Tropical Marine Ecology 2005 Biological and Social Causes of High Frequency of Hypertension in People of the Caribbean Reading The Enchanted Braid has caused me to take a new perspective on my research topic. At first when I was researching for this subject, I was focusing on the human aspect of this topic. The braid theme that Davidson described in terms of the coral reef opened my eyes to what I was overlooking in my research. All of my research consisted of numbers and statistics from scientific studies examining human health issues in the Caribbean. Looking back at the articles and studies I had uncovered, studies that I was thrilled to find when researching in the library a few months ago, I was sorely disappointed. The studies were thorough, informative, and well written, but something was missing. Most of the research studies I found only explored one aspect of this health issue. While the question “what is causing frequent hypertension in populations of the Caribbean” may be too big to tackle in the scope of a single study, only one of the papers I had read explored more than one exploring hypertension. Most of the studies explored only one strand of the complex braid behind this issue. Hypertension is a condition caused by increased blood pressure. Blood pressure increases as a result of an increased volume of blood in the body’s circulatory system. While chronic high blood pressure, hypertension, can be genetically inherited within families, the most preventable cause of high blood pressure is a diet high in salt. A diet high in salt causes the body to retain water, thus increasing the body’s blood volume. Smoking, drinking, obesity, and the use of oral contraceptives can increase a person’s chance of having hypertension. The incidence of hypertension increases as age increases. Recent studies have shown a high incidence of hypertension in people native to the Caribbean. One study found that 32.3% of adults native to the Bahamas experience chronic hypertension (Halberstein, 1984). Another study found that in Panama City, Panama, over half of adults over the age of 60 have high blood pressure (Hollenberg et al, 1997). Several other studies confirm that there is a high occurrence of hypertension on several islands throughout the Caribbean. While it is established that a high incidence of hypertension does exist, the causes of this health problem are complex. The causes of this chronic disease range from human habits to biological factors to genetics. Humans can impact their health in many ways through their actions. Hypertension is obviously not the only disease that humans can bring upon themselves with poor health habits, and the Caribbean is not the only part of the world where high blood pressure occurs frequently. A combination of factors unique to this part of the world has been found to contribute to high incidence of hypertension. In a study done of people of Curacao, researchers found that many of 2248 individuals interviewed had poor health habits. 17.1% were smokers, 20.5% heavy drinkers, 75% did not exercise, and over half did not eat fruit or vegetables daily (Grol et al, 1997). These numbers seem startling, but perhaps similar studies in the United States would reveal similar statistics for Americans. What is more interesting about this study is the correlation it revealed between health habits and economic class. Those of higher economic status exercised more, ate healthier, and therefore had fewer health problems. This makes perfect sense, and this is probably true in many cultures. Not only can wealthier people afford to eat better, exercise, and have less physically demanding jobs, but they can afford better health care as well. These socioeconomic problems are not limited to people living on the islands of the Caribbean. Davidson addressed the division between the few rich and many poor in The Enchanted Braid. This economic rift is present in the Caribbean, Indonesia, the Philippines, and developing nations across the world. In areas that are financially stressed, health issues take a backseat to economic ones. The tropical environment of the Caribbean has also contributed to the hypertension epidemic of the area. Because islands such as the Bahamas are surrounded by ocean, it is natural that most of people’s diets consist of seafood. The main sources of protein in the Bahamian diet consist of conch, rock lobster, land crabs, and fresh fish. All of these creatures thrive in salt water, and the salt in the flesh of the fish is passed onto the human. A diet high in salt content, such as the seafood-rich diet of a person living the Bahamas, is the main preventabe cause of the high frequency of hypertension in this part of the world. The economic issues play a role in the diet. Once again, the wealthy can afford a variety food such as fresh fruits and vegetables. While hypertension has shown up frequently in the Caribbean, from the Bahamas to Panama, the Kuna islanders have seemed to resist the trend. The indigenous Kuna people inhabit islands in the Caribbean near Panama. In this population, blood pressures are generally low, both in the old and the young. On the mainland of nearby Panama, in Panama City, over half of adults over 60 have high blood pressure. When a small suburban community of Kuna was established near Panama City, it was assumed that the blood pressures of individuals in the community would greatly increase due to higher salt intake from processed foods, and exposure to more “urban” habits such as smoking and drinking alcohol. However, this was not the case. The average blood pressure of the transplanted Kuna increased only slightly despite acculturation (Hollenberg et al, 1997). This resistance to hypertension in this population could be genetically inherited. If resistance to hypertension could be genetically inherited, then susceptibility to hypertension could be a heritable trait as well. Because most of the populations living in the Caribbean are isolated on islands, there is a small genetic pool from which genes come from. Because of this small pool, it is more likely that genes causing resistance or susceptibility to a disease such as hypertension will be present in more individuals. In the Bahamas and other islands in the Caribbean, medicine for treating hypertension is made from indigenous plants. Medicinal plants were known to be very effective. Recently, these medicines have been supplemented with synthetic drugs. Because these drugs are not yet widely available, the best treatment of hypertension in this environment is prevention. Local governments have instituted programs to educate people on the importance of good health habits. A recent issue of the Bahamian capital, Nassau’s newspaper contained an article outlining the keys to a healthy lifestyle for all ages. The education of the people is the first step in improving health and reducing hypertension in the Caribbean. But, for many people just trying to get by, suggestions in newspapers to exercise and eat fruits and vegetables will make these habits become a priority in their lives. In The Enchanted Braid, Davidson recalled a conversation with John McManus, a researcher working for the International Center for Living Aquatic Resources Management in the Philippines. Referring to the problem of overfishing occurring in the Philippines, McManus said, “A fisheries person said the people (fishermen) were silly for not taking the advice.” Just as the fishermen in the Philippines could not take ecologist’s advice for fear of losing money, many people in the Caribbean may not be reasonable to take the advice of doctors to improve their diet. Something must be done, some solution must be found, which will help Caribbean people improve their health reasonably and affordably. In the end, this is really an economic issue creating a health problem.
Cooper R, et al. The prevalence of hypertension in seven populations of West African origin. American Journal of Public Health. v 87. 1997:160-168.
Davidson, Osha Gray. The Enchanted Braid: Coming to Terms with Nature on the Coral Reef. New York: John Wiley & Sons, 1998.
Dominguez L, et al. Cardiovascular risk factors in South America and the Caribbean. Ethnicity and Disease. Fall 1999: 468-478.
Grol M, et al. Lifestyle in Curacao: Smoking, alcohol consumption, eating habits and exercise. West Indian Medical Journal. v 46. 1997: 8-14.
Halberstein R. Blood pressure in the Caribbean. Human Biology. Aug 1999: 659-684.
Halberstein R, Davies J. Biosocial aspects of high blood pressure in people of the Bahamas. Human Biology. v 56. 1984: 317-328.
Hollenberg N, et al. Aging, acculturation, salt intake, and hypertension in the Kuna of Panama. Hypertension. v 29. 1997: 171-176.
Taylor, J et al. Loss of Bearing: How spiritual and cultural factors affect blood pressure in a sample of Afro-Caribbean women. Ethnicity and Disease. v 12. 2002: 121.