Allostatic Loading: What It Is, How It Hurts Health

No one is entirely sure for the reasons behind this disparity in menopause experiences, but researchers believe it all has to do with a specific type of wear and tear on the body, something called “allostatic load,” says Karlamangla. The body is constantly trying to maintain homeostasis, keeping its physiological parameters tightly regulated — your blood pressure, heart rate, blood glucose level, and more. But when faced with challenges or adversity, these systems temporarily go outside that normal operating range: Your heart rate and blood pressure go up. “It goes outside the usual resting state to react to stimuli — a normal and healthy allostatic response. The long-term negative consequence of responding too often is allostatic load; the stress response systems get worn down.

Allostatic loading is what happens to these physiological systems if the challenges come too frequently, or the stress is severe or chronic. This could mean they lose the ability to react to new challenges, or take a very long time to calm down and come back to the resting state, or the resting state itself could become altered. “We see that allostatic load is higher in people who have had chronic stressors in their lives,” says Karlamangla. “More generally speaking, we find on average that people from disadvantaged communities have greater allostatic load than people from more advantaged communities.”

Since people of color more often experience the trauma that goes with racism and poverty, the thinking goes that this leads to more allostatic load and is causing the disparity in menopause outcomes.

 “We’ve seen that socioeconomic status predicts your age at the time of menstrual period. And that women from disadvantaged communities tend to have their final menstrual period earlier. It’s possible that allostatic load may be responsible,” says Karlamangla.

Several SWAN publications show what the impact of diabetes and more inflammation means for bone strength and fracture risk, Karlamangla adds. Bone strength is lower in diabetic women

and they experience more fractures than women without diabetes.

This may be due to lower bone quality, earlier menopause, and faster bone loss in diabetic women.

SWAN participants with higher levels of C-reactive protein, a marker of inflammation that has been related to life stresses and adversity, had more fractures than women with lower levels of C-reactive protein.

 In addition, in a study published in March 2021 in JBMR Plus, increase in C-reactive protein level over time was associated with faster decline in bone density.

Nature vs. Nurture? Genetics vs. Socioeconomics?

No researcher so far has been able to definitively untangle race and ethnicity from socioeconomic factors or genetics from environmental influences on the menopause transition, says Santoro. She adds that the only site that recruited Latina women (New Jersey) wound up with a relatively socially disadvantaged group, so the data may not be as broadly applicable to, for example, college educated Latina women, who are not well represented in SWAN. (Neither are Latina women of Mexican descent, as there are fewer in New Jersey.) “SWAN was able to recruit substantial numbers of Black women, and also substantial numbers of middle-class Black women, so we think we captured a fairly representative group of Black women, and we were one of the first studies to do so,” she says.

Race as a Social Construct

Santoro adds that since the SWAN study was conducted, researchers have recognized that race and ethnicity are a social construct. “The social environment has shifted to more of a de-emphasis on race and ethnicity per se as predictors and more on the sorts of things that go along with race and ethnicity, such as BMI, education, income, and perceived discrimination that may be responsible for the differences we are observing between ethnic groups. Doctors can and should ask questions about employment status, housing status, food insecurity, and some very basic things that lead to stress and allostatic loading.”