Effect of Flaxseed Consumption on Blood Pressure, Serum Lipids, Hemopoietic System and Liver and Kidney Enzymes in Healthy Humans

Flaxseed Reduces Cancer Risk by Altering Bioenergetic Pathways in Liver: Connecting SAM Biosynthesis to Cellular Energy

This article illustrates how dietary flaxseed can be used to reduce cancer risk, specifically by attenuating obesity, type 2 diabetes, and non-alcoholic fatty liver disease (NAFLD). We utilize a targeted metabolomics dataset in combination with a reanalysis of past work to investigate the "metabo-bioenergetic" adaptations that occur in White Leghorn laying hens while consuming dietary flaxseed. Recently, we revealed how the anti-vitamin B6 effects of flaxseed augment one-carbon metabolism in a manner that accelerates S-adenosylmethionine (SAM) biosynthesis. Researchers recently showed that accelerated SAM biosynthesis activates the cell's master energy sensor, AMP-activated protein kinase (AMPK). Our paper provides evidence that flaxseed upregulates mitochondrial fatty acid oxidation and glycolysis in liver, concomitant with the attenuation of lipogenesis and polyamine biosynthesis. Defatted flaxseed likely functions as a metformin homologue by upregulating hepatic glucose uptake and pyruvate flux through the pyruvate dehydrogenase complex (PDC) in laying hens. In contrast, whole flaxseed appears to attenuate liver steatosis and body mass by modifying mitochondrial fatty acid oxidation and lipogenesis. Several acylcarnitine moieties indicate Randle cycle adaptations that protect mitochondria from metabolic overload when hens consume flaxseed. We also discuss a paradoxical finding whereby flaxseed induces the highest glycated hemoglobin percentage (HbA1c%) ever recorded in birds, and we suspect that hyperglycemia is not the cause. In conclusion, flaxseed modifies bioenergetic pathways to attenuate the risk of obesity, type 2 diabetes, and NAFLD, possibly downstream of SAM biosynthesis. These findings, if reproducible in humans, can be used to lower cancer risk within the general population.

The comparison of omega-3 and flaxseed oil on serum lipids and lipoproteins in hyperlipidemic male rats

Hyperlipidemia affects a significant number of patients despite treatment with cholesterol-lowering drugs. Due to the low efficacy of synthetic drugs, there is a need for new agents with low side effects. Therefore, the effects of flaxseeds oil and animal omega-3 on the hyperlipidemic rats were investigated. Forty male Wistar rats were assigned to four groups (n = 10): 1) control group that was fed with a standard diet (pallets). 2) high-fat diet (HFD) control group that was fed with high-fat food for 42 days, 3) Omega-3 group that received HFD for 21 days, followed by HFD + omega-3 capsule (600 mg/kg; 21 days/gavage), and 4) flaxseed oil group that received HFD for 21 days, followed by HFD + flaxseed oil (10 ml/kg; 21 days/gavage). Blood samples were collected three times and at the stages one to third of the experiment from the rats' tail. The results showed that high levels of fat significantly increased cholesterol, triglyceride (TG), and low-density lipoprotein (LDL) in the flaxseed, HFD control, and omega-3 groups in the second stages of the experiment. Inverse, omega-3 or flaxseed oil supplementation decreased cholesterol, TG, and LDL levels and increased high-density lipoprotein (HDL) level in comparison with the HFD control group in the third stages of the experiment. There was no significant difference in the studied parameters between the flaxseed- and omega-3-treated groups. It can be concluded that flaxseed oil similar to omega-3 is effective in the treatment of hyperlipidemia.

Combination of cafeteria diet with intraperitoneally streptozotocin in rats. A type-2 diabetes model

Purpose

To develop a model of induction of type-2 diabetes (DM2) by combining low doses of streptozotocin (STZ) and a cafeteria diet.

Methods

Forty male Wistar rats (200 g) were allocated into four groups: control (non-diabetic, n = 10); STZ 30 mg/kg (diabetic, n = 10); STZ 35 mg/kg (diabetic,n = 10); and STZ 40 mg/kg (diabetic, n = 10). DM2 was induced with a single intraperitoneal injection of STZ after four weeks of cafeteria diet in the three diabetic groups. All animals were evaluated as for anthropometric, and biochemical analyses, as well as liver, kidney and pancreas histological analyses.

Results

Lower weight gain, higher water intake, higher Lee index, hyperglycemia and modified total protein, urea, alpha-amylase, as well as insulin resistance, hepatic steatosis, pancreas, and kidney injury were observed in animals treated with 35 and 40 mg/kg of STZ.

Conclusions

The results show that the experimental model using cafeteria diet associated with 35 mg/kg of STZ is a low-cost model and efficient in order to develop DM2, confirmed by the presence of polydipsia, hyperglycemia, altered biochemical tests, insulin resistance and damages to the liver, pancreas and kidney, which is similar to the disease found in humans.

Effects of flaxseed on blood pressure, body mass index, and total cholesterol in hypertensive patients: A randomized clinical trial

OBJECTIVES

Given the antioxidant properties of flaxseed and its biologically active ingredients, this study was conducted to determine the effects of flaxseed supplementation on body mass index (BMI), blood pressure, and total cholesterol levels in patients with hypertension.

METHODS

In this triple-blind clinical trial, 112 patients, with an age range of 35 to 70 years, were randomized to 2 groups receiving 10 g (n = 45) and 30 g (n = 45) of flaxseed supplementation and 1 group receiving placebo (n = 45) for 12 weeks by stratified block randomization. They were evaluated in terms of systolic (SBP) and diastolic blood pressure (DBP), BMI, and total serum cholesterol. Physical activity was measured using the International Physical Activity Questionnaire-Short Form (IPAQ-SF) and food intake was assessed using the Food Frequency Questionnaire (FFQ). The data were analyzed with SPSS, version 22, using the chi-square, Kruskal-Wallis, repeated measures analysis, ANOVA, and ANCOVA tests.

RESULTS

The interaction effects among the study groups and time on the mean SBP (p = 0.001), DBP (p = 0.001), total cholesterol level (p = 0.032), and BMI (p < 0.001) were significant. During the study, the 30-g group achieved the best results, so that a 13.38-unit decrease in SBP was observed compared to a 1.72 unit increase in the placebo group and a 5.6-unit decrease in DBP was measured compared to a 2.39 unit increase in the placebo group. BMI decreased by 0.86 units compared to 0.06 units in the placebo group. Total cholesterol also decreased by 20.4 units compared to 11.86 units in the placebo group.

CONCLUSION

The results of this study showed that flaxseed can be effective in reducing blood pressure, total cholesterol, and body mass index in hypertensive patients in a twelve-week period.

Flaxseed and Its Components in Treatment of Hyperlipidemia and Cardiovascular Disease

This paper describes the effects of flaxseed and its components (flax oil, secoisolariciresinoldiglucoside[SDG], flax lignan complex [FLC], and flax fibers] on serum lipids (total cholesterol [TC], low-density lipoprotein-cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], and triglycerides [TG]) in animals and humans. Ordinary flaxseed reduces TG, TC, LDL-C, and TC/HDL-C levels in a dose-dependent manner in animals. In humans, it reduces serum lipids in hypercholesterolemicpatients but has no effects in normocholesterolemicpatients. Flax oil has variable effects on serum lipids in normo- and hypercholesterolemic animals. Flax oil treatment, with a dosage containing greater than 25 g/day of α-linolenic acid, reduces serum lipids in humans. Although FLC reduces serum lipids and raises serum HDL-C in animals, its effects on serum lipids in humans are small and variable. Flax fibers exert small effects on serum lipids in humans. Crop Development Centre (CDC)-flaxseed, which contains low concentrations of α-linolenic acid, has significant lipid lowering effects in animals. Pure SDG has potent hypolipidemic effects and raises HDL-C. In conclusion, flaxseed and pure SDG have significant lipid-lowering effects in animals and humans, while other components of flaxseed have small and variable effects.

Effect of Flaxseed Powder on Cardiovascular Risk Factor in Dyslipidemic and Hypertensive Patients

Background:

Hyperlipidemia and hypertension are the most important causes of ischemic heart disease. There is evidence that flaxseed powder can improve lipid profile and blood pressure. In this study, we want to investigate the effects of flaxseed powder consumption on patients with hyperlipidemia and hypertension.

Methods:

This randomized double-blind placebo-controlled clinical trial was performed on 80 hyperlipidemic and hypertensive patients (men and women between 20 and 60 years old). In this study, participants were recruited from Imam Khomeini hospital clinics of Shiraz University of Medical Sciences in 2017 randomly allocated to flaxseed powder group and placebo group. The intervention group received 36 g of flaxseed sachet (n = 40), and control group received 12 g placebo sachet (n = 40) for 8 weeks. Serum lipid profiles, blood pressure, fasting blood sugar, and anthropometric indices were measured. Data were analyzed by using SPSS.

Results:

We found significant reduction (P < 0.001) in anthropometric indices (waist circumference and waist-to-hip ratio) and lipid profiles (triglycerides [P = 0.015], total cholesterol [P = 0.018], and low-density lipoprotein [P < 0.001]) within flaxseed group in comparison with placebo group.

Conclusions:

Based on beneficial effects of flaxseed on cardiovascular risk factors, it seems that flaxseed consumption can be considered as a useful therapeutic approach for reducing lipid profile and anthropometric indices.

Importance of Flaxseed and its Components in the Management of Hypertension

This review paper describes the effects of flaxseed and its components (flax oil, secoisolariciresinol diglucoside [SDG], flax lignan complex [FLC], and flaxseed protein hydrolysate [FPH]) on blood pressure (BP) in Sprague Dawley rats (SDR), spontaneously hypertensive rats (SHR), and humans. Flaxseed, flax oil, and FLC had variable effects on BP in humans, while SDG and FPH significantly reduced the BP in SDR and SHR. The effect of SDG was dose-dependent and long lasting. The lowering of BP is mediated through inhibition of soluble epoxide by α -linolenic acid in flax oil, stimulation of guanylate cyclase and inhibition of angiotensin converting enzyme (ACE) by SDG, and inhibition of renin and ACE activity by FPH. Flaxseed, flax oil, and FLC have variable effects on BP (none, slight, and significant). They are effective in lowering BP in individuals with hypertension and metabolic syndrome but ineffective in healthy individuals' ineffectiveness of flaxseed and its compounds in lowering BP may be due to their low doses, long interval of dosing, short duration of consumption, and patient status. In conclusion, the data at present suggest that flaxseed, flax oil, and FLC cannot serve as therapeutic agents for the treatment of hypertension. However, they can be used as an adjunct in the treatment of hypertension. A clinical trial should be conducted of these agents with higher doses which would be given twice daily for long duration. Pure SDG and FPS may serve as therapeutic agents for the treatment of hypertension but they have not been tried in humans.

The effects of seed from Linum usitatissimum cultivar with increased phenylpropanoid compounds and hydrolysable tannin in a high cholesterol-fed rabbit

Background

Dietary fat is considered one of the most important factors associated with blood lipid metabolism and plays a significant role in the cause and prevention of atherosclerosis that has been widely accepted as an inflammatory disease of the vascular system. The aim of the present study was to evaluate the effect of genetically modified flaxseed (W86) rich in phenylpropanoid compounds and hydrolysable tannin in high cholesterol-induced atherosclerosis rabbit models compared to parental cultivar Linola.

Methods

Twenty-Eight White New Zealand white rabbits aged 6 months were randomly divided into four groups, control group, high cholesterol group (10 g/kg), Linola flaxseed group (100 g/kg) and W86 flaxseed group (100 g/kg). The rabbits were fed a normal diet or a high cholesterol diet for 10 weeks. Levels of blood lipids, hematological values, total antioxidative status and superoxide dismutase activity in serum were determined. Moreover, body weight and feed intake were measured after sixth and tenth weeks. After each stage of the experiment atherogenic indexes (non-HDL-C/HDL-C, LDL-C/HDL-C, and atherogenic index of plasma) was calculated.

Results

The intake of a dyslipidaemic diet negatively influenced lipid profile in rabbits at the 10 weeks of feeding. W86 flaxseed significantly decreased total cholesterol, LDL-C, VLDL-C and TG serum levels in cholesterolemic rabbits compared with parental Linola after 10 weeks. Atherogenic indexes decreased over time with a significant difference between the diets and they were the best for W86 flaxseed. Similarly, the experimental addition of W86 significantly decreased atherogenic predictors such as heterophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and the mean platelet volume-to-lymphocyte ratio. In rabbits, W86 flaxseed increased the activity of superoxide dismutase and total antioxidative status compared to Linola.

Conclusions

Results of the presented study suggest that the addition of W86 flaxseed alleviate serum lipid changes in high cholesterolemic diet-administered rabbits. W86 flaxseed significantly reduced atherogenic indexes, as compared with the Linola and indicate that W86 flaxseed more effectively red CVD risk factors during hypercholesterolemia. Moreover, the presented result suggested that W86 flaxseed can be a part of a heart-healthy and antiatherogenic diet for the human.

Electronic supplementary material

The online version of this article (10.1186/s12944-018-0726-4) contains supplementary material, which is available to authorized users.

Flaxseed: its bioactive components and their cardiovascular benefits

Cardiovascular disease remains the leading cause of mortality and morbidity worldwide. The inclusion of functional foods and natural health products in the diet are gaining increasing recognition as integral components of lifestyle changes in the fight against cardiovascular disease. Several preclinical and clinical studies have shown the beneficial cardiovascular effects of dietary supplementation with flaxseed. The cardiovascular effects of dietary flaxseed have included an antihypertensive action, antiatherogenic effects, a lowering of cholesterol, an anti-inflammatory action, and an inhibition of arrhythmias. Its enrichment in the ω-3 fatty acid α-linolenic acid and the antioxidant lignan secoisolariciresinol diglucoside as well as its high fiber content have been implicated primarily in these beneficial cardiovascular actions. Although not as well recognized, flaxseed is also composed of other potential bioactive compounds such as proteins, cyclolinopeptides, and cyanogenic glycosides, which may also produce biological actions. These compounds could also be responsible for the cardiovascular effects of flaxseed. This article will not only summarize the cardiovascular effects of dietary supplementation with flaxseed but also review its bioactive compounds in terms of their properties, biological effects, and proposed mechanisms of action. It will also discuss promising research directions for the future to identify additional health-related benefits of dietary flaxseed.

β-Adrenergic Blockers as Antiarrhythmic and Antifibrillatory Compounds: An Overview

β-Adrenergic blockers have a wide spectrum of action for controlling cardiac arrhythmias that is larger than initially thought. Data from the past several decades indicate that, as an antiarrhythmic class, β-blockers remain among the very few pharmacologic agents that reduce the incidence of sudden cardiac death, prolong survival, and ameliorate symptoms caused by arrhythmias in patients with cardiac disease. As a class of compounds, β-blockers have a fundamental pharmacologic property that attenuates the effects of competitive adrenergic receptors. However, the net clinical effects of the different β-receptor blockers may vary quantitatively because of variations in associated intrinsic sympathomimetic agonism and in their intrinsic potency for binding to β-receptors. These individual compounds also differ in their selectivity for β1- and β2-receptors. Metoprolol is a β1-selective blocker, whereas carvedilol is a nonselective β1- and β2-blocker, an antioxidant, and has a propensity to inhibit α1-receptors and endothelin. Evolving data from controlled and uncontrolled clinical trials suggest that there are clinically significant differences among this class of drugs. Recent evidence also suggests that the antiarrhythmic actions of certain β-receptor blockers such as carvedilol and metoprolol extend beyond the ventricular tissue to encompass atrial cells and help maintain sinus rhythm in patients with atrial fibrillation, especially in combination with potent antifibrillatory agents such as amiodarone. This introduction provides a current perspective on these newer developments in the understanding of the antiarrhythmic and antifibrillatory actions of β-blockers.

The effect of flaxseed powder on insulin resistance indices and blood pressure in prediabetic individuals: A randomized controlled clinical trial

BACKGROUND

Designing the effective and early interventions can prevent progression of prediabetes to diabetes. Few studies have shown the effect of flaxseed on glycemic control. This study aimed to assess the effect of flaxseed powder on insulin resistance (IR) indices and blood pressure in prediabetic individuals.

MATERIALS AND METHODS

In a randomized clinical trial, 99 prediabetic individuals were randomly divided into three groups: two groups received 40 g (FG40) and 20 g (FG20) flaxseed powder daily for 12 weeks and the third group was the control (CG). Before and after the intervention, anthropometric measurements, blood pressure, fasting serum glucose (FSG), insulin, homeostasis model assessment IR index (HOMA-IR), beta-cell function, and insulin sensitivity were measured.

RESULTS

FSG significantly declined overall in all groups compared to the baseline (P = 0.002 in CG and FG20 groups and P = 0.001 in FG40). In contrast, mean of the changes in FSG was not significantly different between groups. Insulin concentration did not change significantly within and between the investigated groups. Although HOMA-IR reduced in FG20 (P = 0.033), the mean of changes was not significant between the three groups. Mean of beta-cell function increased in CG and FG40 groups compared to the baseline (P = 0.044 and P = 0.018, respectively), but mean of its changes did not show any difference between the three groups. The mean of changes in IR indices was not significant between the three groups. FG40 group had significantly lowered systolic blood pressure after the intervention (P = 0.005).

CONCLUSION

Daily intake of flaxseed powder lowered blood pressure in prediabetes but did not improve glycemic and IR indices.

A review of the effect of omega-3 polyunsaturated fatty acids on blood triacylglycerol levels in normolipidemic and borderline hyperlipidemic individuals

Circulating levels of triacylglycerol (TG) is a recognized risk factor for developing cardiovascular disease, a leading cause of death worldwide. The Institute of Medicine and the American Heart Association both recommend the consumption of n-3 polyunsaturated fatty acids (PUFA), specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), to reduce serum TG in hyperlipidemic individuals. Additionally, a number of systematic reviews have shown that individuals with any degree of dyslipidemia, elevated serum TG and/or cholesterol, may benefit from a 20-30 % reduction in serum TG after consuming n-3 PUFA derived from marine sources. Given that individuals with serum lipid levels ranging from healthy to borderline dyslipidemic constitute a large portion of the population, the focus of this review was to assess the potential for n-3 PUFA consumption to reduce serum TG in such individuals. A total of 1341 studies were retrieved and 38 clinical intervention studies, assessing 2270 individuals, were identified for inclusion in the current review. In summary, a 9-26 % reduction in circulating TG was demonstrated in studies where ≥ 4 g/day of n-3 PUFA were consumed from either marine or EPA/DHA-enriched food sources, while a 4-51 % reduction was found in studies where 1–5 g/day of EPA and/or DHA was consumed through supplements. Overall, this review summarizes the current evidence with regards to the beneficial effect of n-3 PUFA on circulating TG levels in normolipidemic to borderline hyperlipidemic, otherwise healthy, individuals. Thus demonstrating that n-3 PUFA may play an important role in the maintenance of cardiovascular health and disease prevention.

Dietary flaxseed independently lowers circulating cholesterol and lowers it beyond the effects of cholesterol-lowering medications alone in patients with peripheral artery disease

BACKGROUND

Dietary flaxseed lowers cholesterol in healthy subjects with mild biomarkers of cardiovascular disease (CVD).

OBJECTIVE

The aim was to investigate the effects of dietary flaxseed on plasma cholesterol in a patient population with clinically significant CVD and in those administered cholesterol-lowering medications (CLMs), primarily statins.

METHODS

This double-blind, randomized, placebo-controlled trial examined the effects of a diet supplemented for 12 mo with foods that contained either 30 g of milled flaxseed [milled flaxseed treatment (FX) group; n = 58] or 30 g of whole wheat [placebo (PL) group; n = 52] in a patient population with peripheral artery disease (PAD). Plasma lipids were measured at 0, 1, 6, and 12 mo.

RESULTS

Dietary flaxseed in PAD patients resulted in a 15% reduction in circulating LDL cholesterol as early as 1 mo into the trial (P = 0.05). The concentration in the FX group (2.1 ± 0.10 mmol/L) tended to be less than in the PL group (2.5 ± 0.2 mmol/L) at 6 mo (P = 0.12), but not at 12 mo (P = 0.33). Total cholesterol also tended to be lower in the FX group than in the PL group at 1 mo (11%, P = 0.05) and 6 mo (11%, P = 0.07), but not at 12 mo (P = 0.24). In a subgroup of patients taking flaxseed and CLM (n = 36), LDL-cholesterol concentrations were lowered by 8.5% ± 3.0% compared with baseline after 12 mo. This differed from the PL + CLM subgroup (n = 26), which increased by 3.0% ± 4.4% (P = 0.030) to a final concentration of 2.2 ± 0.1 mmol/L.

CONCLUSIONS

Milled flaxseed lowers total and LDL cholesterol in patients with PAD and has additional LDL-cholesterol-lowering capabilities when used in conjunction with CLMs. This trial was registered at clinicaltrials.gov as NCT00781950.

Effects of dietary milled seed mixture on fatty acid status and inflammatory markers in patients on hemodialysis

BACKGROUND

Plant seeds have gained interest for their health benefits due to their fatty acid content. The objective of this study was to determine the effects of dietary consumption of milled sesame/pumpkin/flax seed mixture on glycemic control, serum lipids, phospholipid fatty acid status, and inflammatory factors in patients on hemodialysis.

METHODS

Thirty patients with well nutrition status (18 male, 12 female) were enrolled in the study. Participants consumed 30 g of milled sesame/pumpkin/flax (6 g/6 g/18 g, resp.) seeds mixture added to their habitual diet.

RESULTS

Total n-6 and n-3 polyunsaturated fatty acids and levels of linoleic, dihomo-gamma-linolenic (DGLA), arachidonic, alpha-linolenic (ALA), eicosapentaenoic, docosapentaenoic, and docosahexaenoic (DHA) acid were increased after 12 weeks of supplementation. A significant decrease of the serum triglyceride level (P < 0.001), glucose, insulin, calculated IR HOMA (P < 0.05), and inflammatory markers (TNF-alpha, IL-6, and hs-CRP, P < 0.001) was observed after seed mixture treatment. The serum levels of CRP and TNF-alpha negative correlate with ALA, DHA, and DGLA.

CONCLUSION

Results of this study indicated that dietary milled sesame/pumpkin/flax seed mixture added to a habitual diet lowered triglyceride and CRP, TNF-alpha, IL-6 levels, affect glycemic control and improved fatty acid profile and pruritus symptoms in hemodialysis patients.

Potent Antihypertensive Action of Dietary Flaxseed in Hypertensive Patients

Flaxseed contains ω-3 fatty acids, lignans, and fiber that together may provide benefits to patients with cardiovascular disease. Animal work identified that patients with peripheral artery disease may particularly benefit from dietary supplementation with flaxseed. Hypertension is commonly associated with peripheral artery disease. The purpose of the study was to examine the effects of daily ingestion of flaxseed on systolic (SBP) and diastolic blood pressure (DBP) in peripheral artery disease patients. In this prospective, double-blinded, placebo-controlled, randomized trial, patients (110 in total) ingested a variety of foods that contained 30 g of milled flaxseed or placebo each day over 6 months. Plasma levels of the ω-3 fatty acid α-linolenic acid and enterolignans increased 2- to 50-fold in the flaxseed-fed group but did not increase significantly in the placebo group. Patient body weights were not significantly different between the 2 groups at any time. SBP was ≈10 mm Hg lower, and DBP was ≈7 mm Hg lower in the flaxseed group compared with placebo after 6 months. Patients who entered the trial with a SBP ≥140 mm Hg at baseline obtained a significant reduction of 15 mm Hg in SBP and 7 mm Hg in DBP from flaxseed ingestion. The antihypertensive effect was achieved selectively in hypertensive patients. Circulating α-linolenic acid levels correlated with SBP and DBP, and lignan levels correlated with changes in DBP. In summary, flaxseed induced one of the most potent antihypertensive effects achieved by a dietary intervention.

The antiatherogenic, renal protective and immunomodulatory effects of purslane, pumpkin and flax seeds on hypercholesterolemic rats

BACKGROUND

Atherosclerosis remains one of the leading causes of death all over the world. Flax, pumpkin and purslane seeds are rich sources of unsaturated fatty acids, antioxidants and fibers, known to have antiatherogenic activities.

AIMS

This study was to examine the efficiency of using either flax/pumpkin or purslane/pumpkin seed mixture (components of ω-3 and ω-6) on hyperlipidemia, kidney function and as immunomodulators in rats fed high cholesterol diets.

MATERIALS AND METHODS

40 male albino rats were divided into four groups: control group, hypercholesterolemic rats, fed the balanced diet supplemented with cholesterol at a dose level of 2 g/100 g diet; the other two groups of animals fed the same previous hypercholesterolemic diet supplemented with either flax/pumpkin seed mixture or pumpkin/purslane seed mixture at ratio of (5/1) (ω-3 and ω-6).

RESULTS

The present study showed that 2% cholesterol administration caused a significant increase in total cholesterol, total lipids, and triacylglycerol in both serum and liver. Serum phospholipids, LDL-C, and atherogenic index AI also significantly increased compared to control group. Cholesterol-enriched diet significantly increased serum urea, creatinine, sodium and potassium levels as well as significantly increased serum IgG and IgM compared to healthy control. Consumption of flax/pumpkin or purslane/pumpkin seed mixtures by hypercholesterolemic rats resulted in a significantly decrement in lipid parameters and significant improvement in IgG and IgM levels as compared with hypercholesterolemic rats.

CONCLUSION

Our results suggests that both flax/pumpkin and purslane/pumpkin seed mixtures had anti-atherogenic hypolipidemic and immunmodulator effects which were probably mediated by unsaturated fatty acids (including alpha linolenic acid) present in seed mixture.

The cardiovascular effects of flaxseed and its omega-3 fatty acid, alpha-linolenic acid

Preventing the occurrence of cardiovascular disease (CVD) with nutritional interventions is a therapeutic strategy that may warrant greater research attention. The increased use of omega (&omega;)-3 fatty acids is a powerful example of one such nutritional strategy that may produce significant cardiovascular benefits. Marine food products have provided the traditional dietary sources of &omega;-3 fatty acids. Flaxseed is an alternative to marine products. It is one of the richest sources of the plant-based &omega;-3 fatty acid, alpha-linolenic acid (ALA). Based on the results of clinical trials, epidemiological investigations and experimental studies, ingestion of ALA has been suggested to have a positive impact on CVD. Because of its high ALA content, the use of flaxseed has been advocated to combat CVD. The purpose of the present review was to identify the known cardiovascular effects of flaxseed and ALA and, just as importantly, what is presently unknown.

Dietary milled flaxseed and flaxseed oil improve N-3 fatty acid status and do not affect glycemic control in individuals with well-controlled type 2 diabetes

OBJECTIVE

To determine the effects of dietary consumption of milled flaxseed or flaxseed oil on glycemic control, n-3 fatty acid status, anthropometrics, and adipokines in individuals with type 2 diabetes.

DESIGN

Thirty-four participants were randomized into a parallel, controlled trial.

SUBJECTS

The participants were adults with type 2 diabetes (age 52.4 +/- 1.5 years, body mass index 32.4 +/- 1.0 kg/m(2), n = 17 men and 17 women).

INTERVENTIONS

Participants consumed a selection of bakery products containing no flax (control group [CTL], n = 9), milled flaxseed (FXS, n = 13; 32 g/d), or flaxseed oil (FXO, n = 12; 13 g/d) daily for 12 weeks. The FXS and FXO groups received equivalent amounts of alpha-linolenic acid (ALA; 7.4 g/day).

MEASURES OF OUTCOME

The primary outcome measures were fasting plasma hemoglobin A(1c), glucose, insulin, and phospholipid fatty acid composition. The secondary outcome measures were fasting circulating leptin and adiponectin, as well as body weight, body mass index, and waist circumference. Dietary intake assessment and calculations for homeostasis model assessment for insulin resistance and quantified insulin sensitivity check were also completed.

RESULTS

The FXS and FXO groups had increases in plasma phospholipid n-3 fatty acids (ALA, eicosapentaenoic acid [EPA], or decosapentaenoic acid [DPA], but not docosahexaenoic acid), and the FXO group had more EPA and DPA in plasma phospholipids compared to the FXS group. All groups had similar caloric intakes; however, the CTL group experienced a 4% weight gain compared to baseline (p < 0.05), while both flax groups had constant body weights during the study period. All other parameters, including glycemic control, were unchanged by dietary treatment.

CONCLUSIONS

Milled FXS and FXO intake does not affect glycemic control in adults with well-controlled type 2 diabetes. Possible prevention of weight gain by flax consumption warrants further investigation.

Fatty acids and lignans in unground whole flaxseed and sesame seed are bioavailable but have minimal antioxidant and lipid-lowering effects in postmenopausal women

Fatty acids and lignans in ground flaxseed and sesame seed are absorbed, metabolized, and exert some health benefits in vivo. However, it is unclear if they are absorbed, metabolized, and exert health benefits when consumed as unground whole seed; therefore, it was investigated in this study. In a randomized crossover study, 16 postmenopausal women supplemented their diets with food bars containing either 25 g unground flaxseed, sesame seed, or their combination (12.5 g each) (flaxseed+sesame seed bar, FSB) for 4 wk each, separated by 4 wk washout periods. Total serum n-3 fatty acids increased with flaxseed (p<0.05) and FSB (p=0.064) while serum n-6 fatty acids increased with sesame seed (p<0.05). Urinary lignans increased similarly with all treatments (p<0.05). Plasma lipids and several antioxidant markers were unaffected by all treatments, except serum gamma-tocopherol (GT), which increased with both sesame seed (p<0.0001) and FSB (p<0.01). In conclusion, fatty acids and lignans from unground seed in food bars are absorbed and metabolized; however, except for serum GT, the 25 g unground seed is inadequate to induce changes in plasma lipids and several biomarkers of oxidative stress.

Dietary flaxseed lignan extract lowers plasma cholesterol and glucose concentrations in hypercholesterolaemic subjects

Lignans, derived from flaxseed, are phyto-oestrogens being increasingly studied for their health benefits. An 8-week, randomised, double-blind, placebo-controlled study was conducted in fifty-five hypercholesterolaemic subjects, using treatments of 0 (placebo), 300 or 600 mg/d of dietary secoisolariciresinol diglucoside (SDG) from flaxseed extract to determine the effect on plasma lipids and fasting glucose levels. Significant treatment effects were achieved (P < 0.05 to < 0.001) for the decrease of total cholesterol (TC), LDL-cholesterol (LDL-C) and glucose concentrations, as well as their percentage decrease from baseline. At weeks 6 and 8 in the 600 mg SDG group, the decreases of TC and LDL-C concentrations were in the range from 22.0 to 24.38 % respectively (all P < 0.005 compared with placebo). For the 300 mg SDG group, only significant differences from baseline were observed for decreases of TC and LDL-C. A substantial effect on lowering concentrations of fasting plasma glucose was also noted in the 600 mg SDG group at weeks 6 and 8, especially in the subjects with baseline glucose concentrations > or = 5.83 mmol/l (lowered 25.56 and 24.96 %; P = 0.015 and P = 0.012 compared with placebo, respectively). Plasma concentrations of secoisolariciresinol (SECO), enterodiol (ED) and enterolactone were all significantly raised in the groups supplemented with flaxseed lignan. The observed cholesterol-lowering values were correlated with the concentrations of plasma SECO and ED (r 0.128-0.302; P < 0.05 to < 0.001). In conclusion, dietary flaxseed lignan extract decreased plasma cholesterol and glucose concentrations in a dose-dependent manner.