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Hunter-gatherers and forager-horticulturalists who live off theland and grow what they need to survive have lower age-relatedincreases in blood pressure and less risks of atherosclerosis,according to two new studies in the American Heart Associationjournal Hypertension. High blood pressure and atherosclerosis -- a disease in whicharteries stiffen and fill with plaque -- increase with age in theUnited States and other countries, raising risks for heart attack,stroke, kidney disease and death. Age-related increases in bloodpressure have been observed in almost every population, exceptamong hunters-gatherers, farmers and pastoralists. "Surprisingly, heart disease and stroke aren't necessarilyinevitable with age," said Michael Gurven, Ph.D., study authorand anthropology professor and chairman of the University ofCalifornia-Santa Barbara's Integrative Anthropological SciencesUnit. Gurven's team followed 2,296 indigenous adults in 82 Tsimanevillages, an area in the tropical lowlands of Bolivia's Amazonbasin. Tsimane are lowland forager-horticulturalists (pop. ~11,000)subsisting on plantains, rice, corn, manioc, fish and hunted game. "The Tsimane living conditions are similar to those of ourancestors, with greater exposure to pathogens, active lifestyle,high fertility and traditional diet. Studying chronic diseases inthese populations can be very insightful," Gurven said. Researchers found: Per decade, Tsimane women had a systolic blood pressure increase of2.86 millimeter of mercury (mm Hg) and a diastolic blood pressureincrease of 0.95 mm Hg. Per decade, Tsimane men had a systolic blood pressure increase of0.91 mm Hg and a diastolic blood pressure decrease of 0.02 mm Hg. About 3 percent of Tsimane adults have high blood pressure,compared to 33.5 percent of U.S. adults. Among Americans over age 40, systolic pressure increases by about 7mm Hg per decade. Around the world, 52 other societies have blood pressure two toeight times higher than the Tsimane. Americans' blood pressures aretwo to four times higher. "Our classic risk factors such as high blood pressure are notuniversal," Gurven said. "Nor does all modernizationautomatically lead to poorer health, contrary to popular beliefs.While overall blood pressure was somewhat higher with more exposureto modernization, there was no evidence of a greater increase inblood pressure with age." Between July 2002 and December 2010, researchers measuredparticipants' blood pressure one to eight times during multiplephysical exams in the Tsimane villages. Degree of modernization was based on village distance to thenearest town, smoking status, Spanish fluency and education level. Gurven also noted that prior research done in 2009 published in PLoS ONE showed no evidence of subclinical atherosclerosis in Tsimaneadults. In a smaller study, researchers compared the risks ofatherosclerosis in traditional Pygmies -- subsistencehunters-gatherers living in the equatorial forests of Cameroon --to two neighboring groups: semi-urbanized Pygmies and farmers knownas the Bantou. The researchers gauged atherosclerosis risks based on theelasticity of the participants' arteries, using two markers: pulsewave velocity, a direct measure of arterial stiffening; and aorticaugmentation index, an indirect measure of atherosclerosis. Atherosclerosis risks were about 20 percent lower among traditionalPygmies than that of the other two groups. Pulse wave velocity for traditional Pygmies was 5.8 meters/second,6.82 meters/second for contemporary Pygmies and 6.93 meters/secondfor Bantou farmers. The augmentation index for the three groups weren't different, butthe traditional Pygmies' shorter height suggests theiratherosclerosis risks are lower than the others. "Our study shows that the effect of aging on atherosclerosisis blunted by a traditional lifestyle," said Daniel Lemogoum,M.D., M.P.H., study lead author and cardiologist at theHypertension Clinic at Hôpital Erasme of theUniversité Libre de Bruxelles in Brussels, Belgium. In clinical exams, the Belgium researchers measured 62 adults'blood pressure, heart rate, weight, height, body mass index, pulsewave velocity and augmentation index. They calculated effects offactors including blood pressure and age. "By focusing our attention on people with very differentlifestyles from our own, we might better be able to understand thatmaintaining heart health is possible even as we age," Lemogoumsaid. Lifestyle factors specific to hunters-gatherers might explain theminimal increases in blood pressure in the Tsimane and lowatherosclerosis risks in the traditional Pygmies, the study authorssaid. The factors include: high physical activity, low stresslevels and potentially protective diets high in fruits, vegetablesand potassium and low in calories, salt and alcohol. Gurven's co-authors are: Aaron Blackwell, Ph.D.; Daniel EidRodriguez, M.D.; Jonathan Stieglitz, Ph.D.; and Hillard Kaplan,Ph.D. Lemogoum's co-authors are: William Ngatchou, M.D.; ChristopheJanssen, M.D.; Marc Leeman, M.D., Ph.D.; Luc Van Bortel, M.D.,Ph.D.; Pierre Boutouyrie, M.D., Ph.D.; Jean Paul Degaute, M.D.,Ph.D.; and Philippe Van de Borne, M.D., Ph.D. The National Institute on Aging funded the Tsimane study and theFrench Foundation for Research on Arterial Hypertension funded theCameroon study. We are high quality suppliers, our products such as Slewing Ring Bearings , China Ball Joint Bearings for oversee buyer. To know more, please visits Spherical Roller Bearing.
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