Nutrients, bioactive compounds, and immune function
Published on 8 June 2011 in Food, health and wellbeing
Introduction
Inflammation can help us or hinder us. On one hand, it helps the body to fight against infection. On the other hand, inflammation is a key feature of many chronic diseases often associated with ageing.
There are two types of inflammation: acute and chronic. Acute inflammation is an initial response of the body to an injury or infection. It directs immune cells from the blood to the infected part of the body, allowing it to repair itself. In this case, acute inflammation successfully restores the body’s normal function to heal the wound or fight the infection in a regulated manner.
However, if this process is deregulated, the injury or infection will persist and the body turns into a dysfunctional state of prolonged or chronic inflammation where the immune cells destroy more tissue than they repair. This puts the body in a state of persistent, low-grade inflammation which disrupts the body’s overall function.
Low-grade inflammation occurs in the early stages of conditions such as obesity, diabetes, cardiovascular diseases and disorders of the gut; all associated with diet-related poor health in Scotland. Strong evidence suggests links between the body’s metabolic dysfunction during these conditions and an impaired immune function which deregulates the inflammation process (Hotamisligil & Erbay, 2008). Thus, the body’s ability to regulate inflammation is imperative for maintaining good health.
Poor dietary habits, such as high intake of saturated fats, are associated with the development of obesity- and cardiovascular-related morbidity. Conversely, a high intake of foods of plant origin, such as fruit, vegetables and cereals; and marine sources is associated with a lower risk of these chronic diseases. This is partly due to their content of secondary plant compounds, micronutrients, and fatty acids, which have been reported to inhibit low-grade inflammation in laboratory studies (Calder et al 2009).
However, in people, there is a lack of strong evidence for the benefits of these specific dietary constituents to the immune system’s control of the inflammatory process. There is no robust clinical data on how biologically effective they are in the body following the consumption of whole foods as part of the normal diet. It is also not clear how the variation in the body’s immune function and inflammatory process among healthy individuals relates to their risk for developing disease.
Key Points
- Persistent, low-grade inflammation is associated with an impaired immune function. This is a key factor in the development of obesity, cardiovascular diseases, and dysfunction of the gut.
- Foods which comprise various protective nutrients and secondary non-nutrient compounds may improve immune function and the inflammatory process in laboratory studies. However, these effects and their benefits to human health after the consumption of whole foods are not established.
Research Undertaken
Research at the University of Aberdeen, Rowett Institute of Nutrition and Health, is investigating how certain dietary bioactive compounds and nutrients within foods, including those of Scottish origin, may influence the immune response and health in human subjects. This is being achieved through robustly designed intervention studies in human subjects to address how effective healthy diets and their components are in improving immune function and health. The work undertaken will help to provide greater understanding of the way in which these foods and their components exert their protective effects in individuals. For example, current and ongoing research is investigating the role of plant-based diets, such as fruit and vegetables, in improving health and the immune response. The work will also help unravel the mechanisms of action involved in producing these beneficial effects.
Policy Implications
Chronic, low-grade inflammation is an early indicator of the susceptibility to many chronic, diet-related diseases in Scotland. By recognising the onset of these chronic diseases at a very early stage and by evidencing dietary effects on the regulation of the inflammatory process, this research will provide health professionals and the general population sufficient warning and know-how to change dietary habits and prevent or delay the onset of these conditions. By increasing the education and awareness of the public, the work undertaken will contribute towards reducing the economic burden associated with the treatment of these diseases. Further, the identification of beneficial components within foods, which may improve immune function and reduce susceptibility to disease, may provide promising targets for functional food development and novel strategies within the food industry.
Author
Dr Vanessa Rungapamestry V. Rungapamestry@abdn.ac.uk
