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Health Benefits of Coffee and Caffeine | Global Integrative Medicine Academy

by Dr. Jamesh Meschino on

December 13, 2023 in

Nutrition / Natural Medicine Update

In a recent Lifestyle Medicine Update video, I explained the relationship between caffeine, sleep and performance. Essentially, I reviewed how moderate amounts of caffeine and coffee have been shown to sustain alertness and performance in a sleep propensity state (feeling that sleep is required). 

I also explained that when the need for sleep is very high,caffeine becomes ineffective at sustaining alertness and performance, and can create dangerous outcomes, such as falling asleep at the wheel, as well as decrements in performance of many tasks and the development of irrational or flawed decision-making. 

The bottom line is, caffeine can forestall the need for sleep in a mild state of fatigue and allow you to keep functioning well, but eventually the sleep debt has to be repaid or health and performance consequences will result.

Does caffeine affect metabolism?

In addition to this area of study, there are some other aspects of caffeine and coffee consumption that are worth exploring which I would like to shed some light on. Let’s start by talking about how caffeine gets metabolized. 

After you ingest some coffee or a product with caffeine, it gets absorbed and will eventually find its way to the liver. 

95% of caffeine is metabolized or broken down in the liver by the specific enzymes that are part of the CYP1A2 pathway. These enzymes convert caffeine into a series of different end products that appear in the urine; 80% of which is the end product paraxanthine. 

Only about 3% of caffeine intake escapes liver detoxification and shows up in the urine as caffeine in it’s original state. The average half-life of caffeine in the blood stream is 4-5 hours, but liver disease slows metabolism, as does pregnancy. Smoking speeds it up due to its effects on CYP1A2 metabolism. 

Half-life refers to the time it takes to detoxify 50% of a particular dose of caffeine. It normally takes about 4-5 hours to detoxify 50% of the caffeine you ingest as a single dose. Some people make detoxification enzymes that are slightly more effective than others, or slightly less effective. This is known as polymorphism. 

Due to polymorphism in the enzymes that detoxify caffeine (the CYP1A2 family of enzymes), some people metabolize caffeine much faster than the norm, and some people metabolize caffeine much slower than the norm. 

Slow metabolizers are more prone to insomnia, anxiety and jitters from caffeine compared to fast metabolizers, whereas fast metabolizers can tolerate higher amounts of caffeine without feeling these effects.

Can coffee or caffeine intake reduce various diseases? 

With respect to the positive health effects related to the consumption of caffeine and coffee intake, there is mounting evidence that caffeine, and especially coffee intake, reduces the risk of a number of diseases. 

Let me give you an overview of the latest studies showing that caffeine and coffee consumption can help reduce risk of some important diseases. 

In addition to caffeine, coffee is known to contain many various antioxidants and accounts for 60-70% of the total antioxidant intake in the form of polyphenol antioxidants in the modern diet. Some of these antioxidants are thought to help reduce risk of a number of conditions, including type 2 diabetes and certain cancers.

Parkinson’s Disease: Some studies show that caffeine consumption protects nerve cells in the brain from undergoing changes linked to Parkinson’s disease, and some preliminary studies show that caffeine may slow the progression of Parkinson’s disease. 

At this time the suggestion is that caffeine exerts what’s called a neuroprotective effect that may help guard against the development of Parkinson’s disease – a degenerative disease that affects 1% of the population over 60 years of age.

Type 2 Diabetes: Coffee is strongly linked to the prevention of type 2 diabetes in a dose-dependent manner – meaning, the more you consume, the lower the risk. 

This is true for both caffeinated and decaffeinated coffee intake, implying that non-caffeine ingredients in coffee help to confer protection against type 2 diabetes. Studies suggest that drinking 4-6 cups per day appears to provide more protection than drinking less than that amount.

How caffeine impacts athletic performance ?

Athletic Performance: Caffeine ingestion has been shown to enhance athletic performance. The ideal dose to increase athletic performance is 3-6 mg per kg of body wt (for me: 90 kg X 3= 270 mg; 90 kg X 6 = 540 mg) caffeine ingested about 30 mins prior to competition or training. 

Doses above 6 mg per kg have no further benefit on athletic performance. In general, 3-5 mg per kg body weight is associated with a 3% increase in athletic performance, whereas at a dose of 6 mg per kg body weight, the associated increase is as high as 7%. Thus 5-6 mg per kg body weight appears to produce best results for both endurance and explosive exercise events.

Why coffee or caffeine for cancer prevention?

Cancer: With respect to Cancer Prevention, here are what some recent studies have shown:

Prostate Cancer (The Health Professionals Follow-up Study) – 6 cups per day cut risk by 60%.

Brain Cancer (Glioma) – 5 cups of coffee per day cut risk by 40%.

Colon Cancer – 2 cups per day cut risk by minimum of 25% and up to 50% in one study.

Breast Cancer – 2-3 cups of coffee per day linked to significant decreased risk of breast cancer in women.

Liver Cancer and Liver Disease – Coffee has also been related to a reduced risk of liver diseases and cirrhosis, which can lead to liver cancer.

Studies show decreased hepatocellular carcinoma by 29% in coffee drinkers.

Endometrial Cancer – 3 cups per day associated with a 19% reduction in risk.

Melanoma – 5th leading cause of cancer in the US – Coffee drinking associated with a decreased risk in a number of studies.

Anticancer Compounds in Coffee – Caffeinated and Decaffeinated coffee contain various substances shown to inhibit cancer development and growth. In addition to caffeine itself, chlorogenic acid shows very remarkable anti-cancer effects and is the primary phenolic compound (antioxidant) found in coffee.

Studies suggest that chlorogenic acid found in coffee is a key anti-cancer constituent.

NASH (Non-alcoholic Steatohepatitis or fatty liver) – Moderate Coffee consumption is shown to slow or block the progression of NASH to liver fibrosis and cirrhosis in those with fatty liver degeneration. 

NASH is very common in people who are overweight and in patients with type 2 diabetics (especially overweight type 2 diabetics – 80% of type 2 diabetics are overweight).

So, before you label caffeine and coffee as major health offenders, the emerging research suggests that both caffeine and coffee may have a role to play in reducing risk of some important diseases. 

This is good news for coffee drinkers. 

Of course, green tea is also a fantastic choice. The key is to drink amounts that don’t cause side effects for you. Most people know if they are a fast or slow metabolizer of caffeine. And remember that even decaffeinated coffee contains significant amounts of chlorogenic acid and other phenolic compounds that appear to have impressive cancer fighting properties.

I have included links to all the research I cited below if you would like to explore any of these areas in more detail.


1. Caffeine Pathway, Pharmacokinetics Overview

2.Type 2 Diabetes: Shearer J, Graham TE. Performance effects and metabolic consequences of caffeine and caffeinated energy drink consumption on glucose disposal. Nutrition Review. 2014. Vol 72 (s1): 121-136

3.Coffee consumption associated with reduced risk of advanced prostate cancer

4.Coffee, Tea, Caffeine Intake, and Risk of Adult Glioma in Three Prospective Cohort Studies

5. New study links coffee consumption to decreased risk of colorectal cancer

6. Coffee May Protect Against Breast Cancer, Study Shows

7.Liver Cancer

8.Anticancer Compounds in Coffee

9.Fatty Liver Degeneration (Non-alcoholic Steatohepatitis – NASH)

Eat Smart, Live Well, Look Great!

Dr. James Meschino

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