Nutrition Epidemiology Zuzana Derflerová Brázdová Dept. of Preventive Medicine, School of Medicine, Masaryk University, Brno Chronology of application of the science of nutrition • 2300 B.C., China: salt and cerebrovascular disease • 47 B.C., Scribonius Largus: importance of diet in general health • 25 B.C., Celsus: classified foodstuffs and emphasized their role in maintaining health • 1542 A.D., Andrew Borde: A Dyetary of Health: factors affecting the health of man • 1628 A.D., William Harvey: publication on circulation of the blood based on convicing experiments Chronology of application of the science of nutrition • 15th century, Albeek from Unitchov: excessive intake of fats and energy as a cause of premature death Diseases related to nutrition (developed countries) Diseases related to nutrition (developing countries) Nutrition status at the beginning of the 3rd millenium • 520 million of severely malnourished • 15 - 20 million victims of hunger a year • 300 million suffer by deficiency of vitamin A • 3.5 billion suffer from IDA • 853 million suffer from IDD • 75% of total population live in developing countries, but they consume only 15% available energy • 1 billion drink contamined water Nutrition status in the beginning of the 3rd millenium • 11-15 million children die because of hunger • 250 thousand children get blind because of deficiency of vitamin A • 50% anaemic children (SE 52% vs. NW 10%) • 15 million children < 5 yrs get sick from contamined water • More than 40% of all death in developing countries are among children < 5 yrs • 54% from them are related to undernutrition CVD in the Czech republic • 1982: SMR 840.2 men and 546.6 women • 1995: SMR 708.0 men and 454.9 women • 1986: SMR IM 239.0 men and 233.0 women • 1995: SMR IM 175.4 men and 77.9 women • 1986: SMR Cer.d. 258.5 men and 203.2 women • 1995: SMR Cer.d. 176.3 men and 134.8 women Role of Nutrition Epidemiology • Problem detection – epidemiologic studies • Development of methods of dietary assessment • Definition of nutrition needs at the population level • Formulation of dietary recommendations • Implementation of dietary guidelines • Influence of research trends • Education of professionals Development of dietary assessment methods • Recall • Record (weighting, estimation) • Double portions • FFQ • Dietary history • Dietary habits • Food balance sheets • Inventory method • Food supply Exact result of any dietary assessment method? People eat. Model of influence dietary behaviour at the population level • Knowledge • Attitude • Behaviour • Behaviour • Attitude • Knowledge Atributes of dietary guidelines • Based on scientific background • Analysis of local dietary habits • Social and cultural acceptance • Limited number of recommendations (the most relevant from the prospective of population health) • Easy to understand and remember, attractive, motivating to compliance and real behaviour changes Dietary guidelines in terms of nutrients and energy Dietary guidelines for the Czech republic • Cereals, bread, rice, pasta: 3-6 servings • Vegetables: 3-5 servings (a 100 g) • Fruit: 2-4 servings (a 100 g) • Milk and milk products: 2-3 servings (equiv. 300 mg Ca) • Meat, poultry, fish, eggs, pulses: 1-3 servings • Others: 1+1 servings (equivalent of 10 g fat or sugar) Serving size • Cereals, pasta, bread, rice: 1 slice of bread (60 g) 1 cup of rice or pasta (125 g) 1 cup musli • Vegetable 1piece approx. 100 g • Fruit 1piece cca 100 g Serving size • Milk and milk products 1 glass of milk - 300 ml 1 cup of yogurt approx. 180 ml 1 serving of „average“ cheese - 55 g • Each serving is equivalent of 300 mg calcium Serving size Fish, poultry, pulses, meat,… • 80 g or • 1 cup of pulses • boiled egg yolk Preventive programmes • High risk strategy • Population strategy Recommended physical activity • Minimum 3 times a week • Aerobic excercise • Minimum 20 minutes • + regular walking 1 hr daily Evidence about non pharmacological intervention • Physical activity 3 times a week, 30-40 minutes aerobic, i.e. lactates < 4 mmol/l by intensity > 7 kcal/min HDL-chol increases, > 9 kcal/min total serum cholesterol decreases Relation of physical activity to total cholesterol, HDL-chol, atherogenic index is linear, and to the level of TG logaritmic Assessed sample before intervention • Sample 1426 person, 882 men, 544 women • Age 39,3 + 10,7 years • T-chol >5,2 mmol/l in 38,8% sample Intervented sample • 279 person • 168 women, 111 men • Age 43,5 + 10,3 yrs Changes of HDL-chol before and after intervention • Before intervention 1,04 + 0,13 mmol/l • After intervention 1,16 + 0,14 mmol/l • P < 0,001 Changes of t-chol before and after intervention • Before intervention 6,1 + 0,75 mmol/l • After intervention 5,36 + 1,24 mmol/l • P < 0,001 Cholesterol decreasing nutrients • MUFA • PUFA • Sitostanol • Campestanol • Guar gum • Pectin • Fytosterols • Stilbenols Cholesterol decreasing nutrients • Beta- caroten • Lycopen • Cycloartenol • Beta-sitosterol • Sitostanol • Saponins • Mevinolin • Niacin ? Cholesterol decreasing foods • Vegetables • Fruits • Soya • Peanuts • Corn • Cereals • Psyllium • China green tea Cholesterol increasing foods • Fats with high content SFA • Non filtered caffee (cafestol) • Animal sources with high content of cholesterol…. (offals, eggs, skin, butter, …) CINDI Dietary Guidelines – CVD prevention Twelve steps of healthy eating: 1. Eat a nutritious diet based on a variety of foods originating mainly from plants rather than mainly from animal origin CINDI Dietary Guidelines – CVD prevention 2. Eat bread, grains, pasta, rice or potatoes several times per day 3. Eat a variety of vegetables and fruits, preferably fresh and local, several times per day (at least 400 g per day) CINDI Dietary Guidelines – CVD prevention 4. Maintain body weight between the recommended limits (BMI between 20-25) by taking moderate levels of physical activity, preferably daily 5. Control fat intake (not more than 30% of daily energy) and replace most saturated fats with unsaturated vegetable oils or soft margarines CINDI Dietary Guidelines – CVD prevention 6. Replace fatty meat and meat products with beans, legumes, lentils, fish, poultry or lean meat. 7. Use low fat milk and dairy products (kefir, sour milk, yoghurt and cheese) that are low in both fat and salt. CINDI Dietary Guidelines – CVD prevention 8. Select foods which are low in sugar and eat refined sugar sparingly, limiting the frequency of sugary drinks and sweets. 9. Choose a low salt diet. Total salt intake should not be more than one teaspoon (5 gr) per day, including the salt in bread, processed, cured and preserved foods. (Universal salt iodization where iodine deficiency is endemic). CINDI Dietary Guidelines – CVD prevention 10. If consumed, limit alcohol intake to no more than 2 drinks (each containing 10 gr of alcohol) per day. 11. Prepare food in a safe and hygienic way. Steam, bake, boil or microwave to help reduce the amount of added fats, oils, salt and sugars. CINDI Dietary Guidelines – CVD prevention 12. Promote exclusive breast feeding for about 6 months and recommended the introduction of appropriate foods at correct intervals during the first years of life. Epilogue: Man has to eat foods which he likes. But he should learn to like these foods, which are good and healthy for him.