It is true that your body goes through a wide variety of changes, right from the time you hit puberty and in case of women, till you reach menopause and even later. All these changes do take a toll on your body and the often affect your health.
While you may not have complete control over your health, there are many conditions that you can actually prevent. Here are a few health myths that you may have heard about, but that are not always true.
1. You Cannot Prevent Cancer
The sad fact is that almost 50 percent cancer-related deaths in the US are a result of unhealthy lifestyle choices along with various environmental or social causes. Unhealthy lifestyle choices such as poor or unhealthy diet, lack of sleep, smoking and alcohol consumption as well as lack of exercise can all lead to cancers that are otherwise preventable, such as cancers of the skin, colon, lung or rectum.
What You Can Do: Cut down on your smoking and drinking, engage in regular exercise, always take adequate protection while going out in the sun, sleep for at least eight hours a day and make sure you include lots of fresh fruits and vegetables in your daily diet.
2. You Cannot Prevent Diabetes
While most people believe that diabetes is a result of your genetic features coupled with environmental factors, in most cases diabetes (especially in the case of type 2 diabetes) occurs due to poor dietary and lifestyle choices.
Not eating healthy or not having a balanced diet, lack of sleep and exercise as well as engaging in a sedentary lifestyle can often increase your risk of diabetes. Take this quiz to know your diabetes risk. 
What You Can Do: Engage in regular exercise, sleep for at least eight hours a day, drink at least eight glasses of water and add more fluids, apart from adding fresh fruits and vegetables to your diet.
3. You Don’t Need Vaccines Once You Are A Grown-Up
Even grown-ups need vaccines, and not just when you are planning to travel outside your country. Taking the necessary vaccine at the right time will prevent various infections and illnesses that can even turn life-threatening. 
What You Can Do: Speak to your doctor about vaccinations such as tetanus-diptheria, influenza, pneumococcal, hepatitis A and B, MMR, Varicella and others if you plan to travel.
4. If You Don’t Have Any Signs, You Do Not Have An STD
Most STDs do not have any symptoms, if you wait till you see something amiss, it may often be quite late to prevent the damage it can cause to your reproductive organs. Going for regular tests can help you assess your sexual health and take the necessary preventive measures at the right time. 
What You Can Do: Speak to your doctor about the tests that you and your partner can take to look for any STDs. Always use protection while having sexual intercourse.
1. Lifestyle And Cancer Risk. 1: Weiderpass E. Lifestyle and cancer risk. J Prev Med Public Health. 2010 Nov;43(6):459-71. doi:10.3961/jpmph.2010.43.6.459. PubMed PMID: 21139406. (Accessed 16 Sep 2015)
2. Primary Prevention Of Diabetes: What Can Be Done And How Much Can Be Prevented? 1: Schulze MB, Hu FB. Primary prevention of diabetes: what can be done and how much can be prevented? Annu Rev Public Health. 2005;26:445-67. Review. PubMed PMID: 15760297. (Accessed 16 Sep 2015)
3. Adult Vaccination: An Important Step In Protecting Your Health. Site http://www.cdc.gov/features/VaccinesChronicConditions/index.html (Accessed 16 Sep 2015)
4. Sexually Transmitted Diseases: STDs And Pregnancy. Site http://www.cdc.gov/std/pregnancy/STDFact-Pregnancy.htm (Accessed 16 Sep 2015)