Food and Nutrition-Related Diseases: the Global Challenge

Economic development, education, food security, and access to health care and immunization programs in developed countries have resulted in dramatic decreases in undernutrition-related diseases. Unfortunately, many of these factors have also led to unhealthy behaviors, inappropriate diets, and lack of physical activity, which has exacerbated the development of chronic diseases, also known as noncommunicable diseases (NCDs). These NCDs are now the main contributors to the health burden in developed countries (these are countries with established market economies). In 2002, 28.2 million global deaths (58.6%) were from NCDs. In the same year the predicted mortality for 2020 was 49.6 million (72.6% of all deaths). This is an increase from 448 to 548 deaths per 100,000, despite an overall downward trend in mortality rates. Although the burden will fall increasingly on developing Countries NCDs remain the major cause of death in developed countries. The NCDs that are related to diet and nutrient intakes are obesity, hypertension, atherosclerosis, ischemic heart disease, myocardial infarction, cerebrovascular disease, stroke, diabetes mellitus (type 2), osteoporosis, liver cirrhosis, dental caries, and nutrition-induced cancers of the breast, colon, and stomach.

They develop over time in genetically susceptible individuals because of exposure to interrelated societal, behavioral, and biological risk factors. Together with tobacco use, alcohol abuse, and physical inactivity, an unhealthy or inappropriate diet is an important modifiable risk factor for NCDs. Diet, therefore, plays a major role in prevention and treatment of NCDs. NCDs are sometimes called “chronic diseases,” but some infectious diseases such as HIV/AIDS and tuberculosis are also chronic. They have also been called “diseases of affluence,” which is a misnomer because in developed, affluent countries, they are more common in lower socioeconomic groups. Some scientists have a problem with the term “noncommunicable” because lifestyles, including diets, are transferable between populations. The term “noncommunicable” should therefore be seen as no transfer of an infectious agent from one organism to another. Because of its first emergence in “Westernized” societies and associations with Western lifestyles, it is often called “Western” diseases, also a misnomer. It is becoming more prevalent in developing countries in other parts of the world.

Another misconception is that it is a group of diseases affecting only older people. The risk factors for NCDs accumulate throughout the life course – from infancy to adulthood, and manifest after decades of exposure. The increase in childhood obesity is especially of concern because it has long-term implications for NCDs in the developed world. The evidence that diets and specifi c nutrient deficiencies and excesses influence the development of NCDs and may therefore be used in prevention and treatment is solid. It comes from extensive research which collectively gave convincing evidence of the relationships between nutrition and NCDs: first, from ecological studies which compared different populations, the effects of migration of populations, food availability during economic development, and differences in dietary and nutrient intakes.

Second, numerous epidemiological studies have established the associations between diet and biological risk factors of NCDs. Third, interventions with specific nutrients and foods in placebo-controlled trials using both healthy and diseased subjects confirmed the relationships seen in epidemiological studies. And last, molecular and genetic research has elucidated many mechanisms through which diet and nutrients affect genetic mutation and expression, adding to our knowledge of how nutrition influences NCD development. This body of knowledge has led to several sets of international dietary recommendations and guidelines to reduce the burden of nutrition-related NCDs. An example of one such set of guidelines from the World Health Organization (WHO) . These generic recommendations could be used as the basis for the development of country-specific strategies and food-based guidelines for dietary prevention of NCDs.