According to the latest review, adopting a plant-based diet could well relieve the swollen joints and pain of rheumatoid arthritis (RA).
RA is autoimmune in origin, a painful joint disorder caused by inflammation of the joints, affecting 1 in 100 people all over the world. Both genetic predisposition and lifestyle factors participate in its etiology. The latter includes factors like infections, diet and the gut microbiome.
How does diet affect the joints? One theory is that dietary factors may reduce the strength of the intestinal barrier which allows food molecules to bacteria to breach the defenses and enter the blood stream. This produces an inflammatory response.
Another mechanism by which diet affects RA is the known fact that being overweight reduces the response of the body to RA medications and thus the chances of the disease becoming quiescent. For this reason, dietary modification could be important in managing RA.
Now a large review of trials as well as observational studies has concluded that a diet that primarily includes plants reduces the symptoms significantly and consistently.
Meet free grillsteak, made with Mycoprotein, in pepper coating. Image Credit: Bartosz Luczak / Shutterstock
How does a plant-based diet help?
Less inflammation: according to a study done in 2015, when people were assigned to a plant-based diet for two months, their scores for inflammation were lower compared to those who were eating more fat and animal products. One obvious reason is the ease with which dietary fat targets (≤30% energy from fat) can be achieved on a plant-based diet, since animal foods are rich in fat. Blood tests show higher levels of chemicals that are produced in inflammation, like C-reactive protein (CRP) and TNF-α, in high-fat diets or processed meat diets, but these are lower on diets rich in plant-based fiber-containing diets.
Less pain and swelling with RA: one trial randomly assigned people with RA of moderate to severe intensity to a low-fat vegan diet, and in just four weeks the results showed that they enjoyed a significant lessening of morning stiffness, pain, tenderness and swelling in the joints. The authors of the trial also suggested that the low fat and high fiber content of a diet based primarily on plants leads to reduced pain and swelling, along with reduced CRP and inflammation.
Reduced BMI: people who are overweight are at increased risk for RA and are less likely to go into remission. The presence of too much fat inside cells causes higher rates of inflammation. The extra weight on the weight-bearing joints also worsens the inflammation in these sites. On the other hand, in 2018 a study showed that among RA patients, a body weight loss of over 5 kg pushed up the chances of symptomatic improvement by three times or more, compared to those who lost less than this. People on plant-based diets are much more likely to lose weight. Another study showed a 50% risk of RA by adult age if the individual was overweight at 18 years. Thus, weight loss could stabilize hormonal and fat-related disruptions of immune function. Weight loss is effectively achieved on plant-based diets.
Healthy gut microbiome: the microbial ecosystem in the human gut play a key role in health and disease. It is also responsive to significant changes in the composition of the diet, showing altered numbers of different species as the proportion of plant-based and animal-based foods changes. A diet which is rich in plants and fiber leads to a higher proportion of certain species, and also increases the overall number of species (called “diversity”). This is often low in patients with RA, and the change may favor a reduction in RA and inflammation. On the other hand, dietary fiber is broken down by gut microbes to yield many beneficial products, including short-chain fatty acids (SCFAs) which help maintain the health of intestinal cells.
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Along with atopy, food sensitivities to both plant and animal food antigens are problematic in RA patients, and eliminating these in favor of elemental diets has been shown to produce a marked favorable change which disappears once normal diet is resumed.
Researcher Hana Kahleova says, “This study offers hope that with a simple menu change, joint pain, swelling, and other painful symptoms may improve or even disappear. A plant-based diet comprised of fruits, vegetables, grains, and legumes may be tremendously helpful for those with rheumatoid arthritis.”
And this is not all: a plant-based diet could also prevent thyroid dysfunction, multiple sclerosis and an overactive thyroid.
The research is published in the journal Frontier in Nutrution.
Nutrition Interventions in Rheumatoid Arthritis: The Potential Use of Plant-Based Diets. A Review. Jihad Alwarith, Hana Kahleova, Emilie Rembert, Willy Yonas, Sara Dort, Manuel Calcagno, Nora Burgess, Lee Crosby and Neal D. Barnard. Frontiers in Nutrition. https://www.frontiersin.org/articles/10.3389/fnut.2019.00141/full