Age goes ↑ so does blood pressure Hypertension: High Blood pressure –Part of heart disease, strokes, kidney failure –They kill 500 k/year Risk factors: overweight, high salt diet, long term mental stress, physically inactive, drinking alcohol to excess Overweight Pets
Cause of death for 10% of whites 20% of blacks WHY THE DISPARITY?
Are people of African Descent more susceptible? Is it race or another variable? Is it genetic? What does the evidence show? BE CAREFUL OF OVERSIMPLIFICATION
Another way to look at it Hypertension results from Complex interaction of –Stress/diet, physiology, and genetics Better understanding of causes = better treatment
If you hold genetic background of people in distinct environments constant You can focus on variations in living conditions and behavior Can’t be perfect because everyone has some of the risk factors
Look to Africa Rural West Africa has the lowest rate of hypertension in the world. How can people of African descent in US and UK have some of the highest rates This is evidence that it is not genetic. That it is because of way of life.
Rural NigeriaUrban JamaicaChicago Polygamous, Patriarchy Large, complex families, Average woman = 5 kids Lean, physically active people Rice & fruit diet Infection/Malaria biggest killer High mortality for adults B.P. does not rise with age Rare Hypertension Developing country Low risk for infections Higher risk for chronic disease than Nigeria Women head households Men: unemployment Small, fragmented families Physically active Local foods and modern commercial foods eaten Poorer than US Life expectancy for blacks is 6 years longer than US Many residents born in S. US Northern Migration improved health and economic status Men: Unionized jobs Women: integrated into workplace Diet: High in Fat and Salt
Americans & Jamaicans in study 75% genetically similar to Nigerians BMIs over 25 = overweight Overweight, unexercised, & poor diet explains 40 -50% of the risk for h. tension African Americans face compared with Nigerians 7 % hypertension Lowest B.M.I. (23.5) Lowest Salt intake 26 % Middle B.M.I. (25.9) Middle Salt intake 33% Highest B.M.I. (29.5) Highest Salt intake
Will the rate of hypertension increase for any group that lives a modern lifestyle? Within Nigeria people living in Nigerian cities have higher B.P. than rural Nigerians, but the two groups are similar on BMI and Salt intake What’s dif. Between city and country? Stress and exercise plays a part. What does this say about man’s evolutionary history?
Are there stresses blacks in N. America and Europe face that blacks in Africa do not? Racism? Does racism affect blood pressure? In Trinidad and Cuba black, spanish, and white rates of similar B.P. levels –Do they have better race relations? Havana Bay
The environment at work Kidneys play a part in B.P. They control salt (sodium) levels in blood They keep ~98% of it. –Sodium was once very precious in our diet –Too much sodium raises B.P. DON’T EAT TOO MUCH SALT
FDA's recommended daily value of sodium is 2,400 mgs, about a teaspoon Department of Health and Human Services' recommends no more than 1,500 per day for adults middle-aged or older Really: the average daily intake of salt is more like 3,400 mg
Questions Was this an experiment or a study? What are the pitfalls or dangers of investigating this topic? –Reducing humans to fictitious inherent differences in race. What does the dif. in B.P. suggest about human evolution? –We developed in a low sodium diet environment, that’s what we’re built for. What is the role of environment? What is the role of genetics? What is the strongest/weakest evidence? What was the sample size? –They don’t say here, but they do site where you could read up on their study.
Who Wrote this article? Epidemiologists Richard Cooper, from Loyola Charles Rotimi, from Nigeria, now working for Human Genome project Ryk Ward, British guy, round the world type