Your blood type may reveal more about your health than you think. Recent medical research shows that people with blood type A could face a higher risk of certain diseases — not because of lifestyle choices alone, but due to genetic and immune system differences that subtly influence how their bodies respond to infections, stress, and inflammation.
While everyone is susceptible to common illnesses, scientists say that individuals with blood type A have distinct biological traits that may make them more vulnerable to cardiovascular issues, digestive cancers, autoimmune conditions, and stress-related disorders.
Multiple studies, including those published in the European Heart Journal and Harvard Medical School reports, have found that people with blood type A tend to have higher levels of low-density lipoprotein (LDL) — commonly known as “bad cholesterol.”
LDL contributes to the buildup of plaque in arteries, increasing the risk of atherosclerosis, heart attack, and stroke.
In contrast, people with type O blood generally have lower cholesterol levels and a slightly reduced cardiovascular risk.
“Blood type A is associated with higher cholesterol and inflammatory responses,” explained Dr. Rachel Kim, a cardiovascular researcher at Johns Hopkins University. “This combination can accelerate heart disease if not managed through diet and lifestyle.”
To reduce the risk, experts recommend a Mediterranean-style diet, regular physical activity, and periodic cholesterol screening — especially for men and women over 40 with type A blood.
Another major health concern linked to blood type A is stomach (gastric) cancer.
Studies from Japan, South Korea, and the World Health Organization (WHO) have shown that individuals with type A blood are more likely to be infected with Helicobacter pylori — the bacteria responsible for ulcers and many cases of gastric cancer.
This vulnerability stems from the body’s lower production of stomach acid, which makes digestion less efficient and allows harmful bacteria to thrive.
“Low acid levels create a perfect environment for H. pylori infection,” said Dr. Josephine Abbo, a gastroenterologist at Mulago National Referral Hospital in Uganda. “Over time, this can cause chronic inflammation, which increases the risk of stomach cancer.”
To stay safe, people with type A blood should avoid smoking, eat less processed meat, include more fruits, vegetables, and probiotics, and get screened for H. pylori if they experience frequent indigestion or unexplained stomach pain.
Blood type A individuals may also face heightened immune reactivity — a double-edged sword that helps fight infections but can backfire when the immune system mistakenly attacks the body’s own tissues.
This makes them more susceptible to autoimmune diseases such as:
• Type 1 diabetes
• Rheumatoid arthritis
• Celiac disease
• Autoimmune thyroid disorders (Hashimoto’s or Graves’ disease)
“Type A immune profiles tend to be more inflammatory,” noted Dr. Samuel Lwanga, an immunologist at Makerere University. “In chronic stress or infection, this hyper-reactivity can trigger autoimmune responses.”
Regular check-ups, a balanced diet rich in omega-3s, and adequate sleep can help regulate the immune system and reduce flare-ups.
Blood type A individuals are also known for higher baseline levels of cortisol, the primary stress hormone.
While cortisol helps the body respond to threats, prolonged elevation can suppress immunity, raise blood pressure, and increase anxiety and fatigue.
According to the American Psychological Association, people with this blood type may need to take extra steps to manage stress — including mindfulness practices, yoga, adequate rest, and limiting caffeine.
“Type A personalities are often high achievers and perfectionists,” says psychologist Dr. Angela Moyo. “Combined with their biological predisposition to higher cortisol, this can make stress management a lifelong priority.”
While blood type A can influence disease risk, it’s not a guarantee of poor health.
Doctors emphasize that lifestyle choices — including nutrition, exercise, and regular medical screening — remain the most important determinants of long-term wellness.
“Your genes set the stage, but your habits write the story,” Dr. Kim added. “Knowing your blood type simply helps you make smarter preventive choices.”
