The effects of Nigella sativa on thyroid function, serum Vascular Endothelial Growth Factor – 1, Nesfatin-1 and anthropometric features

[Bolt_Upright]

The effects of Nigella sativa on thyroid function, serum Vascular Endothelial Growth Factor (VEGF) – 1, Nesfatin-1 and anthropometric features in patients with Hashimoto’s thyroiditis: a randomized controlled trial

ncbi.nlm.nih.gov/pmc/articl...

Methods

Forty patients with Hashimoto’s thyroiditis, aged between 22 and 50 years old, participated in the trial and were randomly allocated into two groups of intervention and control receiving powdered Nigella sativa or placebo daily for 8 weeks. Changes in anthropometric variables, dietary intakes, thyroid status, serum VEGF and Nesfatin-1 concentrations after 8 weeks were measured.

Results

Treatment with Nigella sativa significantly reduced body weight and body mass index (BMI). Serum concentrations of thyroid stimulating hormone (TSH) and anti-thyroid peroxidase (anti-TPO) antibodies decreased while serum T3 concentrations increased in Nigella sativa-treated group after 8 weeks. There was a significant reduction in serum VEGF concentrations in intervention group. None of these changes had been observed in placebo treated group. In stepwise multiple regression model, changes in waist to hip ratio (WHR) and thyroid hormones were significant predictors of changes in serum VEGF and Nesgfatin-1 values in Nigella sativa treated group (P < 0.05).

Conclusions

Our data showed a potent beneficial effect of powdered Nigella sativa in improving thyroid status and anthropometric variables in patients with Hashimoto’s thyroiditis. Moreover, Nigella sativa significantly reduced serum VEGF concentrations in these patients. Considering observed health- promoting effect of this medicinal plant in ameliorating the disease severity, it can be regarded as a useful therapeutic approach in management of Hashimoto’s thyroiditis.

Patients in the intervention group received a daily dose of 2 g Nigella sativa powder per day.

The dose of the Nigella sativa and time period of the study had been selected according to review of the previous studies indicating the effectiveness of 2 g of Nigella sativa or even lesser doses and 8 weeks study duration in treatment of numerous metabolic disorders including immune disturbances and lipid abnormalities.

[greygoose]

It doesn't say if the patients were taking thyroid hormone replacement or not, or how much. Surely that would also have an effect on the outcomes, no?

[Bolt_Upright in reply to greygoose]

You just have to read further into the article: Participants were treated with levothyroxine while the drug dosage was stable from 6 weeks prior participation in the study to the end of the trial. The average full replacement dose of levothyroxine sodium was approximately 1.7 mcg/kg/day (e.g., 100–125 mcg/day for a 70 kg adult).

[greygoose in reply to Bolt_Upright]

OK, thank you. But, I still have grave doubts about this study!

[catrich in reply to greygoose]

Why, Greygoose?

[helvella Administrator in reply to catrich]

In Table 3, TSH was over 20% lower in the Nigella sativa-treated group than the Placebo group before the trial. No mention of time of day the blood draws were done and it is well-known that TSH can change by at least 1 every day.

T3 was 23% lower.

Nesfatin was over 61% higher. And didn't get even near the control group by end of trial despite a very obvious drop.

VEGF was over 67% higher. The after value was almost exactly the same as the before of the control group. And quite remarkable that the after values for both groups was identical to the two decimal places presented. (Ignoring a typo in the after results.)

Those are substantial differences.

Also, only 40 subjects. Enough to raise a question but far too few to draw any reliable conclusions.

The 15% of the treated group stopped due to itching and nausea is a very high level. Without more detail, it is possible that far more had some such symptoms but not enough to prompt their withdrawal.

I'm no statistician but the above have me not trusting the study. Interesting though it might be as an indicator for further study.

[catrich in reply to helvella]

Thanks for your thoughts Helvella.

Aren't the before/after differences within and between groups controlled for with the t-test and ANCOVA analysis? (Which I'm not sure I didn't see spelled as ANOCOVA (sic) in the paper?)

I'm thinking, too, that the number of subjects involved is probably quite suitable for what it is: the first human trial of the effect of Nigella on various thyroid parameters. As you say, it might well be an indicator for further study.

(As an aside, I work both as a medical English teacher and as a proofreader/editor for research at a dept. of neurosurgery at a hospital here in Switzerland. Nothing whatsoever to do with thyroid disease of course but a very many papers that I work on seem to involve small sample sizes. One good reason is the rarity of some (many) of the conditions under investigation - or the experimental nature of the treatment. An RCT with 40 participants isn't that unusual in what I read.)

[helvella Administrator in reply to catrich]

The statistics might be doing the best they can with the numbers available! But the differences before the trial are pretty substantial.

And I would have hoped "Do you consume any Nigella?" would be asked as part of the recruitment process. (I know they asked about supplements. But perhaps some consume it regularly in their food and didn't think for one moment to mention the fact.)

[catrich in reply to helvella]

Well, this was a double blinded randomised trial. Agree there were some difference in parameters - but these are surely 'by chance' and the statistical significance of any changes in each group were dealt with by the two statistical analyses? Yes - dietary questions may or may not have included the use of Nigella. This much should have made been clear... No idea if it's used often in Iranian cuisine?

I still think it's interesting though, as a study. A bit different - though as I am very interested in medicinal plants, I *would* find it interesting.

Seems more relevant to thyroid cancer, perhaps, than treatment of patients diagnosed with Hashimotos. I notice that there are at least two follow-up papers from 2018 and 2020 by Farhangi et al - might be worth a gander.

[greygoose in reply to catrich]

Well, for a start, once you're on thyroid hormone replacement, the thyroid isn't functioning anymore, so how can you measure the effects of something on thyroid function? Also, were the doses of levo these people were taking optimal? And by 'optimal' I do not mean a dose based on the weight of the subject. Nor do I mean 'stable', which is a word that has no place in the treatment of hypothyroidism. I just have the feeling they are over-simplifying hypothyroidism and aren't comparing like with like.

[helvella Administrator in reply to greygoose]

With average TSH levels well over 6 before the trial, clearly not optimally treated.

[greygoose in reply to helvella]

The whole thing's a bit of a farce, really, isn't it. Not that I'm knocking the possible benefits of Nigella sativa, far from it. I have an open mind as far as that is concerned. I just don't think this study was worth the effort.

[helvella Administrator in reply to greygoose]

I agree.

There have been trials of Nigella sativa in other contexts which used oil rather than milled seeds. Maybe that should be considered as a possibility for reducing the itching and nausea reported?

[greygoose in reply to helvella]

Maybe.

[catrich in reply to greygoose]

I think the use of the term 'stable' in the paper refers to the dose of levothyroxine. Stable for 6 weeks prior to and during the trial. And to be fair, the authors of the paper refer to Hashimotos far more often than they do hypothyroidism. It is possible - and I agree that this could be made clearer - that the participants were newly diagnosed with Hashimotos and just at the beginning of their treatment with levothyroxine.

The authors are nutritionists and interested in the effect of nigella on certain thyroid parameters and BMI. It is what it is, and none the less interesting for that.

[greygoose in reply to catrich]

But the use of the word 'stable' is meaningless. People think that being 'stable' has to be a good thing. But, you can be stable with a TSH of 100 or with a TSH of 0.1. And, I know which I would prefer.

What difference does it make that they refer to Hashi's rather than hypo? And, while we're at it, the last thing a Hashi's patient can be said to be is 'stable'. What exactly are they trying to prove? And what is the point of nutritionists doing a study on the effect of Nigella sativa on thyroid perameters when they know next to nothing about those parameters? And if their interest is BMI, why experiment on hypos? They could do it on anyone. I think the whole thing is a mixed up jumble, proving nothing, and certainly nothing to get excited about.

[catrich in reply to greygoose]

Greygoose. When you conduct an RCT such as this, where you are not measuring the effect of thyroxine dose, it makes quite a big difference that participants are altering their dose of thyroxine just prior to and during the trial. If this happened, the methodology would rightly have been called into question and the study could not claim the results that it does. Stable simply means it didn't change. The dose. Not the patient's condition.The participants may have all felt dreadful prior to and during...but how they felt wasn't the aim of the study and wasn't measured.

Not all studies of the thyroid have the patient uppermost in mind - we all know this as people with thyroid issues - and it may seem unfair or pointless or whatever other adjective you want to use, but I can't agree that it is all a farce or a mixed up jumble. You're being uncharacteristically harsh.

[annca1]

Thank you, that is fascinating. I'm off to do a search for some on line. I love the taste of Nigella, too.

[Bolt_Upright]

I got my Nigella Sativa today!

amazon.com/gp/product/B072F...

I ground it up in my coffee grinder.

I bought a digital scale and learned one level teaspoonful is 2 grams, which seems to be the optimal dose for a number of ailments.

Mixed it with about 4 ounces of water and drank it down.

Should be good for my Hashimoto's and also attack any H-Pylori lurking in my gut!

[tattybogle]

i just looked it up an realised i've been accidentally growing some of this in my back alley. it's certainly very pretty to look at