一項研究發(fā)現(xiàn)，胎兒期和新生兒時期的營養(yǎng)不良會在之后的食品缺乏時期降低人的健康程度,。Adam D. Hayward及其同事檢驗了“預(yù)期適應(yīng)反應(yīng)”（PAR）假說,，該假說尋求解釋在那些于生命早期遇到過食物缺乏的成年人中常常能觀察到的代謝疾病的高發(fā)生率，該假說假定這類個體有一種“節(jié)儉的代謝”,，如果在以后遇到缺乏食物的情況,，這種機制就會帶來進(jìn)化優(yōu)勢。這組科研人員分析了在1866-1868年間發(fā)生在芬蘭的一場災(zāi)難性大饑荒之前50年芬蘭東南部兩個教區(qū)的3000多人的關(guān)于出生,、死亡,、分娩和社會經(jīng)濟地位的教堂記錄。這組作者調(diào)查了出生前后年份的由農(nóng)作物產(chǎn)量決定的食品可供應(yīng)性與在此次饑荒期間的生存和繁殖之間的關(guān)聯(lián),。對于男性和女性而言,，在生命的早期階段更高的農(nóng)作物產(chǎn)量都與在饑荒時期的存活的增加有關(guān)聯(lián)；在社會經(jīng)濟地位較低的男性和年輕的女性中間,，這種關(guān)聯(lián)更為明顯,。更高的生命早期農(nóng)作物產(chǎn)量與女性在饑荒期間的生育力的增加有關(guān)聯(lián)。這組作者說,，這些結(jié)果支持了“銀勺子”假說,，該假說提出，生命早期營養(yǎng)不良限制了發(fā)育并且沒有帶來進(jìn)化上的優(yōu)勢,。 （生物谷 Bioon.com）
生物谷推薦的英文摘要
PNAS Doi：10.1073/pnas.1301817110
Influence of early-life nutrition on mortality and reproductive success during a subsequent famine in a preindustrial population
Adam D. Haywarda,1,2, Ian J. Rickarda,b,1, and Virpi Lummaa
Individuals with insufficient nutrition during development often experience poorer later-life health and evolutionary fitness. The Predictive Adaptive Response (PAR) hypothesis proposes that poor early-life nutrition induces physiological changes that maximize fitness in similar environments in adulthood and that metabolic diseases result when individuals experiencing poor nutrition during development subsequently encounter good nutrition in adulthood. However, although cohort studies have shown that famine exposure in utero reduces health in favorable later-life conditions, no study on humans has demonstrated the predicted fitness benefit under low later-life nutrition, leaving the evolutionary origins of such plasticity unexplored. Taking advantage of a well-documented famine and unique datasets of individual life histories and crop yields from two preindustrial Finnish populations, we provide a test of key predictions of the PAR hypothesis. Known individuals from fifty cohorts were followed from birth until the famine, where we analyzed their survival and reproductive success in relation to the crop yields around birth. We were also able to test whether the long-term effects of early-life nutrition differed between individuals of varying socioeconomic status. We found that, contrary to predictions of the PAR hypothesis, individuals experiencing low early-life crop yields showed lower survival and fertility during the famine than individuals experiencing high early-life crop yields. These effects were more pronounced among young individuals and those of low socioeconomic status. Our results do not support the hypothesis that PARs should have been favored by natural selection and suggest that alternative models may need to be invoked to explain the epidemiology of metabolic diseases.
