魚油與關節炎

17/5/12的分享日誌中談及魚油和關節炎的關係:

再談經濟日報5月3日有關魚油丸的報道「稱治敏感關節炎 無科學證據」

香港營養學會會長丁浩恩表示，魚油主要有兩種功能，包括減少血管發炎及降低三脂肝酸，有助心臟病和中風病人減少復發機會，這些都有足夠的臨床研究結果支持，但部分魚油亦聲稱可治療關節炎和敏感等問題，則沒足夠證據支持．

標題是無科學證據，但內文是沒足夠證據支持．問題是多少才是足夠．其實科學界也有強烈主觀成份，一些藥明明對身體有害，卻不理其足夠證據，讓病人服用（如荷爾蒙補充劑），一些食品有初步證據顯示有幫助效果（但不是治療效果），小心服用應該有幫助，卻被西方醫療界反對．

較早前和一位學員談及他的類風濕關節炎，我從顧小培資料庫及pubmed找不同資料給他，他服用後有明顯進展．從pubmed找到幾份關於魚油及關節炎的醫療研究報告，起碼有初步證據支持，值得更全面研究．對於大受困擾的病友，應了解可能風險及效益，作出抉擇．現抄下四份研究部分內容：

（一）Fish-Oil Fatty Acid Supplementation in Active Rheumatoid Arthritis

A Double-Blinded, Controlled, Crossover Study

Study Objective: To determine the efficacy of fish-oil dietary supplements in active rheumatoid arthritis and their effect on neutrophil leukotriene levels.

Conclusions: Fish-oil ingestion results in subjective alleviation of active rheumatoid arthritis and reduction in neutrophil leukotriene B4 production. Further studies are needed to elucidate mechanisms of action and optimal dose and duration of fish-oil supplementation.

（二）JPEN J Parenter Enteral Nutr. 2010 Mar-Apr;34(2):151-5.

omega-3 Fatty acids infusions as adjuvant therapy in rheumatoid arthritis.

Bahadori B, Uitz E, Thonhofer R, Trummer M, Pestemer-Lach I, McCarty M, Krejs GJ.

BACKGROUND:

The present study investigated the efficacy and safety of parenteral omega-3 fatty acids (omega-3 FA) in patients with active rheumatoid arthritis (RA).

RESULTS:

At baseline, both swollen and tender joint counts were not significantly different between patients in the treatment and placebo groups. Twenty patients completed the infusion portion of the study, and 13 completed the oral portion. Swollen joint count was significantly lower in the omega-3 FA group compared with the placebo group after 1 week of infusion (P = .002) as well as after 2 weeks of infusion (P = .046). Tender joint count also tended to be lower in the omega-3 FA group, although this did not reach statistical significance. Both swollen and tender joint counts were significantly lower in the omega-3 FA group compared with the placebo group during and at the end of oral treatment.

CONCLUSION:

Our pilot study indicates that parenteral omega-3 FAs are well tolerated and improve clinical symptoms of RA. Subsequent oral administration of omega-3 FAs may prolong the beneficial effects of the infusion therapy. These results warrant validation in larger multicenter studies.

（三）　Proc Nutr Soc. 2010 Aug;69(3):316-23. Epub 2010 May 28.

Fish oil and rheumatoid arthritis: past, present and future.

Meta- and mega-analysis of randomised controlled trials indicate reduction in tender joint counts and decreased use of non-steroidal anti-inflammatory drugs with fish-oil supplementation in long-standing rheumatoid arthritis (RA). Since non-steroidal anti-inflammatory drugs confer cardiovascular risk and there is increased cardiovascular mortality in RA, an additional benefit of fish oil in RA may be reduced cardiovascular risk via direct mechanisms and decreased non-steroidal anti-inflammatory drug use. Potential mechanisms for anti-inflammatory effects of fish oil include inhibition of inflammatory mediators (eicosanoids and cytokines), and provision of substrates for synthesis of lipid suppressors of inflammation (resolvins). Future studies need progress in clinical trial design and need to shift from long-standing disease to examination of recent-onset RA. We are addressing these issues in a current randomised controlled trial of fish oil in recent-onset RA, where the aim is to intervene before joint damage has occurred. Unlike previous studies, the trial occurs on a background of drug regimens determined by an algorithm that is responsive to disease activity and drug intolerance. This allows drug use to be an outcome measure whereas in previous trial designs, clinical need to alter drug use was a 'problem'. Despite evidence for efficacy and plausible biological mechanisms, the limited clinical use of fish oil indicates there are barriers to its use. These probably include the pharmaceutical dominance of RA therapies and the perception that fish oil has relatively modest effects. However, when collateral benefits of fish oil are included within efficacy, the argument for its adjunctive use in RA is strong.

（四）Complement Ther Med. 2010 Jun-Aug;18(3-4):171-4.

Fish oil supplementation increases the cyclooxygenase inhibitory activity of paracetamol in rheumatoid arthritis patients.

OBJECTIVE:

To examine interactions between fish oil and paracetamol for inhibition of prostaglandin synthesis in patients with rheumatoid arthritis (RA).

METHODS:

Patients from an early RA clinic who were treated with a standardized combination DMARD regimen were enrolled. They were advised to consume an anti-inflammatory dose of fish oil containing the n-3 fatty acid, eicosapentaenoic acid (EPA), or a comparator oil. High EPA and Low EPA groups were defined by blood EPA levels >3.5% or <2%, respectively, of plasma phospholipid fatty acids. Participants provided a blood sample before, and 1h after ingestion of 1g paracetamol. The blood was incubated in different ways to allow measurement of COX-2 generated prostaglandin E(2) (PGE(2)) and COX-1 generated thromboxane A(2) (TXA(2)).

RESULTS:

Paracetamol suppressed the eicosanoid measures of COX-1 and COX-2 activities and the suppression was greater in the High EPA group. The results indicate that the combination of fish oil and paracetamol suppresses PGE(2) synthesis by an amount equivalent to that from maximum therapeutic doses of NSAIDs.

CONCLUSION:

Paracetamol is recommended for first-line use ahead of NSAIDs for symptom relief in RA or OA. Combining paracetamol with fish oil will enhance suppression of nociceptive PGE(2) synthesis and thereby may provide additive symptomatic benefits.