People who enjoy 2-3 cups of their favorite caffeinated (or decaf) beverage early in the day gain more health benefits than those who drink it later.͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌ ͏‌

There’s rarely bad news about coffee.

Coffee consumption is associated with a lower risk for several chronic diseases, including cancer, cardiovascular disease, and neurodegenerative diseases. It’s even been shown to improve liver function, reduce depression, and enhance cognition.

The health-protective effects of coffee are largely due to the plethora of beneficial compounds it contains—it is a rich source of antioxidants, such as chlorogenic acid and other polyphenols. These antioxidants may play a role in preventing or delaying degenerative diseases. Specifically, polyphenols in coffee may inhibit DNA methylation, which prevents the downregulation of tumor suppressor proteins and DNA repair enzymes.

But unlike other beverages and nutrients, the benefits of coffee might depend on when it’s consumed.

A recent study found that drinking coffee in the morning was associated with a lower risk of dying from all-causes and cardiovascular disease, but drinking coffee in the afternoon and evening wasn’t. Specifically, the morning coffee drinkers had a 12% lower risk of all-cause mortality and an impressive 31% lower risk of cardiovascular disease mortality compared to non-coffee drinkers over a 10-year period.

In contrast, there were no benefits associated with drinking coffee throughout the day—people who drank coffee in the morning, afternoon, and evening didn’t experience the same risk reduction as those who enjoyed their coffee only in the morning.

Why would this be the case? Does starting the day with coffee motivate people to exercise? Does caffeine help reset circadian rhythms? Do later-day coffee drinkers experience worse sleep as a result of their habit?

Regardless of the mechanism, there appears to be a health benefit associated with enjoying coffee early in the day! We’ll explore why in today’s email.

How Coffee Exerts Its Benefits

The bioactive compounds in coffee imbue it with many health-promoting properties, including:

Reduced inflammation: Regular coffee consumption has been associated with lower levels of inflammatory biomarkers.
Increased insulin sensitivity: Coffee consumption has been linked to increased insulin sensitivity and it has been shown to improve postprandial glucose control in people with type 2 diabetes.
Elevated adiponectin levels: Coffee consumption has been shown to raise levels of adiponectin, a hormone that reduces the risk for type 2 diabetes and atherosclerosis.
Improved liver function: Coffee has been shown to improve adipocyte and liver function.
Cholesterol-lowering properties: Although some compounds in coffee can raise cholesterol, filtered coffee has less of these compounds and has not been shown to have adverse effects on plasma lipids.
Improved autonomic function: Consumption of regular (caffeinated) coffee may help to improve the balance of the autonomic nervous system, which plays a role in regulating heart rhythm and function.
Improved endothelial function: Coffee can improve endothelial function, which is important for healthy blood vessels, in people with and without cardiovascular diseases.

Some of the effects apply to coffee in general—decaf and regular—but caffeine also has unique benefits. Caffeine is associated with an increased metabolic rate and diuresis, it activates insulin-independent glucose transport in skeletal muscles, and it even regulates IGF-1 signaling to enhance insulin sensitivity and secretion. Not to mention the alertness- and mood-elevating aspects of caffeine that benefit short-term cognition and long-term brain health.

https://doi.org/10.1093/eurheartj/ehae823

Coffee isn’t all upside though. Drinking too much caffeine late in the day can make it hard to fall asleep and reduce deep sleep by as much as 20%. Because caffeine has a half-life of about 6–7 hours, a cup of coffee consumed at noon is still having effects on your brain at midnight!

This brings up a crucial point. When one drinks coffee is important in determining it’s benefits. That’s what a new large-scale study suggests.

Why Coffee Timing Matters

The study included 40,725 adults from a large cohort study in the United States known as NHANES (National Health and Nutrition Examination Survey). It gathered information on when the participants consumed coffee, how much they consumed, and whether they consumed caffeinated or decaffeinated coffee using a 24-hour dietary recall questionnaire. Their responses classified them as:

Morning coffee drinkers: Drank coffee between 4 a.m. and 11:59 a.m.
Afternoon coffee drinkers: Drank coffee between 12 p.m. and 4:59 p.m.
Evening coffee drinkers: Drank coffee between 5 p.m. and 3:59 a.m.

This resulted in two patterns of coffee drinking used for the analysis: morning coffee drinkers—who concentrated their coffee intake between 4 a.m. and 11:59 a.m.—and “all day” drinkers—who consumed coffee in the morning, afternoon and evening.

The Dose-Response of Coffee and Mortality—Optimal at 2–3 Servings

Drinking more coffee was linked to a lower risk of dying from any cause over a 10-year period, regardless of the time of day, with even greater benefits seen for cardiovascular health.

People who drank anywhere from less than one cup to more than three cups of coffee daily experienced a 14–19% lower risk of dying from any cause and a 28–40% lower risk of death from cardiovascular diseases. The most significant reductions in both all-cause mortality and cardiovascular disease mortality were seen in those who consumed 2–3 cups of coffee per day—a 19% and 40% reduction, respectively.

The Mortality Advantage of Morning Coffee

Compared to people who didn’t drink coffee, those who enjoyed their cup(s) in the morning had a 12% lower risk of dying from any cause and a 31% lower risk of dying from cardiovascular disease. However, those who drank coffee throughout the day saw no such reduction in their mortality risk. Neither morning nor all-day coffee habits were linked to a change in cancer-related death risk.

For morning coffee drinkers, the amount of coffee consumed also seemed to matter. Moderate to heavy consumption was associated with a significantly lower risk of dying from any cause. Specifically, drinking 1–2 cups of coffee in the morning reduced the risk by 16%, 2–3 cups by 28%, and 3 or more cups by 21%, compared to non-coffee drinkers. No such dose-response pattern was found for the “all-day” drinkers.

Surprisingly, it’s not the caffeine.

Among the morning drinkers, both types of coffee—decaf and caffeinated—were associated with a lower mortality risk.

For caffeinated coffee, the risk of all-cause and cardiovascular disease mortality was 11% and 25% lower, respectively, among morning coffee drinkers compared to non-drinkers. For decaf coffee, the risk of all-cause and cardiovascular disease mortality were 21% and 35% lower, respectively, compared to non-drinkers. Neither caffeinated nor decaf coffee drinking was linked to a lower mortality risk among the “all-day drinkers.”

Why Zeitgeber Effects May Limit Benefits Depending on Timing

Why would morning but not afternoon or evening coffee have health benefits?

The explanation I find most likely is that drinking coffee later in the day or into the evening will have a negative impact on sleep quality and quantity, and we know that poor sleep is associated with many health conditions and a higher mortality risk. People who drink coffee “all day”, particularly close to their bed time, may experience disrupted sleep and health consequences as a result.

Coffee—or rather caffeine—also suppresses melatonin production. This is a one-two punch in that it not only disrupts sleep, but also hampers the antioxidant qualities of melatonin on the brain and body. However, the sleep hypothesis is called into question by the fact that “all-day” coffee drinkers, even those who consumed only decaf, did not experience a lower mortality risk than non-drinkers.

Morning coffee might also have indirect effects on long-term health, for example, by enhancing the motivation to exercise or engage in physical activity. Maybe the boost that morning coffee drinkers get from caffeine allows them to be more active. This study did attempt to control for confounding factors like habitual physical activity levels and sleep, among other factors. However, even when careful attention is paid to controlling for these variables, there’s always the possibility that coffee drinkers differ from non-coffee drinkers in other aspects of their lifestyles that haven’t been (or can’t be) accounted for.

Caffeine consumed early in the morning also helps reset the body’s internal clocks (circadian rhythms) and provides a mental boost that helps us start the day off strong—it’s a zeitgeber like light and physical activity and could positively modulate several aspects of metabolism and physical functioning.

Final thoughts

For those who tolerate it, coffee seems to be a beverage with many upsides and few downsides. Not only do drinkers experience the alertness- and physical performance-enhancing effects of caffeine, but they also gain the benefits for heart health, brain health, and mortality reduction. While the associations with death and disease cannot prove causality, I think it’s safe to say that if there were a signal that drinking coffee was bad for your health, we’d have seen it by now. Even at high consumption levels, this doesn’t appear to be the case.

How much coffee is safe or healthy to consume? Around 2–3 cups per day—about 100–300 mg of caffeine—is good for most people. Just make sure to finish your coffee around noon each day to give your body enough time to metabolize it before bed.

For morning coffee drinkers, the productivity buzz from your favorite beverage may also come with a health and longevity benefit.

Interested in learning more about coffee’s health benefits? Check out these member-only Q&A episodes with detailed show notes that we’ve hand-picked to accompany this newsletter.

Q&A #8 with Dr. Rhonda Patrick (2/8/2020)

1:58 - How coffee intake affects Alzheimer’s disease risk
3:46 - Can coffee consumption reduce DNA damage?
5:01 - How polyphenols in coffee activate autophagy
5:39 - Can coffee intake reduce your risk for cancer and Parkinson’s disease?
5:58 - How coffee intake in pregnant women affects risk of miscarriage
6:09 - Decaf coffee vs. caffeinated
6:40 - Why people with this gene polymorphism might want to limit coffee intake
7:15 - What 6 cups of unfiltered (e.g., French press) coffee per day does to homocysteine levels
10:06 - Comparing polyphenol content and caffeine in beans (coffee robusta vs. arabica)

Q&A #16 with Dr. Rhonda Patrick (10/3/2020)

13:05 - What’s the science behind whole fruit coffee extract?
14:54 - Can green coffee extract improve weight loss?
16:28 - How green coffee extract improves blood glucose levels
17:06 - Can coffee consumption protect against type 2 diabetes?
17:32 - Can green coffee extract lower cholesterol levels?
18:32 - The active ingredient in coffee that lowers blood pressure
(chlorogenic acid)
19:45 - How the roasting process affects chlorogenic acid content
20:59 - Why acidic-tasting coffee might be the most beneficial

With appreciation,

Rhonda and the FMF Team