Dietary Flaxseed May Protect Body Tissues After Radiation Exposure
Lung tissue is especially sensitive to radiation, causing injuries such as pneumonia-like inflammation and late-stage fibrosis in up to 30% of patients irradiated for lung cancer and about 10-15% of other thoracic oncology patients. The need to protect this tissue makes it difficult to deliver optimal radiotherapy doses. Researchers from the Perelman School of Medicine may have found a cheap, easy solution in dietary flaxseed.
Oral Flaxseed Beneficial as Preventative Also
In a study, published in the journal BMC Cancer, a research team led by Melpo Christofidou-Solomidou, PhD, a research associate professor of Medicine, Pulmonary, Allergy and Critical Care, fed a group of mice a diet supplemented with 10% flaxseed either at three weeks before a dose of X-ray radiation to the thorax or at 2-week intervals after radiation exposure. A control group of animals received the same radiation dose, but their isocaloric diet did not contain the supplement.
Flaxseed appeared to mitigate the effect of the radiation and protected the mice from radiation pneumonitis. After four months, only 40% of the irradiated control group survived, compared to 70-88% of the flaxseed-fed mice. The animals fed the supplement also had increased blood oxygenation levels, higher body weight, lower pro-inflammatory cytokine levels and reduced pulmonary inflammation.
The flaxseed supplement also appeared to prevent fibrosis, a hardening or scarring of lung tissue that is untreatable. “There’s nothing you can give to patients to prevent fibrosis,” Dr. Christofidou-Solomidou said. “Once a lung becomes “stiff” from collagen deposition, it’s irreversible. We have discovered that flaxseed not only prevents fibrosis, but it also protects after the onset of radiation damage.”
Fibrotic lung disease is believed to occur when reactive oxygen species (ROS) is induced by exposure to ionizing radiation. The active component in flaxseed, known as secoisolariciresinol diglucoside or SDG, is thought to have antioxidant properties. Dr. Christofidou-Solomidou says the bioactive lignan also “regulates the transcription of antioxidant enzymes that protect and detoxify carcinogens, free radicals and other damaging agents.”
Flaxseed also has other qualities that make it attractive as a radioprotector. It is safe, cheap, and readily available, says Dr. Christofidou-Solomidou. It can also be stored for long periods of time, making it especially interesting to government officials looking to stockpile radioprotective substances in case of accidental or terrorist-caused radiological disasters.
The researchers are conducting additional pilot studies on flaxseed, including the mitigation of lung damage in patients awaiting lung transplants and in astronauts on extended deep space missions who face exposure to high levels of solar and galactic radiation on extravehicular activities (EVAs).