Inflammation linked to cancer, lifestyle changes may help
Experts have long suspected that inflammation may play a role in the development of cancer. In 1863, German scientist and physician Rudolf Virchow was the first to make contact and noted that cancer often develops at sites of chronic inflammation. But researchers have only recently identified chronic inflammation as a major risk factor for cancer and other serious health conditions. Among the reasons science has taken so long to confirm the link: Chronic inflammation causes few, if any, outward symptoms. Inflammation itself is a sign that the body is doing its job.
The concept of inflammation is sometimes difficult to understand because it can seem counter-intuitive. For one thing, inflammation is a healthy process that is essential to the body’s ability to heal itself. When you have an infection or injury, your immune system releases white blood cells and chemicals to fight infection or repair damaged tissue. But when inflammation persists, or when your immune system triggers an inflammatory response when you don’t have an infection or injury, such as those caused by arthritis and other autoimmune diseases, it can damage healthy tissue. “Chronic inflammation is sometimes called ‘latent inflammation’ because it’s inflammation that never goes away. It’s the opposite of ‘good’ inflammation, which your body uses to get rid of bacteria and viruses, and then once it hits its target, it recovers,” says Eugene Ahn, M.D., medical director. For clinical research and hematologist/oncologist from. Chicago Hospital.
Today, researchers have a fairly broad understanding of the personal split of inflammation. They have learned that sometimes chronic inflammation is caused by factors beyond our control, such as inherited genetic mutations that increase the risk of chronic inflammation. But it can also be the result of lifestyle choices that can change. This is important because so-called lifestyle-dependent inflammation is on the rise. “The link between inflammation and cancer has been clear for a long time, but it can be brought into focus now more clearly because of the lifestyle-dependent increase in inflammation we’re seeing,” says Dr. Ann.
The role of chronic inflammation in the development of cancer is not small. One in five types of cancer is thought to be caused by or affected by inflammation. One reason is that chronic inflammation can damage DNA, says Cynthia Lynch, MD, medical director of the CTCA. ® Breast Cancer Center, Phoenix and Medical Oncologist at Phoenix Hospital. Other times, the inflammatory process produces molecules called cytokines, which stimulate the growth of blood vessels that carry oxygen and nutrients to the tumor. The process can also generate molecules called free radicals that further damage DNA. These side effects of inflammation can help keep and stimulate cancer growth.
The reason why inflammation turns into a chronic condition isn’t always clear. It can be caused by an infection that does not go away, abnormal immune reactions to normal tissues, or by certain conditions such as obesity. Over time, chronic inflammation can damage DNA and lead to diseases such as heart disease, type 2 diabetes, stroke, and cancer. “Anything that causes inflammation will make the cell’s DNA replicate faster,” says Brad Mons, MD, a head and neck surgeon at our hospital in Tulsa. “The more your cells multiply, the more likely you are to develop cancers.”
Chronic inflammation that causes cancer sometimes comes from a disease characterized by inflammation. The diseases of colitis, pancreatitis and hepatitis, for example, are associated with an increased risk of colon, pancreatic, and liver cancers, respectively. In these diseases, immune cells create highly reactive molecules containing oxygen and nitrogen that can damage DNA. Inflammation can also cause cells to divide.
Chronic inflammation can also result from chronic infections, such as H. pylori, which is associated with gastric cancer, and hepatitis B and hepatitis C, which are associated with liver cancer. HIV increases the risk of infection with viruses and very rare cancers, including Kaposi’s sarcoma, non-Hodgkin’s lymphoma, and invasive cervical cancer.
In other cases, the culprits are environmental factors. Exposure to asbestos, for example, increases the risk of developing mesothelioma. In fact, many cancer-causing environmental factors and risk factors are associated with some form of chronic inflammation. According to the National Institutes of Health, up to 20 percent of cancers are linked to chronic infection, 30 percent are linked to smoking and inhaled pollutants, such as asbestos, and 35 percent are linked to dietary factors including obesity. “Whether it’s from an autoimmune disease like lupus or rheumatoid arthritis, or irritation from a chemical you might be exposed to, like asbestos, if we can reduce the amount of inflammatory processes in our environment, we can reduce the risk of cancer,” Dr. Mons says.
Today, researchers are exploring whether the body’s oxygen sensors can be manipulated to reduce chronic inflammation. One study found that tricking immune cells into thinking they lacked oxygen causes them to withdraw from the site of inflammation to conserve energy. Researchers are now studying whether drugs can be developed to activate specific proteins, which when activated dampen the body’s inflammatory response.
Evidence is also mounting that aspirin can help prevent chronic inflammation. A non-steroidal anti-inflammatory drug works by reducing the production of prostaglandins, which are chemicals that increase inflammation, pain, and fever. In a 2016 report published in the Journal of the American Medical Association , researchers who studied aspirin use in 135,000 patients concluded that “Long-term aspirin use was associated with a modestly lower risk of cancer but a significant reduction in overall cancer risk, especially gastrointestinal tumours.” Regular use of aspirin can prevent a significant proportion of colorectal cancers.“Already in the United States, tens of millions of adults are taking aspirin to reduce the risk of heart attack or stroke.” “Preventing certain types of cancer is unreasonable,” says Dr. Ann. .
The United States Preventive Services Task Force now recommends that some adults ages 50 to 59 take low-dose aspirin to help prevent colorectal cancer and suggests that older adults consider an aspirin regimen as well. “Aspirin is also being considered to treat other types of cancer, but at the moment there isn’t much information on anything other than colorectal cancer,” says Dr. Lynch.
With 35 percent of cancers linked to nutritional factors such as obesity, stress and lack of exercise, the link between lifestyle habits and inflammation remains a concern. These factors trigger an immune response, even without infection, to fight or heal tissues. “The reason inflammation is getting so much attention in the press right now is that so much of it depends on our lifestyle,” says Dr. Ann. “The more sedentary you are, and the poorer your diet, the more inflammation it causes.”
In fact, a 2016 report by the American Institute for Cancer Research found that maintaining a healthy weight may be just as important as avoiding tobacco and excessive sun exposure. The American Cancer Society found that those who lead a healthy lifestyle — by eating a nutritious diet, limiting alcohol consumption, and taking other important steps — are 10 to 20 percent less likely to develop cancer.
Dr. Lynch says diet and exercise top the list of healthy lifestyles. Even small changes can make a difference, like adding more plant foods that contain anti-inflammatory phytonutrients to your plate and eating more fermented foods, like yogurt and miso, which contain natural inflammation-reducing probiotics. Also try to avoid carcinogens such as asbestos, silica and tobacco, and if you have a condition such as hepatitis B or hepatitis C, seek treatment.
Experts also recommend limiting processed foods, which can increase the risk of throat cancer. “It’s not important, but the risk is greater than that of someone who eats fresh produce, because these preservatives act as irritants,” says Dr. Mons. Alcohol can also act as an irritant, especially to the head and neck, the area where food or drink is touched when swallowing. Another concern: alcohol and its products can damage the liver and cause inflammation in the organ.
Bottom line: focus on what you can change. Dr. says. Ahn. “This is where the lifestyle comes in.”