Before walking to the counter and ordering that McDonald’s combo meal you’ve been craving for, think twice on the effect that burger will have on your body. It’s no surprise that eating too much junk food is bad for our health and can cause weight gain, high cholesterol, high blood pressure, and heart disease. However a recent study shows its startling, irreversible effects on our immune system that are not so obvious.
Figure 1 shows a typical fast food meal. Source: Wikimedia Commons
Researchers at the University of Bonn in Germany discovered that our immune system reacts to junk food the same way it reacts to a bacterial infection – by constantly fighting against new attack. Although the idea of rapid inflammatory response sounds like we are increasing our immunity to infection, prolonged activation of our immune system actually causes inflammation which can lead to diseases such as arteriosclerosis, clogging of the arteries.
The results were published on January 11th, 2018 in Cell and showed that after exposing mice to a “Western diet” consisting of high fat and high sugar foods for 4 weeks, the number of immune cells that help the body fight against infection increased significantly in the blood. Meanwhile, mice that were put on a healthy diet had much lower levels of immune cells.
When the mice were taken off the “Western diet”, the high levels of immune cells in the blood disappeared. The study also revealed that certain immune cells in the mice experienced permanent changes in their genes causing the immune system to be continually activated even after feeding the mice a healthy diet. These immune cells contain complexes known as “inflammasomes” which recognize any foreign substances that invade our body resulting in the constant release of inflammatory responses.
Figure 2 shows a normal artery with normal blood flow compared to the narrowing of the artery due to build-up of plaque. Source: Wikimedia Commons
Even a minor stimulus can release a strong inflammatory response which can be very harmful in the long term. Immune cells are a major contributor to the thickening of arteries – a disease known as “arteriosclerosis”. An activated immune system continuously releases immune cells that migrate to the arterial walls. Accumulation of immune cells in the arteries leads to the development of plaque, greatly limiting the flow of oxygen-rich blood from the heart to other tissues in the body as shown in Figure 2.
Scientists have yet to study the mechanism of how inflammasomes can detect the presence of foreign substances brought by the Western diet. For now, immunologist Eicke Latz stresses the importance of educating youth about the consequences of eating unhealthy food as it is “only in this way can we immunize children at an early stage against the temptations of the food industry”.
As for the rest of us, making small changes to our diet can substantially reduce the effects of unhealthy food in the long run. Here are some tips on how to incorporate healthy food into your daily lives:
HEALTHY LUNCHES by Cyril Izarn Source: Vimeo
-Annelie Reyes
References:
- Christ, A.; Günther, P.; Lauterbach, M. A.; Duewell, P.; Biswas, D.; Pelka, K.; Scholz, C. J.; Oosting, M.; Haendler, K.; Baßler, K.; Klee, K.; Schulte-Schrepping, J.; Ulas, T.; Moorlag, S. J.; Kumar, V.; Park, M. H.; Joosten, L. A.; Groh, L. A.; Riksen, N. P.; Espevik, T.; Schlitzer, A.; Li, Y.; Fitzgerald, M. L.; Netea, M. G.; Schultze, J. L.; Latz, E. Cell 2018, 172 (1-2).
- Pietrangelo, A.; Carey, E.; Holland, K. 13 Effects of Fast Food on the Body https://www.healthline.com/health/fast-food-effects-on-body#1 (accessed Jan 22, 2018).
- Fast Food Makes the Immune System More Aggressive in the Long Term http://www.selectscience.net/industry-news/fast-food-makes-the-immune-system-more-aggressive-in-the-long-term/?&artID=45630 (accessed Jan 22, 2018).
- Woollard, K. J.; Geissmann, F. Monocytes in atherosclerosis: subsets and functions https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2813241/ (accessed Jan 22, 2018).
- White Blood Cells https://www.diabetes.co.uk/body/white-blood-cells.html (accessed Jan 22, 2018).
