Religion, diet and research.

Religion seeks its expression in diet, and for many individuals dietary practices reflect religious persuasion. Most religions have dietary norms or instructions. For some religions these precepts are very specific about what, how and when to eat or avoidance of certain foods. In his essay ‘Religion, spirituality and a vegetarian dietary’, Blix (2001) noted: ‘Since the dawn of civilization, there has been an inexorable intertwining of food and religion. The earliest of recorded history is rife with the interconnections. The plethora of cultures with their divergent practices and behaviors still share this one commonality, for humans seem incapable of separating nourishment of the body from sustenance for the soul.’ The connection between diet and religion remains present among many large segments of the populations of developed as well as developing countries. A detailed description of dietary instructions by world religions is beyond the scope of the present commentary. However, most religious dietary precepts fall into two general categories: (1) a temporal abstinence from all or certain foods (fasting); (2) stable and distinctive dietary habits that differ from the general population. Most, but not all, religious diets proscribe a variety of foods on a temporal or permanent basis, and thus those diets become restrictive in nature. In the context of a specific religious diet, a series of sequential questions need to be addressed. How nutritionally adequate is a religious diet? Is it healthy? Perhaps more interestingly, does following a particular religious dietary pattern lead to better health? In the case of a seemingly affirmative answer, how should the purported health effect of the diet be disentangled from other healthful habits of the religious group? The scientific scrutiny of religious diets is relevant to nutritionists, because it helps optimize nutrition for those who choose to follow such diets and improves our overall understanding of diet and health. The practice of going without food at certain times is called fasting, from the Anglo-Saxon fasten or to hold oneself from food. Fasting is defined as abstinence from food, partial or total, or from proscribed foods. Ancient Chinese and Hindu writings contemplate this practice; Jews, Christians and Muslims have observed fasting rituals for millennia. However, little is known of their nutritional and health effects. Muslims practise diurnal fasting, refraining from all food and drink in the light hours of the day during the month of Ramadan. Some Christians practise a modified fast, refraining from a variety of foods, many of animal origin, on certain days of the week or for longer periods. The present issue of the British Journal of Nutrition contains a report on a study by Sarri et al. (2004), assessing the nutritional characteristics and adequacy of Greek Orthodox Christian diets during the annual fasting seasons. The Orthodox Church specifies avoidance of meats, dairy products and eggs during their three fasting seasons, which total more than 180 d per year. Thus, devout followers of these dietary instructions become ‘de facto’ vegetarians for more than half of the year, every year. In the study of Sarri et al. (2004), the diet of sixty subjects adhering to church dietary restrictions was compared with matched controls, who did not follow them at all. The study allowed two types of comparisons: fasters and controls, and among the fasters, preto post-fasting values. Interestingly, the overall diet of the faithful adherents was higher in fibre and most micronutrients except Ca, and lower in total and saturated fat, trans fatty acids and total energy than the non-fasting controls. Thus, the overall nutrient intake profile of those who fasted regularly was more favourable. Moreover, important changes in food intake patterns could be observed among adherents to the church dietary recommendations. Compared with their regular diet, during the fasting periods, the absence of meats, dairy and eggs in the diet was compensated by a fourfold increase in the intake of legumes and moderate increases of fruits and vegetables, potatoes and cereals. In addition, the intakes of pastries and alcohol decreased. The direction of all these changes in food intake is in accordance with current dietary guidelines for chronic disease prevention (Potter, 1997; Nutrition Committee, 2000). In a previous paper concerning the same study, the authors reported a decrease in BMI and improvements in the serum lipid profile of Greek Orthodox fasters at the end of the fasting seasons, but serum lipid values reversed somewhat during their non-fasting periods (Sarri et al. 2003). Beneficial changes in serum apoproteins and lipoproteins have been reported among hyperlipidaemic subjects while fasting during Ramadan (Adlouni et al. 1997; Akanji et al. 2000). However, in other studies serum lipids did not change (Maislos et al. 1998; Temizhan et al. 2000). Unfavourable changes in the lipid profile of diabetic patients have been observed during the Ramadan fast, probably due to changes in diet and biochemical responses to fasting (Yarahmadi et al. 2003). Thus, in a society of plenty, temporal abstinence from animal foods may result in adequate diets demonstrating some health benefits in normal adults. Diurnal total fasting may be appropriate for the healthy, but offers some challenges for the ill. British Journal of Nutrition (2004), 92, 199–201 DOI: 10.1079/BJN20041229 q The Author 2004