Curcumin is an active ingredient from the roots and pods of plants of the Curcuma family. It is also known as turmeric. Curcuma roots look similar to ginger, which we have known for a long time, but much more yellow.
We know the plant primarily as a spice that colors curry yellow. While the substance has been part of the standard repertoire in Ayurvedic medicine for generations, we in Central Europe have only just discovered the active ingredients of the spice and their seemingly endless application possibilities in recent years (1).
The number of scientific publications literally shoots up exponentially and so it is no wonder that the interest of the sports world has also been aroused. Since the use of curcuma or the active ingredient curcumin in our latitudes is still quite "young", there is still a rather small number of really high-quality studies compared to other supplements, such as creatine. Nevertheless, one can already draw one or the other conclusion from this.
Among the many qualities attributed to curcumin, the anti-inflammatory and antioxidant properties are the main reason for its potential use as a regenerative supplement. In alternative medicine, curcumin has been considered a helpful remedy for silent and chronic inflammation for years.
But how effective is the use of curcumin for regeneration after sports really? What is really behind it and does its use really make sense?
What do the studies say? Does curcumin help with sore muscles?
According to a brand-new meta-analysis, which is a statistical analysis and summary of several individual studies from 2021, curcumin does seem to promote recovery after strength training, but with limitations.
If you go a little deeper in this analysis and look at the individual subgroups, you see that a significant reduction in creatine kinase (a marker for exercise-induced muscle destruction) is detectable after 2 days. This is already very positive. Because that would mean that we can counteract muscle soreness.
But, as so often in studies, there is also a downside. On the first, third and fourth day, this could not be measured. Furthermore, only at a dose above 180 mg daily and, most importantly, only in untrained subjects.
The pain in the muscle was thus reduced by the use of curcumin after 3-4 days. But only in weight training with untrained participants. Whereby it must be said, muscle soreness is a very relevant topic in weight training! In endurance training or trained study participants, this positive effect could not be measured (2).
Another summary of the studies, published in 2021, concludes that in general, the supplementation of curcumin reduced inflammatory parameters. Furthermore, oxidative stress was also reduced and even a positive effect on pain and muscle destruction was found. In general, it can be concluded from this summary that curcumin can lead to improved recovery and performance (3).
A systematic review published in 2020 also examined the effect of curcumin on muscle soreness and concluded that its use during the competition phase makes sense. Not, however, as a permanent supplement, but more on that later (4).
In fact, the studies analyzed in these reviews are almost always the same, and this also shows how differently results can be interpreted.
For the nerds among us - more interesting stuff from the lab!
A few individual studies have also appeared in recent years that have not yet made it into larger analyses:
In a randomized control trial, a single dose of 450 mg curcumin approximately 30 min before exercise was shown to improve and decrease muscle pain 48 h and 72 h after exercise, respectively, in a trained group. Muscle circumference was also lower with curcumin ingestion, indicating less swelling. The increase in lactate levels were also lower with curcumin, which probably explains the better performance of the curcumin group toward the end of the experiment. Interleukin 10 and 6 levels (inflammatory mediators in our body) were significantly higher with curcumin. No changes were detectable in creatine kinase, lactate dehydrogenase and myoglobin, C-Reactive Protein, Tumor Necrosis Factor Alpha. Unfortunately, this study, like many in this sector, is sponsored by a pharmaceutical company which, among other things, also sells curcumin, which does not completely throw the trustworthiness out of the window, but at least calls it into question (5).
In a blinded study of 30 athletically active participants, muscle soreness was significantly reduced by a single 500 mg dose of curcumin. Blinded means that the participants did not know whether they received the active substance or a placebo.
creatine kinase, and maximum oxygen capacity could not be significantly influenced compared to placebo. However, also in this study, there is unfortunately the possibility of a conflict of interest, due to financial resources of a curcumin-distributing company (6).
Another study showed lower exercise-induced muscle pain at 48 h and 72 h when taking curcumin (500 mg daily for 6 days pre and 3 days post training). However, creatine kinase was not significantly different between the crucumin and placebo groups. Also very interesting is that jump height did not decrease during training when taking curcumin, but it did in the placebo group. This can be interpreted as an indication of a positive influence on performance support by curcumin. But specifically designed study settings are lacking for this.
Curcumin also seems to have a mental effect. For example, participants in this study rated stress levels during exercise as "better than normal" more often with curcumin than with placebo (7).
How does curcumin actually work?
As already mentioned, the effect is probably based on the antioxidant and anti-inflammatory properties of curcumin. During exercise, reactive oxygen species called ROS or oxidants are produced. These highly reactive molecules are quite natural in our body to some extent, but in high amounts lead to inflammation and altered functions of the cells.
In the long run, these can even attack genetic material or cause cancer if they are produced in excessive numbers and the body's own systems are unable to respond appropriately. This also results in delayed recovery and subsequently reduced performance.
Curcumin has an antioxidant effect because it is a phenolic compound. This means it defuses the reactive oxygen species (8).
Curcumin supplements can reduce some of these pro-inflammatory molecules. However, exactly how this process works is still debated (9,10).
In general, antioxidants (as in chaga mushroom or matcha tea) seem to slightly reduce muscle soreness, but the effect is so small that it hardly seems to be noticeable to humans (3).
Muscle soreness is one of the body's adaptation mechanisms to exercise. In the same way, the increased inflammation levels after training seem to be a trigger for adaptations. It is therefore questionable whether recovery supplements, and thus the attenuation of the inflammatory phase after training, are useful in the long term. This also results in decreased immune cell flow to the affected tissues and the new cells that are created have a smaller diameter. In addition, there may be a risk of fibrosis, a pathological proliferation of connective tissue in tissues (11).
Does curcumin reduce training success?
Studies on the continuous intake of curcumin are still lacking, so it is not yet possible to say to what extent curcumin influences training adaptations. It could be that the reduced inflammation also triggers a reduced adaptation.
In short, you could be reducing the success of your workout with the supplementation of anti-inflammatories or antioxidants. Remember, we are after a well-controlled alternation between damage and recovery. This creates adaptation, we get better, faster, stronger, or wider with the right dose of stress. This is also called the hormesis principle. A little poison, against the disease.
Similar to cold therapy or apnea. You put yourself in a stressful situation to grow from it afterwards. Curcumin and also other basically terrific supplements like Chaga or buffered vitamin C can repair the muscle damage too quickly and should therefore be taken at the right time.
But also the opposite could be the case and curcuma could improve the general condition, so that the regeneration and muscle growth are improved. So exactly we do not know yet.
I have therefore decided for myself not to consume these supplements immediately before or after a workout, but several hours later. I let my body "deal" with the training damage itself. But this is also just a theory.
What about the effect on other health parameters?
Curcumin is studied in many scientific disciplines. For example, curcuma has also been described to significantly improve health-related quality of life (12), aid in weight loss (13), protect against liver disease (14), improve blood lipid levels (15), neuroprotective and anticarcinogenic (16) and probably show many other effects. So there seems to be a lot of potential in the active ingredient of the spice.
For me, curcumin has therefore long been an important supplement in the therapeutic field. For example, in conjunction with intestinal rehabilitation or dietary changes to reduce silent or chronic inflammation.
Safety and side effects
The European Food Safety Authority, also known as Efsa, published the latest statement on curcumin in 2014. This summarizes the literature published up to that time and the authority concludes that curcumin is not carcinogenic. Because this was also once discussed. However, it cannot be ruled out that curcumin has a damaging effect on genetic material. Up to a daily intake of 3mg/kg bw (i.e. about 210 mg daily for a 70 kg man), however, no negative effects are to be expected (17).
This again speaks for a temporary instead of a regular intake. And gives more weight to the well-tried sentence "The quantity makes the poison".
However, this assessment is somewhat older and a new assessment is under consideration. More than half of all publications on curcumin were published after 2014 (18).
A recent review paper additionally describes that curcumin could be harmful to fertility. This goes so far that it has been considered as a contraceptive method. Data so far comes only from animal studies. In addition, curcumin could cause digestive problems, such as abdominal pain, dizziness, diarrhea, or even ulcers in the digestive tract. It is recommended to take curcumin with meals for better tolerance (16). To do this, you can buy ground curcuma at the health food store and stir it into your soup or sauces.
Because curcumin has such a broad spectrum of action, synergies or interactions with other drugs can also occur. For example, it enhances the effect of insulin or blood thinners to the point of bleeding, and promotes the efficacy of antibiotics, anti-inflammatories, or chemotherapy drugs. Curcumin is not recommended for gallstones or kidney stones (16). Anyone taking curcuma regularly and taking medications should be sure to discuss any interactions with their treating medical personnel.
This newer source describes that intakes up to 8 g daily were "well" tolerated (digestive problems may still occur here) (16). Another publication also describes curcumin as generally safe and non-toxic. The authors refer to studies with intakes of up to 6 g daily (19).
Long-term studies and human toxicological data are nevertheless unfortunately missing among the multitude of new publications (16,19). As can be seen, there are always several truths in the world of science.
Pay attention to the quality
Finally, it is important to address the bioavailability of curcumin. It is essential to distinguish the active ingredient from the spice turmeric. Because curcumin, a so-called polyphenol, is one of many components of the yellow spice (1). In the studies and in Western medicine, it is the concentrated curcumin that is used for medical purposes, not the yellow spice powder itself.
The latter contains several other substances and the active ingredient content is difficult to control. In addition, the bioavailability of curcuma, i.e. how much of what ends up in the digestive tract is actually absorbed by the body, is very low. The small amount that is absorbed is then also very quickly metabolized ("glucuronidated") and excreted through the urine. So hardly shows any effect.
It is important to pay attention to the formulation and actually take effective curcumin, otherwise a much higher application dose is probably necessary. There are even protected active ingredient qualities such as CurcuWin. Which guarantees a certain security regarding the active ingredient content. This is also the form in which I prefer curcumin.
There are already many approaches to solutions in which the substance is combined, for example, with piperine, an active ingredient from pepper (8). Piperine potentiates the effect of curcumin many times over when it comes to reducing inflammation. Good preparations on the market therefore combine these two active ingredients.
And the dose?
Unfortunately, the best dose has not yet been determined. No trials have yet compared a range of different dosages and effects are seen from 90 mg to 6 g daily. Dosages are specific to the formulations and to each person's metabolism. More does not necessarily mean better, perhaps too much intake could even weaken one's antioxidant systems. (8).
Conclusion
In summary, it can be said that curcumin very well promotes regeneration by reducing muscle pain or soreness and shortening the necessary recovery time. Presumably, this occurs via antioxidant and anti-inflammatory mechanisms of action. The effect on creatine kinase (muscle damage) is not clearly established. It is also unclear whether the extent of pain relief can be determined at all and is thus relevant for the amateur athlete. It should also be noted that there are still no long-term studies on the long-term use of curcumin and the performance increase. Thus, it is not certain whether curcumin enhances or even attenuates the training effect.
Therefore, I recommend taking curcumin more in the competition phase or in times with little recovery time, such as in a training camp. But not as a daily supplement. The dosage is to be adjusted individually, effects have already been observed from 90 mg. From the official authority (Efsa), a dose up to 3 mg per kg body weight is considered safe. Other recent publications report intakes of up to 6 or 8 g daily without serious side effects. At these amounts, however, digestive problems may still be expected. Since curcumin has a variety of effects, interactions with other drugs (e.g., blood thinners) are also possible and should definitely be clarified beforehand.
As always, be mindful of your supplements and ideally take daily notes on how you are doing from the first dose. Any changes in digestion, muscle soreness or general performance? Remember, each person is individual.
Here's another tip for all exercise addicts:
If you really want to do something useful for your body as an athlete, then I recommend the Btonic Performance product "100% Tennis". A blessing for your joints, ligaments and tendons. No matter what sport you do, the ingredients are just right for high loads.
I developed the product for Btonic and I became the best customer myself 🙂
With the code "richard20" you get 20% Discount on all Btonic Performance products! (Click here to save 20%!)
If you are looking for a good curcumin on CurcuWin formulation, I recommend the brand Bonusan. Just click on the logo below and enter "turmeric longa extract" in the search box.
I'm happy if you send this article to your friends. But you can also find it in spoken version under the same title everywhere where there are podcasts. Or simply here: https://richardstaudner.at/podcasts/
Thank you and sporty greetings
Your Performance Optimizer
Richard Staudner
Sources
17. EFSA. Refined exposure assessment for curcumin (E 100). EFSA Journal. 2014;12(10):3876.
19. Soleimani V, Sahebkar A, Hosseinzadeh H. Turmeric (Curcuma longa) and its major constituent (curcumin) as nontoxic and safe substances: review. Phytotherapy Research. 2018;32(6):985-95.
