艾比盖尔·米勒 2017年7月6日
一项新的研究表明，高脂肪饮食是美国80%的结肠直肠癌的原因。克利弗兰医学中心的研究人员已经发现，通过激活一种能供给异常细胞的分子途径，脂肪饮食可以刺激肿瘤的生长。结肠直肠癌，从结肠或直肠开始，是美国第三常见的癌症，每年报告的病例超过13万例。在过去的几年里，联邦报告显示，55岁以下的病例激增。
研究小组发现，吃高脂肪的食物，无论是油腻的西方饮食，还是吃时髦的鳄梨，都可能导致肥胖。一项新的研究发现，西方饮食与80%的结肠直肠癌有关。克利兰诊所的研究人员发现，高脂肪的西方饮食可以通过特定的分子途径促进肿瘤的生长。
主持这项研究的一位直肠外科医生马修·
卡拉迪说，我们已经知道饮食对结肠直肠癌的影响，这些新发现是第一个通过特定的分子途径显示高脂肪摄入和结肠癌之间的联系。虽然许多高脂肪饮食被普遍认为是导致高胆固醇和快速增重的原因，但生酮类饮食被认为是一种健康的替代品，可以帮助人们减肥。
很多名人，包括金·卡戴珊、梅根·福克斯、阿德迪拉·莉玛、健康传教士格温妮丝·帕特洛都称赞生酮饮食，它减少了碳水化合物的摄入，从而使身体的第一反应是破坏脂肪储存，触发减肥。生酮饮食中碳水化合物占饮食的5%，标准饮食中含有30-50%的碳水化合物。
克利弗兰诊所的这项新研究警告说，即使是这种健康脂肪的生活方式，也为肿瘤在肠道内生长提供了肥沃的土壤。由贾斯廷·拉斯亚博士在临床结肠直肠癌项目中领导的研究小组向实验室老鼠注射了与结肠癌生长有关的异常细胞。他们将老鼠分成两组，一组喂食高脂肪食物，另一组喂食正常饮食。研究小组随后对肿瘤生长的速率进行了监测。他们发现，高脂饮食会迅速增加老鼠体内侵略性癌细胞的生长，而正常饮食的则没有什么变化。
研究人员发现，这完全取决于维生素A的高水平，这开启了一种让正常细胞更容易变异的途径。拉斯亚博士解释说，这些发现提供了对环境影响的了解，比如饮食可以改变晚期癌症的细胞数量。虽然改变一个国家的饮食是一个巨大的挑战，但拉斯亚博士说，这项研究可以为预防不良饮食的发展铺平道路。
在研究中，他们通过用阻断维生素A的途径来抑制肿瘤的生长。卡拉迪博士说，我们现在可以利用这一知识来开发新的治疗方法，以阻止这一途径，减少高脂肪饮食对结肠癌风险的负面影响。
什么是体形健美的人喜欢的高脂肪饮食?
近年来，脂肪已成为营养的宠儿。名流们正在推广的饮食计划如生酮饮食，低碳水化合物和高脂肪食物，如坚果，鳄梨，油和鱼，同时避开牛奶，黄油和奶油中的坏脂肪，碳水化合物占饮食的5%，相比之下，标准饮食中含有30-50%的碳水化合物。
它是如何起作用的?
从理论上讲，饮食中碳水化合物含量较低，身体就会变成酮症，即当体内的脂肪储备分解为酮类时，会为肌肉和大脑提供能量。这就导致了脂肪燃烧和相对快速的减肥。
用来治疗癫痫。
自20世纪20年代以来，该饮食一直用于治疗那些对药物没有反应的儿童的癫痫。最近，健美运动员和一线明星更喜欢减肥饮食。它已经被证明可以减少癫痫的数量或严重程度，也可以对某些儿童的行为产生积极影响。大多数情况下，酮类饮食包括从黄油和油中摄取大量脂肪。它不适合所有患有癫痫症的儿童，但可以帮助患有小孩癫痫综合症和西部综合症的儿童。
原文网址
http://www./health/article-4671722/Fatty-diets-cause-80-cent-colon-cancers.html
High-fat diets are to blame for 80% of colorectal cancers in US:
From fried chicken to avocado toast - America's love of greasy food
'is the culprit'
-
A high-fat diet has been linked to increased growth of
colorectal tumors
-
Colorectal cancer is very common in the US with more than
130K cases annually
-
The term encompasses cancers that start in the colon or the
rectum
-
New study links the fatty diet to aggressive growth of
cancerous cells
By Abigail
Miller For Dailymail.com
PUBLISHED: 17:52
BST, 6 July
2017 | UPDATED: 20:46
BST, 6 July 2017
High-fat diets are the reason 80 percent of
colorectal cancers in America, a new
study claims.
Researchers at the Cleveland Clinic have found evidence that fatty
diets stimulate tumor growth by activating a molecular pathway that
feeds abnormal cells.
Colorectal cancer, which starts in the colon or rectum, is the
third most common cancer in the United States with more than
130,000 cases reported annually. In the
last few years, federal reports have shown a surge in cases in
under-55s.
The
research team found that eating a diet high in fats - whether it's
a greasy Western diet of fast food or a trendy diet of avocado
toasts - could be driving rates up.
Western diets have been linked to 80 percent of colorectal cancers,
a new study has found. Researchers at the Cleveland Clinic have
revealed that a high-fat Western diet causes increased tumor growth
via a specific molecular pathway
Dr Matthew Kalady, a colorectal surgeon who led the study, said:
'We have known the influence of diet on colorectal cancer. However
these new findings are the first to show the connection between
high-fat intake and colon cancer via a specific molecular
pathway.'
While many high-fat diets are widely condemned as causing high
cholesterol and rapid weight gain, the ketogenic diet has been
touted as a healthy alternative that can help people to lose
weight.
Celebrities including Kim Kardashian, Megan Fox, Adriana Lima and
even health preacher Gwyneth Paltrow have lauded the ketogenic
diet, which cuts out carbs so that the body's first instinct is to
break down fat stores to trigger weight
loss.
Carbohydrates make up five percent of the diet, compared to a
standard diet which contains 30-50 percent carbs.
However, the new study by the Cleveland Clinic warns that even this
'healthy fat' lifestyle creates fertile ground for tumors to grow
in the gut.
The research team, led by Dr Justin Lathia and Dr Matthew Kalady in
the clinic's colorectal cancer program, injected lab mice with
abnormal cells that are linked to colon cancer growth.
They then split the mice into two groups; one group was fed a
high-fat diet and the other was fed a normal rodent diet. The team
then monitored the rates of the tumors
growing.
Overwhelmingly, they found that the high-fat diet rapidly increased
the growth of aggressive, cancerous cells in the mice, while their
peers on a normal diet saw little
change.
It is all down to the high levels of vitamin A, the researchers
discovered, which unlock a pathway making it easier for normal
cells to mutate.
Dr Lathia explained: 'These findings provide insight into how
environmental influences, such as diet, can alter cancer stem cell
populations in advanced cancers.'
While changing a nation's diet is a huge challenge, Dr Lathia said
the research could pave the way towards developing treatments to
prevent a poor diet from fueling tumors.
In the study they managed to curb tumor growth by blocking the
vitamin A
pathway.
'We can now build upon this knowledge to develop new treatments
aimed at blocking this pathway and reducing the negative impact of
a high-fat diet on colon cancer risk,' Dr Kalady
explained.
WHAT IS THE HIGH-FAT DIET THAT A-LISTERS
LOVE?
In recent years, fat has become the darling of
nutrition.
Celebrities are promoting meal plans like the keto diet, which is
low in carbohydrates and high in fatty foods like nuts, avocado,
oils and fish - while shunning 'bad fats' in milk, butter and
cream.
Carbohydrates make up five percent of the diet, compared to a
standard diet which contains 30-50 percent
carbs.
HOW DOES IT
WORK?
In theory, of your diet is low in carbohydrates, your body is
shifted into 'ketosis', which is when fat stores in the body are
broken down into ketones, which fuel the muscles and the brain.
This then results in enhanced fat burning and relatively quick
weight loss.
USED TO TREAT EPILEPSY
The diet has been used since the 1920s to manage epilepsy in
children who do not respond to medication. More recently as a
weight loss diet preferred by bodybuilders and
A-listers.
It has been shown to reduce the number or severity of seizures, as
well as to have positive effects on behavior in some
children.
Most often the ketogenic diet involves consuming a lot of fat from
butter and oil.
It is not suitable for all children with epilepsy but can help
those with Dravet syndrome and West syndrome.
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