The Surprising Relationship Between Pulse (Resting Heart Rate) and Cancer

Heart rate (pulse) is a measure of how many times the heart beats in a minute. Our heart rate is an important indicator that offers clues about our health. Our pulse at rest, in particular, provides information about our overall health as well as our heart health.

Heart rate can vary from person to person depending on age, sex, physical activity level, and overall health. The pulse is generally expected to be between 60-100 beats per minute. Today, however, the ideal resting heart rate is considered to be between 50-70 beats per minute.

Risks of a High Resting Heart Rate

Resting heart rate is an indicator of heart health and also provides information about metabolic rate, the autonomic nervous system, and overall health. Although stress, air temperature, body temperature, dehydration (fluid loss), and infections can raise resting heart rate, a high resting pulse is considered to be associated primarily with cardiovascular disease.

Studies have shown that people with a high heart rate at rest have an increased risk of all-cause death and death from cardiovascular disease compared with people with a normal heart rate. But is a rise in our resting heart rate related only to heart health, or could it also be linked to serious diseases such as cancer? The answer to this question is currently a subject of interest to many scientists and a focus of research.

Indeed, numerous studies have provided evidence that a high resting heart rate may be an independent risk factor for cancer-related death .

The Link Between Cancer and Resting Heart Rate

Cancer Epidemiology, Biomarkers and Prevention published a study in 2021 that found a significant association between resting heart rate and overall cancer mortality (death). In this study, conducted in Dallas, Texas, between 1974-2002, 50,108 men and women with an average age of 44 underwent regular health examinations. Participants were followed for an average of 15 years, during which 1090 cancer-related deaths were recorded.

The study found that individuals with a resting heart rate of 80 beats per minute or higher, compared with those whose resting heart rate was below 60 beats per minute, had an overall cancer mortality risk that was 35% higher . This association remained significant even after controlling for potential confounding factors such as age, sex, smoking status, body mass index, physical activity level, and history of cardiovascular disease (Lancaster & al, 2021 June).

Heart Rate and Breast Cancer Survival

The article also analyzed specific cancer types, but found no statistically significant association between resting heart rate and the risk of death from lung, breast, prostate, colorectal, or other cancers.

A meta-analysis that included studies published up to 2017 in the PubMed and Embase databases investigated the relationship between resting heart rate and overall cancer risk. The meta-analysis included 88 publications with data from studies conducted in Europe, the United States, and Asia. These studies covered a total of 615,790 participants and 10,938 cancer cases.

The meta-analysis results showed that each 10-beat-per-minute increase in resting heart rate increased overall cancer risk by 14% . This relationship was observed to be linear: the higher the resting heart rate, the higher the overall risk of developing cancer (Aune, Sen, & al, 2017).

Possible Mechanisms Behind a High Heart Rate

These findings support the hypothesis that resting heart rate may be an independent risk factor for overall cancer risk. The meta-analysis report stated that factors such as smoking, lack of physical activity, or psychological stress might explain this association.

There are also studies suggesting that a high resting heart rate may adversely affect disease-free and overall survival in patients with breast cancer.

A study in Korea involving approximately 4800 patients with stage I-III breast cancer found that a high resting pulse was significantly associated with an increased risk of both all-cause death and breast cancer-specific death. Patients' resting pulse was measured at baseline, and all patients were followed for an average of 5.0±2.5 years.

This study found that patients with stage I-III breast cancer whose resting heart rate was 85 beats per minute or higher had a greater risk of death than those with a heart rate below 67 beats per minute. The group with a high heart rate was reported to have a 57% higher risk of death from any cause and a 69% higher risk of death from breast cancer.

Each 10-beat increase in resting heart rate was also found to increase the risk of all-cause death by 15% and breast cancer-related death by 22%. Although a 6% increase in cancer recurrence risk was also identified, the data could not establish that a high resting pulse significantly increased the risk of cancer recurrence (Lee & al, 2016).

Another study suggested that a high resting pulse could affect metabolic syndrome parameters and thereby adversely influence the course of breast cancer. Obesity and metabolic syndrome are known to adversely affect breast cancer risk and survival. The researchers found that each 10-beat-per-minute increase in resting pulse was associated with increases of 4 mmHg in diastolic blood pressure, 13 mg/dl in triglycerides, and 5 mg/dl in glucose. A rise in resting heart rate was suggested to be an indicator of metabolic risk factors that could adversely affect the course of breast cancer (Lee & al, November 2018) (L.A.Healy & al, 2010).

In conclusion, a high resting heart rate appears to be associated with an increased overall risk of cancer death. However, this relationship is highly complex and has not yet been fully explained. No specific association indicating that a high resting heart rate increases a particular cancer type has been observed.

Possible reasons why a high resting heart rate increases the risk of cancer death include increased sympathetic nervous system activation, hormonal changes, and effects on the immune system.

Cardiorespiratory fitness is the body's capacity to deliver oxygen to the muscles and use it during exercise. It measures how efficiently the heart, lungs, and blood vessels work together. Improving cardiorespiratory fitness through regular exercise and physical activity may play an important role in reducing the risk of cancer death in individuals with a high resting heart rate.

By adopting a healthy lifestyle, exercising regularly, eating a balanced diet, and reducing your stress levels, you can both protect your heart health and reduce your cancer risk.