Turmeric has been touted as a super-spice in recent years but does have longheld roots in Ayurvedic medicine. There’s mixed evidence about its effectiveness, yet sales of its active ingredient, curcumin, are expected to exceed $100m globally by 2024.
So, we decided to look into how turmeric and curcumin can benefit your health or whether it’s just a load of marketing hype.
In this article – we review the scientifically proven health benefits of turmeric and curcumin.
What is Curcumin Good For?
From preventing cancer and treating depression, to healing wounds and reducing cardiovascular disease (CVD), it’s been linked with a variety of antioxidant and anti-inflammatory functions.
But is there scientific evidence behind the promising claims? Or have supplement companies been cherry-picking studies with favourable results? We examine the research to understand whether curcumin really lives up to the hype…
What is the Difference Between Turmeric and Curcumin?
Curcumin is a compound found in turmeric, a yellow spice used in Indian, Thai, and Indonesian cuisine. Traditionally an ingredient in curries, it’s also found in mustard, Worcestershire sauce, and custard (as a food colouring). However, the surge of curcumin-related health claims means turmeric is now popping up in smoothies, lattes, and supplement form too.
How Much Turmeric or Curcumin Do We Need?
Dietary exposure to curcumin is mainly influenced by our cultural background and taste preferences. The average resident of India consumes 2-2.5g of turmeric daily, which equates to 60-85mg of curcumin, however, UK consumption is much lower.
A typical curry contains ⅛-¼ teaspoon (0.4-0.7g) of turmeric per serving, of which 3.4% (13.6mg – 23.8mg) is curcumin. Supplements claim to provide higher concentrations (400mg-1000mg) but how much is actually bioavailable?
Both advocates and sceptics of curcumin agree that it has poor bioavailability, which means it isn’t well-absorbed or utilised by the body. It’s hydrophobic (repelled by water), so has low solubility in the digestive tract. It’s also highly reactive, therefore metabolised quickly. Tests in human study participants usually find undetectable levels of curcumin in blood serum, tissues, and organs.
This may be a potential barrier to supplemental use, particularly for dietary curcumin. Studies have attempted to create more bioavailable forms such as nanoparticles, phospholipid complexes, or promoter combinations such as piperine (the active compound in black pepper). Although they’ve shown some positive results, further study is needed to assess their effectiveness in humans.
Improving Curcumin Absorption
Combining turmeric, black pepper, and oil in cooking may help bioavailability. Being lipophilic (fat-loving), curcumin binds to fats which could aid absorption (in a similar way to fat-soluble vitamins). It’s also been proposed that curcumin benefits gut bacteria, which could explain the reported health benefits despite low absorption. However, neither idea has been adequately tested, so are simply suppositions at present.
Simple smoothie tip ⇒ if you’re making a turmeric smoothie then include ingredients that contain dietary fats (like avocado, soy yogurt, or nut butter) to aid absorption. Check out this spicy smoothie recipe.
Biological Effects of Curcumin
Curcumin has produced exciting results in lab studies, but these have yet to be matched in humans. It binds to Iron, Zinc, and Copper, and interacts with over 30 different proteins. These influence a wide range of targets including enzymes, transcription factors, cytokines, and apoptosis elements. It’s these interactions that have scientists excited about curcumin’s potential to reduce inflammation, treat depression, and decrease the risk of cancer and CVD.
What Is Curcumin Good For Health-Wise?
Some studies have found that it inhibits transcription factors and enzymes related to inflammatory diseases and cancer. These include NF-κB, TNF-α, COX-2, and GSK-3β. This may have implications for numerous diseases including arthritis, depression, CVD, and many types of cancer, such as colon, breast, and lung.
Although interesting results, these interactions demonstrate associations rather than causal links. Just because a transcription factor or enzyme is ‘related’ doesn’t automatically mean it’s the root cause of a disease. Or that regulation via supplementation will prevent (or reverse) it.
Apart from TNF-α, these inhibitions also haven’t yet been demonstrated in humans. It’s possible they’d behave differently in the body to in a petri dish, so wouldn’t have the same effects in people. This doesn’t mean the findings should be dismissed, but they should be interpreted with caution.
Does It Really Work?
Curcumin’s diverse interactions have caused both excitement and skepticism. Some scientists suggest that its chemical instability has confounded results, leading to misinterpretation about its properties. There are also suggestions that cell membrane ‘perturbation’ may have been mistaken for protein binding. This would mean that curcumin doesn’t actually interact with growth factors, transporters, or ion channels, but merely ‘appears’ to. Therefore, to more accurately assess curcumin’s effects, we need to examine human studies…
Curcumin & Depression
Depression is one health area that curcumin has been linked to. A review of six randomised control trials (RCTs) concluded that curcumin can reduce symptoms of major depression. Results from 342 patients indicated it had the most significant effects on middle-aged people, who received 1g/day, for longer than 6 weeks. Whilst the mechanisms aren’t known for certain, it’s suggested that curcumin’s anti-depressive effect is linked to its anti-inflammatory and antioxidant properties.
Although the number of trials analysed was small, they were of high quality with minimal variability. Crucially, they were all human studies rather than lab or animal-based, therefore provide a more accurate reflection of curcumin’s effect in the real world. However, it’s important to note that all the studies tested curcumin in combination with anti-depressants, so there’s no suggestion that these medications should be swapped for dietary or supplemental curcumin.
Curcumin & Cardiovascular Risk
When looking at curcumin health benefits, cardiovascular disease is something that’s frequently studied. Curcumin is thought to influence blood cholesterol, which at abnormal levels are a risk factor for CVD. Studies have provided mixed results in the past, however, a recent literature review analysed seven newly published RCTs with 649 subjects who exhibited CVD risk factors. Overall results indicated that curcumin reduced LDL cholesterol concentrations but didn’t affect HDL or total cholesterol. It’s thought that curcumin may influence LDL by suppressing the LDL-C receptor gene.
Although interesting, the small number of studies and varied curcumin formulations used, make it difficult to draw definitive conclusions. Only four of the seven trials were considered ‘high quality’ and significant variability was detected. Both turmeric and curcumin formulations were studied but weren’t distinguished in results, which could mask even smaller sample sizes. It’s also unclear what dosage is required to deliver LDL-lowering benefits.
How Much is Too Much?
The active ingredient in turmeric appears nontoxic and well-tolerated up to 8000mg/day.
However, curcumin can interact adversely with other drugs and side-effects such as diarrhoea and nausea have been reported.
So, now that we’ve looked at the evidence in detail, what’s the final verdict on curcumin? Well, the supplement shows promise but has yet to definitively prove that it lives up to the hype.
Lab experiments have demonstrated potentially exciting results but should be interpreted with caution. Just because something reacts one way in a test-tube, doesn’t automatically mean it’ll behave the same way in humans. Real world studies suggest curcumin may be beneficial for depression, but inconsistent findings and mixed quality RCTs for other diseases necessitate further large-scale study.
With any supplement, it’s also important to consider them in the wider context of the diet. We don’t eat individual nutrients, we eat real food. It’s not that I’m anti-supplements – vitamin tablets cured my adult acne so I’m actually a big fan! But I do think it’s important that supplements are consumed as part of a wider balanced diet, rather than being considered in isolation.
Best Curcumin Supplements
If you do decide to take curcumin supplements, then it pays to go for the best quality you can afford. Cheap supplements are usually made from crappy ingredients and won’t be as readily absorbed by the body. And definitely don’t buy them from Amazon unless you’re purchasing directly from a brand that you know and trust (there are too many dodgy resellers on there).
Note: this article was prepared by a qualified nutritionist. We may earn a commission if you click some of the product links below but this never influences our editorial choices. Nutrition is an important topic (especially since it relates to people’s health) so we always offer 100% unbiased information.
We like these Curcumin & Vitamin D3 capsules from My Vitamins. They contain a decent curcumin dosage as opposed to turmeric supplements which have a greatly diluted curcumin content. Plus, My Vitamins have a solid reputation as the #1 vitamin company in the UK so are trustworthy manufacturers. Learn more about Curcumin and Vitamin D3 here.