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If You Have This Blood Type, Be Worried About Cancer

Experts explain why you should know your blood type and what you could be at risk for healthwise. 
FACT CHECKED BY Emilia Paluszek

In a medical emergency knowing your blood type can be a matter of life and death, but it can also provide valuable insight into your overall health. There's been several studies that indicate people with certain blood types are at greater risk for GI related cancers and Dr. Tomi Mitchell, a Board-Certified Family Physician with Holistic Wellness Strategies tells us, "It's essential to understand that your blood type is just one risk factor for developing cancer. So even if you have a family history of cancer and your blood type puts you at higher risk, there are still things you can do to lower your risk." Eat This, Not That! Health spoke with experts who explain what to know about your blood type and the association with cancer. Read on—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


The Four Blood Groups

lab assistant holding test tube with blood while standing in

Dr. Mitchell explains, "There are four blood types: A, B, AB, and O. Each blood type has a different combination of proteins called antigens on the surface of red blood cells. These antigens determine which blood type a person has. A person's blood type is determined by which antigens are present on their red blood cells. Type O is the most common blood type, followed by Type A. Type B blood is less common, and Type AB blood is the least common."


Why Sugar Matters

A male scientist/doctor holding a test tube marked Blood Test with group AB circled.

Dr. Srikanth Nagalla, chief of benign hematology, Miami Cancer Institute shares, "There are sugars and then there's a protein, so carbohydrate and protein. So the protein that it's called is the H antigen, and to that, you add these different sugars. And depending upon that, you get a, that it's A,B, AB, or if you're completely lacking the sugars, then it's called the O because O doesn't have the sugars. So, what I'm trying to get at first is how do you get this classification? Okay, what is blood group B? So for that, if you imagine like the red blood cell, because for that red blood cell, you have an H antigen like the alphabet H and to that antigen, you add sugars. And finally, if you don't have any sugars added, that becomes O now the reason this is important to start off with this, because once you know this, you understand that this is present not only on the blood cells, on the red blood cells, it's present in the gastro tract, like the PT cells of the GI tract. That's your stomach pancreas. It's also present in your broncho reference in your bronco, the lungs, the pulmonary area, the bronco pulmonary area, it's in the genital urinary area." 


Blood Types Associated with Pancreatic Cancer

Doctor in white medical lab coat points ballpoint pen on anatomical model of human or animal pancreas

Dr. Nagalla says, "There are a lot of retrospective studies that were done in the past, but the very well done study for us or prospective looked at, or two big cohorts called the Nurses Health Study. And then the Health Professionals follow- up study, which has roughly hundred seven patients or so not patients hundred seven people like health professionals. And then they were, they were followed and everything. What this study particularly showed was something to do with the risk of A, B or AB blood groups and pancreatic cancer. Meaning if you're not an O if you're non O blood groups, you could be a, you could be B or you could be a, then you get some increased risk of pancreatic cancer. Why is this happening?" 

Dr. Mitchell adds, "According to a new study, if you have blood type A, B, or AB, you may be at increased risk for cancer. The study, which is the largest of its kind, looked at almost 140,000 people with cancer and found that those with blood type A or B were more likely to develop the disease than those with blood type O. The risk was even higher for women with blood type AB. While the exact link between blood type and cancer risk is unknown, the study's authors say that it could be due to differences in how blood type A and B cells bind to sugar molecules. This difference could make it easier for cancer-causing agents to attach to blood cells and cause mutations. The findings are preliminary and more research is needed to confirm blood type and cancer risk. However, if you have blood type A, B, or AB, it may be worth discussing your cancer risk with your doctor."


Inflammation is Greater with Certain Blood Types

body inflammation

Dr. Michael Hirt, a Board Certified Nutrition from Harvard University and Board Certified in Internal Medicine and is with The Center for Integrative Medicine in Tarzana California explained, "Chronic inflammation has been linked to increased cancer risk.  Blood types that are associated with increased inflammation (like A and B) have been linked to increased risk of cancers, while the 'O' blood type is associated with lower cancer risks because it is associated with less inflammation.  This is the same reason that type 'O' blood had a small but statistically significant reduction in COVID-19 disease severity."

Dr. Nagalla says, "If you go into the hypothesis, right? The theories of that for example for people who have blood group A and others are more prone to get H Pylori infection. So they're more prone to those infections. What does it mean? Maybe because of that they have higher inflammation and higher inflammatory condition that is causing some of these cancers because blood, the other thing they found that is when you have these changes, when you have, um, these blood group, a people and other things, or when they, when they looked at normal cells versus the pancreatic cancer cells, normal pancreatic based, they found that the pattern of the protein, the sugars that I started saying to tell you about what makes A, B sugars, the pattern was likely different between the cancerous cells and the normal cells. Maybe these things are getting altered in the cancerous cells due to other mutations and took off of that. These cells might have an altered signaling because cells have to signal among each other and inside. And these cells might also escape immune surveillance. What is immune surveillance? Why doesn't everybody get cancer? Because the immune system is constantly looking for bad cells and killing them, or making sure that they don't grow. But when you have some of these alterations, apparently in some of these patients. It's possible that these cells are escaping the immune system and their cancer gets to grow. These are all hypotheses of why it may happen. So there's not a definite reason why certain blood types are more prone to a certain type of cancer." 


Don't Panic


Dr. Nagalla states, "We are not going to use blood groups and say, based on this, you need more screening because you have blood group A blood group, a B or blood group AB, you need to be more closely followed or screened. You are not gonna do anything different because there's no data for that. Because, and a lot of times there's a difference. This is just an association, meaning this just because you have pain, you're not getting pancreatic cancer. It so happens that a little bit more of blood group A patients are having pancreatic cancer compared to blood group O patients. It could be, this is just a marker of something else. And maybe some of the genes that are associated with the ABO gene are getting dysregulated. People with O might be reassured there's a little bit less risk, but it's not like people with A are all going to get cancer or something like that. It's just an association. The main thing we want to stress is that these are all associations. It doesn't mean much because overall the absolute number is still tiny. We don't have to do anything different just because of a blood type."


Lifestyle Changes That Help Prevent Cancer


Dr. Mitchell reminds us, "Remember, cancer is a complex disease, and many factors can contribute to an individual's risk. While blood type is one important piece of the puzzle, many other controllable risk factors can significantly impact cancer risk. For example, I focus on lifestyle factors that prevent and decrease cancer risk in my clinical practice. These include diet, exercise, smoking cessation, and alcohol consumption. While blood type may be out of our control, there are many things that we can do to lower our cancer risk. By making healthy lifestyle choices, we can all play a role in cancer prevention.


Quit Smoking


Smoking is the leading cause of preventable death in the United States and is responsible for more than 480,000 deaths each year. Smoking causes more deaths each year than the following causes combined: human immunodeficiency virus (HIV), illegal drug use, alcohol use, motor vehicle accidents, and firearm-related incidents. Smoking is also a significant contributor to cancer death and disease. Smoking causes an estimated 90% of lung cancer deaths in men and almost 80% of lung cancer deaths in women. Smoking also causes cancer of the larynx, mouth, pharynx, esophagus, kidney, bladder, liver, pancreas, stomach, cervix uteri, and myeloid leukemia. Smokers are also at increased risk for pneumonia and other lower respiratory tract infections. For example, quitting smoking reduces the risk of smoking-related diseases and can add years to your life. In addition, people who quit smoking before age 50 have half the risk of dying from smoking-related causes as those who continue to smoke. Quitting smoking at any age can give back years of life that would be lost by continued smoking.


Eat a Healthy Diet

woman eating salad

Though smoking remains the leading cause of cancer, lifestyle choices such as diet can significantly impact cancer risk. A healthy diet includes plenty of fresh fruits and vegetables, whole grains, lean protein, and healthy fats. It's also low in processed foods, salt, and sugar. Studies have shown that following a healthy diet can lower the risk of several types of cancer, including breast, colon, endometrial, and stomach cancer. There are a few possible explanations for why a healthy diet may reduce cancer risk. First, fruits and vegetables contain antioxidants that help to protect cells from damage. They also contain phytochemicals that can boost the immune system or prevent the formation of cancer-causing substances. In addition, a healthy diet is typically low in fat and calories, which may help reduce the risk of obesity-related cancers. Of course, no single food or group can guarantee cancer prevention. But following a healthy diet is a straightforward way to lower your risk. Combined with other lifestyle choices such as not smoking and maintaining a healthy weight, it could make a big difference in your health.


Exercise Regularly

woman lacing her shoes before a workout

There are many ways that exercise can help to reduce cancer risk. For one, exercise helps to maintain a healthy weight, which is essential since obesity is a risk factor for several types of cancer. Exercise also helps to improve immune function, making the body better able to fight off cancer cells. Additionally, exercise boosts antioxidants and other protective substances in the body, which can help reduce oxidative damage and inflammation, both of which can contribute to cancer development. Research has shown that people who exercise regularly have a lower risk of developing cancer than those who are inactive. So, if you're looking for ways to reduce your cancer risk, adding some exercise to your routine is a great place to start.


Maintain a Healthy Weight

weight fluctuates

Maintaining a healthy weight is one of the best things you can do to reduce your cancer risk. Obesity is a significant risk factor for cancer, and being overweight increases your chances of developing the disease. How exactly does obesity contribute to cancer? One theory is that obesity increases inflammation throughout the body, leading to the development of cancer. Additionally, obese individuals tend to have higher insulin and other hormones linked to an increased risk of cancer. Exercise is one of the best ways to maintain a healthy weight, and it has also been shown to reduce inflammation and improve hormone levels. Furthermore, exercise has been shown to boost the immune system, making it more likely to fight off cancer cells. In other words, maintaining a healthy weight through exercise can reduce your risk of cancer in multiple ways.


Speak to Your Doctor

Healthcare worker at home visit

In addition, some helpful blood tests can give you more information about your specific risks. For example, the genetic test for Lynch syndrome can show whether you have an increased risk for certain types of cancer. For example, if you have a strong family history of cancer, talk to your doctor about these tests and how they can help you make informed decisions about prevention and early detection." And to protect your life and the lives of others, don't visit any of these 35 Places You're Most Likely to Catch COVID.

Heather Newgen
Heather Newgen has two decades of experience reporting and writing about health, fitness, entertainment and travel. Heather currently freelances for several publications. Read more about Heather