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Stress and Race Redux: A ‘Hispanic’ Paradox?

1500 words

American Renaissance published an article the other day titled “Is ‘Racism’ Killing Black People?” and, for the most part, I largely agree with it. However, there are a few faults in it that I need to address.

First, off, as the article rightly noted, it’s not only perceived ‘racism’ that is the cause for these health disparities, but stress from other blacks as well. Gregory Hood (the author of the AmRen article) cites a new study showing that blacks who move out of the ‘hood’ see a subsequent decrease in BP (Kershaw et al, 2017). They followed 2,290 people 974 were men and 1,306 were women. This is data collected from the CARDIA study which has helped us to understand racial disparities in all types of different health outcomes. Blacks who lived in high segregation neighborhoods had higher levels of SBP (systolic blood pressure), and saw a decrease in their SBP when they moved to less segregated neighborhoods. The authors conclude that “policies that reduce segregation may have meaningful health benefits.” What kind of policies will ‘reduce segregation’? Most races/ethnic groups group together in an area, so I don’t see how this would happen.

In regards to the argument on black maternal mortality and ‘racism’, I think it’s much more nuanced. Black women are 2 to 6 times more likely to die giving birth than white women; while the leading causes of maternal death in black women is pregnancy-induced hypertension, and embolism (Chang et al, 2003), though reasons for the mortality rate are not explainable at present (Flanders-Stepans, 2002). Further, in regards to preeclampasia, women who get pregnant at younger ages are more likely to acquire the disease while pregnant, and blacks and other non-whites are more likely to get pregnant at younger ages than whites (Main et al, 2015).

However, there are ways to reduce maternal mortality in black women. In a RCT undertaken between the years of 1990-2011 in Memphis, Tennesee, black women were followed with their live-in children and placed into one of four groups: “treatment 1 (transportation for prenatal care [n = 166]), treatment 2 (transportation plus developmental screening for infants and toddlers [n = 514]), treatment 3 (transportation plus prenatal/postpartum home visiting [n = 230]), and treatment 4 (transportation, screening, and prenatal, postpartum, and infant/toddler home visiting [n = 228])” (Olds et al, 2014). They conclude that pre- and post-natal care greatly reduces maternal/infant mortality in black women, “living in highly disadvantaged settings.”

Further, the racial disparity in post-term neonates is largely driven by “CHD among term infants with US-born mothers is driven predominately by the postneonatal survival disadvantage of African-American infants” (Collins et al, 2017). Though, as can be seen in the study by Olds et al (2014), pre- and post-natal care can greatly reduce both infant and maternal mortality.

Stress can also be measured in pregnant women by measuring the level of blood cortisol (Gillespie et al, 2017). They show that, independent of adulthood stress, stress during childhood may shape birth timing, with cortisol being the biological mediator. This may be an explanation for what Gregory Hood notes. He states in his article that there has to be an explanation for why black women birth earlier, and while I am sympathetic to biological models ala Rushton (1997), Gillespie et al (2017) drive a hard argument that stress during childhood using cortisol as a biological mediator makes a lot of sense.

There are a few studies that attest to pre- and post-natal care having a large effect on the morality of black women, and that having the carers being black women seems to have  a positive effect (Guerra-Reyes and Hamilton, 2017). They conclude that “Recognition, support, and increasing the number of African-American midwives and birth assistants is vital in tackling health inequalities.” In regards to infant mortality rate (IMR), 18 states will achieve racial equality by 2050 if current trends from 1999-2013 hold (Joedrecka et al, 2017).

Now for the main reason I decided to write this: the ‘Hispanic’ paradox. This paradox is that for the past twenty years, ‘Hispanics’ with low SES have similar or better health outcomes than whites (Franzini, Ribble, and Keddie, 2001). However, more recent analyses show that the ‘Hispanic’ paradox does not exist, mostly due to methodological problems and migrant selectivity (Crimmins et al, 2007; Teruya and Bazargan-Hezeji, 2013) and was not noticed in Chile either (Cabiesies, Tunstall, and Pickett, 2013). There is no migrant selectivity in regards to smoking, however (Fenelon, 2013, 2016).

Teruya and Bazargan-Hezejie (2013) write:

Studies which advocate the validity of the Immigrant Paradox are countered by those which report specific, negative physical and mental health outcomes, and higher rates of substance use, especially among immigrant adolescents. Findings may also be compromised by fundamental methodological concerns such as migrant health selectivity, and approaches that consider only selectively healthy groups. Moreover, the Immigrant Paradox’s benefits do not appear to extend evenly and consistently to all races, ethnicities and subgroups. Similarly, the Hispanic Paradox does not protect consistently across all Latino ethnicities, age groups and genders, with Puerto Ricans and Cubans in particular found to enjoy fewer health advantages.

This is good evidence that the people who migrate to America are healthier, and that the symptoms of low SES show in their children, but not in them because they are a self-selected population. There is no ‘Hispanic’ paradox (Smith and Bradshaw, 2006; Schoenthaler, 2016). Even a new meta-analysis on this ‘paradox’ states “Immigrant children and youth suffer from an immigrant mortality disadvantage” (Shor, Roelfs, and Vamg, 2017).

Lastly, Gregory Hood brings up stress and suicide, stating that if blacks were really more stressed than whites then blacks would have higher rates of suicide, but some studies show that whites have a higher rate of suicidal ideation, while others do not show this (Perez-Rodriguez et al, 2010). Though, as Balis and Postolache (2010) show, studies show that while there is conflicting evidence in regards to racial/ethnic differences in suicide, whites still attempt it the most. However, suicide for young black Americans is on the rise. Ahmedani et al (2016) show that “Nearly 27% of White individuals made a mental health visit versus less than 20% of Asian, Hawaiian/Pacific Islander, and Black individuals in this period. Within 4 weeks, all visits and mental health visits remained most common for White individuals (67.3% and 47.4%, respectively) and least common among Asian individuals (52.8% and 31.9%, respectively). Within 52-weeks, more than 90% made any visit. Alaskan Native/Native American (81.5%) and White individuals (79.5%) made mental health visits 10–25% more often than other groups.” However, at least in Fulton County, Georgia, black suicide decedents were less likely to report depression than white suicide decedents (Abe et al, 2008).

However, for whites, as noted in this 1982 New York Times article, suicidal feelings “reflects feelings of loneliness and hopelessness, which can be greater factors as one grows older; for instance, after loved ones have died” whereas for older white men, loss of status may be a cause, which would not be that prevalent in lower SES ethnicities. The article seems to implicate loss of status as a main cause for higher rates of suicide in white Americans, and states that as other, lower SES ethnies attain higher status, that suicide rates would rise for them as well.

Another cause could be prescription drugs, for instance in the Northeast which has been hit hard by the opiate/heroin crisis which leads to more white deaths. Robert Putnam puts this on “the links between poverty, hopelessness and health” and states that the suicide rate has declined for two groups, black males and males over the age of 75. Further, “divorce, economic strain, or political repression are often characterized as suicide risks.” Cheng et al (2010) show that “A high level of identification with one’s ethnic group was associated with lower rates of suicide attempts.” So, it seems that if one keeps their status, and has a high level of identification with their ethnic group, whites would then be protected against suicidal ideation. Nonmetropolitan counties also have higher rates of suicide than metropolitan counties (Ivey-Stephenson et al, 2017). People who livee in rural counties are less likely to seek help for mental problems (Carpenter-Song and Snell-Rood, 2016). Whites are also more likely to live in rural areas. This could explain higher rates of suicide in whites, along with loss of status, depression and drug use.

In conclusion, the ‘Hispanic’ paradox doesn’t exist; whites attempt/commit suicide more due to loss of status and since most whites live in rural areas, they do not seek help for their mental health problems which then leads to suicide. In regards to black maternal mortality/infant mortality rates, if they have midwives present during and after the birth, mortality rates have decreased. If these trends continue, there will be racial equality in terms of maternal/infant mortality in 18 states. The AmRen article was good and well written, but there were a few huge flaws. The author assumed that since the ‘Hispanic paradox’ exists, that this should have one disregard the effects of, say, stress on blood pressure in black Americans, as I have discussed in the past. But since the ‘Hispanic’ paradox does not exist, then you cannot say that (perceived) discrimination and ‘racism’ is not a cause for higher rates of mortality in blacks compared to whites.

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Blood Pressure, Stress, and the Social Environment: On Black-White Differences in Blood Pressure

1800 words

Blood pressure (BP) is a physiological variable. Therefore since it is a physiological variable then it can be affected by environmental and social changes. How do racial differences come into play here, for instance? Since blacks face more (perceived) discrimination, then they should, on average, have higher BP levels than whites. This is what we find—but the effect is mostly seen in low-income blacks. How do psychosocial factors come into play here in the black-white BP gap?

BP is regulated by cardiac output, vascular resistance of blood flow, blood volume, arterial stiffness, and, of course, the individual’s emotional state which can decrease or increase BP. Neural mechanisms also exist which regulate BP (Chopra, Baby, and Jacob, 2011). Knowing how and why BP increases or decreases will have us better understand the social contexts of increased BP in low SES blacks.

BP is a complex physiological trait. It can go up and down due to what occurs in the immediate environment. Values of 120/80 mmHg are cited as ‘average’ values, but we have no idea what an ‘average’ BP is. Nevertheless—like most/all physiological variables—there is a wide range of what is considered ‘normal’. Due to the variance in human physiological systems, what is ‘normal’ for one individual is not ‘normal’ for another. Variation in BP (like, say, 120 SBP (systolic blood pressure) to 140 SBP) is ‘normal’. I believe even around 110 for SBP is within that range. For DPB (diastolic blood pressure) between 75 and 90 is within normal diurnal fluctuations due to activity/eating/etc (Taylor, Wilt, and Welch, 2011). BP, like testosterone, is one of those tricky variables to measure and so must be measured upon waking to see if there are any problems. So even for a trait like BP, there seems to be a ‘normal range’.

About 33 percent of blacks have hypertension (HTN) (Peters, Arojan, and Flack, 2006). Urban blacks are more likely to have higher BP levels than whites, but “At present, there is no complete explanation for these differences and further research is required” (Lindhorst et al, 2007). Low SES is correlated with higher levels of BP in black Americans—especially those with darker skin—but not Africans in Africa (Fuchs, 2011), suggesting that this is an American phenomenon that needs to be addressed. One good explanation, in my view, is the social environment. Physiological traits are extremely malleable due to the need to be able to ‘change gears’ in an instant, for instance to either fight or flight. Though, in our modernized world, these responses—mostly—have no need and so (due to our supposed civilized behavior), one’s BP rises due to social stress and other environmental factors and it is due to the urban environment.

What is the cause of high BP in blacks?

One explanation that has been given to explain higher rates of BP in blacks when compared to whites is discrimination. However, studies show mixed evidence on whether or not so-called discrimination raises BP (Couto, Goto, and Bastos, 2012). The same American effect (American blacks having higher BP than American whites) is seen even in the UK London area (Agyemang and Bhopal, 2003). This, yet again, is more evidence that the social environment drives these differences—again, regardless of whether or not any of the discrimination is real or imagined. Say most of it were imagined: it’d be irrelevant because the imagined discrimination leads to very real physiological outcomes in BP. 

The country of birth also has an effect on BP. In one study, it was noted that Africans had significantly higher BP when compared to Asians (which is identical/lower) and native French living in France (Bahous et al, 2015). Ethnic differences in BP increase due to similar sodium intake is lower than what is usually cited (Graudal and Jurgens, 2015). However, other authors have pointed out that basing conclusions off of observational studies have problems, like the estimation of sodium intake being inaccurate since it’s a one-time measure;  (Gunn et al, 2013; Cobb et al, 2014)

There is also evidence—along with pathways—that show how certain social activities work to lower stress and BP, including participation at church (Livingstone, Devine, and Moore, 1991). Black Americans can make other lifestyle changes in order to decrease BP, such as exercise and other lifestyle interventions. Redman, Baer, and Hicks state that “gene-environment interactions, job-related stress, racism, and other psychosocial factors to racial/ethnic disparities” need to be explored as causes for higher rates of HTN in blacks compared to whites. And with the knowledge of how all physiological systems work in terms of stress and other factors, should be explored as causes for this disparity.

Grim et al (1990) state that factors that influence high BP in blacks compared to whites are inherited and that is the major source of variation between these populations. However, the other mounting social/physiological evidence deserves an explanation; that is not inherited, and what we know about how our physiology responds to stress and discrimination—whether real or imagined—are extremely important and lead to extremely real, and important, outcomes in these populations. It is also argued that since blacks en route to America during the slave trade died from salt-depletive diseases, that blacks with a higher genetic propensity to absorb salt survived and this is why blacks have a higher propensity to absorb salt and are more ‘salt-sensitive’, which also could explain higher rates of HTN in American blacks compared to their cousins in Africa (Wilson and Grim, 1991). However, Curtin (1992) disputes this because “There is no evidence that diet or the resulting patterns of disease and demography among slaves in the American South were significantly different from those of other poor southerners”.

However, in regards to the social environment, Williams (1992) drives one of the best arguments I have encountered in this literature so far, stating that while genetic factors play a small part in regards to the BP gap between blacks and whites, social factors are arguably more important than genetic ones (and with our homeodynamic physiology, this does make sense). Dressler (1990) for instance, argues that skin color is a proxy for both social class and discrimination and these factors explain a large amount of the variation. Psychosocial variables can also explain heightened BP (Marmot, 1985Cuffee et al, 2014). Yan et al (2003) also note how “time urgency/impatience” and “hostility” “were associated with a dose-response increase in the long-term risk of hypertension.” Henry (1988) also argues that calcium, obesity and genetic factors cannot be the aetiology of HTN in blacks, while also proposing that high sodium intakes are due to psychosocial stress (Williams, 1992: 136).

Obesity also leads to hypertension (Re, 2009) while blacks are more likely to be obese than whites, however, black American men with more African ancestry are less likely to be obese (Klimentidis et al, 2016). This would imply that the greater amount of African ancestry in American blacks both protects against obesity and along with it HTN. Williams (1992) makes a convincing argument that environmental and social factors are the cause for the black-white BP gap. And while genetic factors are important, no doubt, environmental  and social factors are arguably more important to this debate.

Kulkarni et al (1998) show that increased stress leads to subsequent BP elevations which, over time, will lead to HTN. In a 2009 meta-analysis, Gasparin et al show how “individuals who had stronger responses to stressor tasks were 21% more likely to develop blood pressure increase when compared to those with less strong responses.”

Further, in support for the ‘perceived stress’ hypothesis in regards to blacks ‘perceiving’ stress and discrimination, “stress denial in combination with abdominal obesity, alcohol consumption, and smoking may be proxy for a high stress level” (Suter et al, 1997). Carroll et al (2001) also show how there are is “modest support for the hypothesis that heightened blood pressure reactions to mental stress contribute to the development of high blood pressure.Sparrenberger et al (2009) also did a systematic review of observational studies, finding that “Acute stress is probably not a risk factor for hypertension. Chronic stress and particularly the non-adaptive response to stress are more likely causes of sustained elevation of blood pressure.

Lastly, Langford (1981) shows that when SES is controlled for, the black-white BP disparity vanishes, implying that social and environmental—not genetic—factors are the cause for elevated HTN levels in black Americans. Sweet et al (2007) showed that for lighter-skinned blacks, as SES rose BP decreased while for darker-skinned blacks BP increased as SES did while implicating factors like ‘racism’ as the ultimate causes. This is solid evidence that both skin color and SES are predictors of higher prevalence of BP in black populations, and since other studies show that this is not noticed in higher class blacks, nor is this noticed in blacks in Africa, then the main causes of this disparity are social and environmental in nature.

(Non, Gravlee, and Mulligan, 2012). Their study suggests that educating black Americans on the dangers and preventative measures of high BP will reduce BP disparities between the races. This is in-line with Williams (1992) in that the social environment is the cause for the higher rates of BP. One hypothesis explored to explain why this effect with education was greater in blacks than whites was that BP-related factors, such as stress, poverty and racial discrimination (remember, even if no racial discrimination occurs, any so-called discrimination is in the eye of the beholder so that will contribute to a rise in physiologic variables) and maybe social isolation may be causes for this phenomenon. Future studies also must show how higher education causes lower BP, or if it only serves as other markers for the social environment. Nevertheless, this is an important study in our understanding of how and why the races differ in BP and it will go far to increase our understanding of this malady. This is a very convincing argument that education and not genetic ancestry cause disparities in BP between blacks and whites.

WebMD states that, of course, both environmental and genetic factors are at play in regards to black’s increased propensity for acquiring HTN. Fuchs (2011) also states that “They [environmental and behavioral factors] could act directly or by triggering mechanisms of blood pressure increase that are dormant in blacks living in Africa” and explain why black Americans have higher rates of BP than Africans in Africa. Further, race and ethnicity are independent predictors of HTN (Holmes et al, 2013).

Conclusion

Blacks and whites do differ in BP, and its aetiology is both complex and hard to untangle Genetic factors probably don’t account for a lot of this variance since Africans in Africa have low levels of BP compared to their black American cousins. Numerous lines of evidence shows that social and environmental factors are the cause, and so to change this, all people—especially blacks—should be educated on how to change these problems in our society. Whether discrimination is real or imagined, the effects of it lead to real physiological outcomes that then lead to increased health disparities between these populations.