The main research area of Biometry and Nutition Group is Human Nutrition with special focus on Nutrition
and Adolescent Growth, Maternal
Nutrition and Fetal Growth, Bioavailibity
of Micronutrients.
Longitudinal growth data collected on rural adolescents showed that ages at onset of peak height / weight velocity, and menarcheal age of girls was delayed by 1-2 yr in comparison to urban affluent children.
Stunting in early life and wasting at take-off of adolescence hampered adolescent growth and the opportunity for catch up growth.
Velocity data revealed slow but gradual height gains at later ages ( beyond menarche in girls and upto 20 yr in boys) indicating partial catch up growth. Continuation of growth at later ages coupled with early age of marriage in rural communities increased risks for pregnancy wastages in rural girls.
Sequence of growth in linear components viz. foot length, leg length, height, sitting height and shoulder width; was similar in boys and girls. Postnatal undernutrition significantly influenced growth in leg length than that in sitting height.
Maternal intakes of macronutrients were not related to birth size in rural India but activity was negatively correlated when major confounding variables were taken care-of.
Food frequency questionnaire data showed strong association of birth size with consumption of specific food groups viz. milk in early gestation, green leafy vegetables and fruits in later gestation. The indication is that micronutrients play important role when diets are limiting in energy.
In contrast, data on urban affluent mothers showed that dietary fat intakes were associated with birth size and fruit intakes in early gestation ( when diets were low in energy due to nausea in majority of women ) were associated with birth size confirming the above speculation about the role of micronutrients in urban affluent mothers also.
Weekly supplementation of iron and folic acid ( dose same as that in the national programme ) if given from preconceptional period was found to be as effective as that of daily supplementation for improving the Hb status during as well as four months postpartum and the infant growth.
Our observations suggest that there is need to identify the critical age window in first five years of life which exerts maximum influence on adolescent growth so that existing intervention programmes like ICDS can be concentrated on such specific age window for improving adolescent growth and adult size.
Appropriate food based nutrition interventions which are better in quality than quantity are required to be planned for combating anaemia and low birth weight problems in rural India.
As early life undernutrition showed significant effect on adolescent growth, it is now more relevant to examine its effect on adult health ( in terms of risks for hypertension, diabetes and cardiovascular disorders ) in view of the recent hypothesis of ‘ fetal origins of adult diseases ’. Since we have long term cohorts studied for various aspects in the past, we would undertake such prospective studies in future.
In view of our observations on maternal nutrition and fetal growth, our future research will pertain to i) identification of key nutrients involved in metabolic programming in utero using animal models ii) food based intervention studies for confirming the role of micronutrients in improving the fetal growth among undernourished mothers iii) examining the effect of prenatal Vs postnatal undernutrition on adult health.
Apparent absorption of zinc and copper studied on 6 human subjects on 6 different diets indicated 15-20% absorption of zinc and copper, a figure 1/3 that of Western diets indicating the risk of deficiency if the gross intakes are below 15mg/day and 3mg/day for Zn and Cu respectively. Unique feature of this work was the multiple regression analysis using 17 different factors which revealed the influence of riboflavin, nicotinic acid, and thiamine on Zn/Cu absorption in addition to confirming the known role of phytate and ascorbic acid.
Habitual intakes of iron, zinc and copper were close to RDA for men but they were 30-60% of RDA for women as observed by weighment survey and laboratory estimation of diets of 34 subjects. Zn:phytate ratio indicated poor bioavailability in their diets.
Enhancing effect of riboflavin and nicotinic acid and promising potential of pearl millet diets, soaking the flour batters, natural and yeast fermentation and use of green leafy vegetables has been shown for increasing iron and zinc bioavailability. This was studied upto absorption stage based on in vitro experiments and using in tact anumal models.
Strategies for improving bioavailable micronutrient intakes:
Based on the past results, strategies using natural fortificants such as GLV, B-complex vitamins and food processing for improving micronutrient status with special reference to iron and vitamin A through human experiments. Potential of some ayurvedic preparations for supplementation of antioxidants and trace elements. Development of food technology for antioxidant and micronutrient rich fruits as natural supplements.
Biotechnology for micronutrient rich single cell protein supplements using algae and lacto baclii.
Role of micronutrients in oxidative stress disorders :
Potential of antioxidants in fruits and vegetables in prevention of oxidation stress related disorders prevalent in Indians.
Potential of vegetarian micronutrient rich diet coupled with yoga practice as complimentary therapy to drugs in treatment of I] Type II diabetes, cardio-vascular disorders, II] cancer.
Molecular approach to iron and zinc metabolism in normal and oxidative stress conditions.
Considering importance of micronutrients in health and in preventive and curative aspects of disease particularly in oxidative stress, more work in this direction is anticipated. As per the new world wide initiative through WHO for remedying iron and vitamin A deficiency, efforts through food-based approach will be continued. The need to study beta carotene and vitamin C and antioxidants from Indian diets has been also emphasised by SERC-DST in ‘Vision for R & D’ in life sciences. Role of herbal drugs and yoga practice in coping up oxidative stress in combination with micronutrients will be studied for prevention and treatment of diabetes, cardio-vascular disease, cataract and cancer. There is a need to study in depth bioavailability at cellular level and also to confirm the results in vitro and animal experiments through human experiments using stable (non-radio active) isotopes.