Juneteenth: How Slavery, Racism, Genes and Diet have Influenced Hypertension in African Americans

African Americans have the highest prevalence of hypertension in the world. According to the National Health and Nutrition Examination Survey (2015-2016), the prevalence of hypertension (high blood pressure) amongst black people is 40.3%, higher than white (27.8%), Asians (25%), and Latinos (27.8%) (Fryar et al., 2017). By age 50, nearly 60% of African Americans will suffer from high blood pressure.

African Americans develop hypertension earlier in life, have higher rates of severe hypertension, and have a greater risk of death from renal failure, stroke, and heart attack associated with high blood pressure. Furthermore, a study of African Americans with high blood pressure found hypertension was associated with poorer general health and lower physical functionality (American Heart Association, 1999; de Forge et al. 1998; Gilliam, 1996).

Numerous studies have demonstrated an association between hypertension and low socioeconomic status, including low levels of education. Research also suggests that chronic discrimination and the struggle for social acceptance can lead to continuous stress and an increased prevalence of high blood pressure (Adams et al., 1999; Dressler, 1996; Krieger & Sidney, 1997; Wilson et al., 2000). We can only imagine what hypertension rates may look like today amongst African Americans with unemployment rates higher than ever, a pandemic, ever-increasing police brutality, and looking over your shoulder every day not knowing if a white supremacist may try to kill you just because of your skin color. My heart rate is increasing over these thoughts, the fight or flight system is constantly on alert, and even the sight of a police officer raises your spidey senses.

What’s interesting is Black Africans have substantially lower rates of hypertension comparatively. Studies show that sub-Saharan African Blacks have the lowest prevalence of high blood pressure, but the rates increase with urbanization (Steyn et al., 1996; Wilson et al. 1991). What could have happened in the migratory process to produce this change?

I am not a historian, but I am going to put myself into the mindset of the free Africans back in the early 1600s: sunny days in the village, family gatherings, listening to the sounds of the native drum, cultivating off of the land, and eating good food from the culture.

Suddenly, in 1617 Africans were stolen by Portuguese slave traders, kidnapped by English pirates, and taken far away from their home. Can you imagine being snatched by strangers, chained, thrown at the bottom of a ship, and then commanded to “Row!” for more than 1,000 miles? There were events of nausea, vomiting, eustachian tubes being thrown off from rough seas, as well as profound sweating from heat exhaustion and experiencing fluid loss from dehydration due to respiratory exacerbation, sweating, inadequate fluids and electrolyte imbalances. The study of sports nutrition did not exist back then; there was no access to salty foods or Gatorade. The body would have only one choice and that is to hold onto salt so that your blood volume doesn’t drop too low causing death from dehydration due to hypovolemia. I am sure only the strongest survived these conditions!

Up to 70% of slaves died within the first 4 years of captivity. Survival may have resulted in a genetic selection for salt retention (Wilson, 186; Wilson & Grim, 1991). You need salt to hold onto water, which causes an increase in blood pressure and blood volume. This was a survival mechanism to prevent dehydration. However, in our current society, where we have an abundant amount of salty processed foods, this becomes counterproductive.

African Americans may be able to override this genetic predisposition by eating low sodium foods and a well-balanced diet that contains plenty of potassium-rich fruits and vegetables. Several studies have suggested that lowering salt intake and increasing calcium, magnesium, and potassium intake may reduce hypertension (Dwyer et al., 1998; Ford, 1998; Kawano et al..; Kawasaki et al., 1998). Additionally, the DASH (Dietary Approaches to Stop Hypertension) diet, which consists of a diet low in total fat, saturated fat, and cholesterol, while also high in fruits, vegetables, and low-fat dairy foods, was found to be effective in reducing blood pressure, especially in African Americans (even with no reduction in salt intake or weight loss). When salt restrictions were added, the diet was still more effective, lowering blood pressure in both people with and without hypertension.

Whatever the cause behind hypertension in African Americans may have been, food habits are proving to be a significant part of the answer (Gadrogue, & Wesson, 1996; National Heart, Lung, and Blood Institute, 2000; Svetkey et al., 1999). African Americans should take nutrition seriously to help reduce health risks and and combat the disparities that we are more predisposed to based on history. As we celebrate Juneteenth and try to overcome the inequities and systemic racism that still exists in our society, I can’t help but wonder: are we really free?