We Are A Species Still Growing

You would not find a couple not concerned about their child's health. A host of nagging questions keeps flickering through their mind. Is the baby's height okay? Is it gaining weight? Is it growing up normally? 

A recently-held seminar on human growth and development threw light on several aspects of a child's growth. The meet was held at Indian Statistical Institute (ISI) in memory of late professor S. R. Das who pioneered the study of human growth and development in India.   

After a baby comes out of mother's womb, it is exposed to various external stimuli that influence its growth. "Mother's health after child birth and parents' educational status play a pivotal role in determining the growth pattern of a growing child," said Dr. P. H. Ananthanarayanan, director of All India Institute of Hygiene and Public Health, in his inaugural address on 'Human Growth and Nutrition: Public Health and Epidemiological Considerations.' 

"Poor sanitation often leads to gastrointestinal infections," he said. According to him, intestinal infection hinders food absorption which, in turn, causes malnutrition among children. "The quality of food that a mother consumes ought to be taken into consideration. Before weaning, a child's growth largely depends on its mother's milk," he said, adding, " After weaning, a child's good growth rate is maintained by adequate intake of proteins and nutrients like vitamins and minerals." 

In his S. R. Das Memorial Lecture on 'Barisha-Sarsuna Growth Study: History, Development and Future Possibilities,' Roland C. Hauspie, professor at the laboratory of anthropogenetics from the Free University of Brussels, discussed the various aspects of linear and longitudinal growth. 

"A total of 563 subjects comprising 303 boys and 260 girls between five months and 20 years were studied," said Hauspie, " measurements regarding height, weight, sitting height and head breadth were taken by late Prof. S. R. Das. When the results were analysed, it was found that during adolescent period increase in height and weight peaked." During adolescence, height of boys far outstripped that of girls, providing a positive indicator of sexual dimorphism. 

Fat is an indispensable constituent that adds to weight gained during growth and development. Dr. Kaushik Bose from the department of anthropology, Calcutta University, spoke on body fat patterns of Bengali girls. 

"The onset of menstruation signals the sexual maturation in girls. At this stage, hormones, particularly, sex hormones, secrete profusely, bringing about perceptible secondary sexual changes among girls," Bose pointed out. "One such sexual change is accumulation of fat throughout the body." Distinct fat deposition is seen in the regions like waist, hip, abdomen, chest and thigh. 

Gene's role, too, cannot be undermined in body fat deposition. Gene's participation in fat deposition was highlighted by Prof. Partha Pratim Majumder, head of anthropology and human genetics unit, ISI. "A small number of genes have been found to have major implications in fat deposition. Sometimes interaction between genes and environment comes into play," said Majumder. 

Dr. M. Henneberg, Wood Jones Professor at the department of anatomical sciences, University of Adelaide, provided a global perspective of growth study with a prehistoric view. "From fossil evidence it had been found that our earliest ancestors who lived nearly five million years ago were nearly 130 cm tall," he said. "Since then, their height continuously increased until the retreat of last ice age." 

Around 10,000 years ago, during the Holocene period, height began to decrease. "Study with present population in South Africa shows that white females achieve 4 mm increase in height per decade," he observed. "Australian aborigines' increase in height resembles that of white males in Australia."