Which Type of Coffee Is the Healthiest?

The choice between Light, Dark or Medium

Coffee has several superpowers, but they’re determined by how long the beans are roasted. Here’s how to choose the right one for your needs.

It wouldn’t be a revelation to say that coffee is a popular beverage for athletes and non-athletes alike. Coffee has been consumed by humans at least since 1000 AD. In the USA, it’s the number one source of caffeine consumption (1,2).

For those who don’t consume much in the way of fruits and vegetables, it’s also an important source of phytonutrients and has various potential health benefits, according to epidemiological studies (3,4).

It remains to be asked, however, if one roast (lighter, medium, or darker) has more healthful qualities than the other. Well, let’s find out.

Roasting

Roasting coffee beans requires that the beans be heated for a specified amount of time. This results in a change in color from green to yellow. The beans then roast further to darken the color. The darker the roast will be, the more you roast at higher temperatures and for longer periods of time.

Light Roast

Light roast coffees are subjected to less heat. This results in: The finished coffee has more chlorogenic acid. These antioxidants are responsible for many health benefits associated with coffee, including the possibility of weight loss ((5)).

Dark Roast

The greatest heat exposure to dark roast coffee results in the destruction and transformation of the chlorogenic oils. However, while dark roast coffee is much lower in chlorogenic acids, it’s rich in N-methylpyridinium, a degradation product of the trigonelline formed during roasting. While not touted as often as the chlorogenic acids, N-methylpyridinium-rich dark roast coffee also has some potential health benefits:

• The dark roast coffee blend decreased DNA damage in healthy people who consumed 500 mL of the beverage per day (4 cups) over four weeks (6). A similar result was also seen in those who consumed 750 mL/day during an 8-week study (7).
• In pre-obese people consuming 500 mL of coffee a day for 4 weeks (8), a dark roast coffee increased weight loss while a light roast didn’t. The difference in weight between normal-weight subjects who consumed dark and light roasts was not significant.
• Another study found that uncoupling protein-2 (UCP-2) expression could increase thermogenesis. This was seen in normal-weight healthy men and women who consumed 750 mL/day black-roast coffee for four weeks (10).
• There’s also evidence that dark roast caused reduced calorie intake, body weight, and body fat, along with a slight gain in fat-free mass in healthy men and women consuming 750 mL/day over 4 weeks (11). A medium roast had a lower body fat percentage, but statistically this was more significant than the average medium roast (11). The 24-week-long study found that a moderate dark roast’s 4 cups per day resulted in a decrease of fat mass (20).
• A darker roast coffee had a higher antioxidative status than a light roast (8).
• In healthy men who ate 4 cups of dark roast for a week (12), glucose metabolism was higher than that of light roast.
• PDE was inhibited in vitro by dark roast to a higher degree than that of light roast at similar concentrations (13). PDE is the enzyme that breaks down cAMP – a second messenger involved in various processes, including lipolysis.
• In vitro studies showed that darker roast coffee may have more anti-inflammatory properties than lighter roasts (14). There’s also evidence suggesting that dark roast may be easier on your stomach than light roast (15).
• In humans, dark roast coffee demonstrated a greater increase in the transcription factor (Nrf2) which is responsible for inducing the expression of antioxidant and cytoprotective/detoxifying enzymes that activate our own body’s naturally evolved defense mechanisms against chronic oxidative stress and xenobiotic harm (16-18). The benefits of foods like broccoli are at least partially due to activation of Nrf2 (19). However, studies have shown that dark roast coffee does not affect Nrf2 in any significant way (7).

Let’s Go to the Scorecard

These points might make dark roast seem like the obvious choice. However, there are limitations.

• In vitro data indicated that PDE was inhibited by dark roast more than by light roast. A human study that tested the effects of dark and medium roast on PDE activity found no difference. Whether a light roast coffee would’ve been different is unknown, but there were substantial differences in the content of chlorogenic acids and N-methylpyridinium (10). (Caffeine itself can’t effectively inhibit PDE in humans at normal concentrations, so this is an interesting finding.)
• With the exception of a greater decrease in body fat, the decreases in body weight, calorie intake, and a slight increase in fat-free mass weren’t statistically different between a dark and medium roast (11). Both medium and dark roasts demonstrated a decrease and slight increase in body fat (11). Additionally, increases in UCP-2 weren’t statistically different between a medium and dark roast, and the increase in the dark roast may have been confounded by time effects (10).
• In vitro data suggested that dark roast may have greater antioxidative or anti-inflammatory benefits than dark roast. Other data, however, show more favorable antioxidative/anti-inflammatory results with light roast (21). Results in animal models were mixed (22).
• While dark roast increased UCP-2 expression in humans, a medium roast was able to increase the hormones adiponectin and leptin, while dark roast wasn’t. These hormones are important in energy homeostasis. They may also have anti-obesity benefits. Only the statistically significant effect on leptin for medium roast was greater than that for dark roast (10).
• One study showed that dark roast coffee increases glucose metabolism. Another found no difference between light and dark roasts in the effects of glucose or insulin (23).
• The study found that overweight people who consumed around 4-5 cups/day over 3 months did not experience any weight loss when compared to dark or medium roasts (24).
• A second study (25) found similar antioxidative effects for people who drank medium and dark coffee.
• Some evidence suggests that chlorogenic acid, which is a major component of light roast, but not dark roast, can cause a reduction in fat mass in people who are overweight (26).

Comparison of Caffeine Levels

There are studies showing that both dark and light roasts may have more caffeine than the other, but more importantly, these differences aren’t substantial enough to base your choice on the potential amount of caffeine present (14,27-30). In other words, it’s a toss-up.

How about Acrylamide Levels

Acrylamide’s presence in coffee has been a hot topic for a few years. This is because acrylamide is a class of a compound that can be used to make coffee. “probable” International Agency for Research on Cancer (IARC) has identified human carcinogens.

The Maillard reaction can create Acrylamide. This requires an amino acid, a reduced sugar (e.g. glucose or fructose) and heat. This is the main mechanism by which it occurs in coffee (31,32).

Baking, grilling and roasting carbohydrate rich foods such as bread, cakes, muffins, and toasting can all lead to acrylamide formation (31-32). It is acceptable to boil or steam.

While vegetables and meat can form some acrylamide when subjected to these cooking methods, it’s generally much less than baked goods and potatoes (31-33). Asparagine and coffee are the major contributors to the formation acrylamide (34).

Despite the fact that acrylamide is consumed in large quantities, epidemiological studies have generally failed to show any evidence of an increase in risk. Cancer 35-38. While risk assessments based largely upon animal model data have indicated concern for acrylamide consumption, intake from coffee alone probably isn’t something to be concerned about (38-42).

Consumption of acrylamide in coffee isn’t done in a vacuum and should certainly be considered distinct from the consumption of foods such as baked goods, fried potato chips, and other potato products, as well as tobacco smoking, which are significant sources (43).

But, coffee is rich in antioxidants. anti-inflammatory There are some effects that may reduce the harmful effects of acrylamide, its metabolite. Besides, the Maillard reaction that’s responsible for producing acrylamide in coffee is also responsible for producing at least some of the antioxidative and anti-inflammatory effects of coffee while also producing many of the smells and tastes of coffee that people covet (34,44,45).

Either a lack of evidence or a decreased likelihood (46-51) have been reported in epidemiological studies.

Let’s get to the bottom of it. Coffee alone isn’t something to be too worried about with respect to acrylamide consumption. In fact, the IARC more recently concluded that coffee itself shouldn’t be considered “possibly carcinogenic” and that increased cancer risk from drinking coffee is specifically related to esophageal cancer and consumption of very hot liquids – tea, coffee, or even water. So, consider drinking your beverages, including coffee, at a reasonable temperature – below 150 degrees Fahrenheit – for risk reduction.

If you want to lower the amount of acrylamide, it is worth choosing medium or dark roasts. As the roasting time and temperature rise, the acrylamide becomes less stable and more volatile. This results in a significant decrease in the amount acrylamide in medium and darker roasts relative to lighter roasts (52-54).

So, What’s the Best Coffee to Drink?

There isn’t enough evidence to suggest that you should only drink one roast versus another. Variety is good for you, as with all things in life. You don’t have to drink light roast coffee. Try medium or dark roast for a few more weeks. Drink the coffee that you love the most.

It must be a light roast. Many moons ago I tried several dark roasts from boutique coffee shops, as well as Starbuck’s Sumatra, and all it did was give me a horrible stomach ache. It’s like motor oil.

I think that’s just Starbucks. I don’t like their coffee but I love dark roasts. I’d recommend trying another.

This conversation about coffee is so much fun. Starbucks coffee tastes terrible, I’m sorry. “over roasted” Or “burnt” In some ways.

I have had the opportunity to taste many types of coffee by buying it at different markets and private roasters. This has really changed the way I taste coffee and allowed me to enjoy it for its health benefits, rather than just because it was on sale.

I’m much more selective now and experiment with new types regularly.

To repeat an analogy TC once used, Starbucks tastes like it was filtered through a Sumo wrestler’s diaper. You should definitely try other dark roasts. There are many great ones.

I LOVE dark roast. Starbucks is something I love. Although I don’t enjoy it all the time due to its high caffeine content, I do enjoy it.

It’s great to see Cy again!!

Thank you! It’s great to be back.

I’m a big fan of dark roast as well. I have experienced gastritis from light roast over the years. I co-owned a small coffee shop. I really enjoyed the experience. At the end of the day, you’re performing extractions (water as the solvent) and depending upon many different variables (time, temperature, grind, humidity) it can influence the compounds being extracted and ultimately the flavor profile. Many journal articles have been published on the topic. This has many other effects when it comes roasting coffee. The number of small roasting companies has increased dramatically to the point that you can try many varieties for the rest your life. I’m definitely not a coffee snob though. I’ll drink instant coffee, gas station (Pilot has a really good cold brew) coffee, you name it.

Curious to know how dark/light can be quantified? – [EDIT: i mean in the papers – so we’re all on the same page about what light/dark are as there are gradations that affect these chemical properties]

There are several types of dark
Have to go to second crack It’s not so bad in french roast/oil on beans territory.

We are grateful

Blackrifle makes a great dark roast. My favorite is the Fitfuel medium roast.

A group of us were formed in the final years of my working days. “coffee snobs.” When we French-pressed our coffee beans from our drum roaster, we reached our pinnacle. Everyone agreed that roasting coffee beans until they crackle and turning the roaster on high was the best. “cool down” made our best tasting coffee. We bought a number of different beans, and I can’t recall our favorite coffee bean.

We are grateful
i’m just curious about what the mechanism for quantifying dark in these papers – are all the “dark” What papers use the same darkness?

Some data has been discovered
eg “The coffee beans were roasted in a cylinder roaster at 220°C as follows: light, 6 min; medium, 9 min; and dark, 15 min.”

“coffee roasting was divided into four degrees: Light, Medium, City, and French.”

It seems that most studies on roast have been done on mice, but there are no human studies.

Some recent reviews/studies focus more on the human response.

here’s a 2020 Summary of the effects coffee has on your health –

Excellent graphics and a great last paragraph. Thank you

It can vary from one study to the next. Some simply buy products that are clearly labeled as “dark” Or “light” Some report grades from medium to heavy, city and French, while others report grades of light, medium, or heavy. This instrument may be used by others: https://www.probat.com/en/products/industry/products/colorette/

The majority of studies I have included in my article concern humans and the effects of different roasts, including darker. A reference list should be included.