Thinking Nutrition

Turmeric: super spice or super overhyped?

July 13, 2021 Dr Tim Crowe Episode 73
Thinking Nutrition
Turmeric: super spice or super overhyped?
Show Notes Transcript

Turmeric has been used in traditional Asian cultures for thousands of years as both a spice for cooking and for medicinal uses. Now medical science is backing up many of the traditional health claims made about turmeric and the compounds it contains. In this podcast, I investigate the turmeric story, outline why the focus seems to be on the bioactive compounds such as curcumin contained in it, what the research says about the many health conditions linked to it, and give you some guidance on the different supplemental forms available. 

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Turmeric has been used in traditional Asian cultures for thousands of years as both a spice for cooking and for medicinal uses. Now medical science is backing up many of the traditional health claims made about turmeric and the compounds it contains. In this podcast, I investigate the turmeric story, outline why the focus seems to be on the bioactive compounds such as curcumin contained in it, what the research says about the many health conditions linked to it, and give you some guidance on the different supplemental forms available.

Turmeric is a spice belonging to the same family as ginger that has been used in traditional cooking for thousands of years. But it is best known for its use in Indian curry dishes. The turmeric that we see on shelves is made from the ground roots of the plant.

There is a lot of interest in the potential health benefits of turmeric, and for this, it is the primary bioactive substance in the spice – curcumin – that gets most of the attention. Curcumin is a yellow pigment so this is the ‘secret sauce’ responsible for the colour of turmeric.

Curcumin is a polyphenol with anti-inflammatory properties. But, while curcumin is all you seem to hear about, there are plenty of other compounds belonging to the wider family of curcuminoids that could be beneficial. So, you can’t always infer from observational studies of people who eat lots of turmeric (so those of an Indian heritage are key groups that are normally looked at by researchers) and any health benefits they main gain and then say it is all from the curcumin in turmeric and then stuff capsules full of the stuff.

Most over-the-counter supplements you’ll find on the shelf have curcumin as their main ingredient as it can be extracted from turmeric to give much higher potency doses than you would find in native turmeric. But curcumin is absorbed poorly, hence the myriad of different formulations that have been created to improve its bioavailability.

A common co-agent to help curcumin absorption is piperine which is a bioactive compound found in black pepper. Then there are a whole bunch of proprietary formulations that combine the curcumin with lipids and other chemical agents, each touted by their manufacturer with fancy-looking graphs for how much more bioavailable their formulation is compared to their competitors. It’s a curcumin arms race. Some of the popular proprietary curcumin formulations you’ll find in supplements go under the trademark of BCM-95, CurcuWIN, Meriva and Longvida, but there are a bunch of others too.

Let’s get to the crux of today’s podcast: apart from the enjoyment of a delicious curry, are there any real health benefits from taking curcumin as a supplement? This is one area where there is a lot of research. But it is also one area that promoters get a bit carried away when proclaiming the miracle health benefits of it too. The truth lies somewhere in the middle.

Curcumin tops the list for being a purported anti-inflammatory agent. I’ve already done a whole podcast on the topic of inflammation so to get up to speed on this topic, check out episode 61. Many of the conditions looked at in clinical trials with curcumin have chronic inflammation as their base.

So, let’s look at joint arthritis first. There have been a bunch of RCTs published in this field and a systematic review and meta-analysis from 2016 could analyse either of them. And I’ll link to this study in the show notes. And what they found was that there was some evidence for a benefit, but the quality and size of the clinical trials that informed the review were not of a high enough standard to make a firm conclusion. https://pubmed.ncbi.nlm.nih.gov/27533649 

Okay, so what about a specific type of arthritis – that being osteoarthritis? Only in the last week, a systematic review and meta-analysis has been published which I’ll link to in the show notes. 15 RCTs made the grade and the overall finding was that curcumin can reduce joint pain and stiffness and improve function - potentially to a level to that seen with common non-steroidal anti-inflammatory drugs. The review advised that it is recommended to trial curcumin supplements for at least 12 weeks to ensure enough time to see a benefit. https://pubmed.ncbi.nlm.nih.gov/34017975 

But the results are not always spectacular in every clinical trial and for every condition so curcumin may not be some cure-all anti-inflammatory supplement for every disease under the sun. In fact. a recent review of clinical trials that used curcumin in people with a wide range of chronic inflammatory conditions could not find any change in blood markers of inflammation, those being CRP, interleukin-1, interleukin-6 and TNF-alpha. So, the evidence for using curcumin lies in a few well-described conditions so far. https://pubmed.ncbi.nlm.nih.gov/31121255

Then there are the clinical trials that looked at if turmeric or curcumin is effective in lowering blood lipids such as LDL-cholesterol in people with multiple risk factors for CVD such as having type 2 diabetes or metabolic syndrome. A review of 7 clinical trials found a statistically significant improvement in LDL cholesterol and triglycerides in people taking turmeric or curcumin compared to the placebo group. I’ll link to this study in the show notes. Whether the changes in serum lipids translate into a long-term real-world reduction in the risk of major CVD events like heart attack or stroke is unknown at this stage. https://pubmed.ncbi.nlm.nih.gov/29020971

And then there is all the research with curcumin in a sport and exercise context where the use of the purported anti-inflammatory action may help with exercise recovery. What does the evidence say? Well, for something completely different, I’m going to cite a systematic review (surprising I know!) published only in April of this year which I’ll link to in the show notes. Eleven papers were included in the review and most of the studies showed positive effects of curcumin supplementation for reducing inflammation and oxidative stress, decreasing pain and muscle damage, improving recovery and muscle performance, better psychological and physiological responses during training and improved gastrointestinal function. All with no side effects reported. The most common doses used in the trials ranged from 180 to 500 mg per day with supplementation only for short periods of just a few days around intense exercise. https://pubmed.ncbi.nlm.nih.gov/32282223 

And to round things out for one further area that has attracted quite a bit of research interest which is the role of curcumin in helping to treat depression. Inflammation is considered one of the underlying pathologies that is part of depression, so a purported anti-inflammatory agent like curcumin could help. In a recent 2020 systematic review and meta-analysis of clinical trials which I’ll link to in the show notes, 9 randomised controlled trials were looked at with most studies involving people with major depressive disorder.

The results were quite surprising for the magnitude of benefit seen for curcumin supplements having a benefit on both depression and anxiety symptoms compared to people taking a placebo. And the benefit was seen across different study designs regardless of study duration, the dosage of curcumin or the type of depression. But a disclaimer here in that sample sizes across all studies combined was just over 500 people. The amount of curcumin used ranged from 150 milligrams to 1,500 milligrams per day in a variety of different forms.

Interestingly though, any benefit in depression may not be all related to a direct anti-inflammatory effect as curcumin has also been shown to raise levels of a brain chemical called BDNF. BDNF is a key molecule involved in brain neuroplastic changes related to learning and memory. Several lines of evidence suggest that BDNF is involved in depression since the expression of BDNF is decreased in people with depression. Curcumin supplementation from 200 to 1820 mg per day and for 8 to 12 weeks can elevate BDNF levels. And you know what else can raise BDNF levels? Exercise. Which is a key lifestyle habit that can help with some of the symptoms of depression. https://pubmed.ncbi.nlm.nih.gov/31423805

There are some other growing areas of interest that curcumin may have a role to help with. Cognitive decline and Alzheimer’s disease, colorectal cancer and ulcerative colitis all come up as being areas that the research is still in an early stage, but some promise is being seen.

Summary

So, let’s wrap all this up. The list of potential benefits of supplemental curcumin seems to be quite broad. But this podcast is not advising you or anyone that you should be taking it for any old condition that ails you. But I’ve presented enough research here that would enable you to dig a bit deeper to see if it may be worth exploring trialling curcumin for a particular condition – the ones I presented in this podcast are where the most research has been done.

By doing that, you can determine what type of dose and formulation may be appropriate to trial. But as a ballpark, it seems 500 mg of curcumin or curcuminoids is likely an effective starting dose. Taking natural turmeric would need a higher amount as the curcuminoids in it are just one component and natural variation and bioavailability can be an issue. Combining turmeric with black pepper for its piperine content in your cooking will help you absorb more of the curcumin.

As for what form of supplemental curcumin is best, there are so many on the market so I would suggest trialling several types either with piperine or using a proprietary form that has solubilised the curcumin in a lipid and I’ve mentioned some of the brand names that would be listed on a supplement ingredient list already in this podcast and ignore the manufacturers’ over-hyped bioavailability claims as these aren’t always from human studies. If you don’t feel one form is benefiting you then you can always trial another.

So that’s it for today’s show. You can find the show notes either in the app you’re listening to this podcast on if it supports it, or else head over to my webpage www.thinkingnutrition.com.au and click on the podcast section to find this episode to read the show notes.

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I’m Tim Crowe and you’ve been listening to Thinking Nutrition.