Kummerow F A
Am J Clin Nutr. 1979 Jan;32(1):58-83. doi: 10.1093/ajcn/32.1.58.
Imbalancing nutritionally adequate diets with an excessive amount of fat calories and cholesterol has obscured the fact that intimal thickening occurs spontaneously in time on low-fat cholesterol-free diets during the aging process, and that intimal thickening can be accelerated by dietary angiotoxic "risk factors." Electron microscopy of arterial tissue from animal models identified degenerated smooth muscle cells in the fetus from sows kept on low-fat cholesterol-free diets. After birth, the degenerated smooth muscle cells increased in number with age. The presence of angiotoxic "risk factors" such as oxidized cholesterol and vitamin D3 (cholecalciferol) in the diet of such animal models increased the frequency of smooth muscle cell death in their arteries. Two types of pathology could be developed in the thoracic aorta by continuous or short term feeding of 12.5 times more vitamin D than normally present in commercial rations: 1) a diffuse fibroelastic intimal thickening in the thoracic aorta (arteriosclerosis) with no evidence of lipid deposition by continuous feeding of vitamin D or 2) an initimal thickening in the thoracic aorta and intimal thickening with foam cells and extracellular lipid deposits (atherosclerosis) in the coronary arteries after a short period of supplemental vitamin D followed by 3 to 4 months of supplement-free diets. These two types of arterial damage were identical to that in the plugs of thoracic aorta obtained as a by-product of elective coronary bypass surgery. Although all of the possible sources of oxidized cholesterol in the diet have as yet not been identified, laboratory studies have identified oxidized cholesterol as an angiotoxic factor. Since population groups that consume less vitamin D-supplemented foods, less deep fat fried cholesterol-containing foods, and less hydrogenated fats have a lower incidence of coronary heart disease than Americans, it seems judicious for food processors to reduce these previously unconsidered risk factors to a minimum. This could be done by eliminating vitamin D2 and D3 from all vitamin supplements, from all food and cereal products and from the diet of livestock 1 month before they were killed so that the intake of vitamin D is no larger than the 400 IU/quart in milk which is necessary to prevent rickets in children. Deep fat fryers, which are kept at almost 200 C for 24 hr/day, could perhaps be replaced with microwave ovens in fast food chain outlets. Processors could hydrogenate vegetable oils to a minimum trans fatty acid content and rearrange this fat with polyunsaturated fats to produce high polyunsaturated fats trans-free margarines and shortenings.
营养充足的饮食中脂肪热量和胆固醇过量,这掩盖了一个事实,即在衰老过程中,低脂无胆固醇饮食会使内膜增厚随时间自然发生,并且饮食中的血管毒性“风险因素”会加速内膜增厚。对动物模型动脉组织的电子显微镜检查发现,以低脂无胆固醇饮食饲养的母猪所产胎儿的动脉平滑肌细胞发生了退化。出生后,退化的平滑肌细胞数量随年龄增加。在这些动物模型的饮食中存在血管毒性“风险因素”,如氧化胆固醇和维生素D3(胆钙化醇),会增加其动脉中平滑肌细胞死亡的频率。通过持续或短期喂食比商业日粮中正常含量多12.5倍的维生素D,胸主动脉可出现两种病理情况:1)持续喂食维生素D会导致胸主动脉弥漫性纤维弹性内膜增厚(动脉硬化),且无脂质沉积迹象;2)短期补充维生素D后,再经过3至4个月无补充饮食,会导致胸主动脉内膜增厚,冠状动脉内膜增厚并伴有泡沫细胞和细胞外脂质沉积(动脉粥样硬化)。这两种动脉损伤与选择性冠状动脉搭桥手术副产品中获得的胸主动脉栓子中的损伤相同。尽管饮食中氧化胆固醇的所有可能来源尚未确定,但实验室研究已将氧化胆固醇确定为一种血管毒性因子。由于食用较少添加维生素D食物、较少深度油炸含胆固醇食物和较少氢化脂肪的人群患冠心病的发病率低于美国人,食品加工商将这些以前未被考虑的风险因素降至最低似乎是明智的。这可以通过从所有维生素补充剂、所有食品和谷物产品中去除维生素D2和D3,并在牲畜宰杀前1个月从其饮食中去除,使维生素D的摄入量不超过牛奶中预防儿童佝偻病所需的400国际单位/夸脱来实现。在快餐连锁店中,每天24小时保持在近200摄氏度的深度油炸锅或许可以用微波炉代替。加工商可以将植物油氢化至最低反式脂肪酸含量,并用多不饱和脂肪重新调配这种脂肪,以生产高多不饱和脂肪且无反式脂肪的人造黄油和起酥油。