Flaxseed ( Linum usitatissimum L.) is composed mainly of bioactive components such as polyphenols, polyunsaturated fatty acids, fiber and lignans. Flaxseed can be found in different presentation forms (grain or flour) and varieties (brown or golden); however, questions have arisen as to whether the presentation form and/or variety may influence the health effects. The objective of this study was to evaluate the effects on blood pressure, anthropometric and oxidative parameters in healthy human volunteers. All subjects received 40 gram aliquots of flaxseed and were instructed to consume them in their entirety mixed with water in the morning for a period of 14 days. Oxidative parameters showed significant reductions (p < 0.05) in oxidative damage to lipids and proteins via dietary intervention with golden flaxseed grains. There were no significant differences in anthropometric parameters, blood pressure, DNA damage and micronuclei frequency after 14-day supplementation. This research indicates that golden flaxseed grains can be a valuable adjunct for disease prevention and protecting the organism against oxidative damage.
Flaxseed (Linum usitatissimum L.) is a functional food that has been studied extensively because of its antioxidant properties, its ability to lower blood lipid levels, and its potential effects on cardiovascular disease (CVD) risk reduction, mainly due to its high content of polyunsaturated fatty acids (mainly alpha-linolenic acid), soluble fiber and lignans [
All reagents were purchased from Sigma Chemical Co. (St. Louis, MO, USA).
Brown and golden flaxseed were obtained from Cerélus Company (Ijuí, State Rio Grande do Sul, Brazil) on February of 2012.
Group/Compound | Brown Flaxseed (in 40 g meal) | Golden Flaxseed (in 40 g meal) |
---|---|---|
Energetic Value (Kcal) | 216.0 | 188.0 |
Carbohydrates (g) | 12.0 | 13.2 |
Protein (g) | 10.4 | 8.0 |
Total Fat (g) | 14.0 | 13.2 |
Saturated Fat (g) | 0.0 | 1.36 |
Trans Fat (g) | 0.0 | 0.0 |
Monounsaturated Fat (g) | 3.2 | 3.2 |
Polyunsaturated Fat (g) | 8.56 | 8.56 |
Cholesterol (g) | 0.0 | 0.0 |
Alimentary Fiber (g) | 5.6 | 10.8 |
Omega―3 (g) | 7.6 | 6.8 |
Omega―6 (g) | 2.0 | 2.0 |
Omega―9 (g) | 2.4 | 3.2 |
Sodium (mg) | 0.0 | 0.0 |
Magnesium (mg) | 120.0 | 148.0 |
Phosphorus (mg) | 280.0 | 200.0 |
Iron (mg) | 7.2 | 2.40 |
Brown and golden flaxseeds were macerated in ethanol-water (70:30 v/v) in the dark and at room temperature for 7 days with daily agitation prior to a phytochemical analysis. Our testes included the determination of total polyphenolic content [
Sixty non-smoking individuals of both sexes, between the ages of 17 and 34 years, were recruited at Uruguaiana and enrolled in the study between March 2012 and April 2012. Participants had to not have hypertension, not be on regular medication, use no antioxidant or mineral supplementation and have no previous history of stroke, myocardial infarction, angina, diabetes mellitus, cancer or any illness that had required hospitalization during the previous 12 months. Female volunteers were excluded if pregnant, lactating or on hormone replacement therapy. At the end of the study, a total of fifty-four individuals remained.
This study, (Protocol N˚. 069/2011), was approved by CEP of Unipampa. All participants signed a consent form.
Sixty participants were randomly assigned into one of five independents groups: control group (without supplementation), brown flaxseed (flour or grain) and golden flaxseed (flour or grain) supplementation groups. The control group comprised twelve individuals, who maintained regular diets and received no supplementation. The purpose of this group was to eliminate laboratory abnormalities unrelated to the experimental protocol. The others groups received 40 gram aliquots [
At the beginning of the study, all participants had their height measured. The weights were evaluated at the beginning and end of test period. BMI was calculated using the equation BMI = weight (kg)/height2 (m2). Blood pressure was checked from the right arm with the participant seated, after a 4 - 5 minutes rest by a person trained to carry out the process in a reproducible way. We use a digital manometer to perform these measures.
Fasting blood samples were taken at day “0” and day “14”, always between 7:00 and 9:00 a.m. Blood was drawn from the antecubital vein into prechilled tubes containing EDTA and Li-heparin and tubes without anticoagulant (Vacutainer-Becton, Dickinson and Company. Trenton, NJ, USA). The blood in tubes without anticoagulant stays at room temperature for 30 minutes to clot. The plasma and serum were obtained after centrifugation of blood samples at 1500 ×g for 10 min and analyzed immediately.
The oxidative parameters such as lipid peroxidation [
Data were expressed as mean ± standard deviation (SD). Comparisons between groups were performed using a two-way analysis of variance (ANOVA), followed by a post-hoc Bonferroni for multiple comparison tests. Results were considered statistically significant when p < 0.05.
Group | Brown Flaxseed Flour* | Brown Flaxseed Grain* | Golden Flaxseed Flour* | Golden Flaxseed Grain* |
---|---|---|---|---|
Polyphenol | 15970 ± 912 | 15940 ± 863 | 10550 ± 749 | 10560 ± 839 |
Total flavonoids | 5050 ± 434 | 13360 ± 748 | 6234 ± 673 | 9740 ± 642 |
*In µg/g of flaxseed. Data from the preparations are expressed as means ± S.D (n = 3).
Parameters | Control Group | Brown Flaxseed Flour | Brown Flaxseed Grain | Golden Flaxseed Flour | Golden Flaxseed Grain | |||||
---|---|---|---|---|---|---|---|---|---|---|
Day 0 | Day 14 | Day 0 | Day 14 | Day 0 | Day 14 | Day 0 | Day 14 | Day 0 | Day 14 | |
Total Volunteers | 12 volunteers | 8 volunteers | 12 volunteers | 10 volunteers | 12 volunteers | |||||
Male Volunteers | 7 | 3 | 6 | 4 | 5 | |||||
Female Volunteers | 5 | 5 | 6 | 6 | 7 | |||||
Medium Age (in Years) | 23 years (17 - 32 years) | 24 years (17 - 33 years) | 23 years (18 - 32 years) | 23 years (17 - 34 years) | 26 years (18 - 33 years) | |||||
Body Mass Index (BMI, in Kg/m2) | 23.74 ± 4.00 | 23.26 ± 4.35 | 23.09 ± 2.33 | 23.16 ± 2.21 | 24.39 ± 5.67 | 24.27 ± 5.46 | 22.89 ± 4.54 | 23.06 ± 4.49 | 23.62 ± 4.15 | 23.58 ± 4.07 |
Systolic Pressure (in mmHg) | 129.00 ± 15.81 | 126.05 ± 10.73 | 131.3 ± 17.27 | 121.3 ± 15.53 | 126.7 ± 14.35 | 115.8 ± 10.84 | 128.8 ± 9.91 | 126.0 ± 11.74 | 123.3 ± 1.55 | 114.2 ± 15.64 |
Diastolic Pressure (in mmHg) | 84.17 ± 11.81 | 80.97 ± 8.74 | 85.00 ± 13.78 | 81.26 ± 11.26 | 83.33 ± 9.84 | 74.17 ± 7.93 | 84.44 ± 8.81 | 83.33 ± 10.00 | 77.50 ± 8.66 | 69.17 ± 7.93 |
Data are expressed as means ± S.D. In all parameter evaluated, there were no statistically different results in the column.
der of 44.37% ± 16.6% and 54.88% ± 20.8% respectively. Similar result was not observed in the ingestion of brown or golden flaxseed flour (
Epidemiologic and clinical evidence supports the beneficial effect of flaxseed consumption in adult individuals. To our knowledge, no study to date has compared the presentation forms (grain or flour) while examining the metabolic effects of the intake of brown and golden flaxseed in healthy volunteers. In this study, the participants’ blood pressure and BMI were within the normal range for healthy people, according to Stahl et al. [
Oxidative stress is a condition resulting from an imbalance between production and inactivation of reactive oxygen species (ROS) and it plays an important role in the pathogenesis of several diseases [
Lipid peroxidation is a complex process that involves the interaction of ROS with polyunsaturated fatty acids of cell membranes, resulting in the formation of hydro or lipoperoxides, which are highly reactive and can initiate an oxidative cascade, with severe damage to the integrity of the membrane [
In agreement with these findings, a study by Prasad [
The oxidative modifications of proteins caused by ROS primarily affect amino acid side chains and carbonyl group formation is one product of these modifications [
In addition to lipid and protein oxidation, reactive species can also cause DNA damage. The impacts include damage and fragmentation of the DNA bases and, if not repaired, may lead to chromosomal mutations that disrupt the normal gene expression and create abnormal proteins that are detrimental to cell viability and cellular function [
Studies have shown that diets rich in antioxidants can protect against oxidative damage to lipids, proteins and nucleic acids [
Humans have several antioxidant defense systems that all operate differently in the detoxification of reactive species. Among them, the antioxidant enzyme system appears to be the main way of removing reactive species formed during intracellular metabolism [
In conclusion, this study showed that golden flaxseed grains are more effective in reducing oxidative parameters even in a short supplementation period.
The results indicate that markers of oxidative damage such as lipid peroxidation and carbonyl protein content dropped significantly with supplementation of golden flaxseed grains. Therefore, even a short supplementation period (2 weeks) with golden flaxseed grains can be an important cofactor in the prevention of diseases that are based on the production of free radicals.
LuísaZuravski,Ritiele PintoCoelho,Jonathaline ApolloDuarte,Manoelly OliveiraRocha,JulianaMezzomo,Bruna CoccoPilar,Leandro LealGalarça,Margareth LindeAthayde,Aline AugustiBoligon,Michel MansurMachado,VanusaManfredini, (2015) Protective Role of Golden Flaxseed (Linum usitatissimum L.) Against Oxidative Damage in Lipids and Proteins of Healthy Volunteers. Journal of Biosciences and Medicines,03,45-53. doi: 10.4236/jbm.2015.310006