Chlorogenic Acid: One of Coffee’s Major Phytonutrients
Chlorogenic acid is one of the primary polyphenols in coffee, and research has linked it to multiple health benefits. In fact, the research on this compound is one of the reasons why the health benefits of coffee are increasingly touted.
The purported benefits of chlorogenic acid include better glucose and insulin regulation, decreased blood pressure, and improved cardiovascular function. But what do the research studies say about this compound? Can it really benefit our health?
What is Chlorogenic Acid?
There is a wide range of naturally occurring acids in a cup of coffee, but among these, chlorogenic acid is the most prevalent. In fact, many different plants contain the compound, but coffee provides substantially higher concentrations than any other food source. In terms of structure, chlorogenic acid is an ester of caffeic acid and the 3-hydroxyl position of L-quinic acid.
Let’s take a look at the health claims in more detail and see what the research says.
Chlorogenic Acid Appears to Reduce Blood Pressure
There have been numerous studies investigating the link between chlorogenic acid and blood pressure;
- A randomized, controlled trial demonstrated that 140 mg per day of chlorogenic acid could decrease blood pressure. In this study, all participants who took chlorogenic acid had “significantly reduced” blood pressure readings shortly after ingestion compared to placebo (1).
- In another randomized study, participants were asked to consume no coffee and 40 grams of black coffee. Compared to no coffee, regularly drinking black coffee decreased both systolic and diastolic blood pressure readings by a small amount. (2).
- A systematic review of randomized trials concludes that the available evidence suggests chlorogenic acid intake causes a statistically significant, moderate reduction in systolic and diastolic blood pressure (3)
Chlorogenic Acid May Improve Glucose Regulation
Another proposed benefit of chlorogenic acid is improved glycemic control. The wealth of observational studies on coffee drinkers as well as the randomized clinical trials cited below show that chlorogenic acid can beneficially affect glucose and insulin levels and may play a role in improving glycemic control.
- In a randomized crossover trial, 1 gram of chlorogenic acid significantly reduced glucose (<0.7 mmol/L) and insulin (-73 pmol/L) levels 15 minutes following an oral glucose tolerance test (4).
- A randomized, controlled, double-blind study tested oral chlorogenic acid versus placebo in patients with impaired glucose tolerance. The participants either consumed 400 mg of chlorogenic acid three times per day or a placebo. After a 12-week intervention period, the patients taking chlorogenic acid had decreased fasting blood glucose, lower rates of insulin secretion, and an improved lipid (cholesterol) profile (5).
Chlorogenic Acid May Protect Against Heart Disease and Atherosclerosis
Atherosclerosis (the buildup of arterial plaque) is an epidemic and the biggest killer in the modern world. While our overall lifestyle can either positively or negatively affect the risk factors involved in developing the disease, some observational studies suggest coffee may be cardioprotective.
However, as always, we cannot imply causation from a correlation, so what do controlled studies indicate? The human studies cited below show that chlorogenic acid can reduce some of the risk factors for cardiovascular disease. Animal studies go one step further, and they demonstrate that chlorogenic acid helps prevent atherosclerosis.
Chlorogenic Acid’s Impact on Cardiovascular Health
- A randomized, controlled study in human volunteers showed that intake of coffee high in chlorogenic acid (light roasts) improved postprandial blood flow and endothelial function. This effect was observed in a single (one cup) intake of coffee (7).
- Placebo-controlled, randomized human trials show that chlorogenic acid intake equivalent to 2 cups of coffee results in “significantly higher” plasma chlorogenic acid, meaning that the compound is well absorbed. They also show that there is a significant reduction in blood pressure (8).
- In a study on insulin-resistant mice with hyperlipidemia (excessive cholesterol levels), intravenous chlorogenic acid administration resulted in vastly reduced cholesterol (<44%) and triglyceride (<55%) levels. Of course, humans are not mice, and we certainly don’t consume chlorogenic intravenously. However, this provides more evidence that chlorogenic acid can exert substantial effects in the body (9).
- In a mice study, chlorogenic acid was shown to promote cholesterol efflux as well as significantly reduce the development of atherosclerotic plaque (10).
How Much Chlorogenic Acid is in Coffee?
The amount of chlorogenic acid in coffee significantly varies depending on the roasting time.
For example, 104 samples of coffee found that the chlorogenic acid content varied from 6 mg to 188 mg per serving (11).
With such a substantial variation, here’s a breakdown of the chlorogenic acid content in espresso by roast level;
- Dark roast: 20 – 81 mg
- Medium roast: 6 – 157 mg
- Light roast: 92 – 188 mg