Compounds found in everyday food additives, such as those used to boost flavor in apple juice, yogurts, and red wine, may hold the key to treating lymphoedema, a condition causing severe swelling in the limbs. Research published in the journal Nature indicates that these compounds, known as cyclodextrins, could potentially reverse the swelling associated with the condition.
The findings, derived from animal studies, could offer significant hope to the estimated 450,000 people in the UK living with lymphoedema. This condition often arises as a consequence of cancer treatment, with approximately one in five individuals developing arm lymphoedema after treatments like lymph node removal surgery or radiotherapy.
Lymph nodes are vital components of the lymphatic system, filtering waste from lymph fluid. However, cancer cells can migrate to these nodes, and treatments aimed at eradicating cancer can damage or block the lymphatic system. This disruption leads to a chronic buildup of lymph fluid, causing swelling that can severely impact a person's quality of life and ability to perform daily tasks.
Existing treatment options for lymphoedema are limited and can be burdensome. These include wearing compression sleeves or stockings daily, which may cause skin irritation and restrict movement. Manual lymphatic drainage, a form of self-massage, requires consistent application. Surgical interventions to reroute lymphatic vessels are available but costly and used sparingly, while liposuction to remove excess fluid and fat is not widely accessible.
The study, conducted by scientists at the National University of Singapore, focused on cyclodextrins, which are derived from starch and have long been utilized in the food and beverage industry. Their unique cellular structure allows them to trap unwanted odors and improve taste. Crucially, cyclodextrins are also employed to remove cholesterol from dairy products.
Researchers observed that reduced lymphatic flow in women with lymphoedema, particularly those treated for breast cancer, was associated with significant cholesterol accumulation in surrounding tissues. Lymphatic vessels normally transport cholesterol, but the study suggests that this buildup of cholesterol actively contributes to lymphoedema by causing inflammation and scarring of the vessels, thereby impeding lymph flow.
In the experimental phase, researchers injected cyclodextrin into the affected areas of mice with lymphoedema over an eight-week period. The results demonstrated a significant reduction in swelling and inflammation. Furthermore, the study noted that cyclodextrin appeared to aid in the regeneration of damaged lymphatic vessels, leading to a gradual reversal of symptoms.
Experts acknowledge the potential of these findings. Babak Mehrara, chief of plastic and reconstructive surgery at Memorial Sloan Kettering Cancer Center, noted that fluid accumulation in lymphoedema leads to inflammation, which impairs lymphatic function, creating a cycle of increased fluid and inflammation, accompanied by fat and cholesterol buildup. Professor Kefah Mokbel, a consultant breast surgeon at the London Breast Institute, described the findings as potentially groundbreaking and a "genuinely new therapeutic avenue" for a condition currently without a cure. However, he emphasized the need for carefully designed human trials to confirm safety and efficacy, noting that systemic cholesterol-lowering drugs like statins would likely not be effective as they target blood cholesterol rather than lymph node-specific accumulation.