104 Asia Pacific J Clin Nutr (2002) 11(2): 104–111 Original Article Influence of fish consumption on the distribution of serum cholesterol in lipoprotein fractions: comparative study among fish-consuming and non-fish-consuming populations Gandham Bulliyya PhD Department of Physical Anthropology, School of Biological Sciences, Sri Venkateswara University, Tirupati, India The objective of this study was to investigate serum lipoprotein levels in order to assess cardiovascular disease (CVD) risk factors between fish-consuming populations and non-fish-consuming populations, as it has been speculated that fish intake reduces CVD risk. A representative sample of one thousand subjects (529 men and 471 women) were selected, with ages ranging from 20 to 70 years, from 40 villages belonging to fish- consuming (500) or non-fish-consuming (500) populations. Serum lipoprotein lipids such as total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were analysed biochemically using standard procedures. The ratios of TC : HDL-C and LDL-C : HDL-C were computed. Mean values of serum LDL-C and the ratios of LDL-C : HDL-C and TC : HDL-C were significantly lower and HDL-C levels were higher in fish-consumers than in non-fish-consumers. The concentrations of HDL-C decreased with increasing age, while the reverse was true for LDL-C and for the LDL-C : HDL-C and TC : HDL-C ratios. There were significant sex differences for certain age groups in both of the population groups. The 5th, 50th and 95th percentile cut-off values for these parameters were lower in fish-consumers than in non-fish-consumers. The prevalence of individuals at risk of CVD because of low HDL-C (<35 mg/dL), high LDL-C (>130 mg/dL) and their atherogenic ratios (LDL-C : HDL-C > 3.5 and TC : HDL-C > 4.5) was significantly greater in non-fish-consumers. This study highlights that the fish-consuming population had a lower atherogenic risk than the non-fish-consuming population. The intake of fish may have substantial implications for public health and health economy by decreasing the risk of CVD. However, more studies are warranted to better define the mechanisms of cardioprotection by dietary fish and fish oils. Key words: cardiovascular disease risk factors, fish consumption, India, long-chain n-3 polyunsaturated fatty acids, serum lipoprotein lipids, Tirupati. Introduction Cardiovascular disease (CVD) is the most frequent cause of morbidity and mortality not only in developed nations but also in developing nations like India. 1,2 India is experiencing a process of rapid epidemiological transition in terms of pat- terns of health and disease as communities transform their social and economic structures. 3 There have been marked changes in the diet and lifestyle characteristics of Indian people, resulting in a rapid emergence of CVD. An increase in CVD mortality has been documented following the recent acculturation and socioeconomic development and the bur- den of disease is predicted to increase over the next 20 years. 4–6 The people living in urban India have CVD rates similar to Indians living overseas, having the highest rates reported for Indian people. 7,8 The prevalence of CVD in rural areas is half that of urban India. 7,9 However, the overseas Indian rates are double those of the United States and four- fold higher than those of rural China and Japan. 10 The role of blood lipids and lipoproteins in predicting morbidity and mortality from CVD has been well estab- lished. 11,12 Cholesterol and its lipoprotein subfractions, such as high-density lipoprotein cholesterol (HDL-C) and low- density lipoprotein cholesterol (LDL-C), have received considerable attention. 13–15 The significance of elevated LDL-C is identified as the major atherogenic plasma lipo- protein. 16–18 Variations in LDL-C concentrations account for a large part of the variance in CVD incidence within high risk populations. 17 Prospective epidemiological studies have shown that low plasma HDL-C is an independent risk factor Correspondence address: Dr Gandham Bulliyya, Regional Medical Research, Indian Council of Medical Research, Chandrasekharpur, Bhubaneswar 751023, Orissa, India. Tel: +91 674 301322; Fax: +91 674 301351 Email: rmrcdir@sancharnet.in Accepted 12 February 2001