Betaine (trimethyl glycine, N⁺(CH₃)₃CH₂COO⁻), named after the sugar beet plant (Beta vulgaris) in which it was discovered, is found in many plants.

Plants that accumulate large amounts of betaine tend to be more tolerant drought,  cold and HEAT (Sakamoto & Murata, 2002). Asan osmolyte betaine helps the cells maintain water potential. It is also proposed to help maintain protein and membrane structure.

Humans ingest af air amount of dietary betaine. It is also added to some foods as a flavour enhancer (like salt and monosodium glutamate). Some betaine may get metabolisedinto other important molecules.

Betaine levels in the blood are too low for an osmotic effect, but it is proposed to helpmaintain membrane and protein structure during heat stress (Willingham et al,2020), functioning much in the same way as in plants.’

Betaine is suggested to make a positive contribution to the integrity of the skin barrier(El Chami et al, 2021). It has been found in sweat (Craig et al, 2010), and frequentlyadded as an ingredient in cosmetic and dermatological products;

So, when the going gets hot, you can reflect on the fact that both the plant and your sweating skin may both be using betaine to cope with the heat stress.

SOURCES:

📖 Sakamoto, A., & Murata, N. (2002). The role of glycine betaine in the protection ofplants from stress: clues from transgenic plants. Plant, cell &env., 25(2), 163–171. https://doi.org/10.1046/j.0016-8025.2001.00790.x 

📖 Stuart AS Craig, Betaine in humannutrition, The American J. Clin, Nutr., Vol. 80, Issue 3, November 2004, Pages539–549, https://doi.org/10.1093/ajcn/80.3.539

📖  Craig, S. S., et al.. (2010). The betaine content of sweat from adolescent females. J. International So. Sports Nutr., 7(1),3. https://doi.org/10.1186/1550-2783-7-3

📖  Willingham, B. D., Ragland, T. J., & Orms bee, M. J.(2020). Betaine Supplementation May Improve Heat Tolerance: PotentialMechanisms in Humans. Nutrients, 12(10), 2939. https://doi.org/10.3390/nu12102939

📖  El-Chami, C.et al.. (2021). Organic osmolytes increaseexpression of specific tight junction proteins in skin and alter barrier function in keratinocytes. Br. J. Dermatol., 184(3), 482–494. https://doi.org/10.1111/bjd.19162

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