The Durk Pearson & Sandy Shaw®
Life Extension News™
|Volume 10 No. 3 ||January 2008 |
Table of Contents This Issue
Science is a long history of learning how not to fool ourselves.
— Richard P. Feynman
But Scientists, who ought to know,
Assure us that they must be so. . . .
Oh! let us never, never doubt
What nobody is sure about!
— Hilaire Belloc
From “The Microbe” (1912)
D&S comment: You can always try to get around the problem by calling everybody who disagrees with you a “skeptic” or “denier.” Oh! let us never, never doubt . . .
Before I came here, I was confused about this subject.
Having listened to your lecture, I am still confused.
But on a higher level.
— Enrico Fermi
Practical Do-It-Yourself Information—
Durk & Sandy’s Anti-Aging Regimen
Glutathione: New Insights into Its Key Role in
Regulation of Oxidative Stress and
If there were an anti-aging pyramid (like the food pyramid) for the elements of an anti-aging regimen, down at the base would be the antioxidant glutathione. As we discuss below (in the “Increasing Glutathione Levels” section of this article), supplementation with the amino acid cysteine is our own approach to increasing glutathione levels.
The importance of glutathione—a tripeptide comprised of glutamine, cysteine, and glycine (L-gamma-glutamyl-cysteinyl-glycine)—the major cell antioxidant, is well known, as are many of the effects (such as immune system depression) of cellular glutathione depletion. A new paper
1 provides evidence of the decline in glutathione levels with aging (and the resulting increase in oxidative stress) as a major causative factor in the
increased inflammatory activity with aging. (See below under “Decline in Glutathione Levels and Increased Inflammation with Aging.”)
Glutathione and Atherosclerosis
A recent paper2 reports that in the atherosclerosis-prone aortic arch of male ApoE-deficient mice, a commonly used model of atherosclerosis, glutathione depletion starts very early (10 weeks), as compared to age-matched wild-type controls. The glutathione depletion precedes the lipid peroxidation and detectable atherosclerotic lesions by several months. Moreover, the reduced synthesis of glutathione was associated with increased oxidative stress and reduced transcription and activity of the rate-limiting enzyme for glutathione synthesis, gamma-glutamylcysteine ligase, together with the glutathione-dependent antioxidant enzyme glutathione peroxidase. The authors conclude, “We suggest that glutathione deficiency is central to the failure of the intracellular antioxidant defenses and is causally implicated in the pathogenesis of atherosclerosis.”
Glutathione and Immune Function
It is well known that many bacterial and viral infections (e.g., herpes simplex, HIV, influenza) are preceded by sharp decreases in intracellular glutathione levels and that this results in oxidative stress and immune depression.3 Increasing glutathione levels (which, in this study, was done with supplemental glutathione) was shown to inhibit influenza infections in cultured Madin-Darby canine kidney cells or human small airway epithelial cells.3 The authors suggest that oxidative stress in vivo may enhance susceptibility to infection.
Increasing Glutathione Levels—Cysteine
Of the three amino acids comprising glutathione, cysteine is in the shortest supply; thus glutathione synthesis is limited by cysteine availability.4 A very recent paper4 reported on the effects of various amino acids on cellular glutathione levels. Cysteine was found to enhance glutathione (GSH) biosynthesis enzyme activity and increase cellular GSH levels. In fact, the researchers noted, “. . . supplementation with Cys [cysteine] would be areasonable strategy for inducing de novo GSH synthesis.” We get our cysteine from our Root Food II™, a supplement we originally designed to support hair growth, which is highly dependent upon cysteine supplies. Each capsule contains 175 mg of cysteine (for comparison, the best food source is eggs, which contain an average of about 250 mg of cysteine per egg). Sandy takes 2 capsules four times a day (about the amount found in 5.6 eggs), while Durk takes 4 capsules four times a day (the equivalent of about 11 eggs, but without all the fat and cholesterol). Caution: To avoid the possibility of formation of cystine stones by oxidation of cysteine, cysteine should be taken with vitamin C in a ratio of 2:1 vitamin C to cysteine (as it is in our Root Food II).
Figure 2. Effects of amino acids on GSH content in H2O2-treated or nontreated Caco-2 cells. (A) The cells treated with amino acids (0–5 mM) for 2 h at 37 °C and then incubated with H2O2 (1 mM) for 6 h. (B) The cells treated with amino acids (0–5 mM) for 2 h at 37 °C. Control refers to cell cultures that were not treated with amino acids and not subjected to oxidative stress treatment by H2O2. #P < 0.05 compared with control cells. *P < 0.05 and **P < 0.01 compared with cells treated with H2O2 alone. Data are expressed as mean ± standard deviation of three experiments performed in triplicate.
In this in vitro cell-culture study,4 researchers evaluated the effects of amino acids at various concentrations (0–5 mM) against hydrogen peroxide-induced (at 50 mM H2O2) oxidative stress using Caco-2 cells (a widely studied human intestinal epithelial cell model). “As shown in Figure 2A, cells treated with H2O2 [hydrogen peroxide] significantly decreased GSH contents compared with the control cells. Pretreatment with Cys [cysteine], Ile [isoleucine], Trp [tryptophan], His [histidine] and Ala [alanine] significantly increased intracellular GSH levels. In particular, we observed that the GSH levels of Cys- and Trp-pretreated cells were clearly higher than that of the control cells. On the other hand, when the cells were treated with amino acids for 2 hours without the following addition of H2O2, a marked increase in GSH levels was observed in the treatment with only Cys (Figure 2B).” Cysteine was found to increase GSH levels by elevating the activity of gamma-GCS, the enzyme that synthesizes GSH.
We have two review papers5,6 by a scientist who proposes that a deficit in cysteine is a possible major causative factor of many aspects of aging and that “everybody is likely to have a cysteine deficiency sooner or later.” As he explains, clinical studies have shown that cysteine (as precursor to glutathione) decreased insulin responsiveness in the fasted state (you do not want insulin signaling unless in response to appropriate food intake), improved skeletal-muscle functions, decreased the body-fat/lean-mass ratio, decreased plasma levels of the inflammatory cytokine tumor necrosis factor-alpha, improved immune function, and increased plasma albumin levels. Moreover, “. . . the thiol/disulfide redox status shifts to more oxidative conditions in old age . . . As all these parameters degenerate with age, these findings suggest . . . that loss of youth, health, and quality of life may be partly explained by a deficit in cysteine and . . . that the dietary consumption of cysteine is generally suboptimal . . .”
As dysfunction of insulin signaling is an important aspect of aging, the results of another paper7 are of interest: here, the researchers found that dietary cysteine alleviates sucrose-induced oxidative stress and insulin resistance in rats fed a high-sucrose diet. They increased dietary cysteine intake with a supplement of cysteine-rich protein (an alpha-lactalbumin-rich whey concentrate) or N-acetylcysteine (a cysteine donor). The high-sucrose-diet-induced impairment in muscle insulin signaling (insulin resistance) was partially prevented by either the alpha-lactalbumin-rich whey supplement or the low-dose N-acetylcysteine supplement (10 g per kg of diet), while the high-dose N-acetylcysteine supplement (20 g per kg of diet) totally prevented the impairment.
Why Not Just Take Glutathione Supplements?
We don’t take glutathione to increase glutathione levels for the simple reason that it is a very costly way to deliver the amino acid cysteine to cells. To get cysteine from glutathione, the glutathione is first disassembled into its constitutive amino acids, and then the cell imports cysteine to manufacture glutathione. It is much less expensive to take cysteine itself rather than glutathione.
Why We Choose Cysteine Rather Than N-Acetylcysteine
N-acetylcysteine (NAC) is a potent nonphysiological (i.e., it is not found naturally in the body) precursor of GSH that increases GSH levels by donating cysteine. The problem with NAC is that, as reported in many papers, it is such a powerful antioxidant that it can inhibit reactive oxygen species (ROS) signaling that is a necessary part of many normal chemical pathways. Hence, we have been very reluctant to use it, at least as an everyday supplement. For example, one recent paper8 reported that NAC interfered with the ROS (reactive oxygen species) signaling pathway by which erythropoietin stimulates the creation of red blood cells. This was in a study of erythropoietin-induced differentiation of erythroid progenitors derived from mouse fetal liver. Treatment with another potent antioxidant, pyrrolidine dithiocarbamate (PDTC), also caused the attenuation of expression of TER119 (an erythroid-specific antigen). The authors conclude, “The results suggest reactive oxygen species are involved in Epo [erythropoietin]-mediated erythroid differentiation.” In fact, this may have happened to one of us (Sandy), who was taking N-acetylcysteine (but no longer does). Upon having her regular lab tests during her NAC supplementation period, she discovered that her red blood cell levels had declined to half of their previous amount.
Decline in Glutathione Levels and Increased Inflammation with Aging
A new paper1 reports on a potentially important link between declining glutathione levels and increased inflammation with aging. The authors discovered that glutathione is a suppressor of the activity of neutral sphingomyelinase-2 (NSMase-2), a plasma membrane enzyme whose increased activity, they found, is associated with the age-associated hyperresponsiveness to the proinflammatory cytokine IL-1beta. The 60–70% decrease in glutathione levels with aging in rat hepatocyte (liver cells) content resulted in increased NSMase-2 activity, which resulted in the age-associated increase in hyperresponsiveness to the proinflammatory cytokine IL-1beta. The researchers found that increasing GSH levels in the old rats to young rat levels with N-acetylcysteine inhibited the NSMase activity and restored normal response to IL-1beta. As we discuss below, GSH levels can be increased with cysteine supplements, which (as we will explain) we consider safer than N-acetylcysteine for use as a daily supplement.
NSMase-2 modulates cellular levels of ceramide, a substance that is an important regulator of cell growth and differentiation, apoptosis (programmed cell death), and inflammation. Ceramide accumulation, as well as increased sphingomyelinase activity, has been found in livers and brains of aged rodents.1 Interestingly, calorie-restricted rats had a higher GSH content in their hepatocytes and also had lower NSMase activity. In addition, calorie restriction prevented the inflammatory hyperresponsiveness seen in noncalorically restricted aged rats.
As the authors conclude, “. . . increased NSMase activity during aging may be causatively linked to the increased state of oxidative stress. Indications to that effect come from the fact that reduced glutathione [GSH] is a potent and reversible inhibitor of NSMase activity. Depletion of GSH in response to TNF-alpha [a proinflammatory cytokine] stimulation or hypoxia activates NSMase and increases ceramide content, whereas increases in cellular GSH levels prevent the hypoxia-induced generation of ceramide and apoptosis [programmed cell death].”
This paper, therefore, importantly identifies glutathione as a suppressor of increased NSMase-2-induced proinflammatory activity with aging and identifies NSMase-2 as “a link between increased oxidative stress and the onset of inflammation during aging.”
Other Ways to Increase Glutathione Levels—Docosahexaenoic Acid
A recent paper9 reports that docosahexaenoic acid (DHA) enhances the antioxidant response of human fibroblasts by upregulating gamma-GCL (gamma-cysteinyl ligase), the limiting enzyme in the synthesis of glutathione, and upregulating the enzyme glutathione reductase (which reduces GSSG, the oxidized form of GSH, back to GSH). The authors of this human-fibroblast cell-culture study reported finding that a 30 µmol/l concentration of DHA, considered a physiological level, induced a significant difference from controls for all biomarkers, including GSH, gamma-GCL, GR (glutathione reductase), and GST (glutathione S-transferase) activities. Our Omega-3 HeartFelt™ contains 1000 mg of a high-quality marine lipid concentrate (fish oils) per capsule that includes 120 mg of DHA as well as 180 mg of EPA (eicosapentaenoic acid). We each take two capsules with meals and another two capsules at bedtime.
Increasing Glutathione Levels—Certain Flavonoids
Another paper10 reported that onion extract, quercetin, kaempferol, and apigenin increased the activity of a transfected reporter gene for a GCS (gamma-glutamylcysteine synthetase) promoter subunit in a COS-1 cell culture study. They found that, as an earlier study, quercetin elevated the GSH level and the expression of both the regulatory and the catalytic subunit of GCS. In addition, they found that quercetin potently transactivates the GCSh promoter. You get quercetin if you take our Personal Radical Shield™. Each 3-capsule serving contains 32.5 mg, while the recommended daily dose (12 capsules total: 3 capsules taken with each meal and 3 capsules at bedtime) provides 130 mg of quercetin.
- Rutkute et al. Regulation of neutral sphingomyelinase-2 by GSH: a new insight to the role of oxidative stress in aging-associated inflammation. J Lipid Res 48:2443-52 (2007).
- Biswas et al. Depressed glutathione synthesis precedes oxidative stress and atherogenesis in Apo-E-/- mice. Biochem Biophys Res Commun 338:1368-73 (2005).
- Cai et al. Inhibition of influenza infection by glutathione. Free Rad Biol Med 34(7):928-36 (2003).
- Katayama and Mine. Antioxidative activity of amino acids on tissue oxidative stress in human intestinal epithelial cell model. J Agric Food Chem 55:8458-64 (2007).
- Wulf Droge. Oxidative stress and ageing: is ageing a cysteine deficiency syndrome? Phil Trans Roy Soc Lond B Biol Sci 360:2355-72 (2005).
- Wulf Droge. Oxidative aging and insulin receptor signaling. J Gerontol: Biol Sci 60A(11):1378-85 (2005).
- Blouet et al. Dietary cysteine alleviates sucrose-induced oxidative stress and insulin resistance. Free Rad Biol Med 42:1089-97 (2007).
- Nagata et al. Antioxidant N-acetyl-L-cysteine inhibits erythropoietin-induced differentiation of erythroid progenitors derived from mouse fetal liver. Cell Biol Int 31:252-6 (2007).
- Arab et al. Docosahexaenoic acid enhances the antioxidant response of human fibroblasts by upregulating gamma-glutamyl-cysteinyl ligase and glutathione reductase. Brit J Nutr 95:18-26 (2006).
- Myhrstad et al. Flavonoids increase the intracellular glutathione level by transactivation of the gamma-glutamylcysteine synthetase catalytical subunit promoter. Free Rad Biol Med 32(5):386-93 (2002).
Importance of PGC-1alpha in Maintaining Skeletal Muscle Function and Integrity
Many of the discoveries about mechanisms of aging cannot be utilized at present, either because the technology for doing so is not developed or because not enough is known about the biochemical pathways involved to be able to safely modify them. For example, a great deal is now known about how to increase the lifespan of fruit flies, nematodes, and rodents by adding or removing or altering the activity of various genes. None of this is of much use to humans trying to increase their lifespan at present. It is the information that we can actually use that we prefer to emphasize in this newsletter. As we have reported earlier, evidence exists that supports the possibility of increasing PGC-1alpha expression through the inhibition of the fat-synthesizing hormone fatty acid synthase by certain types of green and Pu-erh teas (available in our ShapeShifter Teas™).
We have extensively discussed, in an article in the April 2007 issue of Life Enhancement magazine (pp. 4–6), how inhibiting fatty acid synthase (FAS), the enzyme that carries out the final step in the synthesis of stored body fat, by consuming particular types of tea, results in a significant increase in the expression of PGC-1alpha (the transcriptional coactivator peroxisome proliferator-activated receptor gamma coactivator-1alpha). Higher expression of PGC-1alpha, as we explained, results in mitochondrial biogenesis and a higher number of type IIa and type I oxidative, slow-twitch, high-endurance muscle fibers. PGC-1alpha also blunts skeletal muscle atrophy that normally occurs in disuse. This new paper1 provides powerful additional support for these functions of PGC-1alpha.
In the new paper, researchers created a mouse that had its PGC-1alpha knocked out, but only in its skeletal muscle, so that the effects could be evaluated for skeletal muscle rather than being confounded by the very many effects of PGC-1alpha in other tissues. [Mice with whole-body PGC-1alpha knockout were reported to be hyperactive, had circadian abnormalities, and had constitutively (constantly on) gluconeogenic (glucose-creating) and heme-biosynthetic genes in the liver, even in the fed state.]
The PGC-1alpha-skeletal-muscle knockout mice were found to have moderate reduction in the number of oxidative type I and type IIa muscle fibers and reduced exercise capacity. Their skeletal muscle had a low level of damaged and regenerating muscle fibers, indicating low maintenance capacity. These deficiencies were dramatically increased by physical exercise and accompanied by elevated markers of systemic inflammation. “Our data thus highlight the importance of PGC-1alpha in maintaining proper function and integrity of skeletal muscle.”
As the authors explain, “Different factors could contribute to the muscle pathology in MKOs [muscle-specific PGC-1alpha knockout animals]. First, these animals have a reduction in mitochondrial gene expression. Mitochondrial dysfunction is associated with muscle damage in Duchenne muscular dystrophy. Second, reactive oxygen species detoxification is crucially regulated by PGC-1alpha, and the levels of a number of reactive oxygen species detoxification genes are reduced in MKOs, including superoxide dismutase 1 [CuZn superoxide dismutase], superoxide dismutase 2 [Mn superoxide dismutase], adenine nucleotide transporter, and glutathione peroxidase 1. . . . Finally, systemic inflammation, acute and chronic, is a strong promoter of skeletal muscle wasting.”
- Handschin et al. Skeletal muscle fiber-type switching, exercise intolerance, and myopathy in PGC-1alpha-specific knock-out animals. J Biol Chem 282(41):30014-21 (2007).
FDA’s Body Count Mounts as the Agency Increases Its Suppression of New Medical Therapies
Where are all the new treatments for old diseases that continue to kill millions? It’s hard to believe, but the FDA’s rules and regulations for drug development are getting worse, more chaotic, and increasingly more expensive. The Oct. 1, 2007 Genetic Engineering & Biotechnology News provided up-to-date FDA information in an editorial by Henry I. Miller, M.D. (fellow at the Hoover Institution and director from 1989 to 1993 of the FDA’s Office of Biotechnology; e-mail: email@example.com).
According to the editorial, the latest data (2006) from the Tufts Center for the Study of Drug Development reports that on average it takes more than eight years and costs $1.2 billion to develop a biopharmaceutical. (That includes stem cell therapies; one has to wonder whether the politicians and government-funded scientists clamoring to get billions of dollars of taxpayer money to spend on stem cell research have considered—or even care—whether the public will actually get access to treatments based on this research.) Of the $1.2 billion development costs, about $615 million are capitalized out-of-pocket preclinical costs, while clinical testing accounts for $626 million.
According to Dr. Miller, regulatory excesses account for the huge costs and lengthy development times. He notes that, despite highly publicized recent drug safety events, including inadequate warnings on antidepressant drugs and the discovery of previously unknown adverse reactions (increased risk of heart attack) from the use of selective COX-2 inhibitor pain drugs, the common perception that FDA oversight had become lax is incorrect. “. . . drug regulation in the U.S. in recent years has actually become progressively more risk adverse, as the FDA has steadily made it more difficult to initiate and perform clinical testing of new drugs.”
As a result of drug-safety criticisms from Congress, the media, and others, the FDA has been requiring ever larger number of patients in clinical trials, and demands for postmarketing clinical trials have “proliferated wildly.” Dr. Miller also says that “[FDA’s] risk management plans for newly approved drugs have been inconsistently applied, punitive, and often more appropriate for weapons-grade plutonium than prescription drugs.” [Emphasis added]
The following example given in Dr. Miller’s editorial for what would appear to be a minimal-risk drug indication illustrates the FDA problem. In this instance, Somaxon Pharmaceuticals is testing doxepin, an already approved drug (approved for treatment of depression since 1969), for a new indication (where it would be used in very low doses as a sleeping pill). “. . . FDA initially assured the company that it could begin clinical trials without first doing animal tests because of doxepin’s long history of use in people and because Somaxon was using a dose [in the new indication] less than one-tenth of that used to treat depression.” However, in May 2006, after the company had already completed several clinical trials, the regulators suddenly demanded a full battery of testing in animals.
This magnifies the importance of what we call the parallel medical system—therapies developed from natural products (which can be sold without FDA approval) as a result of rapidly expanding knowledge of mechanisms of action of these natural substances. The FDA fly in the ointment here is that this will work well only for those who are knowledgeable about these substances, which hopefully includes those of you reading this newsletter. The market will stay small with FDA-restricted information, as it is very difficult to sell natural products without being able to tell people what they do.
The FDA has also turned down most applications for scientifically well-supported (though not conclusive) qualified health claims, recently disallowing, for example, the health claims that green tea may reduce the risk of cardiovascular disease and that consumption of tomatoes may reduce the risk of prostate cancer.
A Possible Mechanism Contributing to Loss of Estrogen Cardioprotection in Late Postmenopausal Women
Recent clinical trials have indicated that estrogen replacement appears to be protective against cardiovascular disease if taken by postmenopausal women at or shortly after the start of menopause, but that estrogen replacement fails to protect (or even worsens) cardiovascular status for postmenopausal women who begin its use starting several years after menopause. Not surprisingly, there has been much concern, speculation, and data analysis concerning the reasons for this.
One possible mechanism is reported in a new paper.1 Estrogen mediates its hormonal cardioprotective effects via estrogen receptors in vascular cells. The authors show here that “. . . 27-hydroxycholesterol (27HC), an abundant cholesterol metabolite that is elevated with hypercholesterolemia and found in atherosclerotic lesions, is a competitive antagonist of estrogen receptor action in the vasculature.” They found that “27HC inhibited both the transcription-mediated and the non-transcription-mediated production of nitric oxide by vascular cells, resulting in reduced estrogen-induced vasorelaxation of rat aorta. Furthermore, increasing 27HC levels in mice by diet-induced hypercholesterolemia . . . decreased estrogen-dependent expression of vascular nitric oxide synthase and repressed carotid artery reendothelialization [restoration of damaged endothelium].” Thus, they propose, increases in 27HC (the level of which correlates well with cholesterol) “suggest a mechanism whereby decreased circulating levels of estrogens in the presence of hypercholesterolemia, atherosclerosis, or both may lead to increased risk of heart disease, a condition that may be particularly relevant in postmenopausal women.”
As the authors explain, oxysterols such as 27HC are metabolites of cholesterol produced in peripheral tissues to help in eliminating cholesterol. The accumulation by macrophages of excess oxysterols and cholesterol is a diagnostic feature of human developing atherosclerotic lesions.
Premenopausal women have a much lower risk of cardiovascular disease as compared to postmenopausal women. As described in this paper, the development of atherosclerosis after menopause for several years may lead to conditions that greatly reduce the cardioprotective effect of supplemental estrogen. “Whereas most US women have only fatty streaks and minimal atherosclerotic plaques in their coronary arteries at age 35, there is progression of lesion formation between ages 45 and 55, and more complex lesions are present by age 65.”
- Umetani et al. 27-Hydroxycholesterol is an endogenous SERM that inhibits the cardiovascular effects of estrogen. Nature Med 13(10):1185-92 (2007).
If You Find Yourself in a Hole, Stop Digging — Will Rogers
Or Why There Can Never Be “Enough” Money in the NIH Budget
“The doubling of the NIH budget between 1998 and 2003 was intended to increase success rates in obtaining NIH grants, which have been declining since the mid-1970’s. Yet, the budget rise did not have its intended effect, and by 2003, grant application success rates were slightly worse than before. What happened? The budgetary increases were swamped by an equally large escalation in the number of applicants and applications. In 1998, there were about 19,000 scientists applying for competitive awards; in 2006 there were approximately 34,000.”
D&S comment: Surprise! Surprise! When the government made more “free” money available, more people chased after the extra money. This is an incontrovertible law of economic behavior called the rule of supply and demand. There can never be enough “free” government grant money to satisfy all demand for “free” money.
“There are insufficient ‘feedback loops’ linking the production of biomedical researchers to the availability of resources to support them.”
D&S comment: Correct! In a free and private system, the feedback loop linking the numbers of researchers and the availability of resources is the willingness of people with money to invest in more research, either for profits or for other forms of payback (including nonmonetary ones). In a government system, that feedback loop is destroyed, as taxpayers have no real control over what the government does with their tax money. The only limit on government spending is how much they can gouge out of taxpayers, and when they have exhausted that source (i.e., taxes have reached the point where tax increases result in reduced revenues to government), they print more dollars, increasing their capacity to spend by depreciating the value of your money. When you hear the constant complaints and whining from certain journals, such as Science, about how there isn’t “enough” money in their hands, remember that there can never be enough money. These government money-chasers think what they are doing is so much more important than what you are doing that you shouldn’t have the opportunity to spend your money on what you want, rather than what they want.
The quotes above are from Brian C. Martinson, “Universities and the money fix,” Nature Sept. 2007;449:141-2. The interpretations are those of D&S, not those of Mr. Martinson.
Politics is a pendulum whose swings between anarchy and tyranny are fueled by perennially rejuvenated illusions.
— Albert Einstein
© 2008 by Durk Pearson & Sandy Shaw