Xiaomei Yu
[email protected]
1
Tao Huang
Xiumei Weng
1
Tianxing Shou
0
Qiang Wang
1
Xiaoqiong Zhou
1
Qinxin Hu
1
Duo Li
[email protected]
0
0
Department of Food Science and Nutrition, Zhejiang University
,
866 Yuhangtang Road, Hangzhou 310059
,
China
1
Department of Clinical Laboratory, Zhejiang Hospital
,
12 Linyin Road, Hangzhou 310030
,
China
Background: Polyunsaturated fatty acid (PUFA) intake favorably affects chronic inflammatory-related diseases such as cardiovascular disease; however, the relationship between the PUFA and inflammatory factors in the healthy vegetarians were not clear. We aimed to investigate the plasma fatty acids status, and its association with plasma inflammatory factors in Chinese vegetarians and omnivores. Methods: A total of 89 male vegetarians and 106 male omnivores were participated the study. Plasma concentrations of inflammatory factors were detected by ELISA, and as standard methods fatty acids were extracted and determined by chromatography. Results: Compared with omnivores, vegetarians have significant higher interleukin-6 (IL-6), plasma n-6 PUFA, n-6/n-3, and 18:3n-3; while they have significant lower leukotriene B4 (LTB4), cyclo-oxygenase-2 (COX2) and prostaglandin E2 (PGE2), 20:5n-3, 22:5n-3, 22:6n-3, and n-3 PUFA. In vegetarians, plasma 20:4n-6 was significant positively related to TNF-. LTB4 was significantly positively related to plasma 22:6n-3, and negatively associated with n-6 PUFA. Conclusion: Vegetarians have higher plasma n-6 PUFA and IL-6, but lower LTB4, n-3 PUFA, 22:6n-3, COX2 and PGE2 levels. It would seem appropriate for vegetarians to increase their dietary n-3 PUFA, while reduce dietary n-6 PUFA and thus reduce the risk of chronic inflammatory-related diseases.
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Introduction
It is widely recognized that overall mortality, ischemic
heart disease mortality and overall cancer incidence are
lower in vegetarians compared with omnivores [1,2]. The
dietary patterns of vegetarians as well as their healthful
lifestyle practices are thought to at least partly explain
these differences. Vegetarian diets are rich in fiber,
magnesium, Fe3+, folic acid, vitamins C and E, n-6
polyunsaturated fatty acid (PUFA), phytochemicals, and antioxidants
[3]. Another notable difference relates to the type and
amount of fat in the diet. Vegetarian diets are slightly
lower in total fat than omnivorous diets [4,5]. Low intake
of total fat, saturated fatty acids (SFA), and sodium and
high intake of fiber, phytochemicals, and antioxidants in
vegetarians is associated with low blood pressure and body
mass index [3].
However, vegetarians diets are low in sodium, zinc, Fe2+,
vitamins A, vitamins B12, and D, and n-3 polyunsaturated
fatty acid (PUFA) [3,6]. With respect to intake of essential
fatty acid, especially n-3 PUFA, vegetarian diets appear to
offer no advantages over omnivorous dietary patterns. It
has been suggested that vegetarians could be at a
significant disadvantage, as consumption of -linolenic acid
(18:3n-3) islow, resulting in limited conversion of 18:3n-3
to eicosapentaenoic acid (20:5n-3) and docosahexaenoic
acid (22:6n-3) [7]. In addition, ovolacto vegetarian could
get limited amount of 20:5n-3 and 22:6n-3, however,
vegan diet almost has no 20:5n-3 and 22:6n-3, they may
get tiny amount from algae and seaweed [4].
Eicosanoids, which are the mediators and regulators of
inflammation, are generated from 20-carbon PUFA.
Because inflammatory cells typically contain a high
proportion of the n-6 PUFA arachidonic acid (20:4n-6) and low
proportions of other 20-carbon PUFA [8], 20:4n-6 is a
substrate of 2- and 4-series eicosanoids, which are
associated with inflammation. Many anti-inflammatory
pharmacotherapies are directed at inhibiting the production
of these inflammatory mediators and thus possibilities
exist for therapies that incorporate n-3 PUFA [9]. High
level of n-3 PUFA in the diet can suppress the
production of both tumor necrosis factor (TNF-) and
interleukin 1 (IL-1) [10]. Dietary supplementation with
encapsulated fish oil rich in 20:5n-3 and 22:6n-3 has
been shown to result in decreased synthesis of TNF-
and interleukin-1 (IL-1) monocyte by in healthy
subjects [10].
To date, no study reported the relationship of plasma
fatty acids with blood inflammatory factors in Chinese
vegetarians. Therefore, the purpose of the present study
was to investigate the status of plasma fatty acids and to
examine the potential relationship between fatty acids
and plasma inflammatory factors in Chinese vegetarians
and omnivores.
Materials and methods
Subjects
The study protocol was approved by the Ethics
Committee, Zhejiang Hospital, Hangzhou, China, and all
subjects were volunteers who gave their written consent
prior to participation in the study. A total of 89 male
vegetarians (aged 35.39 12.2 year) were recruited in
Linyin Temple, Hangzhou, China. A vegetarian was
defined as someone who ate no red meat, fish and chicken,
and had been following this diet for at least (...truncated)