Quick Answer
Coffee contains small amounts of magnesium, but not enough to be considered a significant source in the diet. An 8-ounce cup of coffee provides around 9 mg of magnesium, which is 2-3% of the Daily Value. While coffee delivers some magnesium, it does not provide nearly as much as foods like spinach, almonds and avocados. Overall, coffee is not a major contributor of magnesium in most people’s diets.
How Much Magnesium Is In Coffee?
The amount of magnesium in coffee can vary depending on factors like bean variety, roasting method and brewing technique. However, on average an 8-ounce (240 mL) cup of coffee contains around 9 mg of magnesium.
Here is how much magnesium is found in different types of coffee:
– Black coffee: 9 mg per 8 oz cup
– Instant coffee: 11 mg per 8 oz cup
– Decaf coffee: 3–12 mg per 8 oz cup
– Espresso: 30–64 mg per 1 oz shot
So while the exact amount can range, plain black coffee and instant coffee provide roughly 9–11 mg of magnesium per 8-ounce serving. A single 1-ounce shot of espresso may contain 30–64 mg.
It’s important to note that coffee’s magnesium content refers to the beverage itself, not the beans. Coffee beans actually do contain significant amounts of magnesium at around 800 mg per 100 grams. However, most of the magnesium is lost during the roasting process.
Magnesium Content of Coffee vs. Other Beverages
Here is how coffee stacks up against other common beverages when it comes to magnesium:
– Coffee: 9 mg per 8 oz
– Tea: 3–6 mg per 8 oz
– Cow’s milk: 10–13 mg per 8 oz
– Almond milk: 40–45 mg per 8 oz
– Orange juice: 10–15 mg per 8 oz
While plain coffee and tea are similarly low in magnesium, milk provides a comparable amount to coffee, and almond milk is higher at around 40–45 mg per serving. Orange juice also contains slightly more magnesium than coffee.
So out of these beverage options, only almond milk can be considered a significant source of magnesium, providing around 10% of the Daily Value per cup. The others offer just 2–4% of the Daily Value per serving.
Daily Magnesium Needs
The recommended daily intake for magnesium is:
– Men age 19-30: 400 mg per day
– Men age 31+: 420 mg per day
– Women age 19-30: 310 mg per day
– Women age 31+: 320 mg per day
As you can see, an 8-ounce cup of coffee containing 9 mg of magnesium only provides around 2–3% of the Daily Value for magnesium.
This small amount of magnesium from coffee can add up if you drink multiple cups per day. But overall, plain black coffee is not considered a meaningful source of magnesium compared to foods.
Best Dietary Sources of Magnesium
While coffee delivers traces of magnesium, the very best sources provide hundreds of milligrams per serving. Here are some top magnesium food sources and how they compare to coffee:
– Spinach: 157 mg per 1 cup cooked
– Almonds: 270 mg per 1 ounce
– Cashews: 74 mg per 1 ounce
– Edamame: 62 mg per 1⁄2 cup
– Peanuts: 50 mg per 1 ounce
– Avocado: 44 mg per 1⁄2 fruit
– Salmon: 53 mg per 3 ounces
– Plain yogurt: 46 mg per 8 ounces
As you can see, just one ounce of almonds provides over 30 times more magnesium than an 8-ounce cup of coffee. And a single serving of cooked spinach contains around 18 times the amount of coffee.
So if you’re looking to increase magnesium intake, dietary sources like nuts, seeds, legumes, leafy greens, whole grains and fatty fish are your best options. Drinking coffee can provide small amounts that may add up, but it cannot compare to magnesium-rich foods.
Should You Drink Coffee for Magnesium?
Given its low magnesium content, coffee should not be relied on as a meaningful source of this mineral in your diet.
The 9 mg of magnesium per cup only provides around 2-4% of your Daily Value, which is negligible compared to the hundreds of milligrams found in plant and animal foods.
That said, there is no harm in consuming coffee in moderation as part of balanced diet. The small amount of magnesium can make a minor contribution to your overall intake.
But if you want to increase magnesium levels for health, focus first on eating more magnesium-rich foods rather than drinking more coffee. For example, snacking on almonds and spinach with your coffee is a smarter dietary strategy.
Potential Benefits of Magnesium
Here is an overview of the major health benefits associated with getting enough magnesium:
– Maintains normal muscle and nerve function
– Supports bone health
– Aids energy production and metabolism
– Helps regulate blood pressure
– May lower type 2 diabetes risk
– Needed for protein, DNA and antioxidant synthesis
Research also shows that many people do not meet the recommended daily intakes for magnesium. So there is potential value in increasing magnesium levels for overall health.
However, it’s unknown if the small amounts found in coffee would provide these benefits. The positive effects seem most applicable to higher intakes from nutritional sources.
Can Coffee Deplete Magnesium?
There are claims that coffee could potentially cause magnesium depletion over time, though the evidence is weak.
Caffeine may modestly increase magnesium excretion in urine. One study found that 100 mg of caffeine (one cup of coffee) led to an extra loss of only 2.5 mg magnesium. This tiny loss is unlikely to cause deficiency.
In theory, coffee could interfere with magnesium absorption. However, research shows coffee consumption does not alter magnesium levels long-term or increase risk of deficiency.
Overall, coffee may slightly affect magnesium metabolism. But there’s no solid evidence that typical intakes lead to negative magnesium balance or deprivation in the body.
Should You Take Magnesium Supplements With Coffee?
There’s no clear benefit to taking magnesium supplements with your morning coffee.
As discussed, coffee is unlikely to meaningfully impair magnesium status. And the small amount of magnesium in coffee is negligible compared to most supplements.
For example, a basic magnesium supplement may contain 100–250 mg per serving, which dwarfs coffee’s magnesium content of around 9 mg per cup.
Supplementing magnesium is worth considering if you have a known deficiency or low dietary intake. But taking magnesium solely to “make up” for coffee doesn’t have a lot of scientific support.
Talk to your doctor before starting any new supplement, including magnesium. They can help determine if a supplement is appropriate for your individual needs.
Maximizing Magnesium Absorption From Coffee
While coffee itself won’t provide significant magnesium, there are ways to maximize absorption of the trace amounts present:
– Add milk: The calcium in milk can enhance magnesium absorption.
– Include fat: Adding fat like cream may help avoid any binding of magnesium to polyphenols.
– Avoid excess sugar: High sugar intake is linked to lower magnesium levels over time.
– Don’t over-filter: Methods like French press retain more magnesium than paper filters.
– Drink in moderation: Excess intake could theoretically impair absorption.
Milk, fat, minimal sugar and more concentrated brews are likely your best bet for getting as much magnesium from coffee as possible. But even then, the amount will be small.
Can You Get Too Much Magnesium From Coffee?
It’s extremely unlikely to get excessive magnesium from coffee alone.
The tolerable upper intake level (UL) for magnesium is 350 mg per day. Consuming over this amount from supplements long-term may cause gastrointestinal side effects like diarrhea.
But to reach the UL of 350 mg magnesium from coffee, you’d need to drink around 40 cups per day. This is well beyond normal coffee intake for most people.
Occasionally having a few extra cups still won’t provide excessive amounts. As a trace source, coffee is generally not a concern for magnesium toxicity.
Signs of Magnesium Deficiency
Since coffee won’t provide significant magnesium itself, make sure you’re getting enough from whole foods. Here are signs of possible magnesium deficiency to look out for:
– Muscle cramps or spasms
– Insomnia
– Headaches and migraines
– Restless leg syndrome
– Fatigue and weakness
– Anxiety or depression
– High blood pressure
– Irregular heartbeat
– Osteoporosis
– Constipation
If you regularly experience these symptoms, check with your doctor. They can test your magnesium status and make personalized nutrition recommendations.
Who May Need More Magnesium?
Certain groups are more prone to magnesium deficiency and may benefit from increased intake:
– Older adults: Absorption and intake tend to decrease with age.
– Athletes: Require more to replace magnesium lost in sweat.
– People with gastrointestinal issues: Conditions like celiac disease can impair absorption.
– Individuals with alcohol dependence: Chronic alcoholism may deplete magnesium reserves.
– People with diabetes: Urinate out more magnesium due to high blood sugar.
Talk to your healthcare provider about the potential need for magnesium supplements or magnesium-rich foods. But for most people who are healthy, focusing on a balanced diet should provide sufficient magnesium.
Magnesium Interactions With Coffee
Coffee may interact with magnesium supplements, making it important to separate dosages:
– Caffeine interaction: Caffeine could theoretically impair magnesium absorption.
– Polyphenol interaction: The polyphenols in coffee can bind magnesium, limiting uptake.
To minimize interactions, try taking magnesium supplements at least 1-2 hours away from drinking coffee. This allows each to absorb properly on its own.
There are no major interactions between magnesium-rich foods and coffee. Absorbing magnesium from dietary sources shouldn’t be affected by coffee consumption.
The Bottom Line
In summary, here are the key points to know about coffee’s magnesium content:
– Coffee contains small amounts of magnesium at 9 mg per 8-ounce cup.
– It only provides around 2-4% of the Daily Value, so is not a meaningful source.
– Magnesium-rich foods like nuts, greens, legumes and whole grains are far better sources.
– There’s little evidence coffee negatively affects magnesium levels long-term.
– Taking magnesium supplements with coffee may result in impaired absorption of both.
– Magnesium from food sources can be consumed normally along with coffee intake.
While coffee lovers may get trace amounts of magnesium in their daily cup, dietary sources will be a much more effective way to increase intake of this essential mineral.