Coffee is pretty much a dietary staple these days. In fact it is the most popular caffeinated drink in the west, with 80% of adults in the USA admitting to sipping on it every single day. There are a tonne of proven health benefits to drinking coffee, but there are also a few drawbacks.
What is coffee? Coffee starts life as the seeds of berries that grow on Coffea plants. Coffee berries, as they are commonly known, once ripe, are picked, processed, and dried. The seeds are then roasted to varying degrees, depending on the flavour profile desired by the grower.
Coffee beans contain caffeine, a natural stimulant that many turn to to feel more awake, power them through the day, enhance brain function, and boost productivity. However, there is an abundance of research that suggests your daily coffee habit could be interfering with the absorption of nutrients from the foods you eat and the supplements you take.
In this article we will take a look at the ways in which coffee - and caffeine in general - may be disrupting your body’s ability to absorb nutrients. What is vital to remember, as with the majority of foods and drinks, is that coffee is not inherently good for you or bad for you. Coffee can indeed be beneficial for your health when consumed in moderation. The effect of coffee on vitamins and mineral bioavailability is more a question of when you consume coffee as opposed to whether you consume coffee.
So does coffee obscure the health benefits of any supplements you take, or of the foods you eat? Here’s everything you need to know about how coffee and caffeine affect nutrient absorption:
The health benefits of coffee.
Coffee is certainly not all bad, and actually for most of the population it could be considered beneficial. These are some of the health benefits of coffee consumption, according to science:
- It's high in antioxidants
- May reduce risk of Alzheimer’s and dementia
- May reduce risk of developing type 2 diabetes
- May reduce risk of developing Parkinson’s
- May protect your liver against hepatitis and fatty liver disease
- Could help fight depression and boost mood
- May reduce the risk of developing certain types of cancer including liver and colorectal
- May lower risk of stroke
- Can improve aspects of brain function including memory, focus, attention and reaction speed.
Caffeine and nutrient absorption.
Any food or drink that contains caffeine - including coffee, tea, chocolate and some fizzy drinks - may inhibit the bioavailability of vitamins and minerals in the bloodstream and prevent the nutrients from doing their job.
Numerous clinical studies have demonstrated the effect that coffee and other caffeinated-containing foods and drinks can have on nutrient absorption.
One randomised placebo-controlled study found that drinking a cup of coffee alongside eating a meal heavy in red meat decreased iron absorption by a whopping 39%. The bigger surprise comes from the finding in the same study that drinking tea alongside the same meal reduced iron absorption by an even more staggering 64%.
As is perhaps common sense, the more caffeine the coffee or tea contained, the less iron was absorbed.
However, the most important thing to note is that the negative effect that caffeine appears to have on nutrient bioavailability also depends heavily on when you consume it. Studies have confirmed that drinking caffeine an hour before taking a supplement or eating a meal has precisely zero effect on nutrient absorption. This is why we recommend that you take your morning dose of LYMA an hour after you've had your coffee, and abstain from drinking another for the next hour. This way your body is primed to absorb everything contained within the capsule.
Interestingly, caffeine may not be the only substance present in coffee, tea and chocolate that interferes with nutrient assimilation. All these drinks and foods contain a number of polyphenols thought to interfere with bioavailability. It may be that polyphenols bind with vitamins and minerals making it more challenging for the body to metabolise them although scientists are still working on the whys. Furthermore, the tannins present in coffee and black tea have been shown to hinder nutrient absorption.
What’s important to know is that caffeinated beverages and foods have been shown to inhibit the bioavailability of nutrients if consumed within an hour of a meal or of taking a supplement.
Coffee reduces the bioavailability of these nutrients in particular:
Caffeine and polyphenols inhibit the function of vitamin D receptors in the gut which has a knock-on effect on the amount of vitamin D that the body is able to absorb from foods and supplements. This is the primary reason that we suggest you drink coffee and take LYMA at least an hour apart. LYMA contains Vita-algae D3™, a highly bioavailable form of vitamin D that helps to support the brain, as well as the cardiovascular, musculoskeletal, immune and nervous systems.
Vitamin D - along with vitamin K2 - is central to the body’s ability to absorb and distribute calcium to the parts of the body that require it, including to the bones. Therefore, coffee consumption within an hour of vitamin D consumption could have a significant impact on bone health and density, and could even contribute to the development of osteoporosis.
This ties into the above section on vitamin D. However, caffeine inhibits the absorption of calcium in another way too: caffeine is a diuretic meaning that it encourages the excretion of calcium in the urine. Scientists have found that for every 150mg of caffeine consumed (that’s less than in an espresso which contains, on average, 212mg of caffeine) results in a loss of 5mg of calcium from the body.
Caffeine inhibits the amount of calcium absorbed in the gut and at the same time depletes the amount stored in the bones. Research has shown that women with high caffeine intake (more than 300mg per day) sustain more hip fractures than those who drink less than that or eschew caffeine altogether.
This is particularly important to note if you’re a menopausal or postmenopausal woman. At a time where bone mineral density is already decreasing due to declining estrogen levels, caffeine can pose an extra risk if consumed at the wrong time.
According to scientists, consuming caffeine within an hour of an iron-rich meal or an iron supplement can reduce absorption of the nutrient by up to 80%,
Iron is fundamental for red blood cell production without which the body cannot function. Therefore consumption of any caffeine-containing food, drink or supplement must be separated from that of any iron-containing food, drink or supplement by at least one hour.
The diuretic effect of caffeine is also implicated in the excretion of water-soluble vitamins, including most of the B vitamins, before the body has had a chance to absorb them.
The exception to the rule is vitamin B12 for which caffeine may actually improve its bioavailability due to caffeine’s proclivity to stimulate the production of stomach acid.
Caffeine may also reduce the bioavailability of trace minerals such as iodine, copper, zinc, manganese and selenium. Caffeine has also been shown to increase the excretion of magnesium and potassium as well as sodium and phosphate.
The bottom line.
At the end of the day a cup or two of coffee or tea each day isn’t likely to do you any harm and may in fact have some potent benefits for your health when consumed in moderation. What’s important to remember is that enjoy your daily brew at least an hour before or after eating a nutritious meal or taking your daily dose of LYMA in order to absorb all the vitamins and minerals, enjoy every benefit and enhance your wellbeing.