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The best diet for arthritis: what the latest research tells us

 

Osteoarthritis is the most common of the more than 200 forms of arthritis, affecting more than 20% of the population. Unfortunately, there are currently no effective treatments or approved drugs for this disabling condition, which causes the joints to become painful and stiff. Some new drugs are in the pipeline, but it will be years before they are tested in clinical trials and approved by regulators.

Many people with osteoarthritis take a bewildering variety of dietary supplements, the favourites being glucosamine and chondroitin sulphate, but the evidence doesn’t actually support their use. However, we are happy to report that our recent review of published evidence shows that eating the right foods, combined with moderate low-impact exercise, can benefit people with osteoarthritis.

Firstly, losing weight and exercising are the most significant things that osteoarthritis patients can do to ease their symptoms. Weight loss reduces the load on the joints and lowers the level of inflammation in the body, reducing arthritis pain. Exercise helps you to lose weight while keeping your muscles strong, which helps protects the joints and makes it easier to move around. So overweight and obese people with osteoarthritis should find ways to lose weight that include exercise aimed at increasing their muscle strength and enhancing their mobility.

Oily fish

Eating certain foods can also help improve patients’ symptoms and reduce their daily joint pain. Evidence shows eating more oily fish such as salmon, mackerel and sardines can improve pain and function in arthritis. This is because the long-chain omega-3 fatty-acids they contain reduce the amount of inflammatory substances the body produces. Fish-oil supplements of 1.5g per day may also help.

But eating fish oils alone may not be enough. It is also important to reduce the long-term consumption of fatty red meats and replace saturated animal fats with vegetable oils such as olive and rapeseed.

Lower cholesterol

Osteoarthritis patients are more likely to have raised blood cholesterol, so eating in a way that reduces blood cholesterol can help, as well as improving general cardiovascular health. Reducing the amount of saturated fat you eat and increasing the amount of oats and other soluble fibres will help to reduce cholesterol.

Other specific ways to reduce blood cholesterol include eating 30g a day of nuts, 25g a day of soy protein from tofu, soy milk or soy beans, and eating 2g a day of substances called stanols and sterols. These are found in small amounts in plants but the easiest way to consume them is in fortified drinks, spreads, and yogurts that have these substances added to them.

Antioxidants

Osteoarthritis occurs when the joints become inflamed by increased amounts of oxygen-containing reactive chemicals in the body. This means that eating more antioxidants, which can neutralise these chemicals, should protect the joints. Vitamins A, C and E are potent antioxidants you should make sure you get the guideline amounts of them to maintain healthy connective tissues throughout the body. However, the evidence that they improve osteoarthritis symptoms is debatable.

Vitamin A is abundant in carrots, curly kale and sweet potato. Fresh fruits and green vegetables are rich in vitamin C, especially citrus fruits, red and green peppers and blackcurrants. Nuts and seeds are a great dietary source of vitamin E and oils derived from sunflower seeds are rich in vitamin E.

Evidence suggests that increasing the intake of vitamin K sources such as kale, spinach, broccoli and Brussels sprouts may also benefit people with osteoarthritis. We also know vitamin D, which your body makes when exposed to sunlight, is important for bone health and many people don’t produce enough. But more evidence is needed before vitamin D supplements can be recommended for osteoarthritis patients.

Though several popular diet books on arthritis advocate avoiding certain foods, there is no clinical evidence that this benefits osteoarthritis patients.

The ConversationWith the help of dietitian colleagues, we have summarised our findings in a food fact sheet on diet and osteoarthritis endorsed by the British Dietetic Association

Ali Mobasheri, Professor of Musculoskeletal Physiology, School of Veterinary Medicine, University of Surrey and Margaret Rayman, Professor of Nutritional Medicine, University of Surrey

This article was originally published on The Conversation. Read the original article.

Spotlight on rheumatology

Gout is in the news this week, with a new study from the BMJ demonstrating that eating well can downgrade your risk of developing this inflammatory condition.

The so-called DASH diet, designed to reduce blood pressure, is also good for lowering uric acid levels, US and Canadian study involving 44,000 people has found. The diet is rich in fruit, vegetables, nuts and whole grains, and low in salt, sugary drinks, red and processed meats.

Gout is also the subject of an ongoing battle in the rheumatology community, reports Health Professional Radio. New guidelines from the American College of Physicians advise doctors against urate-lowering therapy in most patients, in stark contrast to both EULAR and ACR recommendations. It’s angered many gout specialists who have set up two new professional bodies to advocate use of urate-lowering drugs.

New fibromyalgia guidelines have also come under fire. The EULAR recommendations, write two Maltese rheumatologists, underplay the importance of severe anxiety and depression in the debilitating condition.

Meanwhile, biosimilars are making news at the Digestive Disease Week held in Chicago this month. The question of whether they are interchangeable with biologics has been troubling many Australian rheumatologists since the recent PBS listing of the etanercept biosimilar Brenzys for a number of rheumatology conditions.

Three new studies (here, here and here) suggest Inflectra, an infliximab biosimilar that was PBS-listed last year, can be switched with its originator Remicade without any effect on safety or efficacy.

And in other biologics news, abatacept has been found in a phase 3 study to be effective in psoriatic arthritis. In the study of over 400 patients, around 40% of those randomised to the biologic showed improvement compared with 22% in the placebo group.

How common is hand arthritis? A large study from the US crunches the numbers: it finds that one in two women will develop the condition at some stage in their life, while only one in four men will do so.

Hand arthritis affects Caucasians more than African-Americans and is more prevalent among obese people.

But people with any kind of arthritis should go easy on some kinds of painkillers, Canadian researchers say. The BMJ study involving 450,000 people found that taking any dose of an NSAID even for only a week significantly increases the risk of myocardial infarction.

And finally, a US study has found that squeaky knees are a better predictor of osteoarthritis than knee pain.

The study looked at 3500 people at high risk of developing OA and found that 75% had radiographic evidence of the disease despite the absence of pain.

Among those not experiencing pain, crepitus was more common in those who developed OA within a year.

 

Need some fast facts on osteoarthritis? Buy our OA handbook at the Doctorportal bookshop. This comprehensive resource includes:

  • a clear and concise description of the normal joint;
  • a detailed overview of the pathology of osteoarthritis;
  • expert guidance on well-established diagnostic criteria and investigations;
  • up-to-date, practical information on drug therapy, non-pharmacological treatments and surgical options;
  • joint-specific treatments for the hand, hip and knee, including intra-articular corticosteroid injections.

 

 

Controversy over arthritis biosimilar listing

The first biosimilar to be sold in retail pharmacies has been listed on the PBS amid criticism from Australia’s peak rheumatology body.

Brenzys, an etanercept biosimilar for the treatment of several rheumatology conditions, was listed on April 1st with an “a-flagging”, which means pharmacists can substitute it for the originator biologic, Enbrel, without consulting the prescribing doctor.

Brenzys is the second rheumatology biosimilar to get a PBS listing, behind Inflectra (infliximab), which was a-flagged a year ago.

Dr Mona Marabani, chair of the Australian Rheumatology Association’s biosimilars working group, said the new listing was concerning because unlike Inflectra, a hospital-dispensed infusion product, Brenzys is a self-injected medication available at retail pharmacies.

“Pharmacists may stock only the originator or the biosimilar, which means there is potential for the patient to receive a different drug every month,” she said.

And yet multiple switching between biosimilars and their originator drugs is an “evidence-free zone”, she said.

Dr Marabani said responsibility for determining whether a biosimilar is interchangeable with its originator drug was quietly switched last year from the TGA to the PBAC, creating a conflict of interest.

“The funder is making the decision as to whether the drug is interchangeable, and not the regulator. My position is that the regulator should regulate and the funder should look at cost-effectiveness,” she said.

She said one PBAC criterion for determining interchangeability is “absence of proof” to suggest differences in safety and efficacy between a biosimilar and reference drug.

“This is clearly concerning as it reverses the onus of proof. Absence of evidence is not the same as evidence of absence,” she said.

“The powers that be keep asking rheumatologists what’s going to make us confident in prescribing biosimilars. What makes us confident is data. We recognise that biosimilars represent an opportunity. We are all for reducing the cost to the community. But there are data gaps at the moment; there are things we don’t know.”

Dr Marabani said the ‘a’ flagging of biosimilars is the “wrong mechanism”, adopted by only one other country in the world, Venezuela.

The Department of Health has launched a Biosimilar Awareness Initiative to address the lack of information surrounding biosimilars and boost confidence in their use. But a CPD accreditation program for biosimilars won’t be up and running until later this year.

Meanwhile MSD, which is marketing Brenzys in Australia, is pushing back against criticism from the Australian Rheumatology Association.

The company said it had consulted widely on the introduction of the biosimilar.

It said that in Europe, rheumatology biosimilars have been used for a number of years with no reports of enhanced immunogenicity or unexpected adverse events.

It noted that the pharmacy substitution process allows for prescriber and patient choice and is not automatic.

“For any individual prescription, a prescriber may choose not to permit brand substitution. If on the other hand, substitution has been permitted by the prescriber, the patient may choose which brand they wish to receive from the pharmacist,” the company noted.