Cortisol – Part 1 – Relationship to Stress

Cortisol is, in many ways, a perplexing hormone. A certain amount of cortisol is necessary for optimal health, but too much or too little can be unhealthy. During acute episodes of stress, more cortisol is released to help the body cope with physical or psychological stressors (Tomlinson 2004). Its primary functions in the body are:

-Regulation of blood glucose levels in the liver;
-Regulation of the immune system;
-Regulation of carbohydrate, protein and lipid metabolism.

Essentially, cortisol is regarded as an anti-inflammatory hormone, a blood glucose modulator, an immune-modifier, and an adaptation hormone (Chrousos 2000). Depending on diet, exercise, stress, and time of day, serum levels of cortisol can vary.

During healthy conditions, cortisol levels peak in the early morning hours (usually around 8AM) and dip to their lowest between midnight and 4AM. The complex process of cortisol biosynthesis and release is sensitive to disruption by both internal and external factors (Beishuizen 2001; Tomlinson 2004; Weerth 2003). In the face of chronic psychological stress, for example, the adrenal glands excrete an abnormal amount of cortisol in an abnormal rhythm.

Cortisol, being a catabolic hormone (a hormone that breaks down tissues), when out of balance and unregulated, can have detrimental effects on body composition. Moreover, too much cortisol can suppress the immune system, while too little can lead to autoimmunity and rheumatologic disorders (Chrousos 2000; Wu 2008; Muneer 2011; Sapolsky 2002; Tak 2011).

Cortisol receptors are expressed throughout the body, including in the brain; therefore, derangement of the biosynthesis, metabolism and release of cortisol can disrupt many physiologic systems (Beishuizen 2001).

Next week we will explore Cortisol and its relationship to weight.

Can the Bacteria in Your Gut Explain Your Mood

Appeared in NY Times Magazine, June 23rd. By PETER ANDREY SMITH

Eighteen vials were rocking back and forth on a squeaky mechanical device the shape of a butcher scale, and Mark Lyte was beside himself with excitement. ‘‘We actually got some fresh yesterday — freshly frozen,’’ Lyte said to a lab technician. Each vial contained a tiny nugget of monkey feces that were collected at the Harlow primate lab near Madison, Wis., the day before and shipped to Lyte’s lab on the Texas Tech University Health Sciences Center campus in Abilene, Tex.

Lyte’s interest was not in the feces per se but in the hidden form of life they harbor. The digestive tube of a monkey, like that of all vertebrates, contains vast quantities of what biologists call gut microbiota. The genetic material of these trillions of microbes, as well as others living elsewhere in and on the body, is collectively known as the microbiome. Taken

To read more of the article.

Telomeres and Reversing Aging – Part 1 – The Science

This is complex and controversial subject that many are interested in and has spawned a growing industry of testing, research, and products…

First off, what is a telomere:

Telomeres are the caps at the end of each strand of DNA that protect our chromosomes, like plastic caps at the end of shoelaces. Telomeres are an essential part of human cells that affect how our cells age. Without the caps, shoelaces become frayed until they can no longer do their job as well, just as without telomeres, DNA strands become damaged and our cells can’t do their job as effectively.

In recent years, research points to telomeres being the key to cancer and aging. The story goes: the shorter they are, the worse off you are. Can the length of your telomeres help predict how long you’ll live? Can telomere research unlock the key to eternal youth?

What does it mean to lengthen telomeres?

Are we speaking about lengthening all teleomeres in all cells? Can we control which cells this is done to? Is this even a true bio-marker of aging?

Less than 1% of a person’s cells have the enzyme telomerase and tare capable of increasing their chromosome’s telomere length. The other 99% are incapable of doing so. What about neurons, and heart cells that typically do not divide and where their telomeres do not shorten with age? Most liver and kidney cells cannot lengthen telomeres. The 1% that are the most critical include white blood cells and many stem cells.

Should we be increasing telomere length? 90% of cancer cells do this. The fact that telomeres shorten may actually allow us to live longer as it may reduce the risk of some cancers.

Correlation and Cause

It is a fact that many species have longer telomeres than humans but live a fraction of their life span. Many studies have shown a correlation within a particular species between telomere length and length of life. The evidence is that length is a good bio-marker of aging within a particular species and even that telomere attrition causes aging itself.

Testing on telomeres is done with white blood cells. A higher rate of telomere shortening of any kind might indicate an increased rate of cellular damage, but it doesn’t tell you what is causing the damage.

Is this simply another indicator of systemic inflammation? We will examine this more in our next article, and look at the products and “cures” for lengthening telomeres.