Answer:

A number of observational and population studies suggest that drinking a moderate amount of coffee may reduce the risk of cardiovascular disease. However, drinking large amounts of coffee (i.e., 750 mL or about 25 fl oz or more per day of coffee that is not paper-filtered) may increase "bad" cholesterol levels.

For example, a review of 36 long-term (average 10 years follow-up) population studies investigating the relationship between coffee consumption and cardiovascular disease found that drinking 3.5 cups of coffee (caffeinated or decaffeinated) per day was associated with a 15% decreased risk of cardiovascular disease compared to drinking no coffee (Ding, Circulation 2013).

There is also some evidence that drinking coffee may reduce cardiovascular risk in individuals who have a history of heart attack. For example, a large study in Sweden that followed men and women for approximately 8 years after suffering a heart attack found that those who consumed 2 or more cups of caffeinated coffee per day were approximately 40% less likely to die from cardiovascular disease than those who drank none or only one cup per day (Mukamal, Am Heart J 2009). A more recent study among over 4,000 men and women in Netherlands who suffered a previous heart attack found that those who reported drinking 2 to 4 cups, or more than 4 cups daily at the beginning of the study were, respectively, 31% and 28% less likely to die of heart disease over the next seven years than those who reported drinking 2 or fewer cups of coffee per day; in fact, they were, respectively, 16% and 18% less likely to die of any cause over the course of the study compared to those who drank 2 or fewer cups per day. (Dongen, Am J Clin Nutr 2017).

However, it is important to keep in mind that while many of these studies have found an association between coffee drinking and a reduced risk of cardiovascular disease, only double-blind, placebo controlled studies can help to establish cause-and-effect. In addition, in most of these studies, coffee intake was self-reported, and recorded just once, at the beginning of the study, even though cardiovascular events were followed, in some cases, for years after coffee intake was reported.

Be aware that high intake of unfiltered coffee may increase cholesterol — although it is not clear to what extent this translates into increased risk of heart disease. A dose-response analysis of data from 12 trials among healthy people showed that drinking 6 or more cups of coffee per day (with 1 "cup" defined as being 125 mL or about 4.2 fl oz, which is about half a standard 8 fl oz cup) was associated with a 20.11 mg/dL increase in total cholesterol, a 16.63 mg/dL increase in LDL cholesterol, and a 22.14 mg/dL increase in triglycerides. Drinking 3 to 5 cups of coffee per day was also associated with modest increases in total cholesterol, LDL cholesterol, and triglycerides, although these increases were less significant compared to drinking 6 cups or more per day. Drinking only 1 to 3 small of coffee per day was not associated with an increase in triglyceride or "bad" LDL cholesterol levels and was linked with only a modest 4.2 mg/dL increase in total cholesterol. Bear in mind that most coffee mugs hold 11 to 16 fl oz of coffee, with some holding up to 20 fl oz. So, 6 small "cups" (i.e., 750 mL or about 25 fl oz) of coffee may be obtained by drinking 2-3 mugs of coffee. The link between coffee intake and increased total cholesterol and triglycerides was stronger for unfiltered coffee compared to filtered coffee (Du, Nutr Metab Cardiovas 2020).

Unfiltered coffee contains cafestol and kahweol, two cholesterol-raising chemicals found in coffee beans, while coffee filtered through a paper filter (including disposable K-Cups) contains only very small amounts of these constituents. Due to its cafestol and kahweol content, unfiltered coffee — including French press coffee, Turkish coffee, espresso, mocha, moka pot coffee, or coffee prepared using a metal strainer rather than a paper filter — may increase cholesterol or triglyceride levels (Urgert, J Agric Food Chem 1995; van Dam, N Engl J Med 2020). It is unlikely that the use of coffee additives (i.e., milk, creamer or sugar) is responsible for this association, as most of the reviewed studies controlled additive use.

There is also evidence that discontinuing coffee use might lower cholesterol levels. One study among people that had been consuming approximately 24 fl oz of coffee per day for at least a year showed that abstaining from coffee intake for 6 weeks lowered total cholesterol by about 10.8 mg/dL compared to baseline (Christensen, Am J Clin Nutr 2001).

Safety
A study among almost 30,000 postmenopausal women (average age 62) in the U.S. found that neither caffeinated or decaffeinated coffee intake was associated with an increased risk of developing high blood pressure over an average of three years (Rhee, Am J Clin Nutr 2016).

Despite the stimulant effects of caffeine, an analysis of six observational studies in the U.S., Sweden and Denmark among older men and women concluded that caffeine intake (from coffee alone, or coffee, tea, cola and cocoa/chocolate intake combined) is unlikely to cause or contribute to atrial fibrillation. In fact, habitual caffeine consumption might modestly reduce the risk of atrial fibrillation (Cheng, Can J Cardiol 2014).

Drinking up to 3 cups of coffee per day, providing up to 400 mg of caffeine daily, is not associated with an increase in long-term health risks in healthy individuals (Scientific Report of the 2015 Dietary Guidelines Advisory Committee -- pg 50). However, as noted above, daily intake of more than 3 small cups per day (of unfiltered coffee) may increase levels of total and LDL cholesterol and triglycerides (Du, Nutr Metab Cardiovas 2020).

Women who are pregnant should be aware that consumption of caffeine (such as from coffee and soft drinks) during pregnancy is associated with increased risk of stillbirth, particularly at levels greater than 300mg/day — the approximate amount in 3 cups of coffee (Heazell, Eur J Obstet Gynecol Reprod Biol 2020). Moderate caffeine consumption (less than 200 mg per day) does not appear to be a major contributing factor in miscarriage or preterm birth, according to the American College of Obstetricians and Gynecologists.

Although consumption of coffee is fairly safe, be aware that consumption of large amounts of caffeine as supplements or energy drinks carries risks -- possibly because of the more rapid ingestion of caffeine.

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21 Comments

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Dan20946
September 17, 2020

I found it very surprising this article to slipped past a company that people count on to take meaningful measurements and make meaningful recommendations.
The article was all about the number of cups of coffee (filtered or unfiltered) consumed, but had little to use in measuring a life style.

I understand the need for generalization. However, since the article was so specific in relating ounces, some mention of concentration might have been a good idea.

Its very unlikely that 4.2 oz of expresso is the same as 4.2 oz metal mesh drip.
If we were to use one K-cup and set the Keurig to 4oz, is that actually one cup of coffee? How about those that select 12oz. Would that be three cups?

ConsumerLab.com
September 24, 2020

Hi Dan – you are correct that the amount of cafestol and kahweol per cup of coffee differs depending on the brewing method, and not all unfiltered coffee carries the same magnitude of risk for increasing cholesterol. However, earlier studies have quantified the concentrations of these diterpenes per cup of coffee (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1295997/pdf/jrsocmed00049-0024.pdf), and the results align well with what is reported in our answer above (i.e., that paper-filtered and instant coffee have negligible risk, espresso and mocha have moderate risk, and unfiltered coffees prepared by boiling or Turkish coffees have highest risk of increasing cholesterol).

Georgia20943
September 16, 2020

Please advise if Nespresso pods used in Nespresso machines are considered "filtered" like k-cups. Thank you.

ConsumerLab.com
September 29, 2020

Unlike K-cups, Nespresso does not provide capsules or coffee products that use paper filters. Therefore, they would be classified as unfiltered.

Katherine20914
September 10, 2020

As a coffee lover, I was quite interested in this research. However, I often drink a delicious organic instant coffee. Any research or thoughts on the cafestol and kahweol content contained in instant coffee? Thank you.

ConsumerLab.com
September 24, 2020

Hi Katherine – The amount of cafestol and kahweol found in instant coffee is similar to that found in paper-filtered coffee (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1295997/pdf/jrsocmed00049-0024.pdf).

Tim20912
September 10, 2020

I normally use paper filters when brewing coffee, but my sister just gave me a cloth filter (Chemex). Do you know if those are as effective as paper filters? Thanks!

ConsumerLab.com
September 25, 2020

Research has shown that some, but not all, cotton-nylon cloth filters can remove cafestol and kahweol from coffee (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3115845/pdf/1475-2891-10-48.pdf). The difference seems to depend on the material used for the cloth filter, as well as the number of times the coffee is filtered. To be safe, it would be prudent to consider using paper filters.

Teneyke20909
September 10, 2020

I have been using a metal filter for the last year, I had never used one before. I will switch back to now to paper, great article.

Janet 20898
September 9, 2020

Would coffee made from the Keurig machine also raise cholesterol in the same way as unfiltered coffee? Seems like it would, but this is not mentioned in the article. Thanks.

ConsumerLab.com
September 10, 2020

Hi Janet - thanks for your question! We've added information about this to the answer above.

Deborah20894
September 8, 2020

I clicked on the article link, but the details are scarce. I wanted to determine if the study accounted for what trial participants may have added to their coffee, assuming that participants are honest about the additives. I can understand that adding unhealthy fats, such as cream, and possibly also sugar, would definitely raise LDL and triglyceride levels. On the other hand, I just add almond milk and Stevia. Dr. Cooperman, please let me know if you have more details in this regard, because I'm a worrier. Much Thanks!

ConsumerLab.com
September 10, 2020

Hi Deborah - great question! We've reviewed the individual studies cited in the analysis and have updated our full answer above to explain whether coffee additives such as milk, creamer or sugar may have influenced the results.

Richard20885
September 6, 2020

Regarding the recent Chinese analysis showing that heavier coffee consumption is associated with higher cholesterol: Do you know how a "cup" was defined? At least in the US, if you mention a "cup of coffee" the thought these days is of, say, a generous mug, which can be far larger than traditional "coffee cups," or than what you will be served if you request a "cup" of coffee in many other countries. This definition can greatly change one's practical takeaway from the study.

ConsumerLab.com
September 10, 2020

Hi Richard, great points! We've added information related to your comments - including how a "cup" was defined and how this volume compares to a typical mug - to the answer above.

Mike20876
September 6, 2020

I believe the way coffee is brewed has a direct result on LDL levels. Specifically, coffee that is brewed with a paper filter via drip versus percolated has a negligible effect on LDL. Apparently, the paper filter captures the coffee oils which are responsible for the modest effect on LDL.

ConsumerLab.com
September 10, 2020

Hi Mike - You are correct. We've added information about this to the answer above.

Letcher15622
October 2, 2017

I have read that coffee (caffeine?) can be a big problem ( or one cause) for acid reflux.

Michael15589
September 27, 2017

I used to drink up to five mugs of coffee a day. At the age of 70 I started to have an irregular heart beat. Meaing my heart would miss a beart or two and then douible up the next beats. This caused an uncomfortable feeling in my chest and neck. I went to my doctor and I ended up doing a stress test with a cardiogram, etc. The conclusion was to cut way back on the caffiene Result, the irregular heart beats stopped. Now I drink decaffineated coffee.

James20901
September 9, 2020

Do you have any information on how "cold brewed" coffee affects cholesterol levels?
Thanks.

ConsumerLab.com
September 25, 2020

There is limited research about the amount of cafestol and kahweol in cold-brewed coffee, but at least some evidence suggests that cold-brewed coffee contains these chemicals in amounts similar to unfiltered coffee unless the cold-brewed coffee is filtered through a paper filter: https://www.accessscience.com/content/BR0314161.

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