Broccoli could be key to preventing and slowing osteoarthritis

A compound found in broccoli could be the key to preventing or slowing the progress of the most common form of arthritis, according to new research from the University of East Anglia (UAE) in the UK.

The study, which was published in the journal Arthritis and Rheumatism on 28 August 2013, showed that sulforaphane slows down the destruction of cartilage in joints associated with painful and often debilitating osteoarthritis. Sulforaphane is released when eating cruciferous vegetables such as Brussels sprouts and cabbage, but particularly broccoli.

The researchers found that mice fed a diet rich in the compound had significantly less cartilage damage and osteoarthritis than those that were not. Previous research has suggested the sulforaphane has anti-cancer and anti-inflammatory properties, but researchers said this was the first major study into its effects on joint health.

Compound blocks ‘destructive’ enzymes

The researchers discovered that sulforaphane blocked the enzymes that cause joint destruction by stopping a key molecule known to cause inflammation. They said they wanted to find out if the compound got into joints in sufficient amounts to be effective.

“The results from this study are very promising,” said Ian Clark, Professor of Musculoskeletal Biology at UAE. “We have shown that this works in the three laboratory models we have tried, in cartilage cells, tissue and mice. We now want to show this works in humans. It would be very powerful if we could,” he said.

As well as treating people who already had the condition, researchers said it was important to be able to tell healthy people how to protect their joints into the future.

“There is currently no way in to the disease pharmaceutically and you cannot give healthy people drugs unnecessarily, so this is where diet could be a safe alternative,” Professor Clark said.

“Although surgery is very successful, it is not really an answer,” Professor Clark said. “Once you have osteoarthritis, being able to slow its progress and the progression to surgery is really important. Prevention would be preferable and changes to lifestyle, like diet, may be the only way to do that,” he said.

Effects of diet “adds another layer” to understanding of disease

Researchers said the study was “important” because it highlighted the possible effects of diet in osteoarthritis, which could lead to findings about other ‘protective’ dietary compounds and better advice for people on what to eat for joint health.

“Developing new strategies for combating age-related diseases such as osteoarthritis is vital, both to improve the quality of life for sufferers and to reduce the economic burden on society,” Professor Clark said. “Osteoarthritis is a major cause of disability. It is a huge health burden but a huge financial burden too, which will get worse in an increasingly ageing and obese population such as ours,” he said.

More than 8.5 million people in the UK have osteoarthritis, a degenerative disease that affects the hands, feet, spin, hips and knees in particular. According to Arthritis Research UK, the annual cost of the condition is £5.2 billion. In 2011, more than 77,000 knee and 66,000 hip replacements were carried out due to osteoarthritis – approximately one every four minutes.

Ageing and obesity are the most common contributors to the condition and due to their effects, the number of people in the UK consulting a GP about knee osteoarthritis alone could rise from 4.7 million in 2010 to 8.3 million by 2035. Currently one in five people over the age of 45 has osteoarthritis in their knee. There is no cure or effective treatment for the disease other then pain relief, which is often inadequate, or joint replacement.

Osteoarthritis in Australia

Osteoarthritis is the most common form of arthritis in Australia, according to advocacy group Arthritis Australia, with the condition affecting over 1.6 million people in 2007-08. Arthritis Australia said evidence suggests that prevalence of the condition may actually be nearly 3 million people, as many people do not know they have osteoarthritis.

While osteoarthritis is more common with age, it starts in relatively young people. According to Arthritis Australia, more than half of people with osteoarthritis are of working age.

Arthritis Australia said population ageing and increasing rates of obesity are “likely to result in major increases in the future prevalence of osteoarthritis”, predicting that 3.8 million Australian could have the condition by 2050.

“There are lots of myths about osteoarthritis – such as it being an inevitable part of ageing,” Franca Marine, National Policy and Government Relations Manager for Arthritis Australia told Australian Food News. “It’s not. It can be prevented and if you do get it, it can be managed,” she said.

Ms Marine also told Australian Food News that there was “room for improvement” in how the condition was dealt with in the health system, given its prevalence. Arthritis Australia said health system expenditure on osteoarthritis in 2008 was estimated to be over $2 billion, and that the overall economic cost of osteoarthritis, including productivity losses and lost wellbeing, was estimated to be $23 billion in 2008.

Results of study “promising”

Medical research charity Arthritis Research UK, which partly funded the research, said the results of the study were “promising”.

“Until now research has failed to show that food or diet can play any part in reducing the progression of osteoarthritis, so if these findings can be replicated in humans, it would be quite a breakthrough,” said Professor Alan Silman, Arthritis Research UK’s Medical Director. “We know that exercise and keeping to a healthy weight can improve people’s symptoms and reduce the chances of the disease progressing, but this adds another layer in our understanding of how diet could play its part,” he said.

The study, which also examined human cartilage cells and cow cartilage tissue, was funded by Arthritis Research UK, the Biotechnology and Biological Science Research Council’s (BBSRC) Diet and Health Research Industry Club (DRINC) and The Dunhill Medical Trust. It involved research from UAE’s schools of Biological Sciences, Pharmcy, and Norwich Medical School, along with the University of Oxford and Norfolk and Norwich University Hospital.

Small scale human trial planned

Researchers from the School of Biological Sciences and Norwich Medical School are now embarking on a small scale trial in osteoarthritis patients due to have knee replacement surgery, to see if eating broccoli has similar effects on the human joint. If successful, the researchers said they hope it will lead to funding for a large scale clinical trial to show the effect of broccoli on arthritis, joint function and pain itself.

For the small scale trial, funded by DRINC, half of the 40 patients will be given ‘super broccoli’ – bred to be high in sulforaphane – to eat for two weeks before their operation. Once the surgery has taken place, the researchers will look at whether the compound has altered joint metabolism and if it can be detected in the replaced joints.