This is a research study that implies that when FT4 and FT3 levels are at a healthy level they are protective of health. FT3 and FT4 tend to protect again many sources of mortality including cardiovascular-related mortality.
In particular, good FT3 levels protect against cancer.
Here is the research study:
“Thyroid hormones and mortality risk in euthyroid individuals: the Kangbuk Samsung health study.”
Zhang Y, Chang Y, Ryu S, Cho J, Lee WY, Rhee EJ, Kwon MJ,
Pastor-Barriuso R, Rampal S, Han WK, Shin H, Guallar E.
J Clin Endocrinol Metab. 2014; 99(7):2467-2476.
https://www.researchgate.net/publication/261441377_Thyroid_Hormones_and_Mortality_Risk_in_Euthyroid_Individuals_The_Kangbuk_Samsung_Health_Study
The implications of this are pretty clear.
Those that are on T3, T4/T3, and NDT treatment and have good levels of FT3 and feel properly treated (no symptoms), are in a lower risk situation with regard to developing cancer.
Those thyroid patients on T4 therapy that is not converting well enough, that have remaining symptoms are likely to have too low an FT3 level and are more at risk of health issues.
The sooner the entire medical profession wises up to this the better. Keeping thyroid patients healthier will reduce future health issues. This is not only important for the patients but ultimately, this would save health services a lot of money.
All thyroid patients deserve good health!
Far too much emphasis is placed on keeping everyone on the same, simplistic T4 treatment (also the cheapest) without considering the long term costs of other conditions that can come out of this. Cancer is especially a very expensive condition to treat.
It is only right to provide a variety of therapies and put the effort into finding the one that works for the individual.
Here is another of a number of similar articles that support the cancer-protective effect of T3:
“The thyroid triodothyronine reinvigorates dendritic cells and potentiates anti-tumor immunity.”
Vanina A., et al. Oncoimmunology 5.1 (2016): e1064579. doi: 10.1080/2162402X.2015.1064579.
Abstract here (but there are .pdfs available): https://pubmed.ncbi.nlm.nih.gov/26942081/
Also see this blog post that refers to studies that show the increased risk of cancer in long-term Levothyroxine (T4) usage:
https://paulrobinsonthyroid.com/new-study-suggests-cancer-risk-is-raised-in-long-term-levothyroxine-t4-use-in-thyroid-patients/
Best wishes,
Paul
