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FLAX FACTS FLAX FAVOURABLY AFFECTS…
Tags: biomarker, cell walls, chronic diseases, chronic inflammation, crp, diane h morris, dr diane, fat content, flax oil, foam cells, health study, immune cell, immune cells, inflammatory cytokines, nurses health, omega 3, rheumatoid arthritis, rich diet, walnut oil, wound healing,Pages: 2
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Created: Wed Nov 23 00:55:06 2005
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FLAX FACTS
FLAX FAVOURABLY AFFECTS THE IMMUNE SYSTEM
by Dr. Diane H. Morris
When immune cells switch to a chronic
SUMMARY inflammatory mode, they produce more cytokines and
Flax is rich in ALA, which has been shown to decrease inflam- CRP than are needed. The result is that healthy tissue
matory reactions in humans. Lignans have anti-inflammatory becomes inflamed. Indeed, chronic inflammation
effects in rats. has been said to result from the failure of normal
· ALA-rich diets increase the omega-3 fat content of cell wound healing.1
membranes and decrease the production of agents that
promote inflammation.
· ALA-rich diets decrease blood levels of CRP, a biomarker of
Chronic Inflammation and
inflammation and tissue damage. In a clinical study, CRP Chronic Disease
blood levels decreased 75% in volunteers who ate an ALA- Low-grade chronic inflammation is a feature of
rich diet containing a combination of walnuts, walnut oil, many chronic diseases. In atherosclerosis, for example,
and flax oil. In a cohort of women participating in the
TNF, IL-1, and IL-6 are released by macrophages
Nurses' Health Study, CRP levels in blood decreased as their
ALA intake increased.
(a type of immune cell) and foam cells found within
· Lignans decrease levels of pro-inflammatory cytokines like vascular cell walls.4 In rheumatoid arthritis, IL-1 and
TNF in rats. TNF are major pro-inflammatory cytokines found in
affected joints.1 In one study of 74 patients with
rheumatoid arthritis, blood concentrations of IL-1 and
Flax is rich in alpha-linolenic acid (ALA), the TNF were 5- and 15-fold greater, respectively, in
essential omega-3 fatty acid, and lignans, which are arthritis patients than in healthy adults.5
phytoestrogens. ALA and lignans modulate immune Obesity can also be viewed as a state of chronic
reactions and may play a beneficial role in the inflammation.2 The presence of excess adipose tissue,
prevention and management of atherosclerosis, particularly in the abdominal area, is marked by
obesity, the metabolic syndrome, and other chronic increased blood levels of CRP and also of TNF,
diseases in which chronic inflammation is a IL-6 and other pro-inflammatory cytokines.2,6,7 The
key feature. abundance of these cytokines in adipose tissue and
CRP in the bloodstream is believed to contribute to
Features of Chronic insulin resistance a major risk factor for type 2
Inflammation diabetes, hypertension, and blood lipid disorders, and
In healthy tissue there is a balance between possibly a risk factor for coronary heart disease.8-10
agents that promote inflammation and those that Indeed, even in a group of healthy Japanese men and
block it. When there is an infection or injury, the women, there was an association between CRP and
pro-inflammatory agents rally to eliminate the infection increased fasting insulin levels, fasting glucose levels,
or repair the injury and return the tissue to health. and insulin resistance.11
When health is restored after a few days or weeks, the
number of pro-inflammatory agents returns to normal. Flax Effects on the Immune
In some cases, however, the immune system switches System
from an acute mode to a chronic, low-grade Flax contains ALA and lignans, both of which
inflammation that can persist for months or years.1 decrease inflammatory reactions. New research
In both acute and chronic inflammation, immune provides insights on their anti-inflammatory effects.
cells release a variety of pro-inflammatory agents,
including cytokines such as tumor necrosis factor ALA. One way in which ALA influences immune
(TNF), interleukin-1 (IL-1), and interleukin-6 (IL-6). reactions is by changing the fatty acid composition of
These cytokines are part of a large network of cell membrane phospholipids. For example, in a clinical
signaling agents. One of their key actions is to study, the ALA content of red blood cell membranes
stimulate the release of C-reactive protein (CRP). increased 225%, and their content of eicosapentaenoic
CRP is an acute phase pro-inflammatory protein acid (EPA) increased 150%, in healthy men who ate a
formed mainly in the liver in response to acute injury, diet enriched with flax oil (about 2 tbsp daily or
infection, hypersensitivity reactions, inflammatory 15 g ALA/day) for 12 weeks.12
diseases, malignancy, and trauma. CRP is a sensitive This increased omega-3 fatty acid content of cell
biomarker of systemic inflammation and tissue membranes decreases the production of the cytokines
damage. It is strongly associated with atherosclerosis, TNF and IL-1. In a study of 28 healthy men, for
insulin resistance, and the metabolic syndrome.2,3 example, consuming flax oil (about 1 2/3 tbsp daily
providing 13.7 g ALA/day) for 4 weeks resulted in a References
decrease in TNF and IL-1 production of nearly
1. Burman A, et al. Joint Bone Spine. 2005;72:10-16.
30% in mononuclear cells (a type of immune cell).13
2. Wilson AM, et al. Int J Cardiol. 2005 (in press).
Diets rich in ALA have also been shown to decrease
3. Wannamethee SG, et al. Atherosclerosis. 2005;181:101-108.
the blood concentration of CRP. A clinical study
4. Getz GS. J Lipid Res. 2005;46:1-10.
conducted in 23 men and women with high blood
5. Dessein PH, et al. Arthritis Res Ther. 2005;7:R634-R643.
cholesterol found that serum CRP concentration
6. Kern PA, et al. J Clin Invest. 1995;95:2111-2119.
decreased 75% when the volunteers consumed an
7. Weisberg SP, et al. J Clin Invest. 2003;112:1796-1808.
ALA-enriched diet compared with when they
8. Lehrke M, et al. PLoS Med. 2004;1(2):e45 (available at
consumed an average American diet.14 Dietary ALA
www.plosmedicine.org).
was obtained by eating a combination of walnuts,
9. Licastro F, et al. Immunity Ageing. 2005;2:8 (18 May 2005)
walnut oil, and flax oil in this study. [The ALA-rich diet
(available at www.immunityageing.com).
provided about 17 g ALA/day, based on a 2,400 kcal
10. Rudin E, Barzilai N. Immunity Ageing. 2005;2:1
diet, and can be achieved by consuming roughly
(21 Jan 2005) (available at www.immunityageing.com).
2 tbsp flax oil daily.] The average American diet in this
11. Nakanishi N, et al. Intern Med. 2005;44:542-547.
study provided about 2 g of ALA per 2,400 kcal. In the
12. Wilkinson P, et al. Atherosclerosis. 2005;181:115-124.
Nurses' Health Study, ALA intake was inversely related
13. Caughey GE, et al. Am J Clin Nutr. 1996;63:116-122.
to plasma CRP concentrations.15
14. Zhao G, et al. J Nutr. 2004;134:2991-2997.
15. Lopez-Garcia E, et al. J Nutr. 2004;134:1806-1811.
Lignans. Lignans have been shown to decrease the
16. Jin D-Q, et al. Biochem Biophys Res Commun.
production of TNF and IL-6 in microglial cells of
2005;331:1264-1269.
rats.16 (Microglial cells are found in the brain.) The
17. Cleland LG, James MJ. In: Flax in Human Nutrition, 2nd ed.
anti-inflammatory effects of lignans have not been
Thompson LU, Cunnane SC, eds. Champaign, IL: AOCS
studied in humans.
Press, 2003, pp. 333-340.
Flax Has Favourable Effects on
the Immune System
Flax favourably influences immune reactions. ALA
and lignans block the release of pro-inflammatory
cytokines. ALA-rich diets decrease blood CRP levels.
Through these effects, flax consumption may help
prevent and treat disorders characterized in part by an
over-stimulated immune system. Such disorders include
atherosclerosis, obesity, the metabolic syndrome,
diabetes mellitus, rheumatoid arthritis, multiple
sclerosis and systemic lupus erythematosus.17
Flax Council of Canada, 465167 Lombard Ave., Winnipeg, MB, Canada R3B 0T6, E-mail: flax@flaxcouncil.ca Website: www.flaxcouncil.ca 11.2005ED11.05