Understanding arthritis just how vital is diet?
When you have arthritis, it's important to have a good knowledge of what foods to include and avoid. Our resident dietitian has the answers, and explains the two most common types of the condition
According to Arthritis Ireland nearly one million people in Ireland live with arthritis. Osteoarthritis (OA) is the most common form, followed by rheumatoid arthritis (RA). Although the statistics can vary, there are, on average, about 12 hip replacements and five knee replacements daily in Ireland.
As the drugs used to treat arthritis often work through action on the immune system or reduction of inflammation, the role for diet in arthritis is targeted at these functions also. Unfortunately some medications can come with negative side-effects. Nutritional interventions, although perhaps not as consistent and sometimes not as effective as medications, will more often than not help with a condition, without consequences to health. Additionally tailored dietary intervention will offer other health benefits alongside its expected therapeutic aid. This is why many people use dietary manipulation - alongside medications or in some incidences instead of medications - when tackling a health complaint.
A dietitian's role goes beyond treatment and prevention of arthritis. A dietitian must also help combat the side effects caused by the medications such as taste changes, mouth sores, abdominal pain, ulcers, loss of appetite, nausea, thinning of the bones, weight loss and weight gain. In addition to nutrition-related side effects of the medications, dietitians also help with drug-nutrient interactions. For example certain medications interact with folic acid, calcium and potassium within the body.
When it comes to osteoarthritis (OA), obesity is a strong risk factor. Obesity is the greatest modifiable risk factor for OA. People with a BMI>30 kg/m2 are nearly seven times more likely to develop knee OA than people with a healthy weight. The reason for this is twofold.
Firstly, our skeleton and joints are not designed to carry excess weight. When the burden it bears is large or consistent over time, our joints suffer. Nevertheless, the risk of OA goes beyond excess total weight. The second thing that has come apparent through research, is that excess body fat can result in ongoing inflammation within the body. This can contribute to the start and the progression of the deterioration of our joints. The crucial thing to understand is that excess fat cells don't just lie there. The fats within and surrounding our organs a.k.a. visceral fats are very active, constantly secreting little proteins that cause inflammation. Inflammation is comparable to the soil that the seed for disease grows in.
Additionally excess fat can result in insulin resistance - pre-diabetes and diabetes - which has been shown to promote the progression of OA. Unsurprisingly it's common for those with OA to have excess fat around their middle, high cholesterol, high blood pressure and high blood sugar levels. Therefore with OA, the first step in dietary intervention is weight loss in the overweight.
* Rheumatoid arthritis
Rheumatoid arthritis (RA), like type 1 diabetes, is an autoimmune disease. The body's own immune system is wrongly triggered to attack the joints. This causes inflammation, pain and swelling of joints, connective tissue and supporting structures within the body resulting in loss of function. The discomfort experienced may be mild and at times more severe. More often, hands and feet are affected and more women than men have RA. They're not fully sure why.
Weight does factor prominently in RA but in a different way. Obesity results in poorer outcomes and additional health issues for people with RA. Additionally weight loss and muscle wasting also are common. This is why dietitian's assess body composition in those with RA as well as total weight.
* Inflammation - the common denominator
As the link between inflammation and the development and progression of RA and OA is becoming well established so too is a therapeutic anti-inflammatory diet. A person's diet can help regulate inflammation. C-reactive protein (CRP), a compound often used as a marker for inflammation, has been shown to decrease with anti-inflammatory diets. The typical Irish diet that is low in fruit and vegetables and high in processed foods promotes inflammation. If we were to eat better, the inflammation within our body would reduce.
* Cut down on trans fats
Eating trans fats, as found in certain processed and fried foods has been shown to increase the risk of heart disease. Although this is in part explained by its impact on cholesterol levels, it may also be due to its impact on inflammation within the body. Trans fats have been shown in more than one study to increase inflammation, including CRP.
* Be mindful of saturated fat
Saturated fat is an umbrella term for a group of fats found in animal produce - as well as coconut and palm oil. Saturated fat has been positively associated with inflammatory markers such as CRP. However more research is needed to understand which saturated fats would be causing this impact.
* Instead... eat more olive oil
Monounsaturated fats have been touted for their health benefits for years. Olive oil, a monounsaturated fat, supplies the body with oleocanthal, which has been shown to have anti-inflammatory effects. It has been shown to inhibit some of the same inflammatory pathways as ibuprofen.
* Eat more omega 3 fats
Omega fats have been recognised for a long time as anti-inflammatory. This is one of the reasons why walnuts, linseeds, chia seeds and oily fish such as mackerel sardines, salmon, and trout are encouraged. The powerful anti-inflammatory proteins produced from eating omega-3s, such as resolvins and protectins, help to reduce the production of pro-inflammatory cells within the body. In research where participants had RA, omega-3s were shown to improve stiffness in the morning and tender joints. As those with arthritis need protection for heart disease, omega-3 fats could offer a double benefit. For example one study found that 1000mg of omega-3 increased HDL cholesterol levels, the 'good' cholesterol, in females with RA.
* Drink less sugar
The new tax on sugar may help those with RA. Studies have found an association between sugar-sweetened beverages and RA. As for OA, one study showed that frequent consumption of soft drinks may be associated with increased OA progression in men. Although the research on sugar-sweetened beverages and OA is lacking, drinking sugar has been shown to contribute to inflammation making it likely that it would impact OA as well.
* Eat more plants
A plant-based diet is growing in popularity. Plants are a natural source of antioxidants and fibre which are proposed to reduce inflammation. When a plant based diet was followed for six weeks those with OA reported significant improvement in energy levels, pain and physical ability.
A different study investigated the effects of a vegetarian diet with or without a supplement of omega-3 fats on inflammation in people with RA. They compared a normal western diet to an anti-inflammatory diet that specifically provided less than 90mg of arachidonic acid each day. Arachidonic acid is an essential unsaturated fat that can be transformed into a variety of products which mediate inflammatory reactions. In the study they gave some people fish oils while other people got a capsule without fish oils within it. This is because omega-3 fat has been shown to change arachidonic acid mechanisms. The anti-inflammatory diet reduced tender and swollen joints by 14pc and when they received fish oils the impact was even greater improvement in tender (28pc vs 11pc) and swollen (34pc vs 22pc) joints.
* Follow the Portfolio diet
The portfolio diet focuses on nuts, soluble fibre, soya protein and plant sterols. It has been found to reduce cholesterol levels reducing the need for some people to take the cholesterol reducing medication called statins. Interestingly it has been shown to reduce CRP as much as statins too.
Why does it work?
· There are many individual components within the diet that contribute to its anti-inflammatory effects including genistein in soya, sterols in wheat germ and ellagic acid in walnuts.
· The isoflavones found in soya have been shown to significantly reduce CRP in postmenopausal women. Interestingly this was even shown to be the case when researchers used fortified cereal bars.
· The fibre, magnesium, L-arginine, antioxidants and alpha-linolenic acid (ALA) in nuts may help reduce inflammation. Eating nuts regularly has been associated with lower concentrations of inflammation markers and has been shown to decrease CRP.
· The soluble fibre in oats, barley and psyllium within the portfolio diet has been shown to reduce CRP.
· However it may not be exclusively soluble fibre as higher overall fibre intake lowers several markers of inflammation too. As overall dietary fibre increases the amount of CRP within the body reduces. The likelihood of someone having high levels of CRP was 63pc lower if their fibre intake was high. Some benefit is seen with the use of fibre supplements, but considering fibre-rich foods provide a myriad of benefits, a food first approach is advised.
Research showed that when you combine the portfolio diet with a substitution of saturated and trans fats for monounsaturated fats, CRP levels reduced by 76pc therefore proving to be more effective than the standard portfolio diet.
* The Mediterranean Diet
It would be difficult to discuss anti-inflammatory diets without mentioning the Mediterranean diet. The Mediterranean diet model contains both fat and non-fat components that have been shown to exert important anti-inflammatory activities. A Mediterranean diet contains lots of fruits and vegetables, wholegrains, olive oil and healthier sources of protein such as legumes and fish. None too surprising it may play a role in the prevention of OA. Nevertheless there are studies that show that when people with RA patients followed a Mediterranean diet they experienced a reduction in pain and disease activity. These improvements lead to increases in both physical function and vitality. As the Mediterranean diet has been shown to be good for the heart, those with arthritis may find this style of eating doubly beneficial.
* The DASH Diet
The DASH (Dietary Approaches to Stop Hypertension) diet was designed to lower blood pressure. What research also found was that markers of inflammation also decreased when following this diet. Similar to the above, the diet was rich in fruits, vegetables, wholegrains, poultry, beans, nuts, fish and vegetable oils and encouraged fat free or low fat dairy products. It also encouraged people to limit sugar-sweetened beverages, sweets and foods high in saturated fats. Considering everything that is discussed, it's no wonder that this diet is encouraged in people with arthritis.
Supplements are commonly taken. In fact one in four of those with RA are said to be taking supplements. Many of those aged 75 or over take supplements. Therefore it's difficult to discuss any dietary recommendations without discussing supplements.
Research in this area is in its early stages but looks exciting. A systematic review and meta-analysis of randomised clinical trials was conducted to evaluate the strength of the research on turmeric for treating arthritis symptoms. Although initial searches found 29 articles only eight met specific selection criteria. Their conclusions were that there was scientific evidence to support the use of turmeric in the treatment of arthritis.
* Tart Cherry Juice
Cherries have received particular attention for their possible health benefits for those with arthritis. Tart cherry juice is known to be rich in antioxidants and anti-inflammatory properties. It has been shown to reduce pain in athletes when taken appropriately and has now been shown to provide symptom relief for those with milk to moderate knee OA. It was even shown to reduce CRP.
* Vitamin D
Vitamin D has been shown to be important when it comes to autoimmune disease prevalence and therefore has been investigated in RA. A review showed that people with the highest vitamin D intake had a 24pc lower risk of developing RA than those with the lowest intake. A systematic review and meta-analysis reported that after vitamin D supplementation, the rate of recurrence of RA seemed to decrease, albeit not significantly. Therefore more research is required to provide a definitive answer.
Chondroitin is a popular supplement in OA. Previous meta-analyses have shown contradictory results on its efficacy. A systematic review set out to evaluate the benefit and harm of chondroitin for treating OA. Forty-three randomized controlled trials were included. Those who took chondroitin were shown to achieve statistically significantly and clinically meaningful better pain scores. In a different review the use of glucosamine and chondroitin sulfate was reported to be a nonoperative means to protect joint cartilage and delay OA progression.
When the research was evaluated, the strength of dietary intervention in the treatment of arthritis was significant. Yet another area where nutrition can make a difference.
Health & Living