Coffee benefit and risks, side effects
April 2 2014 by
Ray Sahelian, M.D.

Coffee is one of the richest sources of antioxidants in the average person's diet. It is a major source of caffeine, a stimulant. Along with tea and water, it is one of the most ingested beverages, amounting to about a third that of tap water. Coffee has antioxidants but because of the caffeine and other stimulant type substances within it, it may increase blood pressure and increase the risk for heart rhythm abnormalities. There is a debate in the medical community as to the benefits or harm of coffee consumption. My personal thought is that one cup a day could be of benefit, but drinking three or more cups a day could have adverse effects on the cardiovascular system.
   Some people drink coffee for appetite suppression.

Benefits and side effects

Anxiety
Q. When I drink coffee it causes to have anxiety, is this common? Would kava help?
   A. Some people are very sensitive to coffee and do get restless, irritability and anxiety even from one cup of regular coffee with caffeine. Some people even get anxiety from decaffeinated coffee either due to the caffeine remnants or the theobromine. Kava can help relieve anxiety, so can 5-htp, ashwagandha, theanine, and GABA.

Blood pressure
Coffee contains several biologically active compounds, which may have either beneficial or harmful effects on the cardiovascular system. On the plus side, it is a rich source of chlorogenic acid and antioxidants, which are thought to be protective, but in people with hypertension its bad effect on blood pressure appears to cancel this out. Long term use does not seem to increase blood pressure.

Cancer
Drinking coffee lowers the risk of developing cancer of the oral cavity or throat, at least in the general population of Japan. American Journal of Epidemiology, December 15, 2008. Drinking coffee appears to lower the risk of developing liver cancer.

Gynecol Oncol. 2013. Coffee and caffeine intake and breast cancer risk: an updated dose-response meta-analysis of 37 published studies. Findings from this meta-analysis suggested that coffee/caffeine might be weakly associated with breast cancer risk for postmenopausal women, and the association for BRCA1 mutation carriers deserves further investigation.

Cholesterol
Drinking induces an increase in the resistance of LDL cholesterol to oxidative changes, probably as a result of the incorporation of phenolic acids found in coffee into LDL cholesterol.

Diabetes
Coffee drinkers have a substantially lower risk of developing type 2 diabetes than people who abstain from the beverage. Coffee consumption is associated with a decreased risk of type 2 diabetes. Suggested mechanisms underlying the association includ attenuation of subclinical inflammation and a reduction in oxidative stress. American Journal of Clinical Nutrition, 2010.

Heart Attack
Research in the September, 2006 issue of Epidemiology suggests coffee can trigger a heart attack within an hour in some people. The risk is highest among light coffee drinkers (those who consume up to one cup a day). For those people, the risk of heart attack increased fourfold when they indulge. Those with other risk factors for heart disease are also at greater risk of having a heart attack after drinking a cup of coffee. Caffeine causes short-term increases in blood pressure and sympathetic nervous activity that could trigger a heart attack. Moderate coffee drinkers (those who consume two or three cups a day) raise their risk of having a heart attack by 60% by drinking a cup of coffee. But light coffee drinkers increase their risk of heart attack by more than four times with one cup. Little effect is seen among heavy coffee drinkers (those who drink four or more cups per day). What's more, coffee drinkers who have three or more risk factors for heart disease more than double their risk of sustaining a heart attack after downing a cup. Caffeine causes transient increases in blood pressure, so those who are not regular consumers are not used to it, and they get that surge and for a vulnerable heart, that could be the trigger. People who have a genetic variation associated with slower caffeine metabolism are at an increased risk of a nonfatal heart attack when they consume coffee.

This morning I drank a large cup of coffee and shortly thereafter I took a fish oil capsule and my heart has been racing all day – I felt like I was going to black out as well. It was horrible. I have had these attacks before and have noticed if I take any kind of supplement I have an attack if taken close to having coffee.
   This is the first time I have heard of this, I am  much more likely to blame the coffee than fish oil which should not have this effect.

For a better heart, drink less coffee
Consuming moderate-to-high amounts is associated with increased levels of several inflammatory markers, a finding that could help explain previous reports linking coffee to heart disease. The findings, which appear in the October 2000 issue of the American Journal of Clinical Nutrition, are based on a study of about 3000 subjects with no history of cardiovascular disease. Compared with subjects who did not drink coffee, those who consumed more than about 1 cup of coffee per day had significantly higher levels of all the inflammatory markers tested.

Caffeine content in decaffeinated coffee
Decaffeinated coffee most often has about a fifth to a tenth of the amount of caffeine in regular coffee. Instant decaffeinated Folgers Coffee Crystals does not have any caffeine, but decaffeinated coffee from many coffee shops, including major chains such as Starbucks, contain caffeine averaging about 1 mg of caffeine per ounce of decaf coffee. In some people who are sensitive to caffeine and drink several cups a day, even moderate caffeine levels can increase heart rate, blood pressure, agitation and anxiety.
   A regular cup of coffee has from 85 to 100 milligrams of caffeine. In one study, most of the 10- to 12-ounce decafs tested had less than five milligrams. But one decaff contained 32 milligrams of caffeine — about the same amount in 12 ounces of Coca-Cola Classic. Results varied at each chain. The decaffeinating process doesn’t eliminate 100 percent of the caffeine in coffee. On average 16-ounce servings of decaf has a caffeine content ranging from nine to 14 milligrams.

Metabolites
Coffee consumption leads to an increase in coffee-derived compounds, mainly serum caffeine, chlorogenic acid, and caffeic acid metabolites.
 

Roasted coffee
Only a small part of coffee's bitter taste comes from caffeine. Rather, two classes of compounds give coffee most of its bitterness. Both are antioxidants found in roasted coffee beans, not in the green (raw) beans. One class, called chlorogenic acid lactones, is present at high levels in light- to medium-roast brews. Dark roasts, such as espresso, have high levels of phenylindanes, which form when the chlorogenic acid lactones break down and give a more lingering, harsh taste than their precursors. Roasting influences bitter taste in coffee beans. The stronger coffee is roasted, the more harsh it tends to get.

 

Coffee and Blood Vessel Function

Coffee consumption and markers of inflammation and endothelial dysfunction in healthy and diabetic women1,2,3
American Journal of Clinical Nutrition 2006. From the Departments of Nutrition and Epidemiology, Harvard School of Public Health and the Channing Laboratory, Harvard Medical School, Boston, MA
In several short-term studies, coffee consumption has been associated with impairment of endothelial function. The objective was to assess the relation between long-term caffeinated and decaffeinated filtered coffee consumption and markers of inflammation and endothelial dysfunction. These results indicate that neither caffeinated nor decaffeinated filtered coffee has a detrimental effect on endothelial function. In contrast, the results suggest that coffee consumption is inversely associated with markers of inflammation and endothelial dysfunction.

 

Eyes
Coffee drinking may reduce the risk for blepharospasm.

 

Interactions with dietary supplements
Q. Can coffee be drank the same day as lipoic acid, acetylcarnitine or CoQ10?
     A. Anytime a stimulant nutrient or herb is taken with it, there could be an unpleasant effect of overstimulation and restlessness which could occur with the combination of coffee with the above mentioned nutrients and a number of herbs such as ginseng. I prefer limiting coffee intake to one cup in the morning when combined with such supplements.

Q. Are there any herbs which should not be used on days when coffee is ingested?
     A. There are many herbs that have stimulating properties and it would be best to reduce the amount of coffee ingested on those days. Some of these herbs include tongkat ali, horny goat weed, ginseng, lj100 and others.

Q. On your information site about yohimbe, it states "I don't recommend you mix yohimbe with alcohol or stimulant drugs, including high doses of coffee or caffeine." What constitutes high amounts of coffee?
     A. Each person is different, but more than one cup of coffee could contain enough caffeine be high for someone while more than 2 or 3 cups could be considered high for another. Caffeine can stimulate heart tissue and may contribute to palpitations in those taking yohimbe.