What is low-acid coffee? Does it help those who suffer from acid reflux, heartburn, and indigestion?
“Dark roast coffee is more effective than light roast coffee in reducing body weight,” but what is the effect of different roasts on heartburn and stomach upset? I discuss this in my video Does Low-Acid Coffee Cause Less Acid Reflux?.
We know that “coffee consumption sometimes is associated with symptoms of stomach discomfort,” so researchers put pH probes into people’s stomachs to measure the amount of stomach acid generated by different types of coffee. A gastrogram is a way to chart acid secretion in the stomach, as you can see at 0:30 in my video. You give people some baking soda so their stomach starts out alkaline, then measure the pH in the stomach to see how long it takes the body to restore the stomach to an acid bath—about 15 to 20 minutes. If you mix that same amount of baking soda with dark roast coffee, however, it takes longer, which means the dark roast coffee is suppressing stomach acid secretion because it takes longer to normalize the pH. If you give people more of a medium roast coffee, though, there is a dramatically different effect—an acceleration of stomach acid secretion, returning the stomach to acidic conditions three times faster than drinking dark roast coffee. Thus, dark roast coffee is less effective at stimulating stomach acid secretion than medium roast coffee. But you don’t know if that translates into symptoms, or clinical effects, until you put it to the test.
“The most commonly used coffee bean roasting process is referred to as convection or ‘flash’ roasting,” which usually takes less than ten minutes. “An alternative method is conduction roasting….[which] roasts the coffee beans at a lower temperature for a longer time, typically over 3 – 4 h,” and results in so-called low-acid coffee. “Anecdotal evidence from coffee-sensitive individuals has suggesting that this latter roasting method [for low-acid coffee] does not precipitate or aggravate heartburn.” However, when you look up the citation for this finding, the paper just cites data from the Puroast Coffee Co., makers of low-acid coffee. It should therefore come as no surprise that it was the same company that funded the study.
At one point, the Puroast Coffee website claimed, “The health benefits associated with drinking Puroast Low Acid coffee will become almost immediately obvious to those who suffer from acid reflux, heartburn, or indigestion,” with more than 90 percent of customers surveyed receiving symptom relief. So, the company decided to put its money where its mouth was. Before I get to the results, though, it’s important to realize that when they say “low acid,” they aren’t talking about stomach acid, but about roasting coffee beans so long that they destroy more of the chlorogenic acid within them. That’s the antioxidant, polyphenol, phytonutrient chlorogenic acid—that is, the “anti-diabetic, anti-carcinogenic, anti-inflammatory and anti-obesity” antioxidant.
That’s like an orange juice company going out of its way to destroy the vitamin C in its orange juice and then branding the juice as “low acid.” Vitamin C is ascorbic acid, so it would technically be true, but it would be bragging about destroying some of the nutrition, and that’s exactly what low-acid coffee makers are doing. But, if low-acid coffee causes less stomach discomfort, might it be worth it?
In the Puroast Coffee-funded study, 30 coffee-sensitive individuals completed a “randomized, double-blind, crossover study in which the symptoms of heartburn, regurgitation and dyspepsia [stomach upset] were assessed following coffee consumption” of Puroast brand low-acid coffee versus regular, conventionally roasted Starbucks coffee. To the study funder’s chagrin, no benefit whatsoever was found with the low-acid coffee, as you can see at 3:39 in my video. “Consumption of both coffees resulted in heartburn, regurgitation, and dyspepsia in most individuals.” So much for that ridiculous 90-percent-of-customers claim. “No significant differences in the frequency or severity of heartburn, regurgitation, or dyspepsia were demonstrated between the two coffees either in the fasting state or after the test meal.” The researchers couldn’t find any way to make the low-acid coffee look better.
They initially thought that a difference in coffee acidity might explain the company’s claims; however, when put to the test in a randomized controlled study, they found no difference in symptoms, suggesting that coffee acidity does not explain the sensitivity some people have. This, I think, further acts as a reminder that we should never believe claims made by anyone trying to sell us something.
Isn’t that amazing!? I love that Puroast’s own study did it in, but good for the company for allowing it to be published and not just quietly buried. Though, maybe it tried to make it disappear but the researchers held strong. Either way, this is how science is supposed to work, and I’m excited to bring it to you.
If you missed the previous video where I talked about that weight-loss finding, check out Which Coffee Is Healthier: Light vs. Dark Roast.