Introduction
Obesity is one of the most important inflammatory diseases and its
prevalence is increasing across the world
(1). Obesity and overweight are associated
with increased risk of several chronic disorders, and certain types of
cancers (2).
It has been found that expression and secretion of adiponectin within
the adipose tissue decreases in obese individuals
(7). Adiponectin is the most prevalent
adipokine which has beneficial effects on metabolism, fatty acids
catabolism, low density lipoprotein cholesterol (LDL-C) oxidation,
insulin sensitivity and suppression of inflammation
(5, 6).
Moreover, leptin has a energy balance regulation role, various hormonal
functions as well as highly correlated to body fat
mass(8).
Flaxseed or linseed (Linum usitatissimum L. seed) known as a
functional food contains healthy components such as alpha linolenic acid
(ALA), lignans, dietary fibers and a variety of antioxidants and
phytoestrogens (12,
13).
Flaxseed lignans has numerous health benefits. For instance, it can
regulate expression and secretion of adipokines such as adiponectin and
leptin (14-17). It has been shown that
ALA has anti-inflammatory, antithrombotic and anti-arrhythmic effects
(16, 18,
19). ALA can deposit in adipose tissue
where it may affect adipose tissue function and adipokine secretion
(7). Besides ALA, flaxseed is a rich
source of phytoestrogens (lignan) with potential benefits including
cardio-protective and endocrine regulation effects
(20, 21).
These components are proposed to modify blood lipids levels mainly
through regulating the gene expression of enzymes involved in the fatty
acids metabolism (22-24). Previous
studies in experimental models found an attenuating effect of flaxseed
supplementation on serum lipids abnormalities and adiponectin and leptin
secretion (25-28). However, the findings
from clinical trials are conflicting(29,
30).
Therefore, in order to find the
beneficial effects of whole flaxseed supplementation as an adjunct
therapy to balanced diet on serum adipokines, body weight, Waist
Circumference (WC) and lipid levels, we conducted the present trial on
overweight or obese women.