Coffee is good for you—unless it’s not!
Numerous studies have linked drinking coffee with positive health effects like reduced risk of obesity, diabetes, and heart disease. However, recent research suggests that the effects of coffee on health aren’t the same for everyone, and may depend on genetics and other factors.
There’s a lot of research that links drinking coffee with health benefits, including lower risk of cancer, Parkinson’s disease, obesity, diabetes, metabolic syndrome, and heart disease. I covered that research in detail in a recent podcast.
Here’s the bad news: while coffee is undoubtedly beneficial for some people, it may be harmful for others.
Individual response to coffee seems to be linked to some of the factors, including sleep, stress, and intolerance to proteins in coffee beans.
But there’s another important factor to consider: genotype.
Coffee is the primary source of caffeine. Caffeine is metabolized by an enzyme in the liver that is encoded for by the CYP1A2 gene. Unfortunately, about 50 percent of the population in the United States have a variant in the CYP1A2 gene that leads to slow processing of caffeine.
For these “slow metabolizers,” drinking coffee:
- Is associated with a higher risk of heart disease
- Is associated with a higher risk of hypertension
- Is associated with impaired fasting glucose
- May not have the protective effects against some cancers that it appears to for “fast metabolizers”
- In some cases though, coffee appears to be beneficial even for slow metabolizers. Caffeine is neuroprotective and reduces the risk of Parkinson’s disease in both slow and fast metabolizers.
- Other studies have even shown that fast—not slow—metabolizers of caffeine may be at higher risk of bone loss.
Is coffee good for you? That depends.
The most obvious conclusion is that it’s impossible to make a general statement about the health impacts of coffee. The answer to the question, “Is coffee good for me?” is: “It depends.”
Remember… “There’s no one-size-fits-all approach when it comes to diet.”
The most recent research on nutrition, including these studies on coffee and caffeine, confirm that this is true. While we share a lot in common as human beings, we also have important differences: genes, gene expression, metabolic activity, gut microbiome, lifestyle, activity level, and numerous other factors will differ from person to person, and all of these will impact how we respond to a particular food (or beverage, like coffee).
- Post-meal blood sugar among people eating identical meals varies from one person to the other. Also, personalized diets on the basis of dietary habits, physical activity, and gut microbiota are more successful than “standardized” diets.
- Response to low-carb and low-fat diets in overweight people varies considerably and may depend on their insulin sensitivity and other factors that are not yet fully understood.
- Caffeine consumed in the afternoon or evening significantly disrupts sleep in some people, but not in others.
Another conclusion is that some slow metabolizers might be adversely affected by caffeine where others aren’t, and the opposite might be true for fast metabolizers.
So how do you know how coffee affects you? Here’s a suggestion:
- Listen to Chris Kresser’s podcast called “Is Drinking Coffee Good for You?” in which he discusses some of the non-genetic factors that determine individual response to coffee.
- If you haven’t already done this, titrate yourself off coffee (reduce your consumption slowly until you’re off it completely) and other sources of caffeine for at least 30 days. Then add it back in and see how you respond.
- Find out whether you’re a “slow” or “fast” metabolizer. You can get this kind of genetic data through companies like 23andme and SmartDNA. If you’ve done 23andme, log in, go to “My account,” select “Browse raw data,” and type “CYP1A2” into the “Jump to a gene” search box. Once on the search results page, find the rs762551 SNP. In the far right column, it will give your variant of that SNP. If you are AA, you’re a fast metabolizer. If you are AC or CC, you’re a slow metabolizer (with CC being slower than AC).
From Original Article “Coffee is good for you-unless it’s not,” written by Chris Kresser.