Family History: How Your Genes Affect Your Health
- How Your Doctor Uses Your History to Help You
- How to Gather Your Family Health History
- Looking Past Your DNA
There are many things you can do to reduce your risk of developing various diseases, but there is one thing you simply can’t change: your genes.
Indeed, family history is a strong predictor of many health problems, including heart disease and diabetes. Having a first-degree relative (parent or sibling) with either condition increases your risk significantly.
Studies show that if your father experienced a cardiac event or was diagnosed with cardiovascular disease before age 55 (or your mother before age 65), your risk is 60–75 percent higher than it would otherwise be. And having a sibling with this condition increases your risk by 40 percent.
Likewise, diabetes has a genetic component. According to one study, the people at highest risk are those who have a mom and dad with the disease, and those whose parents (but most especially mother) got diagnosed before the age of 50.
Grandparents’ medical history plays a role too—but it’s a much less reliable predictor of risk. The “genetic effect” tends to get diluted the longer a family unit goes without developing a disease. So, if your maternal grandmother had heart disease and had a stroke, but your mother never had any cardiovascular issues, your personal risk is far lower than it would be if your mom suffered these ailments. Still, your grandparents’ history can be useful for your doctor to know, since it’s yet another piece of your health history puzzle.
How Your Doctor Uses Your History to Help You
All of this critical information gives your doctor a lot of insight into your current and future health, and how to best personalize your health care. It allows them to adopt a more aggressive risk-lowering strategy, whether it’s suggesting changes to your lifestyle or environment, adjusting your disease screening schedule, or adding more targeted tests to the mix.
Some medical tests go above and beyond the standard screenings to help your doctor further identify true risk. For example, if you have a family history of premature heart disease, you may be a candidate for more specific blood tests that look for certain biomarkers, like lipoprotein(a)—a lipid similar to (but far more dangerous than) LDL cholesterol that is largely determined by genetics. Other tests, such as coronary calcium scans, can detect specks in artery walls and can diagnose heart disease far earlier than many other tests.
For people at low or average risk, these additional screenings wouldn’t make financial or medical sense. But for high-risk patients, they can be lifesaving.
How to Gather Your Family Health History
If you need a good health goal this year, talk to your parents, siblings, and your and your siblings’ children. Find out what, if anything, ails them, and then share what you learned with your doctor at your next physical. Together, you can make sure you’re one step ahead of your genes.
If you’re comfortable filling out a webform, you can try the Surgeon General’s My Family Health Portrait tool. If you’d rather make the list yourself on pencil and paper, gather at least the following information for each family member, including yourself:
- Age, gender, race and ethnicity
- Biological relationship to you, i.e. do you share one or two parents? How many grandparents?
- If you’ve been diagnosed with any diseases and at what age? Especially ask about the below:
- Heart Disease, Stroke, Heart Attack
- Cancer? What kind?
- Alcohol addiction or drug abuse
- Mental health problems, especially depression, suicide, or schizophrenia
Share this info with your family members and with your doctor at your next visit. Your doctor will be able to help you assess your risk and order appropriate tests.
Looking Past Your DNA
While your genetic makeup does influence in your personal risk, it does not guarantee you will develop diseases. It just means you are more likely to, compared to someone who has no family history or genetic predisposition. Disease is not a certainty.
Regardless, knowing your family medical history is important because that knowledge can help motivate you to change risk factors that you can control—such as lifestyle and environment. Often, it turns out to be the catalyst you need to improve your diet, start exercising, stop smoking, reduce stress, and adopt other healthy habits. And believe it or not, research has shown that genetic predispositions are not carved in stone—there is increasing evidence that your lifestyle can play a more pivotal role in preventing and mitigating disease than your genetics play in causing it.
An emerging field called epigenetics shows that what you eat, where you live, how well and often you sleep, how much you exercise, how you handle stress and other life situations all have a dramatic impact on how your genes behave. As such, your genes are constantly changing and adapting to the different environments to which they’re exposed.
So, you may have “bad genes,” but how well you live your life influences how these genes are expressed—and whether or not they end up hurting you in the long run. And that alone makes your genes far less of a factor than they would be if you lived an unhealthy lifestyle.
- Kolber MR and Scrimshaw C. Family History of Cardiovascular Disease. Can Fam Physician2014 Nov;60(11):1016. Last accessed Jan. 23, 2019.
- Scott RA, et al. The Link Between Family History and Risk of Type 2 Diabetes Is Not Explained by Anthropometric, Lifestyle or Genetic Risk Factors: the EPIC-InterAct Study. Diabetologia. 2013 Jan;56(1):60-9. Last accessed Jan. 24, 2019.