Life Extension Spring Clearance Sale

Life Extension Magazine

LE Magazine March 2000

MEDICAL UPDATES
Studies from throughout the world that can help you live longer

Click here to access this year's Medical Updates.

Click here to access the Medical Update Archives.

Click here to access the Complete Scientific Abstracts Online.



March 2000
Table Of Contents

  1. Aspirin prevents colorectal cancer
  2. Blood homocysteine level and mortality in the middle-aged and elderly
  3. Health effects of legumes and soybeans
  4. Mortality in vegetarians vs. non-vegetarians
  5. Health-promoting properties of common herbs
  6. The Oxford Vegetarian Study
  7. Essential fatty acids in health and chronic disease
  8. Effects of Ginkgo and DHEA on Alzheimer's
  9. Effects of heavy-resistance training on hormonal responses
  10. Melatonin and the reductionor alleviation of stress
  11. Melatonin protects cells from free radical damage
  12. Aminoguanidine vs. E. Coli endotoxin
  13. Wine, beer, and mortality in middle-aged men
  14. Aerobic exercise can reverse age-relaxed circulatory changes
  15. Prospects for cancer prevention

  1. Aspirin prevents colorectal cancer

    Full source: BIOMED. PHARMACOTHERAPY 1999 Vol 53 Iss 7 pp 303-308

    Studies strongly indicate that aspirin use reduces the risk of colon cancer and rectal cancer and benign tumors by approximately 40-50%. However, up to ten years of use may be required before a benefit is apparent in colorectal cancer. Animal studies support the preventative actions of aspirin and other non-steroidal anti-inflammatory agents (NSAIDs) in colon and rectal cancer production. The action of aspirin is also supported by studies on an anti-inflammatory agent, sulindac, which causes regression of benign tumors. However, with chronic aspirin use, there may be increased gastrointestinal irritation and bleeding. The anti-tumor properties of NSAIDs may be related mostly to their inhibition of an enzyme called cyclooxygenase-2 (COX-2). If confirmed, this new generation of selective COX-2 inhibitors may work to prevent cancer with fewer side effects.

    image

  2. Blood homocysteine level and mortality in the middle-aged and elderly

    Full source: ANN.INTERN.MED 1999 Vol 131 Iss 5 pp 321-+

    A mildly to moderately elevated blood homocysteine level is a substantial risk marker for death from all causes. A study sought to determine the relation of homocysteine level to mortality in 1,788 residents of Jerusalem who were at least 50 years of age between 1985 and 1987 with a 9- to 11-year follow-up. During the study period, 405 deaths occurred. An increase in mortality hazard ratios was associated with rising homocysteine levels.

    image

  3. Health effects of legumes and soybeans

    Full source: AMER.J.CLIN.NUTR. 1999 Vol 70 Iss 3 pp 4398-4506

    Soybeans are unique among beans because they are a concentrated source of isoflavones. Isoflavones are weak estrogens, such as genistein, which influence the transmission of signals. Soyfoods and isoflavones have received considerable attention for their potential role in preventing and treating cancer and osteoporosis. The low breast cancer mortality rates in Asian countries and the anti-estrogenic effects of isoflavones suggest that soyfood intake may reduce the risk of breast cancer. Recent data support this hypothesis, including the risk of postmenopausal breast cancer. Even more encouraging is the data suggesting that soy or isoflavones may reduce the risk of osteoporosis is due to the weak estrogenic effects of isoflavones and the similarity in chemical structure between soybean isoflavones and the synthetic isoflavone ipriflavone, (which was shown to increase bone mineral density in postmenopausal women).

    image

  4. Mortality in vegetarians vs. non-vegetarians

    Full source: AMER.J.CLIN.NUTR. 1999 Vol 70 Iss 3 pp 516s-524s

    Combined studies have shown mortality from heart disease to be 24% lower in vegetarians than in non-vegetarians. The lower mortality from ischemic heart disease among vegetarians was greater at younger ages and was restricted to those who had followed their current diet for more than 5 years. In addition, in comparison with regular meat eaters, mortality from ischemic heart disease was 20% lower in occasional meat eaters, 34% lower in people who ate fish but not meat, 34% lower in lacto-ovo-vegetarians (those who consume dairy), and 26% lower in vegans (those who consume only vegetables, nuts, seeds and fruits).

    image

  5. Health-promoting properties of common herbs

    Full source: AMER.J.CLIN.NUTR. 1999 Vol 70 Iss 3 pp 491S-499S

    The essential oils of commonly used herbs used in cooking, such as spices and of herbal teas suppress cholesterol synthesis and tumor growth. Various herbs possess blood lipid concentration reduction, anti-platelet, anti-tumor, or immune-stimulating properties that may help reduce the risk of cardiovascular disease and cancer. In different herbs, a wide variety of active phytochemicals, including the flavonoids, terpenoids, lignans, sulfides, polyphenolics, carotenoids, coumarins, saponins, plant sterols, curcumins, and phthalides have been identified. Several of these phytochemicals either inhibit nitrosation or the formation of DNA adducts or stimulate the activity of protective enzymes naturally produced in the body such as glutathione transferase. Research has centered on the biochemical activity of several herb families, as well as flaxseed, licorice root, and green tea. Many of these herbs contain potent antioxidant compounds that provide significant protection against chronic diseases. These compounds may protect LDL cholesterol from oxidation, inhibit cyclooxygenase and lipoxygenase enzymes, inhibit lipid peroxidation, or have anti-viral or anti-tumor activity.

    image

  6. The Oxford Vegetarian Study

    Full source: AMER.J.CLIN.NUTR. 1999 Vol 70 Iss 3 pp 525S-531S

    Analyses of 6,000 vegetarians showed that vegans (those who consume only vegetables, nuts, seeds, and fruits) had lower total- and LDL cholesterol concentrations than did meat eaters. When fiber intake rose, total-cholesterol concentration dropped in both men and women. Mortality rates were lower in non-meat eaters than in meat eaters for all causes of death, for ischemic heart disease, and for all malignant neoplasms. Death from ischemic heart disease with lower intake of total animal fat, saturated animal fat, and dietary cholesterol.

    image


  7. Essential fatty acids in health and chronic disease

    Full source: AMER.J.CLIN.NUTR 1999 Vol 70 Iss 3 pp 560S-569S

    n-3 fatty acids, such as those found in fish oils (ERA and DHA) and in alpha-linolenic acid have anti-inflammatory, anti-clotting, anti-arthythmic (irregularity of the heartbeat) lipid reducing, and blood vessel dilation properties. N-3 fatty acids are found for example, in green leafy vegetables, flaxseed, grapeseed, and walnuts. The beneficial effects of n-3 fatty acids have been shown in the secondary prevention of coronary heart disease, rheumatoid arthritis, ulcerative colitis, Crohn disease, and chronic obstructive pulmonary diseases. On the other hand, a high intake of n-6 fatty acids shifts the body physicology to one that is pro-blood clotting, characterized by increases in blood viscosity, blood vessel contraction and narrowing.

    image


  8. Effects of Ginkgo and DHEA on Alzheimer's

    Full source: FREE RADICAL BIOL MED. 1999 Vol 27 Iss 5-6 pp 544-553

    Ginkgo biloba extract and DHEA were found to protect against hydrogen peroxide/iron induced lipid oxidation in the brain of Alzheimer's Disease (AD) patients. Studies have shown free radical damage to be elevated in such individuals. One study found that levels of lipid oxidation were significantly elevated in tissues from Alzheimer's cases. Activities of naturally occurring antioxidants, such as catalase and glutathione peroxidase, were also higher in AD cases. However, the activity of another endogenous antioxidant, superoxide dismutase (SOD), was unchanged. The results demonstrate free radical-induced injury and protection by antioxidants in the frontal cortex of the brain of AD cases.

    image


  9. Effects of heavy-resistance training on hormonal responses

    Full source: J.APPL.PHYSIOL. 1999 Vol 87 Iss 3 pp 982-992

    Older men demonstrated a significant increase in total testosterone in response to exercise stress; this occurs along with significant decreases in resting cortisol in the early phase of a resistance training program. A study examined the adaptations of the endocrine system to heavy-resistance training in younger vs. older men. Two groups of men (30 and 62 years old) participated in a 10-week strength-power training program. Researchers analyzed total testosterone, free testosterone, cortisol, growth hormone, lactate, and ACTH. A heavy-resistance exercise test was used for evaluation (4 sets of 10-repetitions of maximum squats with 90 seconds of rest between sets). Results showed that squat strength and thigh muscle cross-sectional area increased in both groups. However, the younger group demonstrated, 1) higher total and free testosterone and insulin-like-growth-factor (IGF) than the older men, 2) training induced increases in free testosterone at rest and with exercise, and 3) increases in resting IGF-binding protein-3. With training, the older group demonstrated a significant increase in total testosterone in response to exercise stress along with significant decreases in resting cortisol. This indicates that older men do respond with an enhanced hormonal profile in the early phase of a resistance training program: the response, however, differs from that of younger men.

    image

  10. Melatonin and the reductionor alleviation of stress

    Full source: J.PINEAL RES. 1999 Vol 27 Iss 2 pp 78-85

    Melatonin can reduce the period of stress due to traveling. A study investigated the effect of melatonin on menstrual characteristics, prolactin, and premenstrual syndrome-like symptoms during simulated eastward travel and after 13 hours. Bright lights were used to simulate eastward movement across six time zones. Melatonin (10 mg) was given to healthy females for 5 consecutive days during the late follicular and early luteal phases of the menstrual cycle. They also completed a "profile of moods" questionnaire upon waking on each of 8 days. The results of the placebo group showed a prolactin peak at 15 hours. The prolactin peak at 13 hours is likely the result of stress, since stress is known to elicit the release of prolactin. However, the delay in administration of melatonin. In addition, the resulting data on stress reduction in the melatonin group was supported by results from the "profile of moods" state questionnaire. The melatonin group consistently demonstrated scores indicative of less stress associated with the simulated travel.

    image

  11. Melatonin and other antioxidants prolong the postmortem activity of the outer hair cells of the organ of Corti: its relation to the type of death.

    Full source: J.PINEAL.RES. 1999 Vol 27 Iss 2 pp 73-77

    The organ of Corti of the ear lies against the membrane in the cochlear duct and contains special sensory receptors for hearing. It consists of hair cells and several types of supporting cells. The outer hair cells of the organ of Corti transform sound into electrical signals, which starts the auditory process. These cells produce acoustic sound emissions when working routinely. The cochlea produces free radicals and nitric oxide. Melatonin, however, is present in the cochlea. A study looked at the influence of: a) melatonin, and b) an antioxidant mixture (vitamin E, vitamin C, glutathione, and N-acetylcysteine) on the after-death activity of the outer hair cells of the organ of Corti of the rat. Acoustic emissions distortion was measured. Results showed that melatonin prolonged the postmortem activity of the hair cells by up to 7 times after death. Similar results were obtained with the antioxidant mixture. The results demonstrate that melatonin and other anitoxidants have, in general, a protective role on hair cell activity in the ear.

    image

  12. Aminoguanidine vs. E. Coli endotoxin

    Full source: EUR.J.PHARMACOL. 1999 Vol 379 Iss 1 pp 73-80

    Aminoguanidine blocked most of the toxic effects on the liver and blood flow in mice that was produced by the E. Coli bacteria. The toxins had caused significant injury to the liver and decreased abdominal wall blood flow without administration of the Aminoguanidine. Mice received the aminoguanidine 10 minutes before they received either a saline solution or the E. Coli endotoxin.

    image

  13. Wine, beer, and mortality in middle-aged men

    Full source: ARCH.INTERN.MED 1999 Vol 159 Iss 16 pp 1865-1870

    A total of 36, 250 healthy men underwent comprehensive health appraisals using a questionnaire in a center of preventive medicine between January 1, 1978 and December 31, 1983. Education, professional and leisure activities, and smoking and drinking habits were evaluated. Blood pressure, white blood cell volume, gamma-glutamyltransferase, glucose, and serum cholesterol levels were routinely measured and electrocardiography was routinely performed, 28% drank beer, 61% drank wine but no beer, and 11% were abstainers; there was not much difference between social classes. During the follow-up, 3,617 subjects died. Death during a 12- to 18-year follow-up across categories of alcohol consumption were recorded. The results showed that moderate intake of both wine and beer was associated with lower relative risk for cardiovascular diseases; the risk was significantly lower with the intake of wine. Only daily wine intake (22-32 g of alcohol) was associated with a lower risk (33%) due to a lower incidence of cardiovascular diseases, cancers, violent deaths, and other causes. Thus, in eastern France, moderately wine consumption was associated with lower death from all causes. Drinking both wine and beer reduced the risk of cardiovascular death.



  14. Aerobic exercise can reverse age-relaxed circulatory changes

    Full source: CIRCULATION 1999 Vol 100 Iss 10 pp 1085-1094

    Aerobic exercise training improves the age-related decline in maximum oxygen consumption. Advancing age is associated with a decline in peak oxygen consumption in muscles when exercised. A study compared effect of exercise training in healthy older and younger individuals. Cardiovascular responses were measured in 10 older and 13 younger men during a cycle exercise test before and after 3-month period of exercise training. Before starting, the heart output and oxygen difference during exercise were significantly lower in older subjects. With training, the older and younger groups increased maximum oxygen consumption by 17.8% and 20.2% respectively. Peak cardiac output was unchanged in both groups. There was a change in systemic oxygen which increased 14.4% in the older group and 14.3% in the younger group and which accounted for the changes in peak oxygen consumption. Peak leg blood flow increased by 50% in older subjects, but the younger group showed no significant change. These findings suggest that the age-related decline in maximum oxygen consumption is the result of a reversible deconditioning effect on the distribution of cardiac output to exercising muscle. The ecline in maximum oxygen consumption also results in an age-related reduction in cardiac output reserve.

    image

  15. Prospects for cancer prevention

    Full source: MUTAT.RES.FUNDAM.MOL.MECH.MUT 1999 Vol 428 Iss 1-2 pp 329-338

    Guidelines recommend avoiding asbestos, smoking, sunlight, alcohol, fatty food and obesity. Women are advised to have a regular cervical smear test. Additional "probably helpful" suggestions include eating plenty of fresh fruit and vegetables and dietary fiber. Fruit and vegetables (e.g. tomato, broccoli, and onions) have particular benefits against individual cancer types. The benefits of increasing dietary fiber come from studies where wheat bran, a good fiber source, was added to the diet. However, it could be various phytocchemicals in the bran, rather than dietary fiber, which is beneficial. Therefore, an increase in whole wheat or wheat bran, rather than fiber, would be a sounder recommendation. There is considerable evidence that multivitamin supplementation can protect against cancer, especially where the population is already significantly vitamin-deficient. For example, a combination of beta-carotene, vitamin E and selenium significantly reduced cancer mortality in a Chinese population. Various other chemopreventive pharmaceuticals, herbal extracts, and vitamin formulations are being actively developed and at various stages in clinical trials.


image

Back to the Magazine Forum