It's no secret that eating hamburgers and fries could affect your waist line but new research has found it can also take a toll on your brain.
Researchers found that higher intake of a western diet by 14-year-olds had scored lower in cognitive tasks by the age of 17.
Within the western dietary patterns, the study found participants with a high intake of take-away food, deep fried potatoes, red and processed meat and soft drinks had negative associations that affected their reaction time, mental ability, visual attention, learning and memory.
While participants who had higher consumption of fruits and leafy green vegetables, had a positive cognitive performance.
Researcher Dr Anett Nyaradi told Science Network that it could be due to increased micronutrient content from leafy green vegetables, which has linked to enhanced cognitive development.
Dr Nyaradi said several factors may be at play in this diet-related decline in cognitive skills, including the level of omega-6 fatty acids in fried foods and red meat.
Metabolic pathways function best with a balanced 1:1 ratio of omega-3 and omega-6 fatty acids, but the western diet can shift this to a 1:20 or 1:25 ratio, according to Science Network.
Dr Nyardi told Science Network that high intake of saturated fat and simple carbohydrates has been linked to impairment in the functioning of the hippocampus, which is a brain structure centrally involved in learning and memory that increases its volume during adolescence.
'Adolescence represents a critical time period for brain development. It is possible that poor diet is a significant risk factor during this period…indeed, our findings support this proposition,' she said.
'These findings have important implications for future health policies and health promotion programs
The University of Western Australia and the Telethon Kids Institute observed 602 participants from the Western Australian Pregnancy Cohort Study.
Each participant were required to fill out a food frequency questionnaire at the age of 14 to identify the factor analysis of 'healthy' and 'Western' dietary patterns.
When they turned 17, a cognitive performance was assessed using a computerised cognitive battery of tests that included six tasks.

参考译文：
吃汉堡包和薯条可以导致肥胖，这已经不是什么秘密和新闻。不过，一项新研究认为，摄入西方模式饮食还会使人变笨。

来自西澳大利亚大学的研究人员对西澳大利亚妊娠队列的602名孩子进行了研究，从14岁开始记录他们的饮食，并进行“健康”和“西方”饮食因素分析。当他们长到17岁时，从六个方面进行认知能力测试。

测试结果发现，在西方饮食模式下，受试者摄入大量快餐食品、油炸土豆、红肉和加工肉类和汽水等，与反应时间、心理能力、视觉注意力、学习和记忆能力呈负相关。相反，摄入较多水果和绿叶蔬菜的“健康饮食”模式则对于认知能力有正面影响。

研究者认为，绿叶蔬菜富含微量营养素可能与提高认知能力相关。而认知能力的负面影响可能涉及多方面因素，比如油炸食品和红肉中的ω-6脂肪酸水平等。

饮食中ω-3与ω-6脂肪酸1:1均衡比例最有利于人体代谢，但西方的饮食模式下这一比例可能是1:20甚至1:25。
也已经有研究认为，大量摄入饱和脂肪和简单碳水化合物不利于青少年学习和记忆相关的海马结构和功能的发育成长。

研究者指出，青春期是大脑发育的关键时期，这项研究发现这个时期不良的饮食习惯对于脑发育是一个显著性危险因素，应该引起人们的关注，并对于未来的卫生政策和健康促进计划具有重要意义。

原始来源：http://www.dailymail.co.uk/news/article-2769050/Eating-burgers-fries-doesn-t-just-make-fat-makes-stupid-well.html