Women who drink two or three cups of coffee a day have been found to have lower total body and abdominal fat than those who drink less, according to a new study published in The Journal of Nutrition.
Researchers examined data from the National Health and Nutrition Examination Survey, organised by the Center for Disease Control (CDC) in the United States and looked at the relationship between cups of coffee drunk per day, and both total body fat percentage and abdominal or ‘trunk’ fat (adiposity).
They found that women aged 20-44 who drank two or three cups of coffee per day had the lowest levels of adiposity, 3.4% lower than people who did not consume coffee.
Among women aged between 45-69, those who drank four or more cups had an adiposity percentage 4.1% lower.
Overall, the average total body fat percentage was 2.8% lower among women of all ages who drank two or three cups of coffee per day.
The findings were consistent whether the coffee consumed was caffeinated or decaffeinated, and among smokers/non-smokers and those suffering from chronic diseases when compared to those in good health.
In men, the relationship was less significant, although men aged 20-44 who drank two or three cups per day had 1.3% less total fat and 1.8% less trunk fat than those who did not consume coffee.
Around 7 million tons of coffee is consumed globally every year.
Dr. Lee Smith, Reader in Public Health at Anglia Ruskin University and senior author of the study, said: “Our research suggests that there may be bioactive compounds in coffee other than caffeine that regulate weight and which could potentially be used as anti-obesity compounds.
“It could be that coffee, or its effective ingredients, could be integrated into a healthy diet strategy to reduce the burden of chronic conditions related to the obesity epidemic.
“It is important to interpret the findings of this study in light of its limitations—the study was at a specific point in time so trends cannot be established. However, we don’t believe that someone’s weight is likely to influence their coffee consumption.”
Coffee is consumed globally since the 10th century and its frequent consumption continues in the modern world.
Habitual coffee consumption has various beneficial effects on health. Many epidemiologic studies and meta-analyses assessed the relationship between coffee consumption and the risk of lifestyle-related diseases such as cardiovascular disease and diabetes [1,2,3,4,5,6,7].
A meta-analysis by Mostofsky et al. [8] including five epidemiologic studies involving a total of approximately 140,000 subjects revealed a significant positive correlation between drinking four or more cups of coffee per day and a decreased risk of cardiovascular disease.
Coffee comprises many components with pharmacologic effects, such as caffeine [9,10], but the specific components associated with the beneficial effects of coffee consumption are unclear.
Coffee beans contain chlorogenic acids (CGA), polyphenols that have anti-oxidant properties [11]. CGA is abundant in green coffee beans or eggplant exocarp.
It is formed from an esterification reaction between caffeic acid or ferulic acid and quinic acid, and occurs in the following derivatives: 5-caffeoylquinic acid (5-CQA, formerly called 3-caffeoylquinic acid or chlorogenic acid) [12]; 3-caffeoylquinic acid (3-CQA); 4-caffeoylquinic acid (4-CQA); and their corresponding dimers, i.e., 3,4-dicaffeoylquinic acid (3,4-diCQA), 3,5-dicaffeoylquinic acid (3,5-diCQA), 4,5-dicaffeoylquinic acid (4,5-diCQA); 3-feruloylquinic acid (3-FQA); 4-feruloylquinic acid (4-FQA); and 5-feruloylquinic acid (5-FQA) [13,14].
Clinical trials demonstrated the various effects of CGA consumption on vascular endothelial function [15,16], blood pressure [17], sleep quality [18], and brain function [19].
While many clinical studies report beneficial effects of CGA on various physiologic functions, few studies assessed the effect of daily consumption of coffee containing high levels of CGA on body fat and weight in obese and/or overweight subjects.
Some randomized clinical trials indicate that consuming high levels of CGA [20] or green coffee extract that contain abundant CGA [21] can reduce body weight and/or waist circumference (WC).
The majority of clinical studies, however, did not compare the effects of CGA, caffeine, and a chemical coffee constituent with those of a conventional coffee beverage [22,23,24].
Moreover, the findings of a clinical study performed in 12 healthy volunteers drinking different coffee products containing CGA demonstrated that instant coffee enriched with CGA led to a reduction in body weight in the CGA-enriched and normal instant coffee groups [25].
Our previous study revealed that repeated consumption of pre-packaged caffeinated coffee beverages containing sugar and milk (24 kcal/can), as well as high levels of CGA, reduces visceral fat area (VFA), body weight, and WC compared with placebo pre-packaged caffeinated coffee beverages (22 kcal/can) containing no CGA [26].
The most favorable form for consuming CGA, such as through spray-dried coffee (instant coffee), drip-coffee, or pre-packed coffee beverage; the most favorable source of CGA, such as green coffee beans or roasted coffee beans; and the most favorable roasting method, such as dark roasting or light roasting, however, are unclear.
Moreover, the bioavailability of CGA may be modified as a consequence of interactions with food macronutrients or the food matrix [27]. Previous clinical interventional studies of the components of roasted or green coffee beans were controversial and had limitations, such as being unblinded and not placebo-controlled or having a small sample size and short duration.
To our knowledge, no large-scale randomized clinical trials were conducted comparing instant, spray-dried coffee beverages with high levels of CGA and ordinary levels of caffeine with conventional spray-dried coffee beverages with low levels of CGA and ordinary levels of caffeine on abdominal fat accumulation.
We hypothesized that CGA-containing coffee reduces abdominal fat area compared with common coffee beverages, regardless of the beverage form. The present study compared the effects of the consumption of instant coffee with high CGA levels with that of conventional instant coffee with low CGA levels over the course of 12 weeks on the change in abdominal VFA, as the primary endpoint in overweight individuals, and safety in healthy overweight adult men and women (body mass index (BMI) ≥25 to <30 kg/m2; class 1 obesity according to Japanese criteria).
More information: Chao Cao et al, Regular Coffee Consumption Is Associated with Lower Regional Adiposity Measured by DXA among US Women, The Journal of Nutrition (2020). DOI: 10.1093/jn/nxaa121
