Radiation For Cancer Is Less Effective In Obese Patients

Obese patients are more resistant to radiotherapy and have higher rates of cancer recurrence than non obese patients. Obesity has reached pandemic levels in most parts of the world and has recently surpass smoking as the number one cause of preventable cancer. In order for radiotherapy to be effective, it needs to directly kill cancer cells as well as trigger the immune system to clear out the damaged cells. The success of radiotherapy is based on its ability to cause DNA damage and kill the tumor cells, as well as the immune system’s response to the damage.

Radiotherapy resistance is a phenomenon that occurs when patients have less tumor shrinkage and higher cancer recurrence rates after radiation. It’s an indicator of poor prognosis. According to UC Davis Comprehensive Cancer Center researchers, “Our preclinical data show increased tumor resistance to radiotherapy in obese mouse cancer models. Clinical data also demonstrate that obese cancer patients are more resistant to radiotherapy and have higher rates of cancer recurrence”. Not many studies have addressed what causes radiotherapy resistance in obese patients. “Some researchers have hypothesized that this resistance is a matter of physics, as it’s just harder to deliver radiation in larger patients, which may be true. But we think that there is a biological difference between cancers in obese patients and those in lean patients and the way that cancer responds to radiation.”

How does obesity impair the effects of radiotherapy?

The research team’s previous studies showed that obesity could alter the growth, spread and survival of cancer cells. They found that the obesity linked hormone leptin could influence cell death and post survival pathways of cancer cells. Leptin is a hormone produced by fat cells. It plays a key role in regulating the body’s energy and metabolic status, inflammation and body weight. Leptin is abnormally high in obese patients. You can get a blood test to measure your leptin level if you’re curious. Your immune system plays a role in how tumors respond to radiotherapy. Obesity makes cancer patients more resistant to radiation by causing immune dysfunction. Being overweight suppress the adaptive T cell response in the tumor microenvironment, impairing the immune response.

According to immunologist William Murphy, co-investigator of the study “The microenvironment surrounding the cancer cells provides nourishment for the tumor. Obesity can help feed this environment and protect the cancer cells. Obesity potentially helps tumors adapt and become resistant to radiation in a nutrient rich environment. It can also result in greater inflammatory responses, allowing the cancer to spread more as well as suppress immune attack.”

In the past, cigarettes were the greatest lifestyle factor responsible for cancer. Now obesity has taken over; largely driven by the consumption of sugar, refined carbohydrates and industrial seed oils. Not enough people realise that being overweight creates enormous hormonal and metabolic problems in the body. Fat cells secrete hormones and inflammatory chemicals that create havoc in the body. In women, fat cells produce higher levels of estrogen, and this is associated with a higher risk of breast and endometrial cancer. Overweight people typically have higher blood levels of the hormones insulin and insulin-like growth factor 1. These are both growth promoting hormones and if a tumor is present in the body, these hormones act as fertilizer.

Maintaining a healthy body weight is one of the best ways to look after your health. I recommend the following strategies:

• Berberine is a plant extract that helps to reverse the metabolic disturbance caused by being overweight. This is because it works to reverse insulin resistance. It helps with weight loss (particularly from the torso) and improves blood sugar control in type 2 diabetics.
• If you are having difficulties losing weight, there is a detailed easy to follow guide in my book I Can’t Lose Weight and I Don’t Know Why. It is a low carbohydrate eating plan that will help reduce your blood level of the hormone insulin and leptin.
• A healthy liver is very important for weight control. This is because the liver can store glucose and fat, and also produce glucose and fat. You want your liver to be good at fat burning. People with a healthy liver have a fast metabolism and don’t gain weight as easily. Unfortunately a lot of people have a fatty liver and their liver is doing the opposite of what it should be doing – it is very busy making fat. A healthy liver also helps to control your blood sugar level. If you have not eaten for several hours, your liver is supposed to release some stored glucose into your bloodstream to give you energy and keep hunger at bay. People with a sluggish liver struggle with this and they often feel excessively hungry, weak or irritable if they have gone several hours without food. It makes sticking to a diet extremely difficult! To help improve your liver health I recommend taking a good quality liver tonic like Livatone Plus to provide the nutrients your liver requires in order to burn fat and detoxify your bloodstream more effectively.
• Stress eating is an increasingly common problem. Anxiety, depression and stress are rising in society. Magnesium is a mineral that relaxes your muscles and nervous system. It enables your brain to make more of the calming neurotransmitter GABA. Most people don’t get enough magnesium in their diet because soils in most parts of the world are depleted. Alcohol, caffeine and elevated blood sugar increase urinary loss of magnesium.

For more information about cancer see the book Cancer Survival Strategies.

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The above statements have not been evaluated by the FDA and are not intended to diagnose, treat or cure any disease.