Genes vs. Environment (Nature vs. Nurture)

Your characteristics (phenotypes) are often a combination of your genotype (genetics) and your environment. Both play an interactive role in determining your health.

Examples 1. Lung/mouth cancer and tobacco use There are “cancer” genes that make you more likely to get certain cancers, but … Lung/mouth cancer is PRIMARILY caused by ENVIRONMENTAL exposure to tobacco products. These products mutate DNA to cause uncontrolled cell division.

Pictures of Cancers Caused by Tobacco Product Use

Examples 2. Skin cancer/sun exposure/ folic acid/vitamin D Some people are genetically more susceptible to skin cancer – red/blond hair, fair skin. Environmentally, increased sun exposure increases the risk of skin cancer.

Examples Consuming folic acid (dark green, leafy vegetables, dried beans and peas, vitamins) reduces your sensitivity to sun. Sun exposure causes the skin to produce vitamin D. Vitamin D can prevent or treat many types of cancer, including skin cancer. So, 15 minutes of mild sun exposure a few times a week may be good for you!

Examples 3. Diabetes/Diet/Exercise Diabetes Types 1 and 2 are both genetic disorders. Type 1 is called juvenile-onset diabetes. The lack of insulin production has very little to do with environment. Type 2 usually occurs after age 40 and its onset is usually brought on by obesity. It can be controlled by a proper diet and exercise.

Examples Uncontrolled diabetes can result in dehydration, kidney damage, circulatory and nervous system failure, diabetic coma, and death.

Examples 4. PKU and diet PKU is a recessive genetic disorder that can cause brain damage. However, symptoms of PKU can be controlled or eliminated by giving the baby a diet low in phenylalanine (milk, high protein, etc.)

Examples 5. Heart disease – leading cause of death in US Heart disease can be genetically influenced (“run in your family”) A person’s diet, exercise, and smoking habits also affect this. Warning signs are high blood pressure and high cholersterol.

Examples Sickle cell anemia and malaria SCA is a serious (sometimes deadly) genetic disease, but having SCA or being a carrier for SCA is an advantage against malaria (a communicable disease).