LE Magazine, April 2001 - Medical Updates

April 2001
Table Of Contents

1. Insulin level may help predict breast cancer survival

   Full source: American Society of Clinical Oncology

   Breast cancer patients with high levels of the hormone, insulin (better known for its role in diabetes) in their blood seem to be more likely to die of their disease than other women. Insulin may also predict whether a woman's breast cancer recurs after therapy and whether she will die. Insulin normally helps promote cell growth. Evidence shows that in the breast, insulin spurs the growth of both normal and cancerous cells. In a study of 535 breast cancer patients followed for up to 10 years, those with the highest insulin levels were more than eight times more likely to die than women with the lowest insulin levels. They were almost four times as likely to have their cancer recur at a distant site. Although many of the women in the study were obese, and obesity is known to affect both breast cancer prognosis and insulin levels, obesity alone did not completely explain the link between insulin and poorer cancer survival. Some women of normal weight had elevated insulin as well. It is unclear why insulin levels are elevated in some cases of breast cancer. If the connection between insulin levels and breast cancer prognosis holds true, insulin could become another target for breast cancer treatment. At this time, it is premature to begin routinely monitoring insulin levels in breast cancer patients. More study is needed. (The Life Extension Foundation is researching insulin-lowering therapies at this time.)

   
   
   

2. Systolic blood-pressure reading should define hypertension

   Full source: Hypertension, 2000; May 4
   
   Systolic blood pressure the first or higher, number in a blood-pressure reading, is the important factor in determining whether a person has hypertension. Much evidence points to systolic pressure as the critical factor in determining the risk of heart disease. Systolic blood pressure represents the maximum force exerted by the heart against the blood vessels during the heart's pumping phase. Diastolic pressure is the resting pressure during the heart's relaxation phase. Traditionally, diastolic blood pressure, the second or lower number, was thought to be more important. Making systolic blood pressure the major criterion for diagnosis, staging and therapeutic management of hypertension, particularly in middle-aged and older Americans, represents a major paradigm shift. This shift affects 25 million people in the United States whose lives can be improved by the change. Specifically, the new recommendations are: 1) Systolic blood pressure should become the principal clinical endpoint for detection, evaluation and treatment of hypertension, especially in middle-aged and older Americans; 2) Blood pressure should be maintained below 140/90 mmHg throughout one's lifetime; above this level, early therapy is essential to protect against organ damage; 3) More stringent blood-pressure control is necessary in persons with high-risk conditions: hypertensive patients with diabetes should keep their blood below 135/85 mmHg and persons with kidney or heart failure should reduce their blood pressure to the lowest level possible; and 4) Age-adjusted blood-pressure targets are inappropriate, including the unsubstantiated but persistent clinical folklore that "100-+-your-age" is an acceptable systolic blood-pressure level. The defining systolic number is 140: A higher measurement indicates a need for blood-pressure reduction through drugs or lifestyle change.
   
   

   
   
   

3. Antioxidant and folate intake and male lung cancer risk

   Full source: Cancer Epidemiology Biomarker Prev 2000 Apr; 9(4) 357-65

   Many studies have reported reversed (opposite) associations between vegetable and fruit consumption and lung cancer risk. A study looked at the role of several antioxidants and folic acid in this relationship in 58,279 men of ages 55-69 years at start in 1986, who returned a questionnaire including a 150-item food frequency questionnaire. After 6.3 years of follow-up, 939 male lung cancer cases were registered. The study showed that protective effects on lung cancer incidence were found for lutein + zeaxanthin, beta-cryptoxanthin, folic acid and vitamin C. Other carotenoids (alpha-carotene, beta-carotene and lycopene) and vitamin E did not show significant associations. After adjustment for vitamin C, only folic acid remained oppositely associated. After adjustment for folic acid, only beta-cryptoxanthin and vitamin C remained significantly associated. Opposite associations with carotenes, lutein + zeaxanthin and beta-cryptoxanthin seemed to be limited to small cell and squamous cell carcinomas. Only folic acid and vitamin C intake appeared to be oppositely related to small cell and squamous cell carcinomas and adenocarcinomas. Thus folic acid, vitamin C and beta-cryptoxanthin might be better protective agents against lung cancer in smokers than alpha-carotene, beta-carotene, lutein + zeaxanthin and lycopene.

   
   
   

4. Beneficial effects of NAC in diabetes

   Full source: Diabetes, 1999, Vol. 48, Iss 12, pp 2398-2406

   Free radicals are produced under diabetic conditions and possibly cause various forms of tissue damage in those with diabetes. A study examined the involvement of free radicals in the progression of pancreatic cell dysfunction in type 2 diabetes and evaluated the potential usefulness of N-acetyl-L-cysteine (NAC) in the treatment of type 2 diabetes. The treatment with NAC retained glucose-stimulated insulin secretion and moderately decreased blood glucose levels showing possible protection of pancreatic beta-cells against glucose toxicity. The beta-cell mass was significantly larger in the diabetic mice treated with NAC than in the untreated mice. The antioxidant treatment suppressed apoptosis (programmed cell death) in beta-cells without changing the rate of beta-cell proliferation. The antioxidant treatment also preserved the amounts of insulin content and insulin mRNA, and the activity of a beta-cell-specific transcription factor (transfer of genetic code information from one kind of nucleic acid to another), was more clearly visible in the nuclei of islets of Langerhans cells of the pancreas. Thus, the antioxidant treatment with NAC can exert beneficial effects in diabetes with preservation of beta-cell function. This finding suggests a potential usefulness of antioxidants for treating diabetes and provides further support for the implication of free radicals in beta-cell dysfunction in diabetes.

   
   
   

5. Curcumin extract inhibits LDL oxidation and lowers cholesterol

   Full source: Atherosclerosis, 1999, Vol. 147, Iss 2, pp 371-378

   The oxidation of low-density lipoproteins (LDL) plays an important role in the development of atherosclerosis. Curcumin is a yellow pigment from the Curcuma longa plant and is commonly used as a spice and food coloring. Curcumin extract has several pharmacological effects including anti-tumor, anti-inflammatory, antioxidant and anti-infectious activities. A study evaluated the effect of curcumin extract on LDL oxidation susceptibility and blood lipids in rabbits fed for seven weeks on a diet containing 95.7% standard chow, 3% lard and 1.3% cholesterol, to induce atherosclerosis. Curcumin extract was administered at doses of 1.66 (group A), 3.2 (group B) and 0 (control group) mg/kg body weight. Results showed that the low but not the high dosage decreased the susceptibility of LDL to lipid peroxidation. Both doses had lower levels of total blood cholesterol than the control group. In addition, the lower dosage had lower levels of cholesterol, phospholipids and triglycerides in LDL than the 3.2-mg dosage. Thus, the use of curcumin could be useful in the management of cardiovascular disease.

   
   
   

6. Triglyceride levels, cholesterol and heart attack risk

   Full source: Atherosclerosis, 1999, Vol. 147, Iss 2, pp 243-247

   A 6-13 year study of 12,510 middle-aged men looked at the influence of different levels of triglycerides (fats) in the blood in relation to blood cholesterol on the risk of developing a heart attack. It showed a significant relationship between triglycerides and the relative risk for heart attack. As the levels of triglycerides increased, the impact of a certain cholesterol value for the occurrence of heart attack was increased. The study emphasizes the interaction between cholesterol and triglyceride values for the risk of heart attack. It was concluded that at triglyceride values above 1.0 mmol/l and cholesterol above 6.8 mmol/l there is an increasing interaction between cholesterol and triglyceride levels that might be of importance when evaluating the cardiovascular risk of middle aged men.
   
   

   
   

7. Effect of zinc on pancreatitis in rodents

   Full source: Journal of Clinical Biochemistry and Nutrition, 1999, Vol. 26, Iss 3, pp 213-225

   The effects of zinc on acute pancreatitis were investigated in rats with artificially-induced pancreatitis. The endogenous zinc concentrations in the blood and pancreas after the onset of acute pancreatitis was not different from those in normal rats. Orally administered zinc sulfate was well absorbed and was taken up by the pancreas in normal rats as well as in rats suffering from acute pancreatitis. Oral administration of zinc sulfate before induction of acute pancreatitis reduced the serum amylase activity and the wet weight of the pancreas. Oral administration of zinc sulfate after the induction of acute pancreatitis also reduced the pancreatic wet weight in rats pancreatitis, and decreased the mortality rate as well. A chelate of zinc and L-carnosine also decreased the serum amylase activity and pancreatic wet weight in both types of pancreatitis. These data suggest that zinc compounds may have a therapeutic effect on acute pancreatitis.

   
   

8. Effects of selenium on kidney disease in diabetes

   Full source: Journal of Trace Elements in Experimental Medicine, 1999, Vol. 12, Iss 4, pp 379-392

   Oxidative stress is involved in diabetes mellitus and its complications. Selenium is a nutritional antioxidant, especially because it is required for the activity of selenium-dependent glutathione peroxidase (a crucial enzyme in hydrogen peroxide detoxification). Selenium also may have insulin-like properties and improve insulin sensitivity. Researchers supplemented type I diabetic rats with a selenium-rich yeast, selenomethionine and selenomethionine + vitamin E for 24 weeks. Selenium, and more efficiently selenomethionine + vitamin E, decreased blood sugar level and glycated hemoglobin. Supplementations increased selenium levels in kidney and double supplementation increased kidney vitamin E level. Selenium decreased or normalized the increased arachidonic acid content observed in diabetic kidneys and so may reduce the level of thromboxane (a potent inducer of platelet aggregation and constrictor of arterial smooth muscle) involved in nephropathy. Hyperfiltration is common in early stages of diabetic nephropathy. There was an increased kidney creatinine clearance in diabetic rats, indicating kidney over-filtration. However, selenium supplementations corrected this over-filtration. Supplementations also very significantly reduced or corrected kidney lesions which were markedly increased in diabetic rats. Thus, selenium supplementation could be a useful additive therapeutic to delay diabetic nephropathy.

   
   

9. Effects of fish oil or soy lecithin on platelet adhesion

   Full source: Thrombosis and Haemostasis, 1999, Vol. 82, Iss 5, pp 1522-1527

   A study investigated the possible regulating role of omega-6 and of omega-3 fatty acids on platelet adhesiveness. (Platelets are chiefly known for their role in blood coagulation.) There were three groups of 60 participants: Group A: 20 ml per day of a fish oil supplement (equivalent to 0.3 g omega-6, 3.6 g omega-3; omega-6/omega-3 ratio 0.1). Group B: 25 grams per day of a soy lecithin supplement (equivalent to 1.5 g omega-6, 0.5 g omega-3; omega-6/omega-3 ratio 3). Control Group: usual diet without any supplement for 15 days. The fish oil group showed a significant reduction in stimulated platelet stickiness (from 18.8% to 15.6%; with thrombin: from 24.4% to 20.8%), whereas no difference was noted in the resting condition (from 3.6% to 3.5%, NS). In the soy lecithin group, platelet stickiness was increased in all rest conditions (from 18.7% to 23.2%; with thrombin: from 24.0% to 29.9%; resting: from 3.5% to 6.6%). There were no significant changes in the control group. A good correlation was found between the data on platelet stickiness and the changes in the platelet fatty acid omega-6/omega-3 ratio caused by the different supplementations. The results indicate an inhibitory effect of fish oil rich in omega-3 fatty acids on stimulated human platelet stickiness, and a stimulatory effect of soy lecithin rich in omega-6 fatty acids on resting and stimulated stickiness. The results suggest that the omega-6/omega-3 ratio is a determinant of platelet adhesion.
   
   

   
   

10. Effect of vitamins on hyperhomocysteinemia

    Full source: American Journal of Cardiology, 1999, Vol. 84, Iss 11, pp 1359

    Short-term vitamin administration (folic acid, vitamins B-6 and B-12) effectively reduced homocysteine levels and thereby improved the vasodilation (widening of the blood vessels) in 16 healthy adults after dysfunction induced by post-methionine load hyperhomocysteinemia (excess blood homocysteine). Homocysteine levels decreased from 22.7 to 17.0 mu mol/L, and vasodilation after methionine load increased from 8.6 to 13.8 after vitamin administration.

    
    

11. Male hormone blockade for advanced prostate cancer

    Full source: Anti-Cancer Drugs, 1999, Vol. 10, Iss 9, pp 791-796

    A potentially more effective treatment for advanced prostate cancer than castration alone is the use of a combined androgen (male hormones) blockade, in the form of a luteinizing hormone-releasing hormone analog, or removal of the testes in combination with a non-steroidal anti-androgen. Three non-steroidal antiandrogens are available in the U.S.: flutamide (Eulexin), bicalutamide (Casodex) and nilutamide (Nilandron). Nilutamide offers no benefit over flutamide or bicalutamide, and has the least favorable safety profile. Flutamide must be taken three times a day and there is a relatively high incidence of diarrhea, often intolerable. However, bicalutamide can be taken in one tablet, once-a-day, is at least as effective as flutamide and is better tolerated in terms of diarrhea. Therefore, bicalutamide would seem to be an appropriate first choice for those who are suitable candidates for combined androgen blockade for advanced prostate cancer.
    
    

    
    

12. Prostate cancer treatment in old age

    Full source: Br J Urol International 2000;85:699-704

    Those 75 and older with prostate cancer should not delay treatment. A study evaluated 54 men (avg. age 76) with prostate cancer, who agreed to watchful waiting. The men were monitored regularly until the disease began to progress. In over 47 months, 52% had their disease progress. Gleason scores of six or higher and serum PSA levels of 10 ng/mL or higher were statistically significant predictors of disease progression. Many primary care physicians today will tell older men that they will probably outlive their cancer. This is untrue because men are healthier today and there are interventions for nonmalignant disease that keep people alive. Researchers noted that hormonal therapy given earlier may have some benefit in terms of survival. A 73-year-old gentleman with prostate cancer should consider curative treatment. However, when someone is close to 80, it is a more difficult decision because the side effects of treatment are greater. However, relative to radiation therapy and certainly surgery, hormone therapy is safe for most men.

    
    

13. 3-D radiation zaps prostate cancer more precisely

    Full source: International Journal of Radiation Oncology, Biology and Physics, May 2000

    High-dose radiation is more effective than surgery at treating aggressive prostate cancer in its early stages. Researchers suggest that this type of radiation may be the best choice for men with aggressive prostate cancer that is caught early. During radiation therapy, x-rays are aimed at a tumor to destroy cancer cells. However, the investigators used a specific type of radiation treatment-known as 3-D conformal radiation therapy-that is more precisely targeted at cancer cells. Computer software is used to plot out the exact location of the cancer in the prostate. By being more precise, they were able to increase the dose without causing side effects. A study used the high-dose 3-D radiation on 180 men with an aggressive type of prostate cancer. Overall, about 67% of the men were still alive five years after treatment and about 63% were cancer-free. Among men with early-stage cancer, nearly 80% were cancer-free after five years. Usually, about 50% of men who have surgery or traditional radiation treatment for early prostate cancer experience a cancer recurrence. The study clearly shows the benefits of high-dose radiation for treating early, aggressive prostate cancer. However, a high dose of conventional rather than 3-D radiation would cause too much damage to the area surrounding the prostate, making it impractical. Before 3-D radiation can become the "treatment of choice" for early, aggressive prostate cancer, hospitals will need to upgrade their equipment to provide the therapy. Even though high-dose radiation was tested in men with aggressive prostate cancer, some research suggests that it may also be effective in men with less aggressive forms of the disease.

    
    

14. Prostate cancer vaccine shows promise

    Full source: Clinical Cancer Research 2000;6:1632-1638

    An experimental vaccine aimed at treating prostate cancer may help control the disease once it has spread beyond the prostate gland. The vaccine consists of a genetically modified virus that is designed to stimulate the immune system to attack prostate cancer cells. In a recent study, the vaccine was given to 33 men who had advanced prostate cancer and increasing levels of prostate specific antigen (PSA), a sign that their cancer was not under control. (PSA is a substance that is produced by both normal and cancerous prostate tissue; a high PSA level can be a sign of cancer or other benign prostate conditions). The study participants received three doses of the vaccine at four-week intervals, and after treatment, half of the participants showed no increase in PSA for at least six months, and six men had no increase in PSA for more than two years. All of the men had already undergone standard treatment with surgery, radiation or a combination of both. The vaccine consists of vaccinia virus, which is a relatively harmless virus used in smallpox vaccines that is genetically modified to express human PSA. Once in the body, the PSA-bearing virus is attacked by immune system T-cells. The hope is that by exposing the T-cells to PSA, they will attack not only the virus, but also tumor cells. In the study, the patients did show T-cell responses aimed at PSA; however, it may take multiple booster shots, perhaps with different types of viruses, to maximize patients' immune responses. The long-term goal is to use vaccine therapy before the cancer has spread. Injecting a live virus into cancer patients seems to be not only very safe, but effective in some patients. Vaccine therapy is clearly going to be a major form of treatment for cancer. It makes much more sense than giving people toxic chemicals; it is far more specific (to tumor cells), unlike chemotherapy.
    
    

    
    

15. Genistein inhibits PSA activity in prostate cancer cells

    Full source: Int j Oncol 2000 June 16;(6) 1091-7

    There is convincing evidence for the role of soy-isoflavones, particularly genistein, in the inhibition of prostate cancer cell growth. Prostate specific antigen (PSA) is a biological marker used to detect and monitor the treatment of prostate cancer. Previous studies have documented that isoflavones can inhibit the secretion of PSA in the androgen (male hormones, such as androsterone and testosterone) dependent prostate cancer cells. However, the effects of genistein on androgen-independent PSA activity have not been explored. A study utilized different prostate cancer cells, which activate PSA in an androgen-independent manner, to determine the effects of genistein on cell proliferation and PSA activity. The results showed that genistein inhibits cell growth similarly in both in both types of cancer cells. However, only high concentrations of genistein inhibited PSA activity in VeCaP cancer cells. Thus, this study provides further evidence to support the role of genistein as a chemopreventive/therapeutic agent for prostate cancer irrespective of androgen responsiveness.

    
    
    

16. DHEA speeds the healing process

    Full source: American Burn Association

    DHEA (dehydroepiandrosterone) may offer some hope to burn victims who are often faced with a slow wound healing process that frequently leads to less than satisfactory results. New evidence shows that DHEA improves the rate of wound and skin healing in people who have suffered skin burns. The study evaluated the efficacy of DHEA versus placebo on a graft-site healing in 63 individuals. They received 5, 10 or 15 mg/kg of DHEA intravenously, or placebo. The results showed that at seven days after grafting, skin re-growth rates were 44%, 58% and 46% in the 5, 10 and 15 mg/kg dosage groups, respectively, compared with 43% in the placebo group. The burns, primarily in the upper trunk, face and arms, covered 25% of their total body surface area, on average. The study suggests that, at the 10 mg/kg dose, DHEA treatment may quicken skin and wound healing on burn victims.
    
    

    
    

17. Ginkgo vs. stroke damage

    Full source: American Academy of Neurology

    Ginkgo biloba may help to limit brain damage caused by stroke. Researchers reported that ginkgo reduced the extent of brain damage caused by artificially induced strokes in mice. Strokes occur when blood flow to the brain is disrupted, by either a blocked artery or bleeding. This reduced blood supply can damage or even kill brain tissue. Depending on the part of the brain involved, people are often left with some disability, such as paralysis, speech problems, confusion and memory lapses. In the study, mice had been receiving oral ginkgo supplements for one week before stroke inducement. Results showed that a low dose offered protection against stroke-reducing the area of the brain affected by 30%. However, another larger dose had no beneficial effect. Since ginkgo is also a mild blood thinner, it may be risky to use it in those already on blood thinning medications commonly prescribed in people at risk for stroke. Researchers are working to find drugs that can limit the effects of a stroke on the brain, such as by neutralizing free radicals that are found in abundance in injured tissue. Ginkgo contains antioxidant compounds that counteract free radicals. In addition to reducing stroke injury, gingko may also be useful in improving memory following a stroke. More study is needed to see if gingko has the same effect in humans as found in the mice, and to determine the proper dose. Two thirds of strokes are 'dry' or occlusive strokes, where blood flow to a region of the brain is blocked, causing this region to suffer damage. If we do not have high blood pressure, we want to protect our blood from abnormal clotting. Ginkgo, vitamin E, EPA & DHA (in fish oils) all work to protect against this abnormal tendency to form clots. Now we learn ginkgo also reduces the extent of stroke damage by the interrupted blood flow. Of course, using a high purity, quality standardized extract of ginkgo is essential.

    
    

18. Active life helps to ward off Alzheimer's

    Full source: American Academy of Neurology's, April 29 - May 6, 2000

    Keeping active outside work, either physically or mentally, in the midlife years (40-60) may help prevent Alzheimer's disease. Researchers found that people with higher levels of non-occupational activities, such as playing a musical instrument, gardening, physical exercise or even playing board games, were less likely to develop Alzheimer's disease later in life. People who were less active were more than three times more likely to have Alzheimer's disease. The study is the first to examine levels of activity from at least five years before Alzheimer's symptoms appeared. The researchers used a questionnaire to collect data about participation in passive as well as intellectual and physical activities for 193 people with Alzheimer's disease, (avg. age 73) and 358 healthy people, (avg. age 71). Among the activities categorized as passive were watching television, social activities and attending church. Intellectual activities ranged from reading and painting to jigsaw puzzles, woodworking and knitting. Physical activity ran the gamut from gardening to racquet sports. The healthy participants had been more active between the ages of 40 and 60 than had the patients with Alzheimer's. The study's findings also suggest that it is never too late to get started, at least with intellectual activities. Previous studies have shown that people with Alzheimer's had been less physically active and had lower levels of educational and occupational achievement than people without the disease. An intellectually or physically stimulating hobby will also be helpful. Passive activities, such as watching television, do not lower the risk for Alzheimer's disease.

    
    

19. Very high fiber diet for type II diabetics

    Full source: The New England Journal of Medicine,2000; May 11

    A very high intake of dietary fiber, mostly from fruits and vegetables, lowers blood glucose levels in diabetics. In a study of 13 individuals, those who included 50 grams of fiber in their daily diet-about twice as much as the American Diabetes Association (ADA) recommends-lowered their glucose levels by 10%. The average American consumes about 17 grams of fiber a day. The ADA diet had 24 grams of fiber (8 grams of soluble fiber and 16 grams of insoluble fiber), while the high-fiber diet had 50 grams of fiber (25 grams each of soluble and insoluble fiber). Each patient ate the high-fiber diet and the moderate-fiber diet recommended by the ADA for six weeks, then switched to the other diet for six weeks. Both diets contained the same number and proportion of calories from carbohydrates, fats, and proteins. The high-fiber diet also decreased insulin levels in the blood and lowered blood lipid concentrations in those with type II diabetes, or non-insulin dependent diabetes mellitus-the most prevalent type of diabetes. The study supports the view that diet can improve glucose and lipid levels and thus reduce the risk of long-term diabetic complications. Foods provided to the patients included cantaloupe, grapefruit, oranges, papayas, raisins, beans, okra, sweet potatoes, winter and zucchini squash, granola, oat bran and oatmeal. Fiber is classified according to water solubility. Most foods, such as fruits, vegetables and grains, contain both types of fiber. The 2000 ADA diet supports diets rich in monounsaturated fats, such as those consumed in Mediterranean countries. The study, however, supported a less-emphasized aspect of the Mediterranean diet, namely its content of fruits, vegetables and grains, which are rich sources of dietary fiber.