The most common form of arthritis is called osteoarthritis, a degenerative disease where articular cartilage gradually becomes thinner as its renewal does not keep pace with its breakdown. Eventually the bony articular surfaces come into contact and the bones begin to degenerate. This condition tends to occur in older people; around 12 per cent of people over 65 in the UK are affected (NHS Direct, 2005). Osteoarthritis can develop after an injury to a joint; this can happen months or even years after the injury. The most frequently affected joints are in the hands, knees, feet, hips and spine.
The next most common type of arthritis is rheumatoid arthritis, a chronic inflammatory disease of the joints. This type of arthritis affects up to three per cent of the UK population, and tends to occur in people between the ages of 30 and 50. Women are three times as likely to develop this condition as men (NHS Direct, 2005). Rheumatoid arthritis is a chronic condition characterised by hot painful swelling in the joints. In many diseases inflammation can help towards healing but in rheumatoid arthritis it tends to cause damage. For some people the pain and discomfort caused by this condition has a serious impact on their lives. Rheumatoid arthritis is thought to be an autoimmune disease, caused by a fault in the immune system that causes the body to attack its own tissues. This condition usually starts in the wrists, hands and feet but can spread to other joints in the body.
Other forms of arthritis include ankylosing spondylitis, cervical spondylitis, fibromyalgia, lupus, gout, psoriatic arthritis and Reiter’s syndrome (NHS Direct, 2005). Arthritis can also affect children but the causes of juvenile arthritis are poorly understood. It has been suggested that genetic factors or viral infections may be responsible (NHS Direct, 2005).
Until recently there has been little scientific research into the links between diet and arthritis but recent research suggests that diet may be involved in its development. It is important for people with arthritis to maintain a healthy well-balanced diet. Arthritis Care (the UK’s largest voluntary organisation working with and for people with arthritis) suggest a diet high in fruit, vegetables, pasta, fish and white meat and low in fatty foods such as red meat, cream and cheese can help (Arthritis Care, 2004). Indeed most people could benefit from eating less sugar and saturated fat and eating more complex carbohydrates, fibre, vitamins and minerals.
If you suffer from arthritis it is important to keep as healthy as possible by ensuring that the diet provides all the important nutrients including minerals such as calcium and iron. Some people are concerned that their calcium intake may drop if they cut out dairy foods. Arthritis Care suggests that if you don’t like or are unable to eat dairy products, you should obtain enough calcium from non-dairy sources (Arthritis Care, 2004a). They list several non-dairy sources of calcium including bread, green leafy vegetables and baked beans (also see here). They also warn people with arthritis to be careful not to have too much animal protein, salt or caffeine as excessive quantities of these can reduce the body’s ability to absorb or retain calcium (Arthritis Care, 2004a). Others are worried about iron, particularly people who have recently stopped eating red meat. This should not be a concern as vegetarians and vegans are no more likely to become iron deficient than meat-eaters. Indeed one of the largest studies of vegetarians and vegans in the world (the EPIC Oxford cohort study) looked at over 33,883 meat-eaters, 18,840 vegetarians and 2,596 vegans and found that the vegans had the highest intake of iron, followed by the vegetarians then the meat eaters (Davey et al., 2003). It should be stressed that milk and milk products are an extremely poor source of iron, whereas pulses, dried fruits and dark leafy vegetables are good sources.
The Arthritis Research Campaign (ARC) founded in 1936, raises funds to promote medical research into the cause, treatment and cure of arthritic conditions. ARC has produced dietary guidelines for people with arthritis and they suggest that one of the most important links between diet and arthritis is being overweight. The extra burden on the joints can make symptoms considerably worse. Losing weight can have a dramatic effect in improving the condition. In order to lose weight, you need to use more energy than you consume in the diet. Research shows that vegetarians and vegans weigh less than meat-eaters and ARC suggests that a lacto-vegetarian diet might help some people with rheumatoid arthritis. They also go further to state that a vegan diet may also help (ARC, 2002). Cutting down on sugar and taking regular (even gentle) exercise will help control weight as well.
Saturated fats are the most important kind of fat to cut down on. The body does not require saturated fats and they may aggravate arthritis whereas essential fatty acids (EFAs) have been shown to help some people with arthritis as the body uses EFAs to make substances that help control inflammation (ARC, 2002). When trying to lose weight, it is important to maintain a good intake of vitamins and minerals. This means consuming plenty of fruit and vegetables. A healthy balanced diet containing plenty of fruit and vegetables, pulses and whole grain carbohydrate foods (such as wholemeal bread, brown rice and whole wheat pasta) provides a good supply of vitamins and minerals (and fibre). A diet lacking in fruit and vegetables, and containing processed carbohydrates (such as white bread, white rice and white pasta) does not provide such a good source of these essential nutrients. This can have a deleterious effect on health as the ARC states that a good diet can still help even if strong drugs are being taken to treat arthritis (ARC, 2002).
The subject of food allergy and arthritis is quite controversial. However, research has shown that, in some people, rheumatoid arthritis can be made worse by certain foods including milk products and food colouring (ARC, 2002). If you think you are allergic to a particular food ARC recommend cutting it out of your diet for one month then reintroducing it to see if it makes a difference. In 2001, Swedish researchers reported that nine out of 22 patients with rheumatoid arthritis showed significant improvements in their condition compared to one patient out of 25 after following a gluten-free, vegan diet (Hafstrom et al., 2001). Of course it is difficult to say whether eliminating milk was the reason these patients improved as they eliminated all animal foods and gluten from the diet. However, this work does provide evidence that dietary modification can benefit arthritis patients.
In cows, milk production is influenced by the complex interaction of a range of hormones. Bovine somatotrophin (BST) is a natural growth hormone that occurs in cattle and controls the amount of milk that they produce. In 1994 Monsanto began marketing a synthetic version of BST, known as recombinant BST (rBST), which was sold as Posilac. Injecting dairy cows with rBST alters the metabolism to increase milk production by up to 15 per cent. Since its introduction in 1994, Posilac has become the largest selling dairy animal pharmaceutical product in the US. Sold in all 50 states, rBST is used in around one-third of the nine million dairy cows in the US (Monsanto, 2005).
While the US Food and Drug Administration (FDA) permit the use of rBST, its use is associated with severe welfare problems, for example increasing the incidence of lameness and mastitis. For reasons of animal health and welfare, the use of rBST in the EU was prohibited in 2000. Indeed Canada, Japan and many other countries have banned the use of rBST because of its effects on animal health and welfare. However, there are no restrictions on the import of rBST dairy products, or any requirement to label them.
The Government’s Veterinary Medicines Directorate does not carry out any testing of imported milk (Defra, 2006). Furthermore, Defra confirmed in correspondence with the VVF, that since the EU is a single market once a product has entered, if it is transported on to another country within the EU, then the origin of the product will be the EU country rather than the originating country (Defra, 2006). In 2005, the UK imported over 1,000 tons of dairy products (mainly ice-cream) from the US (Defra, 2006a); these figures have declined from over 5,000 tons in both 2001 and 2002 but still remain a concern, especially as the consumer has a limited chance of discriminating against imports from the US. The sensible option is to avoid all dairy products.
Concern has been expressed over several health issues associated with the use of rBST. The increased incidence of lameness and mastitis in rBST-treated cows inevitably leads to an increased use of antibiotics to treat these and other infections. Over half of the antibiotics that are produced in the US are used for agricultural purposes (Mellon et al., 2001). Antibiotic use is known to promote the development of antibiotic resistance. Thus the widespread use of these drugs has contributed to the high frequency of resistant bacteria in the intestinal flora of farmed animals (Lipsitch et al., 2002). This raises concerns about the development of antibiotic resistant infections in humans. A study in the New England Journal of Medicinein 2000 reported that the emergence of antibiotic-resistant strains of Salmonella is associated with the use of antibiotics in cattle. This study described how a new antibiotic-resistant strain of Salmonella was isolated from a 12-year-old boy admitted to hospital with abdominal pain, vomiting and diarrhoea. The boy lived on a ranch in Nebraska and subsequent investigation revealed the presence of the identical strain of bacteria, resistant to the antibiotic ceftriaxone, among cattle on his family’s ranch and nearby ranches that had suffered outbreaks of salmonellosis. The cattle had been treated with ceftriaxone. This evidence suggests that the boy’s gastrointestinal infection was acquired from cattle (Fey et al., 2000). The obvious concern here is that the widespread use of antibiotics in cattle can lead to an increase in antibiotic-resistant strains that may subsequently transmit to humans. This is a public health concern and the question must be asked: how much evidence of harm do we need before we much further restrict the use of antibiotics in farm animals?
Milk production increases in cows treated with rBST because it promotes the production of the naturally occurring growth hormone insulin-like growth factor 1 (IGF-1) which then stimulates the glands in the cow’s udders to produce more milk. Research shows that rBST use on dairy cows can substantially increase the levels of IGF-1 in their milk (Prosser et al., 1989). This raises concerns about the potential biological action of IGF-1 from cow’s milk in humans especially because IGF-1 from cows is identical to human IGF-1. Professor Samuel Epstein, an international leading authority on the causes and prevention of cancer, warns that converging lines of evidence incriminate IGF-1 in rBST milk as a potential risk factor for both breast and gastrointestinal cancers (Epstein, 1996).
So why should this concern us if we do not allow the use of rBST in the UK? Well in terms of human health, the concern is that milk and milk products imported from countries that permit the use of rBST may lead to the consumption of foods that promote increased levels of IGF-1 in humans. In 1999, the minister of state, Baroness Hayman, referred to a report from the Veterinary Products Committee (VPC) which stated that while the use of rBST does not increase the level of BST found naturally in cow’s milk, there is a two-to-five fold increase the level of IGF-1 in the milk, which she acknowledged may be implicated in the occurrence of colonic cancer. However, Hayman reiterated the VPC’s view that the risk to human health was likely to be extremely small. Hayman also suggested that just 0.3 per cent of total milk and milk products imported into the UK come from the US where rBST is authorised for use (UK Parliament, 1999). (See IGF-1).