News, Commentary & Opinion

The Journal of Holistic Performance
  • Articles
    • Journal
    • Blog
  • For Authors
  • Contact
  • Study

Are Low Carb Diets Safe for the Thyroid?

7/10/2016

Comments

 
Picture
By Cliff Harvey

Low-carb diets have received criticism due to their perceived effects on thyroid function, and the belief that this will have a negative effect on general health, along with performance and fat-loss. But the real picture may be less than clear-cut.
What does the science say?

Reduced carbohydrate diets ( with less than 35% of calories) have been demonstrated to reduce active thyroid hormone levels (triiodothyronine (T3)) [1] without affecting the less metabolically active precursor hormone thyroxine (T4), thyroid stimulating hormone (TSH) nor reverse T3 levels [2, 3]. 

A 16 week trial of a ketogenic diet for the treatment of type 2 diabetes also showed no significant effect on TSH levels [4], likewise no statistical difference was seen between groups in TSH levels in a randomised controlled trial of ketogenic diets for the treatment of obesity and hyperlipidaemia (including 119 participants over 24 weeks) [5]. No statistical difference was observed in T3 uptake between a very low carbohydrate diet group and control, with the VLCD group exhibiting marginally higher T4 levels [6]. 

In their paper on the effects of a eucaloric ketogenic diet LCHF pioneer Stephen Phinney and colleagues noted that despite significant reductions in T3 levels there were no concurrent effects of hypothyroidism noted, nor were there an associated reduction in oxygen uptake [1]. 

What does this mean?

This data suggests that there is:
  • An incomplete association between T3 levels and metabolic rate. 
  • Not necessarily a detrimental effect of carbohydrate restriction on the regulation of thyroid hormone levels
  • Changes in T3 output are due to a potential lower need for T3 in the presence of lower carbs
  • This alters T4-T3 conversion rates

Conclusion

It appears that lower carbohydrate diets may cause there to be less requirement for T3, and the drop in T3 that is observed is not necessarily detrimental. 
This is an important distinction because if someone is still functioning optimally even in the presence of lower T3 levels there is more than likely not any particular health issue that needs to be addressed. 

Individual responses to LCHF and particularly very low-carb diets vary greatly. 

Anyone with a medical condition should seek sound advice from a qualified practitioner, knowledgeable in LCHF diets before embarking on a reduced carb nutrition plan, but it does appear that lower-carb diets may be appropriate, and are likely safe for thyroid function.

LEARN MORE aBOUT sTUDYING nUTRITION WITH hpn


References

1. Phinney, S.D., et al., The human metabolic response to chronic ketosis without caloric restriction: Physical and biochemical adaptation. Metabolism, 1983. 32(8): p. 757-768.

2. Ullrich, I.H., P.J. Peters, and M. Albrink, Effect of low-carbohydrate diets high in either fat or protein on thyroid function, plasma insulin, glucose, and triglycerides in healthy young adults. Journal of the American College of Nutrition, 1985. 4(4): p. 451-459.

3. Fery, F., et al., Hormonal and metabolic changes induced by an isocaloric isoproteinic ketogenic diet in healthy subjects. Diabète & métabolisme, 1982. 8(4): p. 299-305.

4. Yancy Jr, W.S., et al., A low-carbohydrate, ketogenic diet to treat type 2 diabetes. Nutr Metab (Lond), 2005. 2: p. 34.

5. Yancy, J.W.S., et al., A Low-Carbohydrate, Ketogenic Diet versus a Low-Fat Diet To Treat Obesity and HyperlipidemiaA Randomized, Controlled Trial. Annals of Internal Medicine, 2004. 140(10): p. 769-777.

6. Volek, J.S., et al., Body composition and hormonal responses to a carbohydrate-restricted diet. Metabolism, 2002. 51(7): p. 864-870.
Comments

    RSS Feed

    Categories

    All
    Brain Health
    Carb Appropriate
    Clinical Nutrition
    Dairy
    Disease
    Exercise
    Fasting
    Genetics
    Gut Health
    Health
    Infographics
    Interviews
    Keto
    LCHF
    Lifestyle
    MCTs
    Meat
    Media
    Meet Our Advisors
    Meet Our Graduates
    Mushrooms
    Nutrition
    Paleo
    Pregnancy
    Public Health
    Research Review
    Skin Health
    Sleep
    Sugar
    Supplements
    Time Rich Practice
    Women's Health

    Archives

    September 2020
    June 2020
    May 2020
    March 2020
    March 2019
    May 2018
    April 2018
    March 2018
    February 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    March 2014
    February 2014
    December 2013
    February 2013
    January 2013


Sign up for articles and nutrition news



Donate

© 2020 Holistic Performance Limited
Photos used under Creative Commons from marcoverch, wuestenigel, Rawpixel Ltd, wuestenigel, Rinet IT, Infinity Studio, Herbert Guedes, Brett Jordan
  • Articles
    • Journal
    • Blog
  • For Authors
  • Contact
  • Study