14.10.4 In Rheumatoid Arthritis (RA)
Rheumatoid arthritis is an autoimmune chronic inflammatory disease characterised
by long-lasting pain and swelling in joints, connective tissues, muscle, tendons and
fibrous tissue. It is surprising to note that the people who have obesity, heart
diseases, diabetes or other chronic diseases are at a higher risk of developing
arthritis. In RA, the inflammation is mainly caused by the overproduction of AA
metabolites such as PGE2, PGH2, interleukins-2, TNF-α, cytokines and other
pro-inflammatory compounds. The overproduction of these pro-inflammatory eicosanoids could be due to excess consumption of LA-rich oils (regular vegetable oils),
suboptimal diet including processed foods and trans-fats, stress, inadequate physical
activity, etc. A number of clinical and animal studies have demonstrated that regular
consumption of omega-3 fatty acid-rich oils (marine and fish, flaxseed, chia seed and
walnut) and/or GLA-rich oils (borage, evening primrose, black currant) decreases
the prevalence of developing rheumatoid arthritis by producing anti-inflammatory
compounds (Dawczynski et al. 2011; Kast 2001; Reed et al. 2014; Belch and Hill
2000; Veselinovic et al. 2017; Vasiljevic et al. 2016; Labrousse et al. 2018;
Lindqvist et al. 2019). Dawczynski et al. (2011) conducted a double-blind, placebo-controlled parallel designed trial in which the patients having rheumatoid
(n ¼ 54) and/or psoriatic (n ¼ 6) arthritis were divided into four groups and given
omega-3 LC-PUFA (3 g) (group 1), 3 g GLA (group 2), 1.6 g omega-3 + 1.8 g GLA
(group 3) or 3 g olive oil (group 4: control) per day in the form of capsules for
12 weeks. Results displayed no significant (P < 0.05) change in AA/EPA ratio in
groups 2–4. However, group 1 showed a considerable ( p
0.001) decrease in
AA/EPA ratio from 6.5 Æ 3.7 to 2.7 Æ 2.1 in plasma lipids and from 25.1 Æ 10.1 to
7.2 Æ 4.7 in erythrocyte membranes, indicating a positive effect in arthritis patients.
Nonetheless, the other groups (2–4) exhibited no significant (P < 0.05) increase in
pro-inflammatory AA concentration in plasma lipids, cholesteryl esters and erythrocyte membranes, suggesting a possible positive effect PUFAs in chronic inflammatory diseases. Kast (2001) suggested the possible mechanism behind the
reduction of RA by GLA and/or borage oil. The dietary intake of GLA increases
the PE1 levels in blood, which in turn increases cAMP levels. cAMP is inversely
correlated with TNFα, a potent inflammatory metabolite (Kast 2001). In an
18-month randomised and double-blind trial, the efficacy of fish oil, borage oil
and combination of both was compared in RA patients. Though all the groups
significantly decreased the disease activity in patients, there was no significant
difference in changes in diseases activity among all the three groups (Reed et al.
2014). To study the effects of different drugs or nutraceuticals on RA, there are
several tests that should be examined such as Disease Activity Score 28 (DAS28),
visual analogue scale (VAS) (pain), erythrocyte sedimentation rate (ESR),
C-reactive protein (CRP) and other pro-inflammatory biomarkers. The DAS28 is a
measure of disease activity in RA, where 28 refers to the ‘28 joints’ that are
examined in this assessment (Vander Cruyssen et al. 2005). On the other hand,
visual analogue scale is a unidimensional measure of pain intensity in which
364
B. Tanwar et al.
Rheumatoid arthritis is an autoimmune chronic inflammatory disease characterised
by long-lasting pain and swelling in joints, connective tissues, muscle, tendons and
fibrous tissue. It is surprising to note that the people who have obesity, heart
diseases, diabetes or other chronic diseases are at a higher risk of developing
arthritis. In RA, the inflammation is mainly caused by the overproduction of AA
metabolites such as PGE2, PGH2, interleukins-2, TNF-α, cytokines and other
pro-inflammatory compounds. The overproduction of these pro-inflammatory eicosanoids could be due to excess consumption of LA-rich oils (regular vegetable oils),
suboptimal diet including processed foods and trans-fats, stress, inadequate physical
activity, etc. A number of clinical and animal studies have demonstrated that regular
consumption of omega-3 fatty acid-rich oils (marine and fish, flaxseed, chia seed and
walnut) and/or GLA-rich oils (borage, evening primrose, black currant) decreases
the prevalence of developing rheumatoid arthritis by producing anti-inflammatory
compounds (Dawczynski et al. 2011; Kast 2001; Reed et al. 2014; Belch and Hill
2000; Veselinovic et al. 2017; Vasiljevic et al. 2016; Labrousse et al. 2018;
Lindqvist et al. 2019). Dawczynski et al. (2011) conducted a double-blind, placebo-controlled parallel designed trial in which the patients having rheumatoid
(n ¼ 54) and/or psoriatic (n ¼ 6) arthritis were divided into four groups and given
omega-3 LC-PUFA (3 g) (group 1), 3 g GLA (group 2), 1.6 g omega-3 + 1.8 g GLA
(group 3) or 3 g olive oil (group 4: control) per day in the form of capsules for
12 weeks. Results displayed no significant (P < 0.05) change in AA/EPA ratio in
groups 2–4. However, group 1 showed a considerable ( p
0.001) decrease in
AA/EPA ratio from 6.5 Æ 3.7 to 2.7 Æ 2.1 in plasma lipids and from 25.1 Æ 10.1 to
7.2 Æ 4.7 in erythrocyte membranes, indicating a positive effect in arthritis patients.
Nonetheless, the other groups (2–4) exhibited no significant (P < 0.05) increase in
pro-inflammatory AA concentration in plasma lipids, cholesteryl esters and erythrocyte membranes, suggesting a possible positive effect PUFAs in chronic inflammatory diseases. Kast (2001) suggested the possible mechanism behind the
reduction of RA by GLA and/or borage oil. The dietary intake of GLA increases
the PE1 levels in blood, which in turn increases cAMP levels. cAMP is inversely
correlated with TNFα, a potent inflammatory metabolite (Kast 2001). In an
18-month randomised and double-blind trial, the efficacy of fish oil, borage oil
and combination of both was compared in RA patients. Though all the groups
significantly decreased the disease activity in patients, there was no significant
difference in changes in diseases activity among all the three groups (Reed et al.
2014). To study the effects of different drugs or nutraceuticals on RA, there are
several tests that should be examined such as Disease Activity Score 28 (DAS28),
visual analogue scale (VAS) (pain), erythrocyte sedimentation rate (ESR),
C-reactive protein (CRP) and other pro-inflammatory biomarkers. The DAS28 is a
measure of disease activity in RA, where 28 refers to the ‘28 joints’ that are
examined in this assessment (Vander Cruyssen et al. 2005). On the other hand,
visual analogue scale is a unidimensional measure of pain intensity in which
364
B. Tanwar et al.