We’ve all been there. We’ve been betrayed, hurt— either intentionally or unintentionally— or experienced some form of grief we may deem as downright unfair. Afterwards, everyone is faced with the choice to either forgive and let go, or harbor those ill feelings of pain and disappointment. But studies have linked the latter– holding on to a grudges– to physical illnesses like cancer.
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According to one Howard University scientist, the weight of unforgiveness might do more than just strain relationships— it could take a toll on the body altogether. Although cutting folks off has practically become a cultural sport in the Black community, some experts say the emotional strain that follows might do more harm than good. Said research has led to a deeper conversation about how much it really costs to stay mad.
Stress, resentment, and unresolved anger don’t just live in our heads — they can manifest physically through fatigue, tension, and even illness. Even comedian and former talk show host Steve Harvey gave his take on how holding resentment “is like a cancer,” detailing how it eats away at you from the inside out. And it seems experts agree.
Dr. Patrick Ijewere, a medical consultant at Howard University, said in a 2025 report that these emotional burdens are directly tied to disease. A project known as “The Forgiveness Project” explored the connection between human behavior and disease, reportedly revealing a correlation between difficult-to-treat cancers and unforgiveness, which Ikewere cites in his discoveries.
“Of all cancer patients, 61 percent have forgiveness issues, and of those, more than half are severe,” he stated, per Restored to Freedom. “Harboring negative emotions like anger and hatred creates a state of chronic anxiety that raises cortisol levels and suppresses the immune system.”
“One of the major causes of rapid cancer cell mutation is by the presence of negative emotions which includes, hate, grief and others which can lead to depression,” he stated. “When there is a breakdown of immune system, the normal cells mutate into cancer cells which make them spread fast.”
He continued: “The bad news is that when the body is not relaxed, the mind will not relax sufficiently enough to enter the deep-sleep-cycle to produce melatonin, which is the primary hormone responsible for inhibiting cancer cells growth.’’
Dr. Steven Standiford, chief of surgery at the Cancer Treatment Centers of America, echoes that sentiment, urging that refusing to forgive folks can make people sick and even interfere with the decisions they make leading up to treatment.
“It’s important to treat emotional wounds or disorders because they really can hinder someone’s reactions to the treatments, even someone’s willingness to pursue treatment,” Standiford explained per CBN News.
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