Mendelian Randomization
Teasing out the root cause
Hi there,
Mendelian Randomization.
Sounds kind like something I would skip over reading about :-)
Stick with me here... It is actually pretty cool.
Mendelian randomization is a way of determining whether a correlation likely does mean causation, using genetics.
Mendelian randomization studies use genetic data from hundreds of thousands of people to compare the effect of a risk factor on the disease outcome with the effect of a genetic variant that is directly associated with that risk factor.
Take, for example, the question of whether LDL cholesterol is related to heart disease risk. There are well-known genetic variants that decrease LDL levels. Researchers can take a large group of people and see if the variants associated with lower LDL statistically decrease the odds of a disease - such as heart disease.
A couple of recent Mendelian randomization studies have caught my eye:
A study looked at genetically predicted fatty acid levels compared with over 800 diseases. What stood out to me was that higher omega-6 fatty acids and higher linoleic acid increased the relative risk of coronary heart disease.
However, another MR study found that higher vitamin D levels decreased all cause mortality. "Odds of all-cause mortality in the genetic analysis were estimated to increase by 25% (odds ratio, 1.25 [95% CI, 1.16 to 1.35]) for participants with a measured 25-(OH)D concentration of 25 nmol/L compared with 50 nmol/L."
And then there were a couple of studies that found the exact opposite of what I would have expected:
An MR study found that higher carb intake (genetically predicted) is linked to a more than 50% decrease in the risk of depression.
A study found that there is likely no association between vitamin D levels and cancer risk.
Why am I rambling on about this? When you see a headline about how XYZ supplement cures everything but death, take that with a grain of salt. However, not all studies are fluff. Researchers are getting much closer to figuring out the root causes of many diseases, and Mendelian randomization studies are one tool they use.
Gratefully yours,
~ Debbie
Elevated Fibrinogen: Risk factor for blood clots
Key takeaways:
~ Fibrinogen is essential for making blood clots, but high levels of fibrinogen are linked to several health conditions.
This article explains why fibrinogen levels are important and then shows you how to check your genetic data to see if you are likely to have genetically higher fibrinogen.
LDL Cholesterol Genes
Heart disease is the leading cause of death in the US and around the world, and high LDL-cholesterol levels have been linked in many studies to increased heart disease. Standard medical advice on ideal cholesterol levels and cardiovascular disease is often confusing, ever-changing, and sometimes downright contradictory.
This article digs into the ways your genes can be involved in either high or low cholesterol levels. It includes background from research studies, genetic variants to check in your genetic raw data, and ways that your diet and lifestyle interact with your genes and cholesterol.