Most people are so confused as to what constitutes good health these days and when they turn up to my office in low metabolic states with digestion, sleep, energy, mood and other issues. One of the first things that they say is that they eat really healthily. If you throw into the melting pot the obsession with the keto diet, chronic calorific restriction (CR) or other modalities, those short term gains have turned into long term deficits. I’ve long opined that health in general terms can be defined by:

 

·      Good energy

·      Good Digestion 2-3 bowel movements per day

·      Restorative sleep

·      Balanced mood free of depression or anxiety

·      Desire for life, motivation, hobbies and interests

·      Healthy libido

·      Absence of pain

What does your body temperature suggest about your health?

Get cold…read on

I’ll also add to that list a warm body and the ability to generate efficient energy,  a phrase biologists might use is a state of negative entropy. Entropy is a state associated with decay and disorder and as entropy increases, equilibrium is achieved - where a state of no energy in and no energy out or death of a living system occurs. The basis for life and metabolism is governed by the enzymes. Enzymes function well in an appropriate temperature and in a medium that is neither too acidic nor too alkaline. Mammals and specifically humans are endotherms that regulate their temperature in  tight range at approximately 37 degrees Centigrade (C) or 98.6 Fahrenheit (Bicego, Barros, & Branco, 2007). The central compartment theory of temperature  suggests that the head and the core should maintain a relatively stable temperature, due to the rich vascular supply and that the periphery may vary some 2-4 C.  

In a recent study that I conducted I suggested that the peripheral and core temperatures should remain at a similar level of about 37 C . The suggestion that a decreased body temperature recorded in the head, might be the last place that you would see a reduction due to the large quantities of glucose that the brain uses to maintain function. It’s possible to suggest that the slowing of function in low energy and hypothyroid states might be observed initially in the trunk or core. The well documented symptoms of constipation, decreased heart rate, slowed contraction relaxation of the heart and arteries and reduced peripheral relaxation of tendons (Achilles tendon reflex) might appear in the trunk and peripherally due to the preferential oxidation of glucose initially. Due to the vast systemic implications of low thyroid function, many different paths of decreased function might occur, dependant on nutrition, environmental stimulus and other stressors. In my study I didn’t find this but what I did find is strong linear correlations between low body temperature in both the mouth and armpit, multiple low thyroid symptoms (mean 6.8 per subject) and yet normal blood values.

Thyroid hormone affects all aspects of biology

 

There are many factors that can decrease body temperature such as CR, fasting, estrogen, stress, pollution, over exercise and more. CR has been suggested as a mechanism for maintaining longevity but studies lack any conclusive evidence (Carrillo & Flouris, 2011) and a theory that a cold body, decreases metabolism, oxidation and damage therefore preserving tissues. Another emergent theory and results show in rodent studies, that mammals with a high energy intake, high metabolism and organised biology can increase life span (John R. Speakman et al., 2004) (J. R. Speakman, 2005). Think about this for a minute:

Calorific restriction makes the body cold, decreases metabolic rate  (via inhibition of thyroid hormone) and disorganisation of tissues. Entropy State

Adequate energy, maintains body temperature and organises tissues to function at their best. Negative entropy state.

From an evolutionary perspective fasting due to lack of food was a necessity. Fasting these days could be a useful tool, if you were prone to constant overeating but if your system lacks the flexibility to do so problems can occur. That’s not to say that calorie restriction for weight loss isn’t helpful but sustained CR in a system that doesn’t respond well might be counterproductive. Pollution has increased at a phenomenal rate clearly affecting physiology and hormones (Gore et al., 2015). Does it make sense that a so called detox diet, low in calories, protein, carbohydrates can enhance the function of detoxification, when liver function is energy and thyroid dependant? Skipping breakfast alone in some is associated with increased cortisol, glucagon and metabolic inflexibility (Jakubowicz, Wainstein, Ahren, et al., 2015) (Jakubowicz, Wainstein, Ahrén, et al., 2015). These factors can also decrease the mitochondrial uncoupling proteins which are responsible for increased body temperature.

Ageing is also associated with decreased metabolic rate, colder bodies and accepted increases in thyroid hormone stimulating values (TSH) (Laurberg, Andersen, Pedersen, & Carlé, 2005) . If symptoms of failing biology are present with isolated thyroid symptoms such as increased cholesterol,  , high blood pressure and sugar, cardiovascular issues and even cancer the acceptance of TSH and other thyroid hormone analysis to accurately predict hypothyroidism should be considered. Body temperature and metabolic rate was reliably used in the last century to diagnose hypothyroidism with qualitative analysis of symptoms and symptoms resolved with thyroid hormone treatment (Barnes, 1942) (McGavack, Lange, & Schwimmer, 1945) (Peat, 1999). Whilst thyroid is useful for restoring function, food and other factors can be used to restore and maintain function (previous blog on maintaining the aerobic system)

Certain nuances exist in temperature regulation that are dependant on acute or chronic exposure to stressors and a slowing down of the system through  a functionally, subclinical or overt hypothyroid state. In short term fasting, TSH is initially raised then decreases, negating thyroid blood tests. In the same manner the time frame of any stressor can dictate whether short or long term compensations of  the sympathetic adrenergic system is supporting the system. In well established feedback mechanism it’s known that as TSH increases so does cortisol and as body temperature approaches hypothermic levels (around 35C) cortisol, adrenaline and noradrenaline can increase body temperature as a protective response.

In a world where excess environmental and social stressors are ever increasing - it might make sense to maintain an efficient, organised warm body rather than reducing its function and heat.

 

References:

 

Barnes, B. (1942). Basal temperature versus basal metabolism. Journal of the American Medical Association, 119(14), 1072–1074. http://doi.org/10.1001/jama.1942.02830310006003

Bicego, K. C., Barros, R. C. H., & Branco, L. G. S. (2007). Physiology of temperature regulation: Comparative aspects. Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology. http://doi.org/10.1016/j.cbpa.2006.06.032

Carrillo, A. E., & Flouris, A. D. (2011). Caloric restriction and longevity: Effects of reduced body temperature. Ageing Research Reviews. http://doi.org/10.1016/j.arr.2010.10.001

Gore, A. C., Chappell, V. A., Fenton, S. E., Flaws, J. A., Nadal, A., Prins, G. S., … Zoeller, R. T. (2015). Executive Summary to EDC-2: The Endocrine Society’s second Scientific Statement on endocrine-disrupting chemicals. Endocrine Reviews. http://doi.org/10.1210/er.2015-1093

Jakubowicz, D., Wainstein, J., Ahrén, B., Bar-Dayan, Y., Landau, Z., Rabinovitz, H. R., & Froy, O. (2015). High-energy breakfast with low-energy dinner decreases overall daily hyperglycaemia in type 2 diabetic patients: a randomised clinical trial. Diabetologia, 58(5), 912–919. http://doi.org/10.1007/s00125-015-3524-9

Jakubowicz, D., Wainstein, J., Ahren, B., Landau, Z., Bar-Dayan, Y., & Froy, O. (2015). Fasting until noon triggers increased postprandial hyperglycemia and impaired insulin response after lunch and dinner in individuals with type 2 Diabetes: A randomized clinical trial. Diabetes Care, 38(10), 1820–1826. http://doi.org/10.2337/dc15-0761

Laurberg, P., Andersen, S., Pedersen, I. B., & Carlé, A. (2005). Hypothyroidism in the elderly: Pathophysiology, diagnosis and treatment. Drugs and Aging. http://doi.org/10.2165/00002512-200522010-00002

McGavack, T. H., Lange, K., & Schwimmer, D. (1945). Management of the myxedematous patient with symptoms of cardiovascular disease. American Heart Journal. http://doi.org/10.1016/0002-8703(45)90476-5

Peat, R. (1999). Thyroid Therapies, Confusion and Fraud. Retrieved from www.raypeat.com/articles/articles/thyroid.shtml

Speakman, J. R. (2005). Body size, energy metabolism and lifespan. Journal of Experimental Biology. http://doi.org/10.1242/jeb.01556

Speakman, J. R., Talbot, D. A., Selman, C., Snart, S., McLaren, J. S., Redman, P., … Brand, M. D. (2004). Uncoupled and surviving: Individual mice with high metabolism have greater mitochondrial uncoupling and live longer. Aging Cell. http://doi.org/10.1111/j.1474-9728.2004.00097.x