Food additives used to enhance the flavor of apple juice, yogurt and red wine could hold the secret to treating lymphedema – severe swelling in the arms and legs.
Research published in the journal Nature found that compounds called cyclodextrins may be able to reverse swelling.
The findings, based on animal studies, could potentially improve the lives of up to 450,000 people in Britain living with the condition, many as a result of treatment for cancer.
For example, about one in five people develop lymphedema in the arm after treatment for breast cancer, such as surgery to remove lymph nodes or radiotherapy to remove cancer cells.
Lymph nodes are bean-shaped structures located throughout the body that filter waste from lymphatic fluid, which is fluid and waste produced by tissues.
The nodes clean the fluid carried in the lymphatic vessels before it enters the bloodstream.
But the nodes are also often the first place cancer cells migrate to when they develop in nearby tissues such as those in the chest, head or neck, before traveling on to other vital organs such as the lungs.
Surgically removing the glands – to reduce the risk of cancer spreading – or treating them with radiotherapy can damage the lymphatic system and cause blockages, leading to a chronic build-up of lymphatic fluid, causing swelling – sometimes so severe that simple tasks such as dressing or finding suitable clothing can become extremely difficult.
The new study’s findings, based on animal studies, could potentially improve the lives of up to 450,000 people in Britain living with lymphedema.
Research shows that the impact on quality of life can be significant. Treatment options are limited. Patients are initially told to try compression stockings or stockings on their swollen limbs.
But these need to be worn daily and can cause skin irritation and itching, which can be uncomfortable and also restrict movement.
Another option is a form of massage, manual lymphatic drainage, which patients can do themselves. To get good results, this must be done regularly.
Surgery is available on the NHS to ‘refill’ the lymphatic vessels so that fluid does not build up, although the procedure is used sparingly for around £15,000. Similarly, liposuction – which breaks down excess fluid and fat using lasers or high-frequency sound waves, before being sucked out by a machine – can help, but this is not widely available on the NHS.
The latest research from scientists at the National University of Singapore shows that a cheaper and more practical solution exists.
The researchers focused on cyclodextrin, which is produced from starch, which has been used in the food and beverage industry for years to improve the smell and taste of numerous products.
This is because it has a unique cellular structure, which means it can ‘trap’ unwanted odors in foods and drinks that can sour the overall taste and experience.
Professor Kefah Mokbel, a breast surgeon at the London Breast Institute, said the findings open a ‘new therapeutic avenue’.
Crucially, cyclodextrin is also widely used to remove cholesterol from dairy products such as cheese and butter to produce low-fat versions. It does this by encapsulating cholesterol crystals in the hollow interior and then attracting water to flush them away.
This is significant because when the Singapore team analyzed skin tissue from women with lymphedema undergoing treatment for breast cancer, they found that reduced lymphatic flow was associated with large amounts of cholesterol accumulating in the surrounding tissue.
Lymphatic vessels transport cholesterol from the tissues back to the bloodstream. But this study showed that a buildup of cholesterol in surrounding tissues plays an active role in causing lymphedema. This cholesterol was found to cause inflammation and scarring in the blood vessels, which also blocked normal lymph flow.
The next step was to see whether the cholesterol-lowering effect of cyclodextrin could relieve this swelling.
The researchers treated mice with lymphedema by regularly injecting cyclodextrin into the affected area for eight weeks.
The results showed that it significantly reduced swelling and inflammation – but as a bonus, researchers also found that cyclodextrin appeared to help regenerate damaged lymphatic vessels, leading to a gradual reversal of symptoms.
Babak Mehrara, chief of plastic and reconstructive surgery at Memorial Sloan Kettering Cancer Center in New York, who wrote a review of the recent study for Nature, said: ‘Lymphedema is a fluid retention problem, but fluid retention causes inflammation, which impairs the function of existing lymphatic vessels.
‘That leads to more fluid retention and more inflammation. As a result of the inflammatory changes, fat deposits and cholesterol deposits then arise.’
Professor Kefah Mokbel, a breast surgeon at the London Breast Institute, said the findings open a ‘truly new therapeutic avenue’.
He added: ‘This is potentially groundbreaking as lymphedema remains a chronic condition with no cure.
‘The study identifies excessive cholesterol deposition in affected tissues as a potential target for treatments. But we need carefully designed human trials to establish safety and efficacy.”
He added that cholesterol-lowering drugs such as statins are unlikely to work because they target cholesterol in the bloodstream, and not specifically the lymph nodes.
