Based on the present study, we examined the associations between children’s dietary patterns and cognitive ability. We found that child with higher score of the ‘High protein’ dietary pattern was associated with better cognitive ability. However, children with higher score for the ‘High fat’ dietary pattern was associated with poorer cognitive ability. Thus, it is of great importance for families to select a suitable dietary pattern.
Sociodemographic Characteristics And Cognitive Ability Of Children
The current study indicated that parents’ higher education and better family education environment were related to higher cognition of children. A study reported that the parent’s educational level can interpreter 19% of the children’s intelligence variation[16] and children whose parents had higher educational level were more likely to get higher IQ scores[17, 18]. In addition, parents with higher degree of education usually pay more attention to children’s education, and they would more consciously cultivate their children and promote children’s cognition[18].
This study found that children who live in the rural areas and lived in a larger family tend to have lower cognitive ability. The reason might be that in the rural areas or in a lager family, many families live a poor life and parents might contribute less to their children’s school performance, children would get less educational resources and then have a poorer performance in cognition[19, 20]. Our discussion of the relationship between family annual income levels and cognition also support this view, similar to that found in Australia and America[21, 22]. In our study, about half of the parents just finished primary school or less and 33.5% children whose family annual income were less than 3,500RMB per person. According to these results, although our country is developing and making progress, the education and overall economic level of the country still needs to be improved.
Diet And Cognitive Ability Of Children
Cognitive ability has been shown to be affected by a good diet (such as fish[5] and milk[23]) and a bad diet (such as French fries, hot dogs, drinks, red meat[24, 25]). These previous reports were basically consistent with our current findings that showed relationships of ‘High protein’ and ‘High fat’ dietary pattern and children’s cognition.
In current study, children with higher score of ‘High protein’ dietary pattern had higher intake of milk, dairy products, beans, bean products and eggs, and usually got higher cognitive ability scores. Studies in Kenya and South Korean both showed higher milk and dairy products intake was associated with better academic achievement[23, 26]. Besides, previous study on Korean adolescents showed that higher milk consumption could also improve overall nutritional status[27]. Childhood is a period of rapid growth and development of children, and the demanding of nutrition is the highest in the whole life. It is necessary to meet the intake of protein, especially high-quality protein. Milk, beans and eggs are the source of high-quality protein and play an important role in three meals a day. Research and analysis of food consumption of Chinese residents found that the annual consumption of milk, bean, eggs and other food is increasing, but there is still a considerable gap between people actual intake of milk, beans and eggs and the recommended amount of Chinese dietary guideline[28, 29].
In addition, this study showed that ‘High fat’ dietary pattern was related to poorer cognitive ability and this might because children had higher intake of red meat or refined meat. In recent years, the contradiction between food consumption and demand of Chinese is mainly manifested in the excessive supplement of grain and meat but the shortage of milk, beans, eggs, fruits and other food, besides, the consumption of meat has approached the maximum recommended intake of 75 g in the Chinese dietary guidelines[28, 29]. A study reported that ‘Western’ dietary pattern at the age of 14 (high intake of takeout foods, red and processed meat, soft drinks, fried and refined foods) has a negative impact on the cognitive performance of 17-year-olds[30]. Furthermore, red meat contains more saturated fatty acids, and excessive intake of saturated fatty acids may have a negative effect on cognition.
Strengths And Limitations
One of the strengths was that we used dietary patterns as a whole to analyze their effects on cognitive ability instead of analyzing the effects of a single food or nutrient on cognitive ability. In addition, the cognitive ability test in CFPS 2010 was based on the educational level of the interviewees to choose the corresponding starting point of the answer questions and the test questions were based on primary and secondary school textbooks. The results of these tests were reliable and could be used as a means to determine the level of cognitive ability. Furthermore, we were able to adjust and analyze for a series of family socioeconomic covariates and the characteristics of children that may have represented confounding factors.
A limitation of the study was that CFPS 2010’s annual diet data were limited to the frequency for each type food and could not be quantitatively calculated, this might result in poorer accuracy of the dietary results. Another was that we just analyzed the data of CFPS 2010 and it was a cross-section study. However, the findings could be valuable to provide directed public health messaging and interventions. Finally, we acknowledged that we failed to rule out the possibility of other confounding factors that we were not able to adjust in the analysis, and which might have been important driver of cognitive ability.