Nutrition is a basic human need and a prerequisite to a healthy life. A proper diet is essential from the very early stages of life for proper growth, development and to remain active. Food consumption, which largely depends on production and distribution, determines health and nutrition of the population.
Nutrition is the process of ingesting and assimilating the nutrients. Food is a concern of the mankind beginning from the time of conception and extending through the entire life span of the individual. Food supplies the energy for physical activity and other metabolic needs of the body. Nutrients are necessary for maintaining growth of the individual and for repair of the worn out and aging tissues.1
Nutritional status of an individual is often the result of many interrelated factors. It is influenced by the adequacy of food intake both in terms of quality and quantity and also by the physical health of the individual. The major food issues of concern are insufficient/ imbalanced intake of foods/nutrients. The common nutritional problems of public health importance in India are low birth weight, protein energy malnutrition in children, chronic energy deficiency in adults, micronutrient malnutrition and diet related non-communicable diseases. However, diseases at the either end of the spectrum of malnutrition (under-and over-nutrition) are important. Recent evidences indicate that undernutrition may set the pace for diet related chronic diseases in later life. Population explosion, demographic changes, rapid urbanization and alterations in traditional habits contribute to the development of certain unhealthy dietary practices and physical inactivity, resulting in diet-related chronic diseases.2 3
Nutritional status during school age is a major determinant of nutritional and health status in adult life. Globally, health hazards associated with undernutrition and micronutrient deficiencies remain a major public health problem. The past three decades have witnessed the emergence of overnutrition as a problem in school-age children in developed countries and in affluent urban segments in developing countries.3
Anthropometric measurements such as height, weight, mid arm circumference, skin fold thickness are valuable indicators of nutritional status. WHO has recommended various indices based on anthropometry to evaluate nutritional status of school children. BMI is the most appropriate variable for nutritional status.2
As India is entering the era of dual nutrition burden of under and overnutrition, it is important that under/overnutrition are correctly diagnosed taking into account appropriate weight-for-height. Though weight / (height)2 i.e., (BMI) is widely used as a criterion for assessment of nutritional status in adults, this index has not been used to assess nutritional status in childhood. This is mainly because the BMI in children and adolescents varies with age and so it is not easy to use it to assess the nutritional status. Realizing the importance of a uniform reference for international comparisons, the Working Group on Childhood Obesity of the IOTF has recently proposed age and sex specific BMI criteria to define overweight and obesity in children. CDC has also developed a similar BMI-for-age norm which is also widely used. Though, the BMI-for-age curves were developed for assessment of overweight and obesity, logically they should be used for assessment of both over and undernutrition.4
Undernutrition includes both protein-energy malnutrition and micronutrient deficiencies. Undernourishment not only affects physical appearance and energy levels, but also directly affects many aspects of the children's mental functions, 4
growth and development which has adverse effects on children's ability to learn and process information and grow into adults that are able to be productive and contributing members of society. Undernourishment also impairs immune function leaving them more susceptible to infection. Children with infections are more susceptible to malnutrition and the cycle of poverty and malnutrition continues. Child malnutrition is responsible for 22 percent of India's burden of disease.5
Malnutrition is associated with both structural and functional pathology of the brain. It results in tissue damage, growth retardation, disorderly differentiation, reduction in synapses and synaptic neurotransmitters, delayed myelination and reduced overall development of dendritic arborization of the developing brain. There are deviations in the temporal sequences of brain maturation, which in turn disturb the formation of neuronal circuits .Long term alterations in brain function have been reported which could be related to long lasting cognitive impairments associated with malnutrition.5
Numerous studies have shown the devastating effects on intelligence and brain development of a lack of basic nutrients in the prenatal period, in infancy and in early childhood. Programs such as the Special Supplement Program for Women, Infants, and Children can be effective in ensuring that babies receive the kinds of foods they need to thrive. Educational and outreach campaigns to alert women to the importance of nutrition in the first trimester of pregnancy would also be helpful in preventing problems that can arise in this critical period when brain cells begin to form.6
Stunting in early childhood is common in developing countries and is associated with poorer cognition and school achievement in later childhood.3
Cognition is the mental action or process of acquiring knowledge through thought, experience and senses. The components of cognition involve attention, memory, 5
executive functions, visual-spatial functions, comprehension, learning, motor speed and expressive speech. A wide range of cognitive deficits has been observed in malnourished children in India.7
Out of these, memory implies the encoding, storage, and retrieval of information, which is very important from a developmental perspective because the capacity to hold information and process it supports various higher level accomplishments such as language, categorization, and social cognition.7 Working memory is the ability to actively hold information in the mind needed to do complex tasks such as reasoning, comprehension and learning. Working memory tasks are those that require the goal-oriented active monitoring or manipulation of information or behaviors in the face of interfering processes and distractions. The cognitive processes involved include the executive and attention control of short-term memory which provide for the interim integration, processing, disposal, and retrieval of information. Working memory is a theoretical concept central both to cognitive psychology and neuroscience.8
The differential nature of cognitive deficits associated with malnutrition suggests that different areas of the brain are compromised to different degrees. A neuropsychological assessment would be able to delineate the pattern of brain dysfunction. Neuropsychological measures can demonstrate delay in normally developing cognitive processes as well as permanent cognitive deficits. Short-term working memory would certainly appear to be a prime target as an index of how nutrition affects cognitive development in young children.5 6
NEED FOR THE STUDY
According to UNICEF 2009 statistics, 36.96% of the total Indian population are under the age of 18 years. In India, 48% of under-five children are suffering from moderate and severe undernutrition.9 According to NHFS, 2010 report, around 20 per cent of school-going children in India are overweight. Population projections indicate that over the next decade this age group will show by far the largest increase in numbers. It is therefore essential that over the next decade efforts should be focused on improving the health and nutritional status of school-age children, so that they reach adult life with optimal nutrition and health status.10
Malnutrition is a major problem in our country as 52% of our children were malnourished in 2006. National Family Welfare Survey , (2005-06), shows that 40% of Indian children under 3 years are underweight , 45% are having stunted growth and 23% are having muscle wasting. Proportion of children who are stunted or underweight increases rapidly with the child's age. The WHO cites malnutrition as the gravest single threat to the world's public health. There were 923 million malnourished people in the world in 2007. On the average, a child dies every 5 seconds as a direct or indirect result of malnutrition - 700 every hour - 16 000 each day and 6 million each year. Hence, 60% of all child deaths are due to malnutrition (2002-2008 estimates).3About 35% of preschool children in sub-Saharan Africa are reported to be stunted.11
According to reports from Centre for Disease Control, childhood obesity has more than tripled in the past 30 years. The percentage of children aged 6-11 years in the United States who were obese increased from 7% in 1980 to nearly 20% in 2008. Similarly, the percentage of adolescents aged 12-19 years who were obese increased from 5% to 18% over the same period. Overweight is defined as having excess body 7
weight for a particular height from fat, muscle, bone, water, or a combination of these factors.3 Obesity is defined as having excess body fat.7 Overweight and obesity are the result of ―caloric imbalance--too few calories expended for the amount of calories consumed-and are affected by various genetic, behavioral, and environmental factors.12
A recent study on effects of deficiencies in zinc, iodine, iron and folate on the cognitive development of school children highlighted that the cognitive ability and performance of the brain is susceptible to moment-to-moment metabolic changes and that this is more pronounced in children with low nutritional status. Further, that among the well-nourished, augmentation of nutrient intake has less of an impact on cognitive performance.13
A study was conducted in UK to assess the effect of breakfast in reducing the declines in attention and memory over the morning in schoolchildren. Twenty-nine schoolchildren were tested throughout the morning on 4 successive days, having a different breakfast each day (either of the cereals Cheerios or Shreddies, glucose drink or No breakfast). A series of computerized tests of attention, working memory and episodic secondary memory was conducted prior to breakfast and again 30, 90, 150 and 210 minutes later. The glucose drink and no breakfast conditions were followed by declines in attention and memory, but the declines were significantly reduced in the two cereal conditions. This study provides objective evidence that a typical breakfast of cereal rich in complex carbohydrates can help maintain mental performance over the morning.14
The social competence, visual motor coordination and memory functions of 1336 rural primary school children in India, between the age group 6-8 yr were studied in relation to their nutritional status and socio-environmental factors. Children 8
with grades, I, II and III malnutrition scored 4.4, 8.5 and 11.8 points lower respectively as compared to those in normal nutrition. Stunted wasted rural children performed poorly on areas like communication, socialization and occupation. Environmental factors like family size and type, economic sufficiency, and father's education also played a significant role in determining the social competence in girls. Observations on memory test indicated that malnutrition had a significant but very weak relationship with immediate and delayed memory. The boys in grade II malnutrition had significantly lower immediate memory scores, as compared to normal boys. Further, for delayed memory, boys in grade II malnutrition scored poorly for pictures and words.15
A comparative study was conducted in Brazil on Intelligent quotient of obese children and adolescents by the Weschler scale. The intellectual characteristics of 65 obese children and adolescents (weight for height > or = 140%), aged 8 to 13 years and 11 months, were compared to those of 35 normally nourished children and adolescents (weight for height between 90 and 110%; and stature for age > 95%) of the same age group, utilizing the WISC. The obese group was composed of new patients assisted at the Department of Pediatrics of the Federal University of S. Paulo, Brazil. The control group was made up of children from public primary schools, from the same geographical area as those studied. The normally nourished group presented significantly better performance in the intelligence test than the obese group. Normally nourished children and adolescents revealed a wider range of interests, better capacity for social adaptability as well as greater speed and dexterity. The study concluded that despite these findings, causality could not be determined, because of the cross-sectional nature of the study and as the other intervening variables may have been related to the observed pattern of results.16 9
Children are the wealth of any nation as they constitute one of the important segments of the population. Although various government schemes are set up to combat the nutritional problems, they have not had the expected impact in reducing malnutrition or micronutrient deficiencies. The foundation of good health and a sound mind is laid during the school age period. Normal cognitive abilities like attention, concentration and most importantly the memory are essential factors which directly or indirectly determine the scholastic and overall achievements of an individual. These are the basic milestone of an individual and it is responsible for many changes that take place during the later life. Moreover school age is considered as the dynamic period of growth and development because children undergo physical, mental, emotional, and social changes. The school children are easily accessible, capacitive and responsive group. Keeping in view all these facts, student researcher has taken up this study to assess the relation between nutritional status and memory of school children. 10
