There were no differences in plasma catecholamine , glucose or insulin levels sample d after breakfast on the two dietary regimes . Conclusions : The blood pressure-lowering effect of a lacto-ovovegetarian diet , which occurs throughout the working day , is associated with lower heart rates , suggesting a central nervous or cardiac mechanism . The possibility that the lower glycaemic index of a lacto-ovovegetarian diet has some effect needs to be investigated further in relation to major meal-times and studied in both normotensive and hypertensive subjects
Conclusions Plant-based diets are associated with decreased total cholesterol , low-density lipoprotein cholesterol , and high-density lipoprotein cholesterol , but not with decreased triglycerides .
Context Although a recent meta- analysis of r and omized controlled trials showed that adoption of a vegetarian diet reduces plasma lipids , the association between vegetarian diets and long-term effects on plasma lipids has not been subjected to meta- analysis .
Objective The aim was to conduct a systematic review and meta- analysis of observational studies and clinical trials that have examined associations between plant-based diets and plasma lipids .