Comparison of the effects of flaxseed oil and sunflower seed oil consumption on serum glucose, lipid profile, blood pressure, and lipid peroxidation in patients with metabolic syndrome.

2018-01
Journal of clinical lipidology 12(1)
- Atefeh Akrami
- Farzad Nikaein
- Siavash Babajafari
- Shiva Faghih
- Hassan Yarmohammadi

PubMed: 29229363
DOI: 10.1016/j.jacl.2017.11.004

Study Design

Type: Randomized Controlled Trial (RCT)
Sample size: n = 60
Population: 60 volunteers aged 30 to 60 years who were diagnosed with MetSyn in Shiraz, Iran
Methods: Randomized controlled interventional trial; block randomization to SO (25 mL/d SO) and FO (25 mL/d FO) groups; identical diets; measurements at baseline and end of week 7
Duration: 7 weeks
Funding: Unclear

Background

Metabolic syndrome (MetSyn) increases the risk of type II diabetes and morbidity and mortality due to cardiovascular diseases. Flaxseed oil (FO), as a functional food, is one of the major vegetal sources of essential omega-3 fatty acids.

Objective

This study aimed to compare the effects of consumption of FO and sunflower seed oil (SO) on lipid peroxidation and other symptoms of MetSyn.

Methods

This randomized controlled interventional trial was conducted on 60 volunteers aged 30 to 60 years who were diagnosed with MetSyn in Shiraz, Iran. The participants who fulfilled the inclusion criteria were randomly assigned to SO (n = 30, receiving 25 mL/d SO) and FO (n = 30, receiving 25 ml/d FO) groups using block randomization. The diets were identical for all the participants. Blood pressure (BP), serum lipid, fasting blood sugar, and malondialdehyde were measured at baseline and at the end of week 7.

Result

The results showed no significant difference between the 2 groups regarding blood lipid levels and fasting blood sugar at the end of the study. However, significant reductions in total cholesterol, low-density lipoprotein cholesterol (5.6% in FO and 10.8% in SO), and triglyceride levels were seen within each group after treatment with FO and SO (P < .05). Nonetheless, between-group changes were significant (<0.05) for systolic BP (mean [±standard deviation {SD}] changes were -14.0 ± 22.41 in the FO group [P = .004] and 0.92 ± 8.70 in the SO group [P = .594]) and diastolic BP (mean [±SD] changes were -4.26 ± 7.44 in the FO group [P = .007] and 1.30 ± 6.91 in the SO group [P = .344]), but marginally significant (P = .053) for malondialdehyde level (mean [±SD] changes were -1.29 ± 1.48 in the FO group [P < .001] and -0.52 ± 1.34 in the SO group [P = .52]). A significant decrease in weight was also found in both groups. However, waist circumference decreased significantly only in the FO group at the end of the study (P < .05).

Conclusion

Our results indicated that dietary FO could be effective in amelioration of some symptoms of MetSyn and decrease BP and lipid peroxidation.

Research Insights

Flax→Reduced Blood Cholesterol
significant reductions in total cholesterol... were seen within each group after treatment with FO and SO (P < .05)
Effect
Beneficial
Effect size
Small
Dose
25 mL/day
Flax→Reduced Body Weight
A significant decrease in weight was also found in both groups.
Effect
Beneficial
Effect size
Small
Dose
25 mL/day
Flax→Reduced Diastolic Blood Pressure
between-group changes were significant (<0.05) for... diastolic BP (mean [±SD] changes were -4.26 ± 7.44 in the FO group [P = .007] and 1.30 ± 6.91 in the SO group [P = .344])
Effect
Beneficial
Effect size
Moderate
Dose
25 mL/day
Flax→Reduced Fasting Blood Glucose Levels
The results showed no significant difference between the 2 groups regarding blood lipid levels and fasting blood sugar at the end of the study.
Effect
Neutral
Effect size
Small
Dose
25 mL/day
Flax→Reduced Low-Density Lipoprotein Level
significant reductions in... low-density lipoprotein cholesterol (5.6% in FO and 10.8% in SO)... were seen within each group after treatment with FO and SO (P < .05)
Effect
Beneficial
Effect size
Small
Dose
25 mL/day
Flax→Reduced Malondialdehyde Level
marginally significant (P = .053) for malondialdehyde level (mean [±SD] changes were -1.29 ± 1.48 in the FO group [P < .001] and -0.52 ± 1.34 in the SO group [P = .52])
Effect
Neutral
Effect size
Small
Dose
25 mL/day
Flax→Reduced Systolic Blood Pressure
between-group changes were significant (<0.05) for systolic BP (mean [±standard deviation {SD}] changes were -14.0 ± 22.41 in the FO group [P = .004] and 0.92 ± 8.70 in the SO group [P = .594])
Effect
Beneficial
Effect size
Large
Dose
25 mL/day
Flax→Reduced Triglyceride Levels
significant reductions in... triglyceride levels were seen within each group after treatment with FO and SO (P < .05)
Effect
Beneficial
Effect size
Small
Dose
25 mL/day
Flax→Reduced Waist Circumference
waist circumference decreased significantly only in the FO group at the end of the study (P < .05)
Effect
Beneficial
Effect size
Small
Dose
25 mL/day