With a Starbucks on virtually every corner, one would think there was something magical being served up in those white paper cups. Sure, there’s the issue of pure caffeine addiction, but what if there actually was something to that dark brown elixir that did more than simply rev us up and get us going in the morning?
What if coffee held the secret to avoiding complications associated with one of today’s most notorious health conditions: metabolic syndrome?
The problems that often accompany metabolic syndrome include:
- Elevated blood glucose levels
- Elevated blood pressure
- Abdominal obesity
- High cholesterol levels
- Cardiovascular changes
- Liver changes
Interestingly, coffee has been shown in previous studies to reduce the risk for type 2 diabetes, cardiovascular disease, and cholesterol levels. Given this, researchers questioned if coffee could reduce the severity of metabolic-related changes in rats that were intentionally pushed into metabolic syndrome by feeding them an unhealthy diet.
To accomplish this, researchers divided 40 male rats into four groups:
- Cornstarch-rich diet-fed (control)
- Cornstarch-rich diet-fed plus coffee extract
- High-carb, high-fat diet-fed (plus 25 percent fructose in drinking water)
- High-carb, high-fat diet-fed (plus 25 percent fructose in drinking water) plus coffee extract
All groups ate their respective diets for eight weeks. Then, for the next eight weeks, groups two and four were also given 5 percent coffee extract, along with their specific diets, for an additional eight weeks. The first and third groups continued to simply eat their allotted diets. At the end of the study period, the 40 rats were tested for a variety of biomarkers.
Coffee Eases Metabolic Symptoms
For starters, researchers found that the high-carb, high-fat rats weighed more than the cornstarch rats, and the high-carb, high-fat rats given the coffee extract were even heavier.
That’s not great news, but here’s where coffee helped offset the unhealthy diet:
First, coffee normalized higher blood glucose and insulin levels caused by the high-carb, high-fat diet.
Next, as expected, the high-carb, high-fat diet raised triglycerides and total cholesterol, but total cholesterol was lower in those rats given coffee, although triglyceride levels were higher in that group.
The coffee rats also had lower blood pressure compared to those just eating the high-carb, high-fat diet.
With respect to the heart, rats fed the high-carb, high-fat diet had heavier hearts (literally) than the cornstarch-fed rats, but heart weight was lower in those given coffee in addition to their unhealthy diet. Left ventricles of high-carb, high-fat rats had more inflammatory cells than cornstarch rats. But the coffee extract appears to have prevented the proliferation of inflammatory cells.
Similarly, the high-carb, high-fat rats had both greater liver weight and more inflammatory liver cells than the cornstarch rats, but the coffee extract showed prevention of inflammatory liver cells.
After gathering all these findings, researchers concluded that coffee extract reduced blood pressure and glucose impairment and limited changes in structure and function of both the heart and liver of rats. However, it did not affect abdominal fat deposits or plasma lipid profiles.
That’s a Lot of Java
Sounds like a great excuse to continue your caffeine habit, doesn’t it? Improved blood pressure and glucose and insulin levels, and reduced inflammation.
But here’s the rub: The amount of coffee used in the study correlates to anywhere from four to eight cups of coffee a day for a person. That’s a lot of java. Most health experts recommend drinking no more than 16 to 24 ounces of coffee per day.
Based on this, limit your coffee consumption to two to three 8-ounce cups a day. And opt for boiled versus filtered. It keeps more of the good stuff in your cup.
 VanDam RM and Hu FB. Coffee consumption and risk of type 2 diabetes: a systematic review. JAMA. 2005;294:97–104.
 VanDam RM. Coffee consumption and risk of type 2 diabetes, cardiovascular diseases, and cancer. Appl Physiol Nutr Metab. 2008;33:1269–83.
 Aro A et al. Boiled coffee increases serum low density lipoprotein concentration. Metabolism. 1987;36:1027–30.
 Panchal SK et al. Coffee extract attenuates changes in cardiovascular and hepatic structure and function without decreasing obesity in high-carbohydrate, high-fat diet-fed male rats. J Nutr. 2012 Apr;142(4):690-7.