Article at a Glance
- Curcumin is a type of antioxidant, known as a curcuminoid, found in the popular Indian spice turmeric.
- Although there are many human studies which demonstrate curcumin’s ability to help with conditions ranging from digestive problems to arthritis, curcumin supplements are generally not regarded as “bioavailable,” meaning they are difficult to absorb.
- To address concerns about bioavailability, the supplement industry has created different formulas that increase absorption by pairing curcumin with black pepper, and with fats, such as lecithins and phosphatidylcholine. While these formulas do work to increase absorption, they may also come with unwanted side effects, such as slowed drug metabolism and increased risk for heart disease.
- Curcumin blends that utilize antioxidants and water, rather than phospholipids (fats) are more bioavailable and may be safer for some people.
- Studies in rats, as well as in vitro human studies, have shown curcumin to be effective at raising levels of superoxide dismutase, an important antioxidant the body uses to neutralize free radicals.
- We rank curcumin’s reported health benefits using the Gene Food Science Score.
Updated January 18th, 2017
So, you’re researching curcumin, one of the antioxidants found in the popular eastern spice turmeric. You may be on to something, because as we will see in a minute, curcumin does have tangible health benefits, many of which have been proven in human studies, however, there is a catch: curcumin can be tough to get into the bloodstream, meaning it’s thought to lack “bioavailability.”
In an effort to make curcumin more readily absorbable, the supplement world is doing some questionable things with this Ayurvedic antioxidant. One of the worst is adding curcumin to phospholipid blends as the trendy curcumin supplement Meriva has done. These new formulas increase bioavailability in the short term, but they might not be heart healthy, and their long term safety is not know with certainty. Our take: some of the modern curcumin formulas have the potential to be dangerous for some people, which makes the world of curcumin supplements more of a minefield than you may have realized.
But not to worry, we have you covered.
In this guide, we will explain the potential benefits of curcumin supplements, why you need to know what you’re taking alongside your curcumin before you take the plunge, and last, we compare a few popular brands so you can make an educated decision.
- Why I take curcumin
- Curcumin health benefits in humans
- Caveats – Negatives in the Curcumin Data
- Curcumin side effects
- Curcumin and phospholipids: cause for concern?
- Curcumin is fat soluble, but it’s also water soluble
- Lesson: Curcumin is amphiphilic
- Why I avoid phospholipid curcumin products
- Phosphatidylcholine and trimethylamine-N-oxide (TMAO)
- Choosing a curcumin supplement
- Curcumin Supplement Comparison
- Technical fun facts
- Genes targeted by Curcumin
Why I take curcumin
I’ve written before about why I do not take a fish oil supplement, but I do take curcumin, usually about 3 times a week. My reasons for taking curcumin are perhaps a bit strange, as they center around genetic polymorphisms associated with endogenous antioxidant production. Endogenous antioxidant is just a fancy way of saying the antioxidants our bodies produce internally. Of this bunch, glutathione is the most famous, but superoxide dismutase is perhaps just as important. Superoxide dismutase, or SOD2, mops up free radicals produced when we use oxygen at the cellular level. It neutralizes the harmful free radical superoxide. I carry a genetic variant of the SOD2 gene that is associated with lower SOD2 levels, so I am always on the lookout for effective antioxidants.
Where does curcumin fit in this equation?
Animal studies have shown that curcumin increases levels of SOD2 significantly in rats. (R) In fact, the study I reference here actually showed a reverse of age related heart problems in old rats given curcumin.
To quote the study:
Curcumin supplementation ameliorates age-associated large elastic artery stiffening, NO-mediated vascular endothelial dysfunction, oxidative stress and increases in collagen and AGEs in mice. Curcumin may be a novel therapy for treating arterial aging in humans.
Now, I know what you’re thinking. That’s nice that curcumin has positive effects on mice, but given the issues with bioavailability, are the benefits of curcumin proven by human studies?
The answer is yes.
For this portion of the post, I am passing the mic to Dr. Aaron, who is our head of research here at Gene Food.
Curcumin health benefits in humans
Thanks John, and our research did find that, based on human studies, curcumin has shown the most efficacy as an anti-inflammatory and for treating IBS, ulcerative colitis and other digestive disorders, as well as arthritis. There are also human studies to support curcumin’s use as an antioxidant, but the data isn’t as established.
Many beneficial effects have been ascribed to curcumin, including in those with no existing health conditions, so healthy people can benefit from curcumin (R); below we cover some areas where repeated studies have demonstrated a significant positive effect in those with existing health issues.
It remains unclear exactly how curcumin induces its anti-inflammatory response. Both inhibition of immune-cell activity and blocking of key inflammatory cell-signalling pathways, such as the NF-κB pathway, have been demonstrated. The exact mechanism of action in both instances has not been described and requires further research.
This anti-inflammatory response links in with several disorders including irritable bowel syndrome (IBS) (R), the more severe inflammatory bowel disease (IBD) (R – in conjunction with standard medication), osteoarthritis (R) and psoriasis (R). In all instances patient outcomes were improved with significant reductions in inflammatory markers. However, as discussed above a mechanism to describe curcumins potent anti-inflammatory mechanism remains unknown.
Digestive disorders impose a significant health burden on individuals worldwide, ranging from the milder end of the spectrum and IBS (although sufferers are unlikely to class it as mild) through to the clinical disorders such as IBD and various ulcerous diseases such as ulcerative colitis. In the UK, where I live, such digestive disorders were estimated to cost the national health service in excess of £8 billion (~$11 billion) in 1997 (R), and these costs are only likely to have increased since.
Tumeric shown to protect digestive health
In pre-clinical trials, turmeric demonstrated ability to protect the digestive system through its anti-inflammatory effects, and also by secreting enzymes to promote proper digestion, and overall digestive health (R). In a randomized control trial (the best quality trial where individuals are randomized into treatment groups, and researchers are blinded to results) significantly more patients who received turmeric displayed reduced digestive disorder symptoms compared to patients in the placebo group (R).
Taking this further, another study investigated the activity of purified curcumin compared to two standard ulcerative colitis (UC) treatments. In this instance no difference in effect was observed as between the medication and curcumin, suggesting that curcumin is performing as well as current therapeutics. However, the authors did report a reduction in rate of relapse with curcumin users, a particularly important factor in disorders of the gut (R). A further systematic review (a review of all currently available studies) reported a beneficial effect for curcumin as a co-therapy with established drugs in UC (R).
Figure adapted from Hanai et al. Curcumin Maintenance Therapy for Ulcerative Colitis: Randomized, Multicenter, Double-Blind, Placebo-Controlled Trial. Clinical Gastroenterology and Hepatology. 2006. The top line shows patients receiving curcumin remained in remission for longer, and to a greater extent than patients receiving a placebo.
A full review of the role of curcumin in all digestive disorders is currently underway, and should be available shortly (R).
A similar anti-inflammatory effect is hypothesized to describe the protective effect of curcumin in several studies investigating both rheumatoid and osteoarthritis. Arthritis is a disorder affecting the joints often associated with chronic pain and reduction in motility, the incidence of both is increasing significantly due to increases in lifespan and changes in lifestyle.
In both rheumatoid, which is an autoimmune disorder, and osteoarthritis, which is associated with long term mechanical damage; an inflammatory environment in the joint leads to the breakdown of both cartilage and bone, giving rise to the disease symptoms.
Other members of the ginger family have traditionally been used as medicines for arthritis, inhibiting inflammation (R) and leading to reductions in reported pain (R), but with little effect on actual disease progression. Therefore investigating turmeric and curcumin was of obvious interest.
Curcumin performed on par with standard drug therapy
A study on rheumatoid arthritis demonstrated a beneficial effect following treatment with 500 mg/day of curcumin with or without a standard anti-inflammatory drug (diclofenac sodium). Curcumin performed as well as the standard therapy alone, and significant improvements were observed following co-treatment (R).
Figure adapted from Chandran et al. A randomized, pilot study to assess the efficacy and safety of curcumin in patients with active rheumatoid arthritis. Phytother Research. 2012. Disease activity score was improved in all instances, with a slightly better response seen for curcumin and curcumin + standard therapy. Disease activity measures not just pain, but also motility so improvements can be functional as well, although the authors do not specify an effect.
Again, another systematic review has been performed, and in this instance the authors state that a dose of approximately 1000 mg/day of curcumin was effective in the treatment of arthritis (R).
Note: It should be noted that this dose was recommended for those currently suffering with severe arthritis and was delivered under the supervision of medical personnel. While below the maximum levels observed in some studies, starting supplementation at a lower dose to check tolerance is always to be recommended.
As John mentioned at the outset, another major positive aspect of curcumin is its anti-oxidative capacity. Oxidising agents generated in the body, or ingested, can rapidly induce cellular and genetic damage with lasting impacts. The body maintains anti-oxidative pathways, however in some individuals these pathways can demonstrate reduced activity, or due to chronic exposure to environmental oxidising agents (heavy metals, some pesticides and herbicides) these systems can become overwhelmed.
Curcumin increases Total Antioxidant Activity
Curcumin has been shown to increase total anti-oxidant activity in both healthy individuals (R) and in those with a chronic environmental exposure, as in the following study performed in a population exposed to environmental arsenic (R).
Figure adapted from Biswas et al. Curcumin protects DNA damage in a chronically arsenic-exposed population of West Bengal. Human & Experimental Toxicology. 2010. In the first figure treatment with curcumin was initiated at point a) following three months exposure to arsenic. The occurrence of doubled stranded DNA, a measure of DNA breakdown, was reduced suggesting DNA was being protected from oxidative damage. A similar effect was seen in a confirmatory experiment.
In animal and human cell studies curcumin has been shown to both increase the expression and activity of key anti-oxidant enzymes. However, and in contrast to the positive effects observed in inflammatory disorders, confirmatory clinical trials have not yet been reported in human subjects.
Turmeric and curcumin have been linked with a beneficial effect for a variety of other disorders, although the evidence supporting some of these claims is less robust than for the examples discussed above.
Several early studies demonstrated that curcumin exhibited potent anti-cancer properties for a wide variety of cancers including colorectal (R), pancreatic (R), breast (R), lung (R) and prostate cancer (R). These effects were modulated by altering cell signaling pathways typically associated with cancer development and also by promoting anti-oxidative effects. These promising results led researchers to undertake wide-ranging clinical trials in patients, however results were rather poor (R,R,R), often failing to meet primary outcomes. In part this is likely due to the relative complexity and time-courses of each disease. Identifying what may be quite small beneficial effects in either disease population will likely be difficult, and may require large scale studies. Ongoing, completed and withdrawn trials can be observed at the clinicaltrials.gov website.
Asthma and rhinitis
Due to its potent anti-inflammatory effect in disorders such as IBS or arthritis other disorders with an inflammatory aspect were also investigated. Asthma was of particular interest due the occurrence of inflammation but also a dysregulated immune response. Some studies in animal models have demonstrated a positive effect (R,R), but to date no clinical trials have been performed.
However, an early pre-clinical trial in patients suffering from perennial allergic rhinitis (PAR) (allergy to things such as dust mites, animal furs or fungi and molds present all year round) did show a positive effect (R). Inflammatory markers were reduced in PAR suffers following an oral dose of curcumin for 2 months. Importantly those taking curcumin also reported a reduction in symptom frequency and severity. As a relatively recent study (December 2016), a larger trial is unlikely to be available for a few more years.
A major concern in the majority of papers was the lack of bioavailability associated with curcumin. It is possible that more advanced formulations as discussed at the start of this post may improve outcomes. Another distinct possibility is that certain patients subgroups carrying particular SNPs that put them at risk, or promote a beneficial effect, may be present. However, there is currently no data available describing any such groups. This is a perfect example of watch this space.
Cardiovascular disease and diabetes
In a study of healthy individuals a dose of 80 mg/day curcumin was associated with markers potentially associated with good health (R). Following on from this no beneficial effect for those at risk of, or already suffering from, cardiovascular disorders has been reported.
In a small study of pre-diabetic patients (i.e. those at a high risk of developing type 2 diabetes [T2D]) a protective effect following curcumin supplementation was observed (R), a later study also demonstrated improvements in the metabolic profile of patients with T2D but did not report on improved health outcomes (R).
There are a few studies reporting on the potential use of curcumin as a contraceptive due to its ability to kill, or impair the movement of sperm (R,R). No clinical trials have been performed to date with existing studies either using human sperm outside the body, or mouse models. Due to issues surrounding application methodology and timing, and the relatively poor contraceptive action (compared to existing contraceptives) this finding seems more like an interesting quirk of curcumin rather than something that will be used clinically or commercially.
Caveats – Negatives in the Curcumin Data
To provide a balanced review of curcumin and turmeric it is important to discuss some caveats associated with the research. Whilst some beneficial effects are repeatable, numerous others are not. Some researchers put this down to the relative reactivity of curcumin and its lack of bio-availability (R) making it difficult to identify its true activity. This has led some researchers to term curcumin a PAIC, a compound which regularly flags up in drug screens, but whose mechanisms of action cannot be determined.
Curcumin side effects
Ok, back to John.
Thanks Aaron. I’d now like to talk about potential curcumin side effects as well as what to consider when looking for a formula.
The actual side effects of curcumin are limited for most people and curcumin is generally regarded as safe. There are no serious side effects when ingested even at doses as high as 8g per day (which we DO NOT recommend) (R). However, in the same study some participants did report mild nausea or diarrhea.
IV Curcumin is higher risk
Some practitioners offer intravenous injections of curcumin/turmeric extract however the evidence supporting this delivery method is poor and is associated with much higher risks (R).
Curcumin and phospholipids: cause for concern?
As we’ve learned already, curcumin is poorly absorbed and quickly metabolized, which is why supplement manufacturers are always testing ways to make curcumin easier to absorb. However, not all of these new formulas are without risk.
For example, if you’re into supplements, you may have hear that black pepper increases the bioavailability of curcumin.
As a result, the conventional wisdom has been that black pepper and curcumin should be taken side by side, as black pepper has been shown to increase curcumin’s bioavailability by 2,000% over curcumin alone. (R) As this study shows, pairing curcumin with black pepper will increase bioavailability, but black pepper has the potential to slow the metabolism of multiple drugs, potentially blunting the health benefits of curcumin by causing the unhealthy accumulation of pharmaceuticals in the body.
But the supplement companies haven’t stopped with black pepper. New studies have introduced a fresh way of increasing curcumin’s bioavailability even further: pairing it with fat.
Curcumin is fat soluble, but it’s also water soluble
Just like carotenoids, curcuminoids are also fat soluble, meaning they are better absorbed when paired with fat. For this reason, “curcumin phytosome” products, which dissolve curcumin in either phosphatidylcholine or lecithin, are all the rage right now, and some have short term data to back them up.
For example, this study examining Meriva, a curcumin phytosome product, and its impact on ostearthritis, seems to justify the practice of blending curcumin with phospholipids. Meriva uses a phosphatidylcholine blend produced from sunflower.
To quote the study:
These results show that Meriva® is clinically effective in the management and treatment of osteoarthritis and suggest that the increased stability and better absorption of curcumin induced by complexation with phospholipids have clinical relevance, setting the stage for larger and more prolonged studies.
The Meriva study seems to corroborate others that have looked at ways of enhancing curcumin’s bioavailability with phospholipids, but is the added fat necessary?
Methods for increasing curcumin bioavailability
Take a look at this chart Aaron put together, which summarizes the efficacy of the various formulas used to make curcumin more bioavailable:
CS = standardized curcumin mixture, CTR = curcumin with volatile oils to aid absorption, CP = curcumin with lipophilic phytosomes (lipid loving molecules to aid absorption), CHC = curcumin with PVP and natural antioxidants. Values are relative absorption of various curcuminoids into the blood, actual values are available in the paper (R). Red colored values are the worst performing for each type of curcuminoid, greens the best.
As you can see in the table above, the CHC preparation (which features Polyvinylpyrrolidone (PVP) and vitamin C and E) significantly outperforms all other preparations, especially pure curcumin alone. So, while phospholipids elevate the bioavailability of curcumin, the water soluble formula plus antioxidants outperforms them all. Now, keep in kind that both the Meriva and PVP studies appear to have been conducted by interested parties, but I see the willingness to engage in actual clinical trials encouraging, and will take the data at face value (subject to our Science Score of course) until it is supplanted by something better.
Bottom line is this is what we have to go on at the moment.
Lesson: Curcumin is amphiphilic
The bioavailability data cited above demonstrates that curcumin is amphiphilic, meaning it loves fat and it loves water.
Curcumin pairs well with antioxidants
The table above also suggests that curcumin bioavailability is enhanced when paired with antioxidants, which as an aside, is why our Curcumin Pro blend adds Vitamin C, quercetin and bromelain to a 95% curcuminoid standardization formula.
While phosphatidylcholine blends also increase the bioavailability of curcumin, I don’t use them because there is reason to believe they are not heart healthy.
Let me explain.
Why I avoid phospholipid curcumin products
As consumers of supplements, we all hold our noses and swallow a litany of “other ingredients,” such as magensium stearate or soy lecithin, because they are included in very tiny amounts to facilitate delivery of nutrients we believe are good for us.
However, what happens when those ingredients become part of the main dish? In the world of curcumin supplementation, phospholipids are becoming a bigger part of the pie.
Some brands, like Gaia for example, are dissolving curcumin in phospholipid solutions that contain unknown amounts of soy lecithin. Others, like the Seeking Health Liposomal Curcumin product add curcumin to phosphatidylcholine in a similar fashion to Meriva.
Does the addition of these fats alter the health benefits of curcumin? You could argue they do, and not in a beneficial way.
Phosphatidylcholine and trimethylamine-N-oxide (TMAO)
TMAO is a metabolite of phosphatidylcholine and lecithin that has been linked to an increased risk of heart disease. How? Our gut bacteria break down these phospholipid fats into a substance (TMAO) that is thought to damage our arteries. I generally stay away from lecithin and liposomal supplements because of this TMAO data.
A New England Journal of Medicine study found that increased levels of TMAO were a significant independent risk factor for heart disease, even for people with otherwise normal markers.
To quote the NEJM study:
After adjustment for traditional risk factors and other baseline covariates, elevated plasma levels of TMAO remained a significant predictor of the risk of major adverse cardiovascular events.
The NEJM study calls out phosphatidylcholine directly as a causative agent in producing TMAO:
We recently described the potential role of a complex phosphatidylcholine–choline metabolic pathway involving gut microbiota in contributing to the pathogenesis of atherosclerotic coronary artery disease in animal models.7 We also reported an association between a history of cardiovascular disease and elevated fasting plasma levels of trimethylamine-N-oxide (TMAO), an intestinal microbiota-dependent metabolite of the choline head group of phosphatidylcholine that is excreted in the urine.
Some dismiss the NEJM study saying that eating fish, long thought to be heart protective, causes a spike in TMAO as well. This is undoubtedly true. However, as long as TMAO labs are not performed regularly, we’re basically flying blind here, which is why I keep an eye on lecithins in supplements. The NEJM study seems very sound to me. Its conclusions are reasonable and do not recommend avoiding phosphatidylcholine altogether.
It should also be noted that choline is a semiessential nutrient and should not be completely eliminated from the diet, since this can result in a deficiency state. However, standard dietary recommendations, if adopted, will limit the intake of phosphatidylcholine- and choline-rich foods, since these foods are also typically high in fat and cholesterol content.
Limit phosphatidylcholine to keep TMAO levels in check, got it.
From where I’m sitting, I want to use my limited choline intake on foods I enjoy, like the occasional steak, or fried egg, not on sunflower oil goo unnecessarily added to a supplement.
As with many issues, including balancing dietary histamine, TMAO levels must be balanced. TMAO can be excreted in urine rendering it harmless. It is only when levels build that problems can arise. What better way to build TMAO levels than to take phosphatidylcholine on a daily basis in the form of a supplement?
If phospholipids aren’t necessary for proper absorption of curcumin, why use them?
Choosing a curcumin supplement
The gold standard to begin with is to look for products that contain 95% curcuminoid standardization. When processed, approximately 5% of turmeric root extract is made up of curcuminoids. Of these curcuminoids approximately 80% is curcumin (the one of most interest to us) with the rest comprising of other curcuminoids, such as demethoxycurcumin or bisdemethoxycurcumin, which are seemingly less bio-active than curcumin (R).
This raises an interesting issue about standardization between plants and processing, and then, for end users, the content of their nutritional supplements. It is possible to both purify and standardise curcumin content in supplements, and many supplements are manufactured to contain at least 95% curcumin, known as 95% curcuminoid standardization, to maximise bio-availability.
Below, we’ve included a table which shows some of the best curcumin formulas available on the market and what to consider for each.
Curcumin Supplement Comparison
|Brand||95% curcuminoid||Piperine||Phytosome||Antioxidant||Bioavailable score||Price|
|Seeking Health Liposomal Curcumin||N||N||Y||Resveratrol||8||$43.65 (8 ounces)|
|Gaia Turmeric Supreme||N||Y||Y||N||7||$16.32 (60 capsules)|
|Jarrow Curcumin||Y||N||N||N||3||$17.77 (120 capsules)|
|Gene Food Curcumin Pro||Y||N||N||Vitamin C, quercetin, bromelain, and rutin||7||$39.95 (30 capsules)|
|Meriva Curcumin by Thorne||N||N||Y||N||8||$40.66 (120 capsules)|
Seeking Health Liposomal Curcumin (Not Recommended)
Seeking Health is a reputable company that makes good quality products. The issue with this liposomal curcumin formula is that it is heavy on the phosphatidylcholine, which triggers TMAO concerns as well as concerns about inflammation. The goal for many people taking curcumin is to reduce levels of inflammation. Heavy doses of phospholipid fats can raise the levels of omega 6 fatty acids in some people. (R) When omega 6 ratios rise in proportion to omega 3 ratios, the result is greater inflammation.
Gaia Turmeric Supreme (Not Recommended)
Again, I have sampled this product. If you were to break apart a capsule, you’d find a gooey liquid blend of curcumin, black pepper and lecithin oozes out. This leads me to believe the product is heavy on the lecithin. For those taking medications, the black pepper could prevent proper metabolism, keeping the drugs in your system longer than is safe. Further, the product does not use 95% curcuminoid standardization.
Jarrow Curcumin (Recommended)
This formula is packed with good quality curcumin at 95% standardization and is good for daily use. However, I have two problems with the blend. One, there are no antioxidants added to increase bioavailability. Two, the curcumin powder escapes the capsule such that when you touch it, your hands get yellow. If you touch a dress or a shirt after handling the Jarrow product, it will stain.
Gene Food Curcumin Pro (Recommended)
What a shocker, we like our formula. But consider this: what other supplement manufacturer would list competitors next to their own product? Zero would, that’s how many. We like Curcumin Pro because in addition to 95% curcuminoid standardization, we add vitamin C, quercetin, bromelain, and rutin. Each of these ingredients are designed to work in synergy to reduce inflammation and increase bioavailability. For example, studies have shown that quercetin and bromelain, when paired together, increase bioavailability of quercetin, and quercetin is a powerful anti-inflammatory supplement in its own right with studies showing benefits ranging from reduction in cytokines to possible anti-cancer activity. (R)
Meriva Curcumin by Thorne (Possibly recommended for short term use)
The study we cited to above shows that Meriva is an effective supplement for relieving short term inflammation. My concern is that the marketing is way out in front of the science and we don’t know how heart healthy these types of products are for people over the long term. Short term use, for example as an alternative to NSAIDs, could be considered.
Technical fun facts
As Aaron discusses in his post on BH4, curcumin is a BH4 co-factor.
Genes targeted by Curcumin
There are several genes and SNPs which may be of interest for those considering curcumin supplementation.
The risk ‘A’ allele of rs4073 in the IL8 gene is associated with an increased risk of bacterial infections of the gut (R), leading to the potential for stomach ulcers to form (R), impaired nutrient uptake and development of IBS (R).
As an inflammatory disorder there is some evidence that turmeric/curcumin can alleviate the development of the more severe symptoms (R, R). Results for IBS were more confusing with one study reporting no effect (R), whereas another reported a significant beneficial effect (R).
Several SNPs in the AOC1 gene (rs10156191, rs1049742, rs1049793, rs45558339 and rs35070995) are associated with reductions in the breakdown of histamine (R). Histamine plays a major role in the immune response generating inflammation to fight infection, however its incorrect release is associated with severe allergic reactions. Those carrying the risk alleles for the above SNPs demonstrate a prolonged inflammatory response following histamine release. Several trials have demonstrated that curcumin can reduce the inflammatory response associated with histamine release (R,R), meaning supplementation may be of interest to those at risk.
The superoxide dismutase 2 and 3 (SOD2, SOD3) genes are potent antioxidants. The risk ‘T’ allele of rs4880 in SOD2 and the risk ‘G’ allele of rs1799895 in SOD3 are both associated with impaired antioxidant capacity putting carries at risk of cardiovascular disease (R,R), diabetes (R) and cancer (R).
Animal studies have shown that curcumin supplementation can increase SOD2 expression and activity (R) in rats, and increase total SOD activity in human cells cultured in the lab (R). However, to date no trials have been performed in humans which directly assess the impact of curcumin on SOD activity, although a general improvement to antioxidant response has been observed (R).
See also: SOD2A16V: the oxidative stress gene?