|MadSci Network: Immunology|
If you don't eat healthily - lots of fruits and vegetables - you could get sick. Fruits and vegetables contain lots of vitamins and minerals that are essential for healthy humans. So if you didn't get them you might be in poorer health and keep coming down with colds etc. For example, scurvy is a deficiency in vitamin C which can be avoided by making sure you eat fruits containing vitamin C. Unlike some other animals, humans don't make vitamin C and need to obtain it through diet. So if you don't eat a healthy and balanced diet - lean meat, lots of fruits and vegetables and exercise, your health will suffer in the end. So long term, the type of diet that you have can affect whether you will end up with heart disease or other problems. As to ethnicity, it's a really interesting question. You could think about ethnicity in a genetic way. You don't get sick because of your ethnicity, but some genetic groups are more prone to certain diseases. Where you come from, or more importantly where your ancestors come from may influence your genes and which diseases you may be more susceptible to. This doesnít mean that you will get a disease if you come from a certain country Ė only that there may be a higher risk. Letís have a look at some simple population genetics. Imagine 10 families move to a new village in Scotland called Old Glasgow. They have lots of children and some of the children from the 10 different families eventually get married and have children of their own. These children will have traits from both the mother and the father. Some new people move to Old Glasgow and the village gets bigger, introducing new people who get married to and have children with those of the 10 original families and so on. In the end, lots of people in Old Glasgow, over lots of years, will have a genetic link Ė imagine that they are really distantly related. You can imagine that if there havenít been many people moving into the area introducing new genes, whole areas of people can be genetically similar i.e. distantly related. Letís go back to Old Glasgow. Imagine that 8 of the 10 families had parents with red hair and lots of the children had red hair. Many, many years later, people from that area would have a higher incidence of red hair than in other places or countries. In the same way as you could introduce a predominance of hair colour over many generations, you could also increase disease susceptibility. For example, diabetes mellitus (DM) is more common in Finland than in China. Why? Because lots of the people in Finland have a difference in an amino acid in a protein that makes them more susceptible to DM. People of Chinese origin more often than not, don't have this amino acid difference and are less likely to have DM. People in the west coast of Scotland have a higher incidence of many diseases - partly because the population there is made from fewer people and genetic susceptibility to certain diseases is increased. Psoriasis is more common in Caucasians than in Asians. Most people who have sickle cell anaemia (a disease in which the oxygen carrying red blood cells are deformed and canít carry enough oxygen) are of African descent. So ethnicity doesnít make you ill Ė more like the genetics of where you come from. I hope that answers some of your question.
Try the links in the MadSci Library for more information on Immunology.