Aging and the Endocrine System

by rod

Important: balance hormones to maintain vitality

by Sue Kira, Naturopath & Clinical Nutritionist

This article originally published Here & Now Magazine August 2004 and since updated

The endocrine system is made up of a collection of glands in the body that produce hormones. The system is involved in all of the integrative aspects of life, including growth, sex differentiation, metabolism and adaptation to an ever changing environment. This system is connected with your feelings and emotions and whether you feel energetic, tired, aggressive or passive.

Endocrine glands are ductless glands i.e. organs that produce and secrete hormones directly into the blood. The glands include the pituitary gland, thyroid gland, adrenal glands, pancreas, ovaries, testes, pineal gland, parathyroid gland, hypothalamus and thymus gland.

The hypothalamus lies above the pituitary gland at the base of the skull, the thyroid gland is in the lower neck, as is the parathyroid gland, and the adrenal glands lie on the top of the kidneys. The pancreas, sitting just behind the stomach, not only has a part to play in digestion but also functions as part of the endocrine system in regulating blood sugar levels. The thymus gland is just below the breast bone and the pineal gland is at the back of the brain. Other endocrine glands are the ovaries in women and the testes in men.

Endocrine glands generally work in conjunction with one another, so that the release of a hormone in one gland will influence the operation of another gland. Hormones released by the endocrine glands are generally thought of as chemical messengers that are transported in the body’s fluids.

Of particular interest for some time is the human growth hormone. Research suggests that somatropin or human growth hormone (GH) – controlled by the pituitary gland – is useful as an anti-aging hormone. GH has a pulsatile pattern of release during various life periods and under diverse clinical circumstances.

There are several factors such as exercise, levels of fitness, androgen and oestrogen production, sleep, body mass and nutritional status, which impact on the production and release of GH. Levels certainly decrease with age. The decline in the overall GH level with age is called somatopause.

Signs of somatopause in adults are decrease in lean body mass, decreased joint cartilage, decreased cardiac endurance, decreased rate of wound healing, decreased sleep quality and quantity.

Symptoms can be fatigue, anxiety, increased social isolation, depression and weight gain. These signs and symptoms can have a significant impact on the quality of a person’s life. GH has profound effects on tissue growth and metabolism. Most of these actions are thought to be mediated through GH dependent production of insulin-like growth factors (IGF) and associated binding proteins. GH apparently stimulates IGF production after binding to specific cell surface receptors in the liver and possibly other tissues.

As mentioned, there are a number of lifestyle factors that influence GH including stress, sleep, diet, exercise and body fat. In the case of prolonged stress, the production of GH will increase initially, but overall levels will reduce significantly over time.

An increase in cortisol levels experienced during prolonged stress, will inhibit release of GH. Also there will be a reduction in the release of testosterone and luteinizing hormone (a hormone that helps the reproductive system).

GH is usually released during the first 30-90 minutes of sleep. Decreased sleep causes an increase in cortisol, and a decrease in GH and testosterone. High cortisol also causes weight gain, which means you could gain weight by not getting enough sleep. Also the release of melatonin will be affected which further reduces the production of GH and quality of sleep.

Low GH has also been linked to Chronic Fatigue Syndome, Fibromyalgia, Osteoporosis and even Leaky Gut Syndrome.

Circulating GH is filtered through the kidneys and while most is reabsorbed, a small amount is secreted in the urine, making urine the best medium for testing GH levels. We have heard of athletes using human growth hormone to increase lean muscle mass to give them the athletic ‘edge’.

But naturopathically speaking, we prefer to look at what is causing the reduction of GH and adjust these factors, using diet, herbs and lifestyle changes to influence the natural production of these hormones.

In recent years a herb, Tribulus, has gained a reputation as a natural ‘Viagra’, but is also known to help increase of GH and DHEA levels. Clinically documented benefits of Tribulus include GH regulation via Hypothalamic-Pituitary Axis, intensification of protein synthesis (anabolic), and improvements to male and female fertility, menopause, andropause, impotence, erectile dysfunction and libido enhancement.

Adrenal hormones DHEA and Cortisol also play an important role in how well we age. DHEA, the principle adrenal adrogen, and it’s sulphonated ester DHEA-S, decrease with age. In addition to it’s adrogenic function, DHEA has been reported to have considerable other functions such as improving carbohydrate metabolism, neurological function and general well-being.

Low levels of DHEA-S are involved in the decline in immunity, chronic fatigue, arthridites, insomnia, decreased libido, obesity, depression and osteoporosis.

Cortisol influences the activity of insulin, thyroid hormones and DHEA. Cortisol is involved in balancing blood glucose levels, immune system responses, bone turnover rate, mood and thought, sleep and protein catabolism.

Elevated cortisol is associated with anxiety, insulin resistance, obesity, osteoporosis, sex hormone imbalance, onset insomnia (difficulty getting to sleep), accelerated aging and immune suppression and disrupts gastrointestinal microflora levels causing dysbiosis such as Candida overgrowth.

Low cortisol levels on the other hand relate to CFS, depression, PMS, menopause, fibromyalgia, impotence in men, fertility and maintenance insomnia (difficulty staying asleep).

Now let’s look at the thyroid hormone (TH). Thyroid function has a profound impact on overall health via it’s modulation of carbohydrates, protein, fat metabolism, vitamin utilization, mitochondrial function, digestive process, muscle and nerve activity, blood flow, oxygen utilization, hormone secretion and sexual and reproductive health.

An important function of TH is to help the body convert food into energy and heat. TH exists in two major forms T3 and T4. Levothyroxine (T4) has four iodine atoms per molecule and is an inactive form that converts to T3 and is produced exclusively by the thyroid gland.

Nutritionally the thyroid gland requires Tyrosine and iodine to produce adequate levels of T4. Triiodothyronine (T3) has three iodine atoms per molecule and is eight times more biologically active than T4. It is converted from T4 in the thyroid, brain, liver, blood stream and in various tissues in the body. 90% of circulating T3 is produced by peripheral conversion.

Iodothyronine deidinase (IDI) regulates the conversion of T4 to T3. IDI is expressed in the liver, kidneys, brain, pituitary and brown fat cells. With 80 % of conversion done in the liver, one can see the importance of a healthy liver to have a healthy thyroid.

Although much of this article is somewhat scientific, the main takeaway is that hormone balance plays an important role in how well we age.

The first step is hormone testing. Request sheets are available through my clinic or your doctor. All but the thyroid test are best done by saliva, while thyroid tests are best done with a blood sample.

Once tested, the next step is evaluation. Although many results fall within the ‘reference range’ and otherwise appear to be ‘normal, I have often found that many of those results are less than ideal. While they may not need medical attention, this is where further naturopathic support can help to balance and optimise hormones with herbs, nutrients, and diet modifications.

The following two case studies provide examples:

From hypothyroidism to healthy normal hormones

Reverse T3 corrected naturally

Balance your hormones to regain and maintain vitality (irrespective of your age)


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