Fall Skin Care Sale

Life Extension Magazine

LE Magazine October 2000
image



Page 1 of 2

B12

Nutritional and botanical interventions to assist with the adaptation to stress

Prolonged stress, whether a result of mental/emotional upset or due to physical factors such as malnutrition, surgery, chemical exposure, excessive exercise, sleep deprivation, or a host of other environmental causes, results in predictable systemic effects. The systemic effects of stress include increased levels of stress hormones such as cortisol, a decline in certain aspects of immune system function such as natural killer cell cytotoxicity or secretory-IgA levels, and a disruption of gastrointestinal microflora balance. These systemic changes might be a substantial contributor to many of the stress-associated declines in health. Based on human and animal research, it appears a variety of nutritional and botanical substances—such as adaptogenic herbs, specific vitamins including ascorbic acid, vitamins B1 and B6, the coenzyme forms of vitamin B5 (pantethine) and B12 (methylcobalamin), the amino acid tyrosine, and other nutrients such as lipoic acid, phosphatidylserine, and plant sterol/sterolin combinations—may allow individuals to sustain an adaptive response and minimize some of the systemic effects of stress.

Altern Med Rev 1999 Aug;4(4):249-65

Methylcobalamin decreases mRNA levels of androgen-induced growth factor in androgen-dependent Shionogi carcinoma 115 cells

Methylcobalamin (MeCbl) is an important enzyme cofactor required for methionine synthase activity. It also inhibits, in a dose-dependent manner, the proliferation of an androgen-dependent cell line, SC-3, derived from an androgen-dependent mouse mammary tumor (Shionogi carcinoma 115). In SC-3 cells, androgen induces the production of androgen-induced growth factor (AIGF), an autocrine growth factor increasing the proliferation of SC-3 cells. MeCbl treatment suppressed the androgen-induced, AIGF-mediated growth of SC-3 cells, as well as the androgen-induced increase of AIGF mRNA. In SC-3 cells, androgen receptors linked with androgen form complexes that tightly bind DNA and act as transcription factors in the nucleus to regulate the expression of specific genes such as AIGF. The number and dissociation constants of androgen receptors in control and MeCbl-treated SC-3 cells were the same. Similarly, the extent of binding of normal androgen receptors in nuclei from control and MeCbl-treated cells was virtually identical. The androgen receptors from control and MeCbl-treated cells showed similar capacities for conversion to a form that tightly binds to DNA on heat activation. These results suggest that the reduction of AIGF mRNA, subsequent to the nuclear binding of androgen receptors, may be a partial cause of the growth-inhibitory activity of MeCbl in SC-3 cells.

Nutr Cancer 1999;35(2):195-201

Can reduced folic acid and vitamin B12 levels cause deficient DNA methylation producing mutations which initiate atherosclerosis?

Atherosclerosis of the vascular system has classically been attributed to elevated serum cholesterol concentrations. Recently, it has been found that reduced serum levels of folic acid, vitamin B12, and vitamin B6 are related to the etiology of atherosclerosis and coronary heart disease. These deficiencies lead to inadequate production of S-adenosyl-methionine, creating a condition of hypomethylation. It is hypothesized that this causes hypomethylation of the DNA in cells in the arterial intima resulting in mutation and proliferation of smooth-muscle cells which lead to the formation of atheroma. It is further hypothesized that such action can be reversed by supraphysiological doses of these three vitamins to reduce or remove existing atheroma. It is recommended that all patients suffering from atherosclerosis and having deficiencies of any of these three vitamins and/or an elevation of serum homocysteine receive supplementation to prevent worsening of their condition.

Med Hypotheses 1999 Nov;53(5):421-4

What level of plasma homocyst(e)ine should be treated? Effects of vitamin therapy on progression of carotid atherosclerosis in patients with homocyst(e)ine levels above and below 14 micromol/L

High levels of plasma homocyst(e)ine (H[e]) are associated with increased vascular risk. Treatment is being contemplated, but the level at which patients should be treated is not known. We compared the response of carotid plaque to vitamin therapy in patients with H(e) above and below 14 micromol/L, a level commonly regarded as high enough to warrant treatment. Two-dimensional B-mode ultrasound measurement of carotid plaque was used to assess the response to vitamin therapy with folic acid 2.5 mg, pyridoxine 25 mg, and cyanocobalamin 250 microg daily, in 101 patients with vascular disease (51 with initial plasma levels above, and 50 below 14 micromol/L). Among patients with plasma H(e) >14 micromol/L, the rate of progression of plaque area was 0.21 +/- 0.41 cm2/year before vitamin therapy, and -0.049 +/- 0.24 cm2/year after vitamin therapy (P2 = .0001; paired t test). Among patients with levels <14 micromol/L, the rate of progression of plaque was 0.13 +/- 0.24 cm2/year before vitamin therapy and -0.024 +/- 0.29 cm2/year after vitamin therapy (P2 = .022, paired t test). The change in rate of progression was -0.15 +/- .44 cm2/year below 14 micromol/L, and -0.265 +/- 0.46 cm2/year above 14 micromol/L (P = 0.20). Vitamin therapy regresses carotid plaque in patients with H(e) levels both above and below 14 micromol/L. These observations support a causal relationship between homocyst(e)ine and atherosclerosis and, taken with epidemiologic evidence, suggest that in patients with vascular disease, the level to treat may be <9 micromol/L.

Am J Hypertens 2000 Jan;13(1 Pt 1):105-10

Vitamin B 12 deficiency in the aged

A COMMON CONDITION: Vitamin B12 deficiency is common in the elderly. Search for deficiency should be undertaken whenever the clinical situation could lead to vitamin deficiency whether macrocytic anemia is present or not as its development may come late. PATHOPHYSIOLOGICAL IMPLICATIONS: The potential relationships between degenerative neuropsychiatric disorders and cerebrovascular or cardiovascular disease, mainly via hyperhomocysteinemia, emphasize the importance of searching for vitamin B12 deficiency in the elderly. SPECIFIC CAUSES: In the elderly, it is important to recognize specific causes of vitamin B12 deficiency, mainly resulting from vitamin malabsorption.

Presse Med 1999 Oct 23;28(32):1767-70

Vitamin B12 deficiency in the elderly

Vitamin B12 deficiency is estimated to affect 10%-15% of people over the age of 60, and the laboratory diagnosis is usually based on low serum vitamin B12 levels or elevated serum methylmalonic acid and homocysteine levels. Although elderly people with low vitamin B12 status frequently lack the classical signs and symptoms of vitamin B12 deficiency, e.g. megaloblastic anemia, precise evaluation and treatment in this population is important. Absorption of crystalline vitamin B12 does not decline with advancing age. However, compared with the younger population, absorption of protein-bound vitamin B12 is decreased in the elderly, owing to a high prevalence of atrophic gastritis in this age group. Atrophic gastritis results in a low acid-pepsin secretion by the gastric mucosa, which in turn results in a reduced release of free vitamin B12 from food proteins. Furthermore, hypochlorhydria in atrophic gastritis results in bacterial overgrowth of the stomach and small intestine, and these bacteria may bind vitamin B12 for their own use. The ability to absorb crystalline vitamin B12 remains intact in older people with atrophic gastritis. The 1998 recommended daily allowance for vitamin B12 is 2.4 micrograms, but elderly people should try to obtain their vitamin B12 from either supplements or fortified foods (e.g. fortified ready-to-eat breakfast cereals) to ensure adequate absorption from the gastrointestinal tract. Because the American food supply is now being fortified with folic acid, concern is increasing about neurologic exacerbation in individuals with marginal vitamin B12 status and high-dose folate intake.

Annu Rev Nutr 1999;19:357-77

Plasma homocysteine is a sensitive marker for tissue deficiency of both cobalamines and folates in a psychogeriatric population

The concentration of blood folates was decreased and the concentration of plasma homocysteine was increased in a psychogeriatric population, whereas the concentrations of methylmalonic acid or serum cobalamins were not changed compared with healthy subjects. The highest frequency of abnormal values was shown by plasma homocysteine concentration, which was increased in 88 of 168 patients. In 29 of these 88 patients increased concentration of plasma homocysteine could possibly be attributed to tissue cobalamin deficiency. One patient had only a lowered concentration of blood folate. Thirteen patients had elevated concentrations of serum creatinine which could explain increased plasma homocysteine concentration. Even if the remaining patients (n = 45) had normal vitamin levels in circulation, the increased plasma homocysteine concentration in most cases must be attributed to tissue deficiency of cobalamins and/or folates. Thus, many patients with increased plasma homocysteine concentrations need further vitamin supplementation despite their normal vitamin levels in serum and blood.

Dement Geriatr Cogn Disord 1999 Nov-Dec;10(6):476-82

 


HRT

Use of HRT and the subsequent risk of cancer

At least 20 million women in developed countries are estimated to be currently using hormone replacement therapy (HRT). Almost 100 epidemiological studies have reported on the relationship between the use of HRT and the risk of cancer of female reproductive organs, namely the breast, uterus or ovary. Cancer at these sites is common and there are a priori reasons why the use of hormonal therapy to 'replace' the endogenous production of ovarian hormones after the menopause might increase the risk of these cancers. The available evidence indicates that the risk of breast cancer or endometrial cancer is increased while women are using HRT, the risk increasing with increasing duration of use. Most of the evidence about these cancers relates to use of HRT preparations containing oestrogens alone. The limited evidence about combination therapy, with oestrogens and progestogens, suggests that, compared to oestrogens alone, the effect on the breast is similar, but the effect on the endometrium is diminished, the diminution in risk being greater the more days each month that progestogens are used. The effect of HRT on breast cancer wears off after use ceases and has disappeared largely, if not wholly, within 5 years, whereas the effects on endometrial cancer take longer to wear off, if at all. The breast and endometrial cancers that are diagnosed in HRT users are less aggressive clinically than cancers in never-users but, as yet, there is little reliable information about the relationship between use of HRT and mortality from these cancers. For other cancer sites, the existing data about the effects of HRT are inconclusive. The longer the period of use of HRT, the greater the excess incidence of cancer of the breast and endometrium is likely to be. Use of HRT for short periods of time should have little effect on the incidence of these cancers. The cumulative excess incidence in 1000 women who used HRT for 10 years, beginning at age 50, is estimated to be six for breast cancer, 42 for endometrial cancer in women with an intact uterus using oestrogen therapy alone and about 20 for endometrial cancer in women with an intact uterus using oestrogen-progestogen combinations. The estimate for combined therapy is based on small numbers and may well vary with the type of preparation used. The overall balance between the excess incidence of these cancers and other effects of HRT needs to be evaluated carefully and will require more reliable data than exist at present.

J Epidemiol Biostat 1999;4(3):191-210; discussion 210-5

Breast cancer diagnosed during hormone replacement therapy

OBJECTIVE: Hormone replacement therapy (HRT) is associated with decreased breast cancer mortality despite increased incidence. We studied postmenopausal breast cancer patients to determine whether this paradox results from earlier diagnosis, biologically less aggressive tumors, or cessation of hormonal stimulation. METHODS: Demographic, clinical, pathologic, treatment, and outcome information for 455 postmenopausal breast cancer patients who had not used postmenopausal hormones was compared with that of 47 breast cancer patients who used postmenopausal hormones prior to diagnosis. RESULTS: Hormone users were significantly younger, more often white, and of lower body mass index than nonusers. Hormone users presented significantly more often with nonpalpable mammographic findings, resulting in significantly smaller tumors with less nodal involvement than nonusers. Cancers of hormone users were more commonly invasive lobular or in situ ductal and were more likely to be steroid receptor positive. Hormone users were treated with breast conservation significantly more frequently than nonusers. These differences persisted after matching for age and year of surgery and after controlling for race. At 5 years, none of the hormone users with invasive cancers had local recurrence compared with 8% of nonusers, and 7% of users had distant disease compared with 10% of nonusers. CONCLUSION: These results indicate that favorable breast cancer survival after postmenopausal hormone use might result from earlier detection through mammography. Possible hormonal influence on tumor biology and prognosis was not supported by our data.

Obstet Gynecol 2000 Apr;95(4):513-8

Randomized trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. Heart and Estrogen/progestin Replacement Study (HERS) Research Group

CONTEXT: Observational studies have found lower rates of coronary heart disease (CHD) in postmenopausal women who take estrogen than in women who do not, but this potential benefit has not been confirmed in clinical trials. OBJECTIVE: To determine if estrogen plus progestin therapy alters the risk for CHD events in postmenopausal women with established coronary disease. DESIGN: Randomized, blinded, placebo-controlled secondary prevention trial. SETTING: Outpatient and community settings at 20 US clinical centers. PARTICIPANTS: A total of 2763 women with coronary disease, younger than 80 years, and postmenopausal with an intact uterus. Mean age was 66.7 years. INTERVENTION: Either 0.625 mg of conjugated equine estrogens plus 2.5 mg of medroxyprogesterone acetate in 1 tablet daily (n = 1380) or a placebo of identical appearance (n = 1383). Follow-up averaged 4.1 years; 82% of those assigned to hormone treatment were taking it at the end of 1 year, and 75% at the end of 3 years. MAIN OUTCOME MEASURES: The primary outcome was the occurrence of nonfatal myocardial infarction (MI) or CHD death. Secondary cardiovascular outcomes included coronary revascularization, unstable angina, congestive heart failure, resuscitated cardiac arrest, stroke or transient ischemic attack, and peripheral arterial disease. All-cause mortality was also considered. RESULTS: Overall, there were no significant differences between groups in the primary outcome or in any of the secondary cardiovascular outcomes: 172 women in the hormone group and 176 women in the placebo group had MI or CHD death (relative hazard [RH], 0.99; 95% confidence interval [CI], 0.80-1.22). The lack of an overall effect occurred despite a net 11% lower low-density lipoprotein cholesterol level and 10% higher high-density lipoprotein cholesterol level in the hormone group compared with the placebo group (each P<.001). Within the overall null effect, there was a statistically significant time trend, with more CHD events in the hormone group than in the placebo group in year 1 and fewer in years 4 and 5. More women in the hormone group than in the placebo group experienced venous thromboembolic events (34 vs 12; RH, 2.89; 95% CI, 1.50-5.58) and gallbladder disease (84 vs 62; RH, 1.38; 95% CI, 1.00-1.92). There were no significant differences in several other end points for which power was limited, including fracture, cancer, and total mortality (131 vs 123 deaths; RH, 1.08; 95% CI, 0.84-1.38). CONCLUSIONS: During an average follow-up of 4.1 years, treatment with oral conjugated equine estrogen plus medroxyprogesterone acetate did not reduce the overall rate of CHD events in postmenopausal women with established coronary disease. The treatment did increase the rate of thromboembolic events and gallbladder disease. Based on the finding of no overall cardiovascular benefit and a pattern of early increase in risk of CHD events, we do not recommend starting this treatment for the purpose of secondary prevention of CHD. However, given the favorable pattern of CHD events after several years of therapy, it could be appropriate for women already receiving this treatment to continue.

JAMA 1998 Aug 19;280(7):605-13

Breast-cancer risk following long-term oestrogen- and oestrogen-progestin-replacement therapy

While use of hormone-replacement therapy (HRT) effectively alleviates menopausal symptoms and prevents osteoporosis and possibly cardiovascular disease, there is concern of a detrimental impact on breast-cancer risk. There is a particular lack of data regarding the effect of long-term use of oestrogen-progestin combinations on breast-cancer risk. We conducted a large epidemiological study in Sweden, where combined oestrogen-progestin treatment has been predominant, to examine the influence of different regimens of menopausal hormone therapy on breast-cancer risk. In this population-based case-control study, 3,345 women aged 50 to 74 years with invasive breast cancer (84% of all eligible) and 3,454 controls of similar age (82% of all selected) were included. Mailed questionnaires and telephone interviews were used to collect detailed information on use of hormone replacement and on potential confounding factors. Odds ratios (OR) and 95% confidence intervals (CI) were estimated through multiple logistic regression. There was a trend of increasing breast-cancer risk with duration of oestrogen/oestrogen-progestin use (OR for women treated at least 10 years, 2.43; 95% CI, 1.79-3.30, as compared to never-users), with statistically significant estimates only for women with BMI<27 kg/m2. Excess risks were observed to current use and use that ceased more than 10 years ago (OR for women treated at least 5 years, OR was 2.68, 95% CI, 2.09-3.42, and OR 2.57, 95% CI, 1.28-5.15, as compared with never-users, respectively). A positive association which was noted for use of oestrogen combined with testosterone-derived progestins appeared especially pronounced with continuously combined regimens. Long-term use of replacement oestrogens with or without progestins may substantially increase the incidence of post-menopausal breast cancer, particularly among non-obese women.

Int J Cancer 1999 May 5;81(3):339-44

Risks of breast and endometrial cancer after estrogen and estrogen-progestin replacement

OBJECTIVE: We studied the risk of breast and endometrial cancer in a cohort of 11,231 Swedish women prescribed different replacement hormone regimens. METHODS: All 10,472 women at risk of developing breast cancer and 8,438 women at risk of endometrial cancer were followed up from the time of the questionnaire in 1987-88 through 1993, by record-linkages to the National Swedish Cancer Registry. Using data from a questionnaire we analyzed the relationships between hormone exposures and cancer risk, with non-compliers and users of less than 1 year as a reference group. RESULTS: For breast cancer, women reporting use of estrogens combined with progestins had evidence of an increased risk relative to women denying intake or taking hormones for less than 1 year; relative risk (RR) = 1.4 (95% confidence interval 0.9-2.3) after 1-6 years of intake, and RR = 1.7 (95% CI 1.1-2.6) after more than 6 years. This excess risk seemed confined to recent exposure. We found no association with intake of estrogens alone using non-compliers and short-term takers as the reference group. The risk of invasive endometrial cancer was increased four-fold in women using medium-potency estrogens alone for 6 years or longer, RR = 4.2 (95% CI 2.5-8.4). Women on such long-term progestin-combined treatment had a lower, non-significant, excess risk (RR = 1.4; 95% CI 0.6-3.3). CONCLUSIONS: We conclude that long-term recent use of estrogen-progestin combined replacement therapy may increase the risk of breast cancer. Exposure to estrogen alone substantially elevates the risk of endometrial cancer, an increase that can be reduced or perhaps avoided by adding progestins.

Cancer Causes Control 1999 Aug;10(4):253-60

Menopausal estrogen and estrogen-progestin replacement therapy and breast cancer risk

CONTEXT: Whether menopausal hormone replacement therapy using a combined estrogen-progestin regimen increases risk of breast cancer beyond that associated with estrogen alone is unknown. OBJECTIVE: To determine whether increases in risk associated with the estrogen-progestin regimen are greater than those associated with estrogen alone. DESIGN: Cohort study of follow-up data for 1980-1995 from the Breast Cancer Detection Demonstration Project, a nationwide breast cancer screening program. SETTING: Twenty-nine screening centers throughout the United States. PARTICIPANTS: A total of 46355 postmenopausal women (mean age at start of follow-up, 58 years). MAIN OUTCOME MEASURE: Incident breast cancers by recency, duration, and type of hormone use. RESULTS: During follow-up, 2082 cases of breast cancer were identified. Increases in risk with estrogen only and estrogen-progestin only were restricted to use within the previous 4 years (relative risk [RR], 1.2 [95% confidence interval [CI], 1.0-1.4] and 1.4 [95% CI, 1.1-1.8], respectively); the relative risk increased by 0.01 (95% CI, 0.002-0.03) with each year of estrogen-only use and by 0.08 (95% CI, 0.02-0.16) with each year of estrogen-progestin-only use among recent users, after adjustment for mammographic screening, age at menopause, body mass index (BMI), education, and age. The P value associated with the test of homogeneity of these estimates was .02. Among women with a BMI of 24.4 kg/m2 or less, increases in RR with each year of estrogen-only use and estrogen-progestin-only use among recent users were 0.03 (95% CI, 0.01-0.06) and 0.12 (95% CI, 0.02-0.25), respectively. These associations were evident for the majority of invasive tumors with ductal histology and regardless of extent of invasive disease. Risk in heavier women did not increase with use of estrogen only or estrogen-progestin only. CONCLUSION: Our data suggest that the estrogen-progestin regimen increases breast cancer risk beyond that associated with estrogen alone.

JAMA 2000 Jan 26;283(4):485-91

Risk of endometrial cancer following estrogen replacement with and without progestins

BACKGROUND: Unopposed estrogen replacement therapy (i.e., estrogen without progestins) increases the risk of endometrial cancer. In this study, we examined the endometrial cancer risk associated with combined estrogen-progestin regimens currently in use, since the safety profiles of these regimens have not been clearly defined. METHODS: We conducted a nationwide population-based, case-control study in Sweden of postmenopausal women aged 50-74 years. We collected information on use of hormone replacement from 709 case patients with incident endometrial cancer and from 3368 control subjects. We used unconditional logistic regression to calculate odds ratios (ORs) as estimates of relative risks. All individual comparisons were made with women who never used the respective hormone replacement regimens. RESULTS: Treatment with estrogens alone was associated with a marked duration- and dose-dependent increase in the relative risk of endometrial cancer. Five or more years of treatment had an OR of 6.2 for estradiol (95% confidence interval [CI] = 3.1-12.6) and of 6.6 for conjugated estrogens (95% CI = 3.6-12.0). Following combined estrogen-progestin use, the association was considerably weaker than that for estrogen alone; the OR was 1.6 (95% CI = 1.1-2.4) after 5 or more years of use. This increase in risk was confined to women with cyclic use of progestins, i.e., fewer than 16 days per cycle (most commonly 10 days per cycle [OR = 2.9; 95% CI = 1.8-4.6 for 5 or more years of use]), whereas continuous progestin use along with estrogens was associated with a reduced risk (OR = 0.2; 95% CI = 0.1-0.8 for 5 or more years of use). CONCLUSION: The risk of developing endometrial cancer is increased after long-term use of estrogens without progestins and with cyclically added progestins. Continuously added progestins may be needed to minimize the endometrial cancer risk associated with estrogen replacement therapy.

J Natl Cancer Inst 1999 Jul 7;91(13):1131-7

Continuation of Medical Abstracts, October 2000



Back to the Magazine Forum