A major review analysing 30 studies and nearly 10,000 cases of rheumatoid arthritis has revealed significant connections between diet and this common autoimmune condition.
The research, spanning from 2000 to 2024, offers new understanding of how specific foods and drinks influence arthritis risk.
In the UK, rheumatoid arthritis and osteoarthritis affect millions of people, with rheumatoid arthritis alone impacting half a million individuals.
While both conditions affect joints, they have distinct causes - rheumatoid arthritis occurs when the immune system mistakenly attacks healthy cells, while osteoarthritis develops through joint wear and tear.
Understanding this difference is crucial as research uncovers dietary factors that may help prevent these conditions.
Regular consumption of oily fish and adequate vitamin D intake demonstrate promising protective effects against rheumatoid arthritis development.
Notably, the research reveals a balanced approach is essential - moderate intake offers benefits, yet these advantages plateau or diminish with excessive consumption.
PhD researcher Yuanyuan Dong explains: "Rheumatoid arthritis is a typical multifactorial disease, driven by both genetic and environmental factors. My research investigates whether dietary factors contribute to the risk of rheumatoid arthritis by increasing inflammation and affecting the immune system."
The NHS provides clear guidelines for both oily fish and vitamin D intake. For oily fish, adults should aim for two portions of fish weekly, with at least one being oily fish like salmon, mackerel, sardines, or fresh tuna. A portion is approximately 140g. Women who are pregnant, breastfeeding, or planning pregnancy should limit oily fish to two portions weekly.
For vitamin D, adults should take 10 micrograms (400 IU) daily, particularly during autumn and winter months. Some groups, including those who spend limited time outdoors, live in care homes, usually cover their skin, or have darker skin tones, should consider year-round supplementation.
During spring and summer, most people can obtain adequate vitamin D through a combination of sunlight exposure and dietary sources.
The findings extend beyond rheumatoid arthritis, offering insights for osteoarthritis management as well. Despite their different causes, both conditions may benefit from similar dietary approaches:
Omega-3 fatty acids in oily fish provide anti-inflammatory benefits for both conditions
Vitamin D plays a crucial role in preventing progression of both types of arthritis
Antioxidants from fruits and vegetables help protect joints from oxidative stress
Weight management through diet proves especially important for osteoarthritis patients, as excess weight increases stress on weight-bearing joints
The evidence points to a protective role for fruits and cereals, including whole grains and breakfast cereals. This finding strengthens existing research on these food groups' importance in overall health maintenance.
In one surprising result, the research identified potential benefits from light alcohol consumption. Around two units of alcohol weekly - equivalent to one pint of lower-strength lager or one standard glass of wine - may offer protective effects.
Yet as Professor Janet Cade points out, these benefits come with clear limitations: "The protective effect diminished with higher intake, disappearing entirely at approximately 7.5 units of alcohol per week."
The research uncovered unexpected associations with daily beverages. Each additional daily cup of tea correlates with a four percent increased risk of developing rheumatoid arthritis.
The researchers emphasise that while this finding warrants attention, tea's baseline risk remains low and its other health benefits should be considered in context.
Similarly, coffee shows a less pronounced but notable association with increased risk, indicating a need for additional research to understand these relationships fully.
Moving beyond generic dietary advice, the research supports tailored nutritional guidance for individuals with autoimmune conditions.
As Professor Janet Cade notes: "This is a comprehensive study taking in the results of thirty different large-scale studies looking into the effects of diet on risk of developing rheumatoid arthritis. The results are promising, showing that by eating higher amounts of foods like oily fish, cereals, vegetables and the nutrient vitamin D, people may be able to lower their chances of developing this painful and debilitating condition."
1. What's the difference between rheumatoid arthritis and osteoarthritis?
Rheumatoid arthritis is an autoimmune condition where the body's immune system attacks the joints, while osteoarthritis is primarily caused by wear and tear of joint cartilage over time. They require different treatment approaches, though some dietary factors may help with both conditions.
2. How does diet influence rheumatoid arthritis risk?
According to the research, dietary factors may contribute to rheumatoid arthritis risk by influencing inflammation levels and affecting the immune system. The relationship is complex and involves multiple factors.
3. What specific foods should I include in my diet to reduce risk?
The research suggests including oily fish, cereals (including whole grains), fruits, and ensuring adequate vitamin D intake. However, it's important to maintain a balanced diet and consult healthcare professionals for personalised advice.
4. How much alcohol is considered moderate in terms of protective effects?
The research indicates that around two units per week (equivalent to one pint of lower-strength lager or one standard glass of wine) may offer protective benefits. However, these benefits disappear at approximately 7.5 units per week.
5. Should I stop drinking tea based on these findings?
No. While the study found a small increased risk associated with tea consumption, the baseline risk remains low. Tea offers numerous other health benefits that should be considered as part of your overall diet and lifestyle.
6. Can diet help with existing osteoarthritis?
While diet cannot reverse joint damage, it can help manage osteoarthritis by reducing inflammation, maintaining a healthy weight to reduce pressure on joints, and providing nutrients that support joint health. The omega-3 fatty acids in oily fish and antioxidants in fruits and vegetables may be particularly beneficial.
This article is for general information only and is not intended to treat or diagnose medical conditions. If in doubt please check with your GP first.
References:
Dose-Response Associations Between Diet and Risk of Rheumatoid Arthritis: A Meta-Analysis of Prospective Cohort Studies. Nutrients. 2024 Nov 26;16(23):4050. doi: 10.3390/nu16234050.
NHS Vitamin D -Vitamins and minerals nhs.uk/conditions/vitamins-and-minerals/vitamin-d/
NHS Fish and shellfish https://www.nhs.uk/live-well/eat-well/food-types/fish-and-shellfish-nutrition/
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