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Life Extension Magazine

LE Magazine August 2008
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Green Tea Compound Reduces Breast Cancer Growth in Animals

Green Tea Compound Reduces Breast Cancer Growth in Animals

The green tea antioxidant epigallocatechin-3-gallate (EGCG) slows breast cancer growth in female mice, a new study reveals.*

University of Mississippi researchers added EGCG to the drinking water of seven-week-old female mice for five weeks, while a control group received unenhanced drinking water. During the second week of the study, researchers injected both groups with breast cancer cells.

Mice treated with the EGCG showed a reduction in tumor size by 66% and tumor weight by 68% compared with the control group. The green tea antioxidant also lowered the density of small blood vessels within tumors and levels of a protein called vascular endothelial growth factor found in a variety of breast cancer types. The researchers suggested that EGCG directly targets tumor blood vessels and cells to suppress new blood vessel formation and the proliferation and migration of breast cancer cells.

“We believe our findings will help lead to new therapies for the prevention and treatment of breast cancer in women,” they concluded.

—Dayna Dye

Reference

* Available at: http://www.the-aps.org/press/journal/08/8.htm. Accessed May 8, 2008.

Daily Aspirin Reduces Hormone-Sensitive Breast Cancer Risk

New research backs the idea that aspirin protects against estrogen receptor-positive breast cancer,1 a hormone-sensitive malignancy that makes up 75% of all cases of the disease.

In this large-scale, long-term study, researchers from the National Cancer Institute evaluated questionnaire-based data on diet, demographics, and medication usage from over 127,000 women who were cancer-free at the start of the study. After seven-year follow-up, using cancer registry information, the researchers found that women who reported daily aspirin use had a 16% lower risk of estrogen-receptor positive breast cancer than women who did not use the drug.

The researchers also evaluated other types of non-aspirin anti-inflammatory drugs, which were found to have no significant association with breast cancer risk. Aspirin is a non-steroidal anti-inflammatory drug (NSAID), but unlike other drugs in this class, it irreversibly inhibits an enzyme called cyclooxygenase-2 (COX-2), which may interrupt the carcinogenic process by a number of pathways, including suppression of estrogen synthesis.

This study also supports other findings that aspirin reduces the risk of hormone-sensitive breast cancer.2,3

—Dayna Dye

Reference

1. Gierach GL, Lacey JV Jr, Schatzkin A, et al. Nonsteroidal anti-inflammatory drugs and breast cancer risk in the National Institutes of Health-AARP Diet and Health Study. Breast Cancer Res. 2008 Apr 30;10(2):R38.
2. Terry MB, Gammon MD, Zhang F, et al. Association of frequency and duration of aspirin use and hormone receptor status with breast cancer risk. JAMA. 2004 May 26;291(20):2433-40.
3. Agrawal A, Fentiman IS. NSAIDs and breast cancer: a possible prevention and treatment strategy. Int J Clin Pract. 2008 Mar;62(3):444-9

Coenzyme Q10 Relieves Muscle Damage in Athletes

Coenzyme Q10 (CoQ10) supplementation significantly reduces muscle injury and oxidative stress due to intensive exercise, a new study reveals.1

In this double-blind study, 18 elite athletes took 300 mg/day of CoQ10 or placebo for 20 days, during which time they exercised intensively for 5.5 hours daily for six days. Various blood markers of muscle wear and tear and oxidative stress were measured before, during, and after the study period.1

Myoglobin and creatine kinase, proteins that indicate muscle damage, increased in both groups, but the increase was significantly less in the CoQ10 group. Levels of lipid peroxide, a measure of oxidative stress, were also lower among subjects taking CoQ10 than among control subjects.1

These results complement recent findings that CoQ10 supplementation may reduce exercise-induced fatigue and improve physical performance.2,3

—Dale Kiefer

Reference

1. Kon M, Tanabe K, Akimoto T, et al. Reducing exercise-induced muscular injury in kendo athletes with supplementation of coenzyme Q10. Br J Nutr. 2008 Feb 20;:1-7 [Epub ahead of print].
2. Cooke M, Iosia M, Buford T, et al. Effects of acute and 14-day coenzyme Q10 supplementation on exercise performance in both trained and untrained individuals. J Int Soc Sports Nutr. 2008 Mar 4;5:8.
3. Mizuno K, Tanaka M, Nozaki S, et al. Antifatigue effects of coenzyme Q10 during physical fatigue. Nutrition. 2008 Apr;24(4):293-9.

Anthocyanins Show Promise for Obesity

Anthocyanins Show Promise for Obesity

Anthocyanins, the colorful antioxidant pigments contained in many fruits and vegetables, help regulate adipocyte function and obesity in mice, according to a recent study.* Adipocyte (fat cell) dysfunction promotes obesity, which in turn is a major risk factor for metabolic syndrome and insulin resistance.

Four groups of mice (six each) were fed a control diet, control + anthocyanins, high-fat diet, or high-fat + anthocyanins. At 12 weeks, mice in the high-fat group weighed significantly more than all three other groups, suggesting that the anthocyanins prevented weight gain in the high-fat + anthocyanins group. Hypertrophy (size increase) of adipocytes occurred in the high-fat group, but not the high-fat + anthocyanins group. In a DNA analysis of human adipocytes, incubation with anthocyanins down-regulated the expression of inflammatory cytokines. The anthocyanins used in this study were derived from purple corn; berries are another rich source of anthocyanins.

According to the author, dietary anthocyanins have “a significant potency for anti-obesity.”

—Laura J. Ninger, ELS

Reference

* Tsuda T. Regulation of adipocyte function by anthocyanins; possibility of preventing the metabolic syndrome. J Agric Food Chem. 2008 Feb 13;56(3):642-6.

Whey Protein Supplement Effective for Weight Loss

Whey Protein Supplement Effective for Weight Loss

A purified whey protein supplement achieves substantial weight loss while sparing lean muscle, a recent study reports.* The supplement contains high levels of leucine from whey protein, bioactive peptides, and calcium.

More than 100 overweight adults (body mass index of 30-42 kg/m2) were randomly assigned to a low-calorie diet plus the whey supplement twice daily before meals or the same diet plus a control beverage of equal calories. After 12 weeks, the supplement group lost more weight than controls, and significantly more of the loss was in body fat (6.2 lb versus 3.6 lb). Supplement users were also less likely to lose lean muscle.

Total body fat loss in the supplement group was 6%, leading the authors to conclude that “because a 5% reduction of body fat mass has been shown to reduce the risk of obesity-related disease, the results have practical significance.”

—Laura J. Ninger, ELS

Reference

* Frestedt JL, Zenk JL, Kuskowski MA, Ward LS, Bastian ED. A whey-protein supplement increases fat loss and spares lean muscle in obese subjects: a randomized human clinical study. Nutr Metab (Lond). 2008 Mar 27;5:8.

Fathers-To-Be Need Folate Too

Ensuring optimal folate intake during the reproductive years is just as important for men as it is for women, according to a new report.* Men who have reduced levels of this B vitamin have a higher rate of chromosomal abnormalities in their sperm, which puts their children at greater risk for genetically determined disorders.

Scientists administered dietary questionnaires to 97 healthy men aged 22 to 80 to determine their intake of folate and other nutrients from food and supplements. Semen samples were then collected and examined for aneuploidy (abnormal numbers of chromosomes), which can lead to genetically determined learning difficulties or Down’s syndrome. Men who consumed the highest amount of folate (722-1,150 mcg) had a 20% lower risk of abnormal sperm, compared with men whose folate intake was low.

If future research confirms these findings, men intending to become fathers may be wise to increase their folate intake for at least three months before attempting to conceive in order to minimize the risk of genetic disorders in their children.

—Dayna Dye

Reference

* Young SS, Eskenazi B, Marchetti FM, Block G, Wyrobek AJ. The association of folate, zinc and antioxidant intake with sperm aneuploidy in healthy non-smoking men. Hum Reprod. 2008 May;23(5):1014-22.

Vitamin D May Protect Against Peripheral Artery Disease

Low serum vitamin D levels are associated with an increased risk of peripheral artery disease, according to a recent report from the National Health and Nutrition Examination Survey (NHANES).1 Peripheral artery disease occurs when arteries in the legs are damaged by atherosclerotic plaque, which diminishes blood flow and can cause leg pain and slow-healing foot wounds.

Researchers divided 4,839 participants into four groups based on their blood levels of vitamin D. They found increasing levels of the vitamin to be associated with a lower prevalence of peripheral artery disease. Participants with the lowest vitamin D blood levels (<17.8 ng/mL) had an 8.1% prevalence of the disease while those with the highest levels (>29.2 ng/mL) had only a 3.7% prevalence. Adjusted analysis of the data showed that peripheral artery disease was 80% more common in individuals with the lowest vitamin D levels, compared with those who had the highest levels.

This study adds to growing evidence of vitamin D’s cardioprotective activity,2,3 leading the study authors to note that further studies investigating the nutrient’s mechanism of action are needed.

—Michael J. Hall, ND

Reference

1. Melamed ML, Munter P, Michos ED, et al. Serum 25-hydroxyvitamin D levels and the prevalence of peripheral arterial disease. Results from the NHANES 2001 to 2004. Arterioscler Thromb Vasc Biol. 2008 April 16 [Epub ahead of print].
2. Wang TJ, Pencina MJ, Booth SL, et al. Vitamin D deficiency and risk of cardiovascular disease. Circulation. 2008 Jan 7 [Epub ahead of print].
3. Lind L, Hanni A, Lithell H, Hvarfner A, Sorensen OH, Ljunghall S. Vitamin D is related to blood pressure and other cardiovascular risk factors in middle-aged men. Am J Hypertens. 1995 Sept;8(9):894-901

Green Tea Combats Exercise-Induced Oxidative Damage

Consuming green tea protects against exercise-induced oxidative damage, according to a new study.* Oxidative damage, which results from metabolic activity and is increased following exercise, is linked to degenerative changes associated with aging and chronic disease.

Fourteen study volunteers participated. One group consumed green tea three times daily for seven days, while a control group did not drink green tea. Researchers then had the subjects perform a strenuous bench-press exercise and measured various blood markers for signs of oxidative stress before and after the activity.

The group who consumed green tea had significantly lower levels of blood markers that indicate oxidative tissue damage both before and after exercising. This group also had significantly higher post-exercise blood levels of glutathione, which is a key antioxidant, and greater blood antioxidant potential.

Green tea, a beverage rich in polyphenols, may thus offer protection against the oxidative damage incurred by athletes and everyone who exercises.

—Michael J. Hall, ND

Reference

* Panza VS, Wazlawik E, Ricardo Schütz G, Comin L, Hecht KC, da Silva EL. Consumption of green tea favorably affects oxidative stress markers in weight-trained men. Nutrition. 2008 May;24(5):433-42.

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