对于很多关心自身健康的人来说，富含蔬菜和水果的天然饮食促进健康和延年益寿功效已不是新闻。与天然饮食相对，充斥着合成化学物、氢化脂肪酸以及盐分和糖分的食物会破坏我们的基因完整性，从而引起新陈代谢功能的紊乱。我们的身体喜欢摄取天然营养成分，居住在远离污染物和人造毒素的环境。研究者现在发现富含蔬菜和水果的饮食能降低39%任何死亡风险。
α-胡萝卜素水平与低死亡风险
α-胡萝卜素是一种强力抗氧化剂，只需消费富含蔬菜和水果的饮食即可获得。该超级营养素在天然果蔬的色彩缤纷的皮肉中很多。刊登在《内科医学档案》(Archives of Internal Medicine)中的一项对15万名男性和女性血液中的α-胡萝卜素水平进行18年追踪调查的研究发现血液中α-胡萝卜素饱和度和死亡风险有直接联系。
健康饮食降低39%各种死亡风险
研究者对α-胡萝卜素水平进行测量以确定死亡风险，发现高血液α-胡萝卜素饱和度的个人与低饱和度的相比，死于任何原因的风险降低了39%。经常食用蔬菜和水果的参与者的血液中α-胡萝卜素水平最高，而消费加工食品的参与者中几乎没有可测量的该抗氧化剂。该研究发现α-胡萝卜素能有效地预防心血管疾病以及脑癌、肝癌和皮肤癌。
增加α-胡萝卜素水平的食品
α-胡萝卜素的抗氧化作用能中和自由基对我们细胞的破坏作用，降低产生线粒体的能量，从而降低死亡风险。最好以有机蔬菜和水果作为α-胡萝卜素的首要来源。黄橘色的蔬菜，如胡萝卜、甘薯、南瓜和番瓜通常富含α-胡萝卜素，而包括花椰菜、绿豆和豌豆、菠菜和莴苣在内的深绿色蔬菜也是其良好来源。
水果降低23%患肺癌风险
发表在《癌症流行病学、生物标记和预防》（Cancer Epidemiology Biomarkers " Prevention）杂志中的一项研究发现使用不同种类丰富水果能降低23%肺癌风险。该研究还发现在此基础上，食用更多种类的水果能进一步降低风险，且和单种水果消费量无关。至少同时消费8种水果的预防效果最为明显，其中，每增加一种水果，风险再降低4%。
越来越多的研究证实适宜饮食在预防不良生活方式带来的疾病（如心血管疾病和癌症）的关键作用。我们的细胞依赖如α-胡萝卜素在内的胡萝卜素保存功能完整性，因此，我们应该食用多种天然蔬菜、水果和食品，以预防疾病和延年益寿。
推荐原文出处：
Arch Intern Med doi:10.1001/archinternmed.2010.440
Serum -Carotene Concentrations and Risk of Death Among US Adults
Chaoyang Li, MD, PhD; Earl S. Ford, MD, MPH; Guixiang Zhao, MD, PhD; Lina S. Balluz, MPH, ScD; Wayne H. Giles, MD, MS; Simin Liu, MD, ScD
Background Much research has been conducted relating total carotenoids―and β-carotene in particular―to risk of cancer and cardiovascular disease (CVD). Limited data are emerging to implicate the important role of -carotene in the development of CVD or cancer.
Methods We assessed the direct relationship between -carotene concentrations and risk of death among 15 318 US adults 20 years and older who participated in the Third National Health and Nutrition Examination Survey Follow-up Study. We used Cox proportional hazard regression analyses to estimate the relative risk for death from all causes and selected causes associated with serum -carotene concentrations.
Results Compared with participants with serum -carotene concentrations of 0 to 1 μg/dL (to convert to micromoles per liter, multiply by 0.01863), those with higher serum levels had a lower risk of death from all causes (P & .001 for linear trend): the relative risk for death was 0.77 (95% confidence interval, 0.68-0.87) among those with -carotene concentrations of 2 to 3 μg/dL, 0.73 (0.65-0.83) among those with concentrations of 4 to 5 μg/dL, 0.66 (0.55-0.79) among those with concentrations of 6 to 8 μg/dL, and 0.61 (0.51-0.73) among those with concentrations of 9 μg/dL or higher after adjustment for potential confounding variables. We also found significant associations between serum -carotene concentrations and risk of death from CVD (P = .007), cancer (P = .02), and all other causes (P & .001). The association between serum -carotene concentrations and risk of death from all causes was significant in most subgroups stratified by demographic characteristics, lifestyle habits, and health risk factors.
Conclusions Serum -carotene concentrations were inversely associated with risk of death from all causes, CVD, cancer, and all other causes. These findings support increasing fruit and vegetable consumption as a means of preventing premature death.
