Toddlers fed a diet of junk food can suffer lasting damage to their brainpower, researchers warn.
Children who eat more chips, crisps, biscuits and pizza before the age of three have a lower IQ five years later, a study showed.
The difference could be as much as five IQ points compared with children given healthier diets with fruit, vegetables and home-cooked food.
But even if their diet improves, it could be too late as the ill-effects can persist for a lifetime.
This is the first study to suggest a direct link between the diet of young children and their brainpower in later life.
The project at Bristol University took account of factors such as social class, breastfeeding and maternal education and age.
Researchers also allowed for the influence of the home environment, for example a child’s access to toys and books.
They said good nutrition was crucial in the first three years of life when the brain grows at its fastest rate.
Young children eating a diet packed with fats, sugar and processed foods consume too few vitamins and nutrients, which means their brains never grow to optimal levels.
The findings are the latest to be published from a major investigation of childhood development called the Avon Longitudinal Study of Parents and Children.
This tracks the long-term health and well-being of around 14,000 children born in the early 1990s.
Parents completed questionnaires about the food and drink consumed by their children at the ages of three, four, seven and eight.
Three dietary patterns were identified; a processed diet high in fats and sugar, a traditional diet of meat and vegetables and a health-conscious diet high in salad, fruit and vegetables.
Researchers Dr Pauline Emmett and Dr Kate Northstone said the effect of a poor diet on brain development could persist forever, even if the diet improved.
In the study published in the Journal of Epidemiology and Community Health, children’s IQ was measured when they reached eight years old.
Dr Emmett said that the diet for children aged four or seven years had no impact on IQ scores.
But the 20 per cent of children with the worst diet at the age of three had on average an IQ score five points lower than the group eating the best diet by the time they got to eight, she said. She added: ‘The brain grows at its fastest rate during the first three years and good nutrition during this period may encourage optimal brain growth.
‘By the age of three, brain development is slowing down which is perhaps why the diet doesn’t have much effect afterwards.’
Dr Emmett said the ‘traditional’ diet of meat and vegetables and the health-conscious diet led to better IQ scores probably because they had more fresh fruit, vegetables, meat, fish and home-cooked foods.
‘This doesn’t mean you should never give your child a fizzy drink, chips or pizza, but these foods and drinks shouldn’t dominate the diet,’ she said.
‘Young children should be eating a normal family diet, with home-prepared fresh foods, but the problem is we have lost touch with food. People are frightened of preparing it from scratch.’
Dr Emmett, who has dietician training, said she admired TV chef Jamie Oliver’s attempts to get families cooking and eating together, using simple recipes and good ingredients.
The study of 4,000 children used a points system to score their diets. For every one point increase in scoring from a processed diet at the age of three, there was a 1.67 point fall in IQ points.
For those children who ate the other diets, every one point increase in the dietary pattern linked to a 1.2 increase in IQ.
Michael Nelson, director of research at The School Food Trust, which aims to improve the quality of food in schools, said: ‘Given that around 23 per cent of children start school overweight or obese, it’s clear that healthy choices as part of their early development will stand children in good stead – not only for keeping a healthy weight as they grow up, but as this evidence suggests, improving their ability to do well at school.’
- By Jenny Hope MailOnline Health
孩子在出生之后的两三年，大脑的成长是最迅速的。在这一作用下，孩子才可以学习行走、说话、开门、问问题等技能。最近有研究发现，这这段时间孩子的饮食也有可能对其大脑成长产生影响，具体地说，那就是两三岁就常吃垃圾食品的孩子很可能智商会比较低。
时代周刊报道：这项布里斯托尔大学进行的研究跟踪调查了3966名出生于1991与1992年的儿童。研究要求父母详细记录孩子在3岁、4岁、7岁以及8岁半时的饮食习惯，并在8岁半时给孩子测定智商。
科学家将家长记录的各种食物分为三类，第一类是高脂肪、高糖、高卡路里的“精加工食物”，第二类是英国人眼中的“传统食物”，即肉类、土豆、面包及蔬菜，最后一类则是“健康食物”，包括全麦面包、新鲜水果、蔬菜、米饭、瘦肉蛋白质等。
结果发现，3岁时就开始吃快餐的孩子，到了8岁半，比吃健康食物的孩子的智商要略低。研究人员坚持说，这已经刨除了其他一些可能影响儿童智商发展的因素（比如家长的受教育水平、怀孕期饮食、经济情况以及生活压力等）作用，因此可以说是单纯的食物影响智商。
结果发现，每多吃一份精加工食物，孩子的IQ就会降低1.67。与此相反，坚持健康饮食的孩子，智商会上涨1.2点。这一影响只发生在三岁，其他年龄段的饮食对智商并没有显著影响。这说明2、3岁时的饮食对孩子的成长，无论身心都是最重要的。
