New research funded by the World Cancer Research Fund (WCRF) Network shows that dietary interventions can improve the quality of life of, as well as lower depression in, colorectal cancer survivors.
The study was carried out by researchers at the University of Hong Kong and the University of Birmingham, UK. The study looked at 223 people with a range of stages of colorectal cancer (stage I to IV). The trial measured both the general quality of life and cancer-specific quality of life, such as levels of pain and fear of dying from their illness.
The research shows that people who ate less red and processed meat and refined grains after their cancer treatment reported a better quality of life after 12 months than those who did not receive the intervention and instead had “usual care.” Those who reported a better quality of life also had significantly lower levels of depression.
The “usual care” consisted of receiving five leaflets on healthy lifestyles by mail over a 12 month period. Whereas the intervention included a mix of face-to-face meetings, motivational phone calls, newsletters, group meetings and information leaflets specific to how motivated each person was to change their behavior.
“Our research shows that a structured intervention with a focus on eating healthier, by reducing red and processed meat consumption and eating more whole grains, can alleviate depression and improve quality of life in colorectal cancer patients who have just completed cancer treatment,” says Dr. Judy Ho, lead researcher of the study. “Next steps and future research should apply these dietary interventions to longer-term studies, and crucially, look at how diet affects cancer recurrence.”
This research focused mostly on colorectal cancer survivors and consumption of red and processed meat and refined grains – both of which are linked to colorectal cancer. Thus, a healthy diet is high in whole grains instead of refined grains, limits red meat to three portions a week and avoids processed meat.
The researchers acknowledge that future research is needed to test whether healthier diets can improve quality of life and depression over a longer time period, as the study only followed people for two years. However, this is an important starting point for research on cancer survivors, diet and quality of life.
“Randomized trials provide causative evidence not just associations,” says Dr. Nigel Brockton, Vice President of Research at the American Institute for Cancer Research (AICR). “Therefore, despite being a relatively small study, this trial provides the highest quality evidence that positive dietary changes can actually improve quality of life.”
“As more and more people are surviving cancer thanks to improved treatments and earlier diagnosis, it becomes increasingly important to find ways to help people live well after a cancer diagnosis,” says Dr. Anna Diaz Font, Head of Research Funding at WCRF. “We know that diet is linked to cancer risk, but it is encouraging that it may also help people have a better quality of life after cancer.”
This study only looked at colorectal cancer survivors in Hong Kong, so more research is needed to see if there are similar results for other cancers, but also for people living in different countries and of different ethnicities. However, this study is a great starting point and shows promising results for cancer survivors.
Q: What is the difference between whole grains and a refined grain?
A: Whole grains are products made from the entire grain seed, which consists of the bran, germ and endosperm. The refining of whole grains usually removes the germ and outer layers of the grain, thereby reducing the presence of fiber and micronutrients. Refined grains include white rice, white bread or white pasta, and the whole grain version would be brown rice, brown bread or brown pasta.
Q: What counts as red meat and what counts as processed meat?
A: Red meat is any pork, beef or lamb. Processed meat, which is usually also red meat, has been smoked, cured or had salt or chemical preservatives added, rather than having just been cooked or reformed (like most sausages and burgers). Processed meat includes bacon, salami, chorizo, corned beef, pepperoni, pastrami, hot dogs and all types of ham.