Moore oversaw the retrospective analysis of more than 41,000 participants from the National Health and Nutrition Examination Survey, or NHANES, which was carried out from 1988 to 2019.
Researchers at the Medical College of Georgia at Augusta University claim that the body’s deterioration brought on by persistent stress over the course of a lifetime may also increase the risk of dying from cancer. Allostatic load, the term for this wear and tear, describes the accumulative effects of stress over time.
Baseline biological measurements that the researchers used to calculate the allostatic load include body mass index, diastolic and systolic blood pressure, total cholesterol, haemoglobin A1C (higher levels indicate a risk for diabetes), albumin and creatinine (both measures of kidney function), and C-reactive protein (a measure of inflammation). A score higher than three was considered to be a high allostatic burden.
The National Death Index, which is kept up to date by the Centers for Disease Control and Prevention and the National Center for Health Statistics, was then matched with those participants to determine who had passed away from cancer and other causes
According to Moore and his colleagues’ article in the journal SSM Population Health, there hasn’t been much study done on the connection between allostatic load and cancer among a current, nationally representative sample of US adults. Examining the relationship between allostatic load and cancer outcomes, as well as whether these relationships differ by race, may shed light on creative strategies for reducing cancer disparities, according to Moore.
The researchers discovered that those with a high allostatic load were 2.4 times more likely to die from cancer than people with a low allostatic load, even after correcting for possible confounders such age, social demographics like race and sex, poverty-to-income ratio, and educational level.
However, Moore argues that confounding variables must be taken into account.
Scientists were aware that allostatic loads vary depending on a person’s age, race, and gender.
In fact, Moore and his colleagues found that persons 40 and older had more than a 100% greater probability of having high allostatic load as compared to those under 30, based on trends in allostatic load over 30 years among 50,671 people. Furthermore, compared to their white counterparts, persons who are Black or Latino had a higher probability of having a high allostatic load, independent of the time period.
Moore claims that institutional racism is largely to blame for issues like the inability to access better educational opportunities or just and equitable mortgages.
The researchers discovered that persons with a high allostatic load still have a 28% higher risk of dying from cancer even after adjusting for age.
According to Moore, if two people of the same age had one of them have a high allostatic load, the other would have a 28% higher risk of dying from cancer.
High allostatic load caused a 21% increase after sociodemographic factors like sex, race, and educational level were taken into account. Additional risk factor adjustments, such as whether participants smoked, had previously experienced a heart attack, or had been previously diagnosed with cancer or congestive heart failure, caused an additional 14% increase.
“As a response to external stressors, your body releases a stress hormone called cortisol, and then once the stress is over, these levels should go back down,” says Dr. Justin Xavier Moore, an epidemiologist at the Medical College of Georgia and Georgia Cancer Center. “However, if you have chronic, ongoing psychosocial stressors, that never allow you to ‘come down,’ then that can cause wear and tear on your body at a biological level.”
Specifically among each racial/ethnic group, Moore and colleagues further investigated the connection between allostatic load and cancer mortality. When the allostatic load was divided into racial categories, there was a less correlation. The enormous size of the original sample may be able to account for these results.
“Epidemiologically, when looking at 41,000 people, there are many cancer-related-death events,” Moore explains. “However, it is more difficult to ascertain a relationship between x (allostatic load) and y (cancer death) when you essentially have fewer data points to measure.” For example, limiting the sample to non-Hispanic Blacks would mean analyzing a sample of 11,000 people, so the relationship may look diminished or attenuated. “The reason race even matters is because there are systemic factors that disproportionately affect people of color,” he says. “But even if you take race out, the bottom line is that the environments in which we live, work, and play, where you are rewarded for working more and sometimes seen as weak for taking time for yourself, is conducive to high stress which in turn may lead to cancer development and increased morbidity and mortality.”