氫化植物油

什麼是氫化植物油

　　氫化植物油也叫反式脂肪酸，俗稱奶精、乳馬林或是人造奶油，是普通植物油在一定溫度和壓力下加氫催化的產物。因為它不但能延長保質期，還能讓糕點更酥脆；同時，由於熔點高，室溫下能保持固體形狀，因此廣泛用於食品加工。氫化過程使植物油更加飽和。或使其中的順式脂肪酸變為反式脂肪酸。這種油存在於大部的西點與餅乾裡頭。還有我們去吃韓國烤肉時，旁邊放的那一塊奶油或是奶油餅里所包的都是這種油脂。珍珠奶茶中是奶香就是使用氫化植物油與甜味劑、香料、木薯粉等材料調製，對身體有害，不宜多吃。

危害

　　氫化植物油的結構在化學上是呈反式的鍵結，它比真正的奶油要毒上好幾百倍。最近研究表明，反式脂肪酸對人體的危害比飽和脂肪酸更大。膳食中的反式脂肪酸每增加2%，人們患心腦血管疾病的風險就會上升25%。還有實驗發現，反式脂肪酸可能會引發老年痴呆症。 Time雜誌在曾經公布，氫化植物油在自然界是不存在的，也就是說在自然情況下，人體是無法吸收消化這種油脂的。食用後會對肝臟產生傷害，進而破壞人體細胞膜，造成細胞的缺陷，影響細胞未來的複製與再生，長期大量使用，可以使人產生身體過早衰老的癥狀。
　　我國對氫化植物油的使用尚無明確標準。如果在配料表上注有「氫化植物油」「植物奶油」「起酥油」等字樣，就意味著食品中含有反式脂肪酸。另外，咖啡伴侶的主要配料「植脂末」也是「氫化植物油」，珍珠奶茶中乳香的主要來源也是「氫化植物油」。
　　氫化植物油不含有膽固醇類物質且相對於動物奶油價格低廉，因此，很多人養成以人造奶油替代動物奶油的習慣。但最近的研究表明，大量食用氫化植物油會對心臟產生一定的危害。還有實驗發現，人造奶油中的反式脂肪酸易引發老年痴呆症。但學術界對這些說法意見不統一，關於反式脂肪酸對人體的危害也是近年來爭論的熱點。

What is Hydrogenated Oil?

Oils have been hydrogenated since the 1930s to prolong their shelf life and make the oils more stable. Hydrogenated oil is oil in which the essential fatty acids have been converted to a different form chemically, which has several effects on the oil. Hydrogenated oil is far more shelf stable, and will not go rancid as quickly as untreated oil. It also has a higher melting point, and is often used in frying and pastries for this reason. Finally, the chemical structure of the oil is changed, which scientists in the 1990s began to realize could result in health effects.

Hydrogenated oil is made by forcing hydrogen gas into oil at high pressure. Both animal and vegetable fats can be and are hydrogenated. In general, the more solid the oil is, the more hydrogenated it is. Two common examples of hydrogenated oil are Crisco and margarine. In the 1990s, it was realized that these products might have deleterious health effects, a tragic irony since they were originally produced and promoted as being healthier than conventional oils.

The unstable fatty acids in oils happen to be unsaturated fats, which have been determined to be healthier for consumers, acting to reduce cholesterol in some cases. When hydrogenated oil is made, these healthy fats are converted into a new type of fatty acid, known as a trans fat. Trans fats are not at all good for one's health. In some highly hydrogenated oils like margarine, trans fats can make up almost half of the total fat content.

Trans fatty acids work to increase LDL, or "bad" cholesterol, and they also decrease HDL cholesterol, which is "good" cholesterol. This means that the fats in hydrogenated oil are far more damaging than even saturated fats, which medical professionals have already determined to be harmful. There is also evidence to suggest that trans fatty acids may bioaccumulate in the body, because the digestive system has difficulty figuring out what to do with them. As a result, a diet high in trans fats will result in weight gain.

Consumption of hydrogenated oil has been linked with diabetes, coronary disease, and obesity in a wide number of scientific studies. In the 1990s, many activists began to lobby for clear food labeling, indicating when products contained trans fats. Other activists went further, attempting to ban trans fats because of their detriment to human health. All medical professionals agree that people should limit their consumption of hydrogenated oil to avoid exposure to trans fats, and should eat foods with healthy fats such as nuts, avocados, and olive oil.