A team of Spanish researchers tested an experimental light roast coffee as well as a commercially available coffee. The light roast coffee resulted in slightly better body composition changes than the regular roast due to increased phenolic compound content.
“Increasing the consumption of foods rich in bioactive compounds, such as polyphenols, could be such a useful strategy, since previous studies demonstrate that these compounds exert beneficial cardiometabolic effects and can protect against obesity,” they wrote in the journal Nutrients.
The phenolic compounds found in coffee can help to reduce fat mass, improve carbohydrate metabolism and have a lipid-lowering effect, they added. Prior research has proven a positive relationship between coffee consumption and reduced hypertension incidence, as well as reduced risk of cardiovascular mortality in adults with hypertension.
Study details
The randomized, controlled, blind crossover study included 38 participants with BMIs between 25 and 35 kg/m2. The median age of the participants was 51.
The coffees used were both Coffea arabica, but one was roasted like typical commercially-available blends, while the other was lightly roasted to retain polyphenol content. While coffee naturally contains polyphenols, the roasting process can drastically reduce the final percentage from 40% to 80% of the original content.
The lightly roasted coffee contained 400 mg of hydroxycinnamic acids (one of the most prevalent polyphenols in coffee) and 130 mg of caffeine per cup while the roasted coffee had 150 mg hydroxycinnamic acids and 70 mg of caffeine per cup. When preparing the coffee, the instructions varied for each type; the dark roast instructions had two scoops per French press, while the light roast was four scoops.
Participants were randomized into LRC or RC groups for 12 weeks, then had a two-week washout period before being assigned to the other group. However, there was an issue with the light roast coffee supply, resulting in a 2:1 ratio of participants for roasted compared to light roasted.
For both types of coffee, fat and body fat percentage decreased and muscle mass and muscle mass percentage slightly increased. The decrease in fat percentage was greater for the light roast group than the dark roast one.
The results showed no significant changes in body weight or metabolic syndrome variables. The order in which participants were assigned to either group did not affect results either.
Besides the benefits of phenolic compounds, some of the results may be be due to the caffeine intake itself. The researchers indicated that caffeine intake can reduce body weight, BMI and body fat— with the dark roasted coffee containing 70 mg of caffeine per cup and the light roast containing 130 mg per cup.
While there was no significant reduction in body weight or waist circumference, the study did observe a trend in reduction of visceral fat after participants completed the light roast supplementation.
“However, the results reported here should be taken with caution, mostly due to the limited number of participants in the intervention study and the high interindividual variability observed,” the researchers noted.
Source: Nutrients
2024, 16(17), 2848; doi: 10.3390/nu16172848
“Consumption of a Coffee Rich in Phenolic Compounds May Improve the Body Composition of People with Overweight or Obesity: Preliminary Insights from a Randomized, Controlled and Blind Crossover Study”
Authors: Fernández-Cardero, Á., et al.