Diet and joint symptoms: A survey of Moroccan patients with osteoarthritis

Introduction. Patients with osteoarthritis not only ask about the impact of weight on their symptoms, but also the impact of food. This includes foods that are described as either inflammatory or anti-inflammatory. The aim of our study was to investigate the possible relationship between food and osteoarthritis symptoms. Methods. The study was based on a questionnaire and it was conducted on patients undergoing osteoarthritis treatment in our department between February and September 2022. Results. We included 322 patients with a mean age of 59.57 ± 10.71, of whom 72.9% were women. The median duration of osteoarthritis was 4 years [2-10]. Only 7.9% reported that food affected their symptoms, with 4.4% experiencing improvement and 3.5% experiencing aggravation. The foods most often cited as improving joint symptoms were fish (1.2%), ginger (1.2%), and olive oil (1.2%), while red meat (1.2%) and soda (0.9%) were the most often cited as worsening symptoms. Approximately 2.2% of the patients exhibited food avoidance behaviors, while 3.7% adhered to specific diets and 1.3% tried fasting to alleviate joint symptoms. In this multivariate analysis, we suggest that certain diet practices have an impact on osteoarthritis symptoms. Conclusion . Our study found that only a minority of patients reported associations between some types of food and worsening or improving joint symptoms.


INTRODUCTION
Poor diet, physical inactivity, and obesity are now known to be associated with multiple comorbidities, including diabetes, cardiovascular disease, and chronic musculoskeletal conditions, including osteoarthritis [1,2].An 18-month randomized controlled trial (RCT) showed that a reduction of at least 10% in body mass through diet, exercise, or a combination of both, improved pain and physical function in 454 elderly people with knee osteoarthritis [3].Not surprisingly, weight loss through appropriate diet improves health in people with osteoarthritis.However, difficult, controversial, and topical questions remain about the possible influence of specific foods on osteoarthritis symptoms [4][5][6].
Despite advances in our understanding of the physiopathology of osteoarthritis, which is considered a major cause of morbidity and disability worldwide [7], no treatment has yet proven effective in the prevention, cure, or slowing of its progression.Long-term use of pharmacological agents, such as anti-inflammatory medications, has potential adverse effects that can lead to serious consequences, including gastrointestinal bleeding and adverse cardiac effects [8,9].Current pharmacological therapies for osteoarthritis (OA) provide only palliative benefits because they do not address the underlying cause of cartilage degradation.Supplements containing nutrients such as chondroitin and glucosamine have been used to treat and alleviate the symptoms of osteoarthritis.However, there is currently insufficient evidence to support their effectiveness in treating OA.Therefore, we can only recommend medication to alleviate pain.In response to this pharmacological limitation, many observational and interventional studies have explored the potential of 'nutritional therapy'.Several studies suggest that diet may impact OA symptoms [10][11][12][13].
We conducted a cross-sectional study to investigate whether Moroccan patients report a relationship between certain foods and joint symptoms of osteoarthritis and to identify different types of foods that may increase or decrease symptoms, which could form a basis for nutrition strategies in the management of patients suffering from OA in the future.

Study design
This is a cross-sectional study, conducted at the University Hospital of Tangier, between February and September 2022.
This study was approved by the University Hospital Center Ethics Committee of Tangier (CEHUT) (identification number: 01/22).

Patients
We included adult patients with all types of osteoarthritis who presented to the rheumatology department.Patients with cognitive disabilities preventing them from completing the questionnaires were the only ones excluded.All patients provided signed informed consent.

Questionnaire: main and other variables
A standardized interview, based on a questionnaire elaborated by two professors of rheumatology (FZT and FEA), who are among the authors, was carried out.It was adapted to the Moroccan context based on previous literature [14,15].To ensure its acceptability and clarity, a cognitive interview was performed with five people to obtain their opinion on each item of the questionnaire and whether it should be added or deleted.Some adjustments were then made.The questionnaire's final version underwent evaluation and approval.
It comprises two parts: the first part collects socio-demographic data, co-morbidities, and osteoarthritis impact characteristics.Pain was assessed using the Visual Analogue Scale (VAS), while the WOMAC knee and hip score measured functional disability in patients with knee or hip OA.
The second section included 12 closed questions with a variety of open and closed sub-questions.Patients were asked about their opinion regarding the impact of diet on their OA symptoms, their experi-ences with foods that either worsen or improve joint pain, and their attitudes towards the influence of different foods on their symptoms.The survey also recorded whether patients had tried specific diets or fasting as a means of relieving their symptoms.This section contains a list of 24 foods.Patients were asked to determine whether these foods worsened, improved, or had no effect on their joint problems.

Statistical analysis
Descriptive statistics were used to summarize the data.The statistical program IBM SPSS version 21.0 was used to conduct the analyses.Qualitative variables were expressed as numbers and percentages, medians and quartiles, or means and standard deviations, depending on their distribution.Statistical significance was considered present when p < 0.05.Binary logistic regression was used to evaluate the factors associated with reporting that diet affects joint symptoms.

Demographic and clinical characteristics of patients
The mean age of the patients was 59.57±10.71years, 47.2% had comorbidities, 69.4% were illiterate, and 91.3% were urban dwellers.The study included 322 patients with a median duration of osteoarthritis of 4 years [2,10].Knee OA was present in 55% of the patients, followed by spine OA (27%), hand OA (17.1%), and ankle OA (0.3%).Table 1 presents the main sociodemographic and clinical data.Impact of diet on OA joint symptoms Around 7.9% of the participants reported that food affected their symptoms.Of these, 4.4% reported an improvement, and 3.5% reported an aggravation.Approximately 2.2% of patients reported food avoidance behaviors, while 3.7% adopted some diets, and 1.3% had tried fasting to relieve joint symptoms (Table 2).
In the multivariate analysis, only the adoption of dietary practices was found to be associated with  3).

DISCUSSION
This study aimed to evaluate the impact of food on clinical symptoms in patients with OA.The main finding was that only 7.9% of the patients reported that food affected their symptoms, with 4.4% experiencing improvement and 3.5% experiencing aggravation.The adoption of dietary practices was the only factor associated with reporting that food affected their symptoms.
Several studies have reported a correlation between diet and symptoms of rheumatic diseases, including osteoarthritis (OA).In a survey conducted by Haugen et al., 742 patients participated, including 290 with rheumatoid arthritis, 51 with juvenile rheumatoid arthritis, 87 with ankylosing spondylitis, 51 with psoriatic arthropathy, 65 with primary fibromyalgia, and 34 with OA.Patients in this diverse group reported varying degrees of worsening disease symptoms after consuming some foods, such as red meat, alcohol, coffee and sugar.Next to 26% of patients with juvenile rheumatoid arthritis and 23% of patients with rheumatoid arthritis, ankylosing spondylitis, and primary fibromyalgia had tried a diet to relieve symptoms.Only 13% of patients with psoriatic arthropathy and 10% of patients with osteoarthritis had tried a diet for the same purpose.The study found that 46% of patients reported less pain and stiffness, while 36% reported reduced joint swelling [8].
Recent studies have shown that some food substances may have specific pharmacologic actions in OA disease, such as anti-inflammatory or antioxidant properties [9,16,17].In our study on dietary lipids and osteoarthritis, fish (1.2%) and olive oil (1.2%) were the most commonly cited foods for im- proving joint symptoms.Although the percentage may seem low, it is actually the highest when placed in its context, since only a minority of patients reported a change in their symptoms through food.This observation is consistent with the existing literature, which suggests that higher intakes of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) are associated with reduced radiographic progression in knee OA [18].For individuals with or at high risk of knee OA, a diet that reduces the ratio of ω-6 fatty acids to ω-3 fatty acids is likely to improve symptoms of osteoarthritis.This effect is similar to what is observed in rheumatoid arthritis, where inflammation related to circulating lipids is reduced [19,20].It is a known fact that safflower oil and sunflower oil are rich in ω-6 fatty acids, while olive oil, which is rich in monounsaturated fats, contains only a small amount [21].Fish is also a good source of omega 3, which may explain the reported positive effect on OA symptoms in some patients.
In our study, 1.2% of patients reported that ginger improved their symptoms, while the percentage did not exceed 0.9% for Curcuma.A systematic review assessed the positive therapeutic effects of Curcuma, a spice from the ginger family that is widely used in Indo-Asian cooking and traditional Eastern medicine, in patients with either OA or rheumatoid arthritis [22].The authors concluded that there is evidence supporting the use of curcumin in the treatment of arthritis.A systematic review suggests that curcumin therapy may be a beneficial addition to the current treatment regimen for patients with knee osteoarthritis [23].
We also observed that the consumption of antioxidant-rich foods, such as dried fruit for vitamins A and E, and tomatoes and pomegranates for vitamin C, had varying effects on patients' symptoms.Specifically, the same percentage of patients reported both relief and worsening of symptoms when consuming dried fruit, which is also rich in carbohydrates.Only 0.3% of patients reported a beneficial effect on their symptoms when consuming tomatoes, while no effect was reported by patients when consuming pomegranates.Some authors have suggested that antioxidants, especially vitamin C, may delay the onset and progression of osteoarthritis, which is necessary for collagen formation [24][25][26].
In addition, red meat, tea, coffee and soda were perceived as aggravating foods.These results are consistent with a survey by Haugen et al, which included 742 patients with rheumatic diseases, 34 of whom were followed for osteoarthritis.The survey reported that the most common foods that aggravate symptoms in patients are red meat, sugary sodas, sugary desserts, coffee, and alcohol [16].
As we described, patients who practiced dieting were more likely to report that diet affects joint symptoms.This suggests that these patients are more aware and attentive to the potential effects of food on their symptoms.
Furthermore, a small percentage (1.3%) of patients were experimented with fasting to relieve joint symptoms.Although there are various fasting schedules, they are typically intermittent and primarily used in weight loss plans, particularly for metabolic osteoarthritis [27].
Limitations of the study: The cross-sectional methodology and the use of a non-validated questionnaire were limitations of our study.Additionally, we only tested 24 foods for their impact on joint symptoms, excluding vegetables, sesame, and other known vitamin K-rich foods that play a role in bone and cartilage health [28][29][30][31][32].

CONCLUSION
Nutritional strategies may be an attractive and potentially promising approach to managing osteoarthritis, if their effectiveness is proven.Our study found that only a minority of patients reported associations between certain foods and worsening or improving joint symptoms, which appeared to be mostly related to personal dietary practices.Some foods, particularly those of Mediterranean origin such as olive oil and fish, have been found to alleviate joint pain.On the other hand, foods high in protein, such as red meat, have been shown to aggravate joint pain.However, the influence of diet on OA remains a controversial issue.Studies in this area are scarce, and future research should focus on food therapy.

TABLE 1 .
Demographic and clinical characteristics of the study population *: Data presented as mean ± SD. †: Data Presented as a percentage (%) ‡: Data Presented as median

TABLE 2 .
Patients' responses regarding the relation between diet, fasting and joint symptoms FIGURE 1. Foods reported to aggravate or ameliorate joint symptoms in percentage %

TABLE 3 .
Uni and multivariate analysis for the influence of diet on joint symptoms