23. Can forgiveness reduce cancer?
In a previous post, I asked if there was a cancer of the soul. There are so many parallels, that there are two cells living right next to each other, cooperating, sharing nutrients and structure. But then, one goes rogue. It becomes feral. It abandons all connection to its’ closest companions and takes off on its’ own path. It lies that it is friendly, but it actually is stealing resources and attacking those right next to it. The same dynamic occurs in cancer as in betrayal. The initial trust and collaboration is secretly undermined by one member of the duo, until the complete selfishness, the lies and the theft explode into view, resulting in terrible devastation and frequently the death of the friendship or marriage. The betrayed person feels anger, rage, depression, or helplessness.
The antidote to the bitterness of betrayal is to choose to forgive. And when people do, they consistently report better health (see here). It is not just a correlation, when people put forth the effort to forgive, they have better blood flow in the heart, less fibromyalgia symptoms, and even more relief from pain medication. These results alone are enough to motivate people to take the steps to forgive. Yet there is a question that pulls at you, as a reader of this blog. Does forgiveness reduce the risk of cancer? Is there another step you can take to improve your health, to keep that dread disease away from you?
The first answer is a ‘yes’. A summary of 103 studies found that forgiveness is clearly associated with better psychological health.[i] This is a robust finding, as it showed up in 17 countries, with over 23,000 people of diverse backgrounds in the studies. One of the criticisms of psychology is that it is too focused on North American, or European samples. But if forgiveness improves mental health in Iran and South Africa, just as much as it improves it in France, then it is a universally validated finding. This actually makes me pause and take a second look at how psychotherapy is done. I have attended multiple workshops and read many books on psychotherapy. Yet forgiveness is not a central theme in how to do therapy . Cognitive-behavioral therapy has people change their negative thoughts, which is helpful for many, but it does not put a spotlight on forgiving people who have caused you harm. Yet if the act of forgiveness consistently improves mental health, then should we not be sure to put that tool in the toolbox?
Now I see a keener (a Canadian version of a nerd) put their hand in the air. Yes, you are right. An association does not prove that forgiveness causes better mental health. Maybe the reverse is true. That is why we need longitudinal studies, which are a lot harder and more expensive to do. Thankfully, several teams have gone to this trouble. One group of researchers followed 332 adults for 5 weeks and had them report every week. When people had higher levels of forgiveness, they experienced lower levels of stress. The decrease in stress then led to better mental health. The reverse pattern was not found, ruling out that good mental health leads to forgiveness[ii] This is good social science. They had a nice sample size, a wide range of ages, and repeated measures.
But there is more. A study of over 54,000 nurses, across three time-periods, confirmed these findings. The nurses who forgave others most frequently had significantly fewer symptoms of depression, anxiety, hopelessness and loneliness than those who seldom forgave others. They also were more socially integrated.[iii] Now, I know what the nerds are thinking, that even though this is a huge sample size, it is of a specific group of people, which is nurses. So, the researchers looked at the adult kids of these nurses. The results were a photocopy of what had been observed with their parents. Young adults who forgave others nearly all the time had significantly more life satisfaction, positive emotions, and self-esteem, and less symptoms of depression and anxiety than those who never forgave others.[iv]
The data is in, and the conclusion is as solid as when my father welded two pieces of thick steel together. Forgiving other people[v] is a reliable and consistent way to improve your mental health. It will increase your satisfaction in life, positive emotions, and decrease your depression and anxiety. And as we saw with the nurses, it will also increase your integration into your social network. People want to be around someone who is calm, and peaceful. However, if someone is radiating anger to someone in their past, even if it is subtle, it causes others to be uneasy. They start to wonder, even unconsciously, if this person hates someone else, will they start to hate me? Bitterness has an effect of repelling the people around you, causing them to detach emotionally.
For you as a cancer survivor (or someone who loves one), the improvement in mental health from forgiving others is a step that is well worth taking. However, you still have a second question. Does forgiving others help me to live longer? Here, the answer is less clear.
We know that being unforgiving of others leads to poor mental health. This raises the question as to how much depression, anxiety, and psychological distress influence cancer recurrence, and mortality. After reading about the impact of various psychological factors on cancer, you can probably guess what the results are. Yup, having symptoms of depression and anxiety result in higher rates of cancer recurrence and mortality. This is a solid finding, based on many studies of over 280,000 breast cancer survivors.[vi] Looking at all types of cancer, a 6 year follow up of over 3000 cancer survivors found that higher levels of depression resulted in higher rates of cancer recurrence and mortality.[vii] [viii] This is an important finding, and we will expand on it in future posts on this blog. It also is motivation to take whatever steps you can to improve your mental health, including forgiving others. Better mental health leads to a longer lifespan among cancer survivors.
Although there are large studies looking at the impact of mental health on cancer recurrence, there are none looking at forgiveness and cancer recurrence. There are studies that looked at whether forgiveness increased the risk of getting cancer in the first place, but the participants (nurses and their offspring) were relatively young, and no effect was found. It could be that the impact of bitterness shows up when cancer usually does, which is among older adults. Research in forgiveness is relatively recent, so our understanding is incomplete.
However, you already have solid reasons to step into forgiveness. There is a punchy saying that “Carrying bitterness to someone is like drinking poison and expecting them to die.” I lived that out for years, experiencing the poison, and working hard to forgive so that I was free of it. Along the way, I experienced exactly what the research said I would. My mood improved, my mind cleared up, my body felt healthier, my sleep was more settled, and my relationships were closer. This is exactly what I want for you as well. Yes, forgiving someone is hard, but carrying your anger to them is a much, much harder way to live. I encourage you to take the steps toward freedom. An excellent guide in this process is the book by Dr. Robert Enright, Forgiveness is a Choice. If the wound is really deep, a therapist or spiritual leader can be quite helpful to guide you along the way. They can facilitate you acknowledging the full scope of the hurt and anger and empathize with you. They can walk with you along the path of forgiveness, to greater mental and physical health. If you have gone through this process, then feel free to leave a comment as to how forgiveness has improved your mental health.
[i] Rasmussen KR, Stackhouse M, Boon SD, Comstock K, Ross R. (2019). Meta-analytic connections between forgiveness and health: The moderating effects of forgiveness-related distinctions. Psychol Health. May;34(5):515-534. doi: 10.1080/08870446.2018.1545906. PMID: 30632797
[ii] Toussaint LL, Shields GS, Slavich GM. (2016). Forgiveness, stress, and health: A 5-week dynamic parallel process study. Ann Behav Med. Oct;50(5):727-735. doi: 10.1007/s12160-016-9796-6. PMID: 27068160
[iii] Long KNG, Worthington EL Jr, VanderWeele TJ, Chen Y. (2020). Forgiveness of others and subsequent health and well-being in mid-life: A longitudinal study on female nurses. BMC Psychol. Oct 1;8(1):104. doi: 10.1186/s40359-020-00470-w. PMID: 33004075
[iv] Chen Y, Harris SK, Worthington EL Jr, VanderWeele TJ. J Posit Psychol. (2019). Religiously or spiritually-motivated forgiveness and subsequent health and well-being among young adults: An outcome-wide analysis. 14(5):649-658. doi: 10.1080/17439760.2018.1519591. PMID: 31360213
[v] and of yourself, and feeling forgiven by God, improve emotional health. However, we do not have time to explore these links.
[vi] Wang X, Wang N, Zhong L, Wang S, Zheng Y, Yang B, Zhang J, Lin Y, Wang Z. (2020). Prognostic value of depression and anxiety on breast cancer recurrence and mortality: A systematic review and meta-analysis of 282,203 patients. Mol Psychiatry. Dec;25(12):3186-3197. doi: 10.1038/s41380-020-00865-6. PMID: 32820237
[vii] Liu ZY, Wang C, Zhang YJ, Zhu HL. (2022). Combined lifestyle, mental health, and mortality in US cancer survivors: A national cohort study. J Transl Med. Aug 19;20(1):376. doi: 10.1186/s12967-022-03584-4. PMID: 35986290
[viii] Yao P, Zhong Y, Wei Z. (2025). Association between sedentary behavior, depressive symptoms, and the risk of all-cause and cause-specific mortality among U.S. cancer survivors. BMC Cancer. Mar 28;25(1):570. doi: 10.1186/s12885-025-13578-2. PMID: 40155883