Growth hormone is essential to health and declines as we age
Growth hormone (GH) is involved in tissue repair, maintaining muscle mass, body weight, insulin sensitivity, immune response and cardiovascular health.
GH is produced by the pituitary gland, which secretes tiny amounts in a series of pulses. GH secretion peaks around puberty and begins to decline by age 21. By age 60, most adults have very low GH secretion.
The Signs and Symptoms of Adult Growth Hormone Deficiency
Adult GH deficiency (AGHD) syndrome generally manifests as central obesity (increased fat deposits in the abdominal area), loss of muscle mass, decreased strength and aerobic capacity, decreased bone mineral density, harmful changes in cholesterol levels (increases in LDL (bad) cholesterol and decreases in HDL (good) cholesterol), low energy, and a reduced quality of life.
Benefits of Healthy GH Levels
Interest in the use of GH to improve quality of life in aging adults has also increased as a result of research reporting that GH has protective and stimulating effects on brain cells, improving cognition and memory in the aging brain in both men and women.
An evaluation of 460 U.S. male doctors (average age 57) participating in the Physicians’ Health Study II found that those with higher midlife levels of GH had significantly better late-life cognitive performance. Similar results were found in a study involving 590 American women aged 60–68 years, and an Italian study of 353 elders 80 years or older, in whom lower levels of GH were strongly associated with poor cognitive performance. In a placebo-controlled trial, 6 months’ of treatment with daily growth hormone releasing hormone (GHRH) greatly improved cognition in healthy older (average age 68) adults.
Other recent studies also show that treatment with GH secretagogues (supplements that promote the secretion of GH) causes improvement in the ability of brain cells to communicate with one another.
GH Association with Cancer and Diabetes
GH is involved in the regulation of cell growth, so it has been hypothesized that GH therapy might promote the survival of pre-cancerous cells. It has been further postulated that the age-related decline in GH secretion may be a protective mechanism against the development of cancer and insulin resistance.
Although no known association exists, those with high GH levels do have increased risk of cancer. A recent meta-analysis that included 21 studies found no association between GH levels in the lower 3/4th of the normal range and any type of cancer. High levels of GH (levels in the highest quartile or top 1/4th of the normal range) were found to increase risk for prostate and premenopausal breast cancers, but no association was noted, even for those with GH levels in the highest quartile, for lung, colorectal or postmenopausal breast cancers.
Studies comparing groups in which GH therapy might be thought to increase cancer risk—cancer survivors, including childhood cancer survivors, and other children and adults treated with GH replacement— have shown no evidence of an increase in cancer risk.
Could GH therapy cause insulin resistance?
Chronic elevation of GH has been found to produce insulin resistance in humans, which suggests daily dosing with GH should be avoided. However, less frequent dosing can improve sensitivity to insulin.
In individuals with Adult Growth Hormone Deficiency, GH replacement therapy given 3 times weekly, in doses that produced GH levels in the mid-normal range for adults ranging in age from 25–35, was found to be as effective as daily dosing in improving cholesterol levels, cardiovascular health, muscle mass, fat loss, and bone mass.
It is well recognized that belly fat (visceral adiposity) is associatd with insulin resistance. A number of clinical trials have demonstrated that GH therapy improves insulin sensitivity and lessens high blood sugar levels in patients suffering from not only severe insulin resistance, but type 1 and type 2 diabetes.26 Thus, while it is possible that chronic, daily GH injections could promote insulin resistance, the use of GH releasing agents, or even injections of GH, several times a week should improve, not reduce, sensitivity to insulin.
Are oral GH releasing agents effective?
Oral GH-releasing agents are certainly more convenient and much less expensive, but are they effective? Yes, a number of studies have conclusively shown that oral supplementation with amino acids (primarily a combination of arginine and lysine) naturally stimulates GH release:27
- In young men given 1.5 gm of arginine plus 1.5 gm of lysine, blood levels of GH increased 2.7-fold one hour later.28
- Similarly, in young men given 1.2 gm of arginine plus 1.2 gm of lysine, blood levels of GH increased nearly 8-fold within 90 minutes. This rise in GH was reproducible, but only when the men took both arginine and lysine. When used singly, neither arginine (1.2 or 2.4 gm), nor lysine (1.2 gm) affected blood levels of GH.29
Restoring GH secretion
In another study involving adults aged 32 to 64 years, consumption of 2 gm of glutamine after a light breakfast caused blood levels of GH to increase 4.3-fold 90 minutes after consumption. What is especially interesting about this study is that the conditions chosen were those expected to result in very little GH secretion. Not only were the participants older (and thus more likely to secrete less GH), but they were given glutamine after eating (digestion typically lessens GH secretion). The researchers were able to reproduce these positive results. They hypothesized that glutamine indirectly caused GH secretion because our bodies convert glutamine into citrulline in the small intestine, and citrulline is then used in the kidney to synthesize arginine. Arginine synthesis is a well recognized stimulus for GH secretion.30
In research conducted in Italy, an oral arginine-lysine supplement given to elderly individuals and cancer patients has been shown to improve immune function by increasing the synthesis and/or release of thymulin (the hormone produced by the thymus gland, the master gland of the immune system) to levels normal for young, healthy subjects. The immune-boosting effect of the arginine-lysine combination was due to its ability to promote the release of GH, which then improved immune function.3132
Women may need higher doses of GH than men In some studies, the beneficial effects of GH therapy have been more pronounced in men than in women. It turns out that women on estrogen replacement therapy are somewhat resistant to GH and may require higher doses to raise GH levels to those producing beneficial effects in men.9
Summary
Over the last fifteen years, a large number of clinical trials have confirmed that Adult Growth Hormone Deficiency plays a key role in unhealthy aging and can be safely and effectively treated without increasing risk of cancer, insulin resistance, or diabetes.
Treatment that restores GH levels to a mid-normal range improves body composition, decreasing fat mass while increasing lean body mass and bone mineral density; promotes cardiovascular health by reducing LDL, total cholesterol and atherosclerosis; increases older individuals’ ability to exercise tolerance; protects brain health and improves cognition, dramatically improving overall quality of life.
Your doctor can help you develop a treatment program, tailored to your unique physiology and needs, which will restore your GH to health-promoting levels.
Does Growth Hormone Really Produce The Startling Results People Claim?
Yes . . . But With Some Caveats!
Growth hormone (GH) is a hormone secreted by the pituitary gland which is located in the center of the brain. A normal pituitary gland stores about 10 milligrams of growth hormone which is usually released in a series of pulses into the bloodstream throughout the day and night.
What does growth hormone do?
Growth hormone has many functions in your body, including promoting cell regeneration in the bones, vital organs and muscles, and repairing damaged tissue. It is responsible for enhancing muscle growth, burning fat, and maintaining the immune system, and even helps support healthy blood pressure and cholesterol levels, and reduces C-reactive protein.
Growth hormone production declines with age, so that by the time we reach 60 almost a third of us are no longer producing any GH. This has led some scientists to believe that growth hormone is a key factor in the speed with which we age … and a contributing factor to the loss of skin and muscle tone, an increase in fat tissue, and the tendency for our skin to wrinkle. In fact, GH levels start to decline as early as age 30—which may be one of the reasons that “crow’s feet” start to appear shortly thereafter.
Why should you consider taking a GH supplement?
The bottom line is we’re all getting older, and the older we get the less growth hormone we produce. Whether you’re 30 or 80 years old:
- if you want to maintain good immunity and cardiovascular health,
- if you want to build lean muscle mass while reducing stored fat,
- if you want to improve your overall health and appearance,
- it’s never too late to start taking a clinically proven growth hormone releaser.
Adult Growth Hormone Deficiency
Years ago it was thought that growth hormone deficiency was something you were born with, or resulted from head injuries later in life that affected the release of growth hormone from the pituitary gland. It was well known that GH levels declined dramatically after early adulthood, but even older adults had detectable levels of GH.
When growth hormone and the tests that measured blood levels of GH became widely available in 1985, scientists and doctors finally recognized that some adults develop a severe deficiency of GH far beyond what is seen in normal aging. This new endocrine condition was termed Adult Growth Hormone Deficiency (AGHD).1
Symptoms of Adult GH Deficiency include increased body fat, decreased muscle mass and impaired exercise capacity, depression, abnormal blood lipids, and cardiovascular problems.
You are probably thinking that the symptoms of AGHD sound a lot like normal aging, and in a sense you are right. GH levels drop dramatically as we age … but people with medically recognized AGHD experience an even more severe version of the GH drop all of us experience. The first studies using GH in people with AGHD resulted in dramatic effects, including: decreased body fat, increased muscle mass, improved exercise capacity, improved mental outlook, increased bone mass, and decreased cardiovascular risk factors.2 In other words, AGHD patients given growth hormone had many of their premature symptoms of aging reversed within a matter of months. Over the last decade, AGHD has become a widely recognized syndrome that is easily and safely treatable with GH replacement, with dramatic positive effects on health and quality of life.3
The # 1 caveat you need to be aware of. . .
It’s important to realize that all of the studies about GH supplementation that are commonly quoted are based on GH injections. The previous study2, which reverses premature aging in a matter of months, is a good example. Regardless of what the manufacturer or supplement company claims, you can not expect this rapid response with an oral GH releaser. Most marketing claims will quote the fast acting results of GH given as an injection. But oral GH releasers are generally not as strong and it may take longer for users to notice the desired benefit.
If you want a significant rise in your GH, and if you don’t mind the cost and the needle pokes, then please go find some GH from an open minded doctor or from an overseas pharmacy (see our web site, www.smart-publications.com). Otherwise, take what we consider the next best thing—a GH supplement that contains APG/Lysine.
GH and aging
It is well established that GH benefits children who are deficient in it, and adults who have abnormally low or undetectable GH levels. But the effect of GH on normal aging adults is still a subject of intense scientific scrutiny. This mostly stems from the fact that deficiencies in the GH/IGF system in animals often result in very long life spans compared to normal animals.4 Additionally, animals that have been genetically modified to produce extra amounts of GH have reduced life spans.5
This may seem surprising, in light of the popular belief that extra GH extends life span. However, we also know that individuals who don’t produce GH and are not given any GH replacement during their entire life have a dramatically shorter life span than normal people, living only about 40 years.6 So, there seems to be some optimum amount of GH needed to maximize life span and health. Too little or too much GH both adversely affect health and life span … while maintaining a proper amount of GH as we age can dramatically improve our number of healthy years.
GH and cardiovascular health
People with a GH deficiency generally have numerous cardiovascular risk factors and increased death from heart disease. On the other hand, GH replacement therapy has been shown to help lower blood pressure, increase HDL (good) cholesterol, and decrease C-reactive protein.7
While we are all familiar with the benefits of raising HDL cholesterol and decreasing blood pressure, the improvement in C-reactive protein is also very significant. C-reactive protein is a newly recognized cardiovascular risk factor related to inflammation in the circulatory system.8 In fact, even if you have normal blood pressure and lipid levels, your risk for heart disease increases dramatically if you have elevated C-reactive protein levels.
The combination of improving HDL cholesterol, blood pressure, and C-reactive protein has dramatic cardiovascular health benefits. The good news is that researchers have also measured the thickness of the carotid artery in the neck as a marker of atherosclerosis and found that GH replacement actually caused a reduction in the thickness of the carotid artery, which is evidence of an actual reversal of artery disease.8
Does GH help you grow taller?
As discussed in “The historical use of GH supplementation” (see side bar), the first use of synthetic growth hormone was as a replacement for growth hormone derived from human pituitary glands obtained from cadavers. With the new availability of synthesized growth hormone, it wasn’t long before scientific debate began about which children would benefit from growth hormone therapy. Before 1985, most children who were given growth hormone therapy had what is called idiopathic growth hormone deficiency. But only a small percentage of short children actually have this condition. In fact, the growth hormone system is very complex and involves hormones that release growth hormone itself, and receptors on cells that growth hormone activates.9 Additionally, one of the major effects on the body of growth hormone is to increase levels of another hormone complex named Insulin-Like Growth Factors (IGFs).10 Many of the effects of GH are mediated by the IGFs released by GH.
So as you can see, the GH/IGF hormone system is quite complicated, and a failure to grow normally can involve defects in one or more parts of this system. Because of this, extra growth hormone will not always result in increased growth. Despite these pitfalls, many short children with normal GH functioning continue to be treated with growth hormone in an attempt to increase their adult height.
Growth Hormone can have two kinds of effects:
Direct effects are the result of growth hormone binding its receptor on target cells. Fat cells (adipocytes), for example, have growth hormone receptors, and growth hormone stimulates them to break down triglyceride and supress their ability to take up and accumulate circulating lipids.
Indirect effects are mediated primarily by an insulin-like growth factor-1 (IGF-1), a hormone that is secreted from the liver and other tissues in response to growth hormone. A majority of the cell health and maintenance effects of growth hormone is actually due to IGF-1 acting on its target cells.
How is Growth Hormone released?
Eating a high protein diet, avoiding stress, engaging in aerobic exercise, fasting, and getting adequate sleep all help stimulate the release of growth hormone. Some amino acids—which we’ll talk about in a minute—also stimulate the release of growth hormone.
Nutritional GH releasers
Nutritional supplements that are used to stimulate GH release in humans became popular in the early 1980s. These early supplements were boldly advertised as “the fountain of youth” which slowed down—if not reversed—the aging process. Even with the advent of synthetic GH in 1985, the idea of releasing GH using nutritional supplements is still attractive, because pharmaceutical GH is very expensive and must be taken by injection, very few people choose to take advantage of it. (GH itself is not effective when taken orally.)
Now here’s where we want to differentiate the popular GH supplements that claim to reverse aging from the GH supplements that have been clinically shown to stimulate the release of GH.
Amino acids that stimulate release of GH
Arginine is the most effective amino acid found to induce GH release. But the GH release from oral arginine is extremely variable, and most people end up with gastrointestinal complaints because of the large dose that is required. In fact, most of the nutritional compounds that release GH only work reliably when they are injected in large doses. These include arginine, lysine, ornithine, tyrosine, and tryptophan.15 To complicate matters, most of the products that are marketed as oral “growth hormone releasers” contain insufficient quantities of the nutrients needed to release GH, so consumers end up wasting their money in the hopes of finding an anti-aging elixir.
The combination of arginine pyroglutamate and lysine makes a very effective GH releaser.
A study published in 1981 used a special form of arginine (arginine pyroglutamate), in combination with lysine (another amino acid), to induce a significant GH release when taken orally in relatively small amounts. Fifteen healthy male subjects, aged 15 to 20 years old, were given 1,200 mg of arginine pyroglutamate combined with 1,200 mg of L-lysine hydrochloride. The results of this specific combination were spectacular, causing a large GH release that was sustained for several hours.16
This breakthrough paper has often been misquoted and discounted, as several other researchers failed to replicate the results.17181920
Unfortunately, these subsequent researchers used arginine hydrochloride and NOT arginine pyroglutamate, which was used with great results in the original study in 1981. This is disappointing, as it had been known since 1977 that the specific chelate of arginine and pyroglutamic acid (arginine pyroglutamate) had effects on the body that are not shared by arginine or pyroglutamic acid when taken individually or together.21
No nutritional supplement has shown equivalent results to the combination of arginine pyroglutamate and lysine for releasing significant amounts of biologically active GH when taken orally in small doses. Interestingly, when both arginine pyroglutamate and lysine are taken individually, even in large doses, they are not effective.16 It is the specific combination of arginine pyroglutamate and lysine, taken in the proper ratio, which makes a very effective GH releaser.
Because of these promising initial results, the combination of APG/Lysine was developed as a pharmaceutical in Italy. Further research showed that it could enhance immune function dramatically both in healthy elderly people, and in cancer patients.222324 Notably, this combination of APG/Lysine was shown to improve immune function by increasing thymus hormone levels. This is an effect you would expect from growth hormone release, as growth hormone is known to enhance functioning of the thymus—the master gland of immunity.252627
People get better results by using GH less often than every day, or just two or three times a week.
If you decide to take a GH releaser
Too much of a good thing can be as bad for you as not enough, and this holds true for GH. Like most hormones, it is the proper dose and timing that gives the most beneficial results. In the case of GH, research has shown that there are significant differences in the effects of GH depending on how often you take it and/or how often it is released.
It’s best NOT to take a GH supplement every day. Here’s why:
A decade ago, it was discovered that many children who were given GH replacement to enhance their growth suffered from a GH tolerance and withdrawal syndrome that resembles the tolerance one develops when he or she takes hormones like cortisone and testosterone.28 Specifically, when children stop getting GH supplementation, they stop growing, which becomes even more of an issue than the short stature they dealt with before they started taking GH. Initially, scientists thought this was a result of the GH injections suppressing the body’s normal production of GH.
Similar hormone suppression is often seen with cortisone and testosterone therapy, where it often takes months for the body to begin normal production of its own hormones after stopping the cortisone or testosterone. Surprisingly, this was not found to be true for GH. After stopping GH injections, the body rapidly resumes its normal production of GH. Yet, the tissue’s response to the normal GH levels was found to be markedly diminished.28 Scientists now believe that this is because the body becomes tolerant to GH from the daily supraphysiological levels of GH caused by the GH injections.
Obviously, this is a huge drawback to using GH replacement therapy. Because as soon as we stopped taking the GH supplement, we would be in even worse shape because we would be resistant to our own GH. Luckily, research has shown that the key to preventing these problems is to not use GH on a daily basis.
In research on short children receiving GH, it was shown that by using GH every other day rather than every day the tolerance and dependence syndrome could be completely prevented.29 It seems that allowing the body a one day break in between GH use allows the tissues to remain sensitive to both its own GH and the GH supplementation. Interestingly, the same is known to be true for cortisone which is often given in an “every other day regimen” to prevent tolerance and dependence. What is troubling, though, is that many short, but otherwise normal children are given GH replacement therapy in the hope that they will grow taller, and many of them are receiving GH every day which in the long-term is likely counterproductive.
In research on adults, using GH two or three times a week has proven to be as effective as using GH every day.30 This makes the rationale of using GH daily questionable—because it is much more likely to not give optimal long-term results. Typically, the companies that market pharmaceutical GH and GH releasing supplements don’t inform doctors or consumers of this fact because obviously they would sell much less product. This is in spite of the research showing that people will get better and safer results by using GH less often than every day.31
Uridine and Growth Hormone?
Uridine is a natural nucleic acid that plays a major role in neurotransmitter function, as well as helping to build membrane phospholipids and promoting neurite growth from brain cells.35 Research has shown that uridine (especially when combined with choline) can support the production and function of both acetylcholine and dopamine, two major neurotransmitters involved in growth hormone release. The decreased activity of these neurotransmitters is believed to be responsible for the age-related decline in natural growth hormone release. It is thought that uridine and choline support these neurotransmitters through the enhanced maintenance of brain cell membranes, as well as direct stimulation of neurotransmitter release. By helping to promote the optimum functioning of brain cells, uridine primes our brain for enhanced growth hormone release.
Is GH supplementation safe?
Although when used according to directions, GH has been shown to be very safe. It should not be used by people with diabetes or cancer unless they are under the care of a physician. For best results, please follow the usage suggestions below.
There are no contraindications with other drugs or supplements. And if you decide to stop taking growth hormone releaser after you start, proper dosing will assure you will not experience any negative effects. Your pituitary gland will most likely, however, start producing the amount of growth hormone it did before you took it … and if you are a senior, that means it will produce very little.
How much should you take?
The good news is that you don’t need to take a GH releaser every day for great results. In research on adults, it has been shown that people will get better results by using GH less often than every day,31 or just two or three times a week.32 However, a minimum of 2 grams of the APG/ Lysine combination should be taken at one time to stimulate growth hormone.
Conclusion
The alternative to GH injections
Convenient and much more affordable than $10,000 per year GH injections—not to mention less painful—a GH releaser is a safe way for athletes to improve their peak performance, as well as for anyone wanting to help prevent cardiovascular disease, improve muscular strength and immunity, and overall health and appearance. The important thing is to make sure you buy a high quality GH releaser with the clinically proven combination of arginine pyroglutamate and lysine.
