爲什麼會擁有蘋果型(或梨型)身材

Where you gain weight isn't a game of chance. Turns out it's all in your genes. (Photo: iStock)

你容易肥胖並不是偶然，而是基因造成的。

If you've ever read a women's magazine, you're familiar with the concept of "apple" versus "pear" body s hapes. They're the two most common presentations of the human body — in the first case, fat gatl around the midsection, in the latter, fat accumulates around the hips, thighs, and rear.

如果你曾經讀過一本女性雜誌，你就會非常熟悉蘋果型或梨型身材的概念。它們是有關身材的兩種最常見描述。前者,脂肪集中在上腹部,後者,脂肪集中在臀部,大腿部和屁股上。

Now, researchers from Duke University have pinpointed a gene, called Plexin Dl, which determines the bod y type you'll have with a great deal more certainty than any magazine quiz ever could.

現在，杜克大學的研究人員們發現了一種基因，稱爲叢狀蛋白D1 ,它能決定體型，這比雜誌更可靠。

Now, for those who think that your body shape is only a barometer of the style of jeans you choose, or if you should opt for the A-line vs. the empire waist wedding dress, take heed: Your body shape has everything to do with your health.

那麼，你以爲你的身材只是在挑選牛仔褲時用來比對號碼的嗎？還是用來選擇vs裙或高腰婚紗的呢？請注意：你的身材代表了你的健康程度。

An apple shaped body, which has greater fat accumulation in the belly, carries with it the risk of heart disease. Fat concentration in the midsection is also thought to induce inflammation and trigger metabolic diseases including high blood pressure, stroke and diabetes.

蘋果型身材，腹部聚集了大量脂肪，會增加心臟病的風險。上腹部脂肪過多也容易誘發炎症並導致代謝病，比如高血壓，中風和糖尿病。

A pear body shape, on the other hand, is considered to be pretty healthy. This shape accumulates fat in the hips and thighs, which is associated with increased fertility and a decreased risk of metabolic diseases like diabetes.

相反，梨型身材意味着身體健康。這種身材的脂肪集中在大腿和臀部，有助於生育，也減少代謝病——比如糖尿病的機率

Now let's get back to that study.

現在，讓我們重新回到主題。

All humans have the Plexin D1 gene. But to simplify their research, the Duke researchers chose to study the gene's effects in zebrafish. Since the fish are transparent, you can actually see where the fat cells are accumulating to easily determine their body shape. John F. Rawls, PhD, and an associate professor of molecular genetics and microbiology at Duke, and James E. Minchin, PhD, a post-doctoral fellow in Rawls' lab, engineered zebrafish without the Plexin D1 gene, and compared them with normal zebrafish who carried the gene.

所有人都擁有叢狀蛋白D1基因。但爲了簡化他們的研究，杜克大學研究人員研究這種基因在斑馬魚身上的影響。因爲這種魚是透明的，他們能清晰的看到脂肪細胞的聚集地，以更容易的確定體型。杜克大學的分子遺傳學和微生物學副教授約翰·F·羅爾斯博士，和羅爾斯實驗室的博士後夥伴詹姆斯·E·明欽，把斑馬魚的叢狀蛋白D1基因剝離，並把它與正常的斑馬魚進行比較。

The fish without the Plexin D1 gene had less visceral fat tissue than their "apple-shaped" counterparts with the gene. Visceral fat is the type of fat that causes an apple-shaped body. It lies deep within the midsection, wedged between organs including the heart, liver, intestine, and lungs. From there, the tissue emits hormones and other chemicals that cause inflammation, triggering high blood pressure, heart attack, stroke, and diabetes.

沒有叢狀蛋白D1基因的斑馬魚比他們"蘋果型身材"的同類擁有更少的內臟脂肪。內臟脂肪是造成蘋果型身材的一種脂肪。它存在與上腹部，充斥在臟器們，包括心臟，肝臟，小腸和肺部之間。這些脂肪組織釋放出荷爾蒙和其他化學物質，導致炎症，誘發高血壓，心肌梗塞，中風，和糖尿病。

Instead, these "pear shaped" fish displayed more subcutaneous fat, which is the type of fat that sits be neath the skin of the hips, thighs, and rear of pear-shaped individuals. This type of fat tissue decrease s insulin resistance in humans 8imdash; which protects us from getting diabetes.

相反，那些“梨型身材”的斑馬魚擁有更多的皮下脂肪，它們存在於臀部和大腿的皮下組織，與梨型身材個體的後身。這種脂肪組織能降低機體的胰島素耐受性;從而避免我們患上糖尿病。

So should we all try to get rid of our Plexin D1 gene? Not so fast. Michin tells Yahoo Health, that whil e "to have such an extreme effect is surprising," it's important to remember that their research also inv olved an extreme amount of genetic manipulation, wholly eliminating the Plexin D1 gene in the mutant zet a fish in a way that is unlikely to ever occur in real life.

那麼，我們都應該拋棄我們的叢狀蛋白D1基因嗎？不用這麼急。Michin告訴雅虎健康板塊，當我們知道“極端影響是這 麼可怕時”,我們也一定要想起，他們的研究也進行了極端的基因操作，完全喪失叢狀蛋白D1基因的變種斑馬魚在現實中是不可能能出現的。

All humans carry the Plexin D1 gene, but we express the gene in different ways. "Body fat distribution is a complex trait that is governed by interactions between multiple genes, says Michin. "We expect that more subtle regulation of Plexin D1 in human populations is likely to occur."

所有人都攜帶着叢狀蛋白D1基因，但是，讓我們以另一種方式描述這種基因，"身體脂肪的分配是十分複雜的，是多種基因互相影響的結果，"Michin說，"我們猜想，叢狀蛋白D1基因在人體內可能存在其他效應。"

Despite the clear health implications of body fat distribution, little is known about the genetics of body shape. A large international study that appeared in Nature in February began to fill in this gap by looking for genes associated with waist-to-hip ratio. The researchers found some association with Plexin D1 in their study.

即使清晰知曉了身體脂肪分配對健康的意義，我們仍然對體型遺傳知之甚少。一個主要研究基因與腰臀比關係的大型國際研究已經在二月份在法蒂爾開始。研究者們已經發現了一些與叢狀蛋白D1基因有關的信息。

In the future, this information could lead to understanding how to genetically manipulate our body types — and, more importantly, improve our health in the process.

在未來，這些信息可能會讓我們理解基因如何控制我們的體型——同時，更重要的是，改善我們的健康。