This document discusses nutritional epidemiology, which is the study of nutritional determinants of disease in human populations. It defines nutrition as the science of how nutrients interact with the body and influence health and disease. Nutritional epidemiology examines the relationship between diet, health, and disease. Some key points made include: - Epidemiological studies have shown relationships between low fruit/vegetable intake and cardiovascular disease and between saturated/trans fats and heart disease/diabetes. - Studies established that increasing folic acid intake reduces the risk of neural tube birth defects. - Objectives include disease prevention, monitoring population nutrient intake and status, and generating hypotheses about diet and disease.

1. NUTRITIONAL
EPIDEMIOLOGY
Maira Jabeen
L1F18BSFT0021

2. Epidemiology
■ It is the study of the
frequency, distribution and
determinants of health
related phenomena in
human populations.
■ The study of the
nutritional
determinants of
disease in human
populations.
Nutritional
Epidemiology

3. What is nutrition?
■ Nutrition is the science that interprets the interaction of nutrients
and other substances in food in relation to maintenance, growth,
reproduction, health and disease of an organism.
■ It includes food intake, absorption, assimilation, biosynthesis,
catabolism and excretion.

4. Nutrition in Epidemiology
■ In terms of epidemiology nutrition can be defined in the
following two ways.
 The way in which the human body reacts with diet.
 The extent to which the diet influences levels of
health.

5. Why it is Important?
■ It enable us to understand the relationship between
 Diet and health
 Diet and diseases
■ It enables us to understand the etiology of many diseases.
 Low intake of fruits and vegetables has been shown to be
related to increased risk of cardiovascular disease.
 Replacing saturated and trans fats with unsaturated fats
can play an important role in the prevention of
 Coronary heart disease
 Type 2 diabetes.

6. Epidemiological Studies &
Folic Acid
■ Epidemiological studies established that women could substantially
reduce their risk of bearing a child with a neural tube birth defect
by increasing their intake of the B vitamin folic acid.
■ Government agencies in several countries are planning to fortify
staple foods with folic acid.
■ Medical organizations have recommended increased intakes of
folic acid for women of childbearing potential.

7. Objectives of nutritional
epidemiology
■ Contributing to prevention of disease and improvement of
public health.
■ Monitoring food consumption, nutrient intake and nutritional
status of a population.
■ Generating new hypotheses about diet and disease
 produce evidence that supports or refutes existing
hypotheses
 assess the strength of diet-disease associations

8. Advantages
■ Its direct relevance to human health.
■ Epidemiologists study real life.
■ They do not need to extrapolate from animal models or in vitro
systems.
■ The results of their work can be translated into specific
recommendations for changes in nutrient intakes or food
consumption patterns.
■ Findings from nutritional epidemiology can have direct
implications for food processing and technology.

9. For example:
MARGARINE
■ Epidemiological studies showed that there is an association
between high intakes of trans fatty acids (found in margarine
and other processed vegetable fats) with increased risks of
coronary heart disease.
■ This will probably prompt margarine manufacturers to seek out
ways to reformulate their products to reduce their trans fatty
acid content.

10. Disadvantages
Possibility of biasing.
■ Bias is defined as systematic error, resulting in over or
underestimation of the strength of association between
exposure and outcome.

11. Difficulty in determining whether
observed associations are causal
 Drinking of alcohol is associated with lung cancer risk.
 Efforts to discourage alcohol consumption would not be likely
to reduce the lung cancer death rate,
 Because the relationship is not causal.
 Instead, it reflects the association of both alcohol intake and
lung cancer with a third factor which is cigarette smoking.

12. Difficulties facing nutritional
epidemiology
■ Complex nature of diet
To understand this complexity, it is helpful to compare
diet with another exposure such as cigarette smoking.
 Do you smoke?
 number of cigarettes smoked per day
 types or brands of cigarettes smoked
 age at which the person began smoking

13. THANKYOU