July 30, 2007
Fish oil better than vegetable oil to reduce inflammation
The August 3, 2007 issue of the Journal of Biological Chemistry published the finding of researchers at the University of Michigan that fish oil is a better choice than oil derived from vegetables to help lower inflammation.
University of Michigan Professor and Chair of Biological Chemistry William L. Smith and associates examined the effects of varying amounts of fish oil and vegetable oil on cultured cells on the formation of compounds called prostanoids which increase inflammation when produced in excess. “Prostanoids help control blood pressure, fight allergies, and modulate inflammation, but too much of them – especially those made from vegetable oils – can also lead to increased pain, swelling, and redness in various tissues,” Dr Smith explained. “Our study shows that prostanoids made from fish oil are less effective at causing pain and swelling than those made from vegetable oil and that adding fish oil to the diet decreases the amount of prostanoids made from vegetable oil.”
While both fish and vegetable oils produce prostanoids via chemical reactions aided by cyclo-oxygenase (COX) 1 and 2, when more fish oil is present, it preferentially binds to COX-1, limiting vegetable oil’s access to this enzyme, yet in reactions involving COX-2, a large amount of vegetable oil was still converted to prostanoids. "This was completely unexpected,” Dr Smith noted. “This new result shows that COX-2 does not ‘prefer’ fish oil to vegetable oil. Regardless of the amount of extra fish oil that we added, COX-2 still helped convert all the vegetable oil available.”
“Drugs that are currently used to inhibit COX-1 and COX-2 provide relief from the symptoms of inflammation and pain, but they still have many side effects,” Dr Smith stated. “By better understanding how prostanoids work at the cellular level, we hope to find new ways to regulate inflammation and create better anti-inflammatory drugs.”
July 27, 2007
Binge drinkers deprive themselves of omega-3s
A report published in the August, 2007 issue of Alcoholism: Clinical & Experimental Research described the discovery of researchers at the National Institute of Health's National Institute on Alcohol Abuse and Alcoholism that men who engage in binge drinking have a low intake of essential fatty acids (EFAs), particularly omega-3 polyunsaturated fatty acids. The finding is yet another illustration of the poor dietary choices observed among individuals who abuse alcohol or suffer from alcoholism.
Norman Salem, Jr, PhD and his colleagues evaluated data from 4,168 participants in the 2001-2002 National Health and Nutrition Examination Survey who provided information on their alcohol consumption. Twenty-four hour dietary recall responses were analyzed for fatty acid intake.
The research team found that while energy intake increases with alcohol consumption, essential fatty acid intake declines, particularly among men. As binge-drinking frequency among men increased, a decrease in total polyunsaturates, linoleic, alpha-linolenic, and eicosapentaenoic acids was observed. "Essential fatty acids are important building blocks of living cells, making up a substantial part of cell walls," explained Dr Salem, who heads the National Institute on Alcohol Abuse and Alcoholism's Laboratory of Membrane Biochemistry & Biophysics. "EFAs also have many biological functions, and a lack of them leads to loss of growth and development, infertility, and a host of physiological and biochemical abnormalities."
"Our most important finding is the decrease in omega-3 EFA intake in binge-drinking men," Dr Salem stated. "The changes we found indicate that those who drink alcohol make food selections in such a way as to decrease foods with this important nutrient. The binge-drinking men have decreases in the longer chain omega-3 fatty acids, the ones that we typically get from eating fish, and so this suggests that they eat less fish."
July 23, 2007
Supplementing with vitamin K2 improves bone strength
The July, 2007 issue of Osteoporosis International reported the finding of researchers at the University of Maastricht in the Netherlands that postmenopausal women given vitamin K2 experienced improvements in hip bone geometry and bone strength. Bone quality declines among many women following menopause, leading to osteoporosis and increased fracture risk.
M. H. J. Knapen, L. J. Schurgers, and C. Vermeer randomized 325 women between the ages of 55 and 75 to receive 45 milligrams vitamin K2 in three divided doses per day or a placebo for three years. Bone mineral density, bone mineral content, and hip geometry, which is a measure of the size and thickness of the bone, were assessed by dual-energy x-ray absorptiometry before and after the treatment period, and compression, bending, and impact strength were calculated. Blood and urine were analyzed for markers of bone resorption and formation before and after treatment.
Two hundred fifty-seven women completed the study. Although bone mineral density was not improved by vitamin K2 supplementation, bone mineral content and femoral upper neck width remained the same in the group that received vitamin K2 indicating maintenance of bone strength, while among women who received the placebo bone strength declined significantly. The benefit associated with vitamin K2 was found for younger as well as older postmenopausal women. Markers of bone formation were higher in the vitamin K group compared to placebo after one year of treatment, and remained the same for the rest of the study.
Noting that the high doses of vitamin K2 used in the study were associated with only minor adverse effects that did not differ from the placebo group, the authors conclude that "it seems desirable to evaluate the cost-benefits of supplementing low dose vitamin K2 to all postmenopausal women."
July 20, 2007
Soy isoflavone intake associated with reduced prostate cancer incidence among Japanese
The August, 2007 Journal of Nutrition reported the finding of Japanese researchers that men who consumed greater amounts of isoflavones from soy experienced a reduced risk of prostate cancer.
Two hundred men with prostate cancer were age-matched with an equal number of men without prostate or other cancers from three areas of Japan. Participants were queried on height, weight, smoking, physical activity, medical history, and diet during the five years before diagnosis. The subjects provided information on the amount and frequency of 11 soybean foods and beverages consumed, including tofu, natto, miso, and soy milk. Total isoflavones and their aglycones genistein and daidzein were calculated, as well as fatty acid, protein, carbohydrate, vitamin, and mineral content.
Analysis of the data found that total isoflavones, as well as genistein and daidzein were associated with a lower risk of prostate cancer. Men whose intake of isoflavones was in the top one-fourth of participants had a 58 percent lower risk of the disease than those in the lowest fourth. The risk was 42 percent lower for the top versus lowest quarter of genistein intake and 45 percent lower for daidzein, with a significantly decreasing risk related to increasing intake. Although isoflavone intake was correlated with that of polyunsaturated fatty acids, omega-6 fatty acids, and magnesium due to soy's high content of these nutrients, adjustment for these factors failed to alter the association of total isoflavones with a reduction in prostate cancer.
The mechanism of isoflavones against the disease is believed to involve apoptosis of prostate cancer cells and growth inhibition due to cell cycle arrest. "Our findings indicate that isoflavones might be an effective dietary protective factor against prostate cancer in Japanese men," the authors conclude.
July 18, 2007
Turmeric compound helps immune system clear Alzheimer's plaques
A report appearing online the week of July 16, 2007 in the Proceedings of the National Academy of Sciences describes the isolation of bisdemethoxycurcumin, the active ingredient of curcuminoids found in turmeric root, which may aid the immune system to clear the peptide amyloid beta from Alzheimer's disease plaques.
Alzheimer's disease is characterized by the brain's accumulation of plaques containing amyloid beta which damage neurons, resulting in cognitive impairment. The findings of previous research suggest that curcumin, derived from turmeric, could help prevent the disease.
Dr Milan Fiala and colleagues at the University of California, Los Angeles used blood samples from Alzheimer’s disease patients for the current study. The team discovered that bisdemethoxycurcumin cleared amyloid beta by stimulating immune cells known as macrophages. They also identified immune genes involved in the process.
The compound's action against amyloid beta relies on the innate immune system, which is present at birth. “This is one of the first studies which pays attention to what we believe may be the crucial problem in Alzheimer’s disease: a defective immune system," Dr Fiala commented. "The research presents further evidence that curcuminoids may improve the function of the innate immune system of patients with Alzheimer’s disease by helping it clear the brain of amyloid beta -- the waste products that accumulate in the brain of patients with the disease."
"We think that medications based on curcuminoids and on the isolated active ingredient, bisdemethoxycurcumin, may be useful, but more work needs to be done. The natural curcuminoid substance is available in pill form at health food stores but it is not clear yet how much is being absorbed when taken orally or how much active ingredient is available in these supplements. The next step are clinical trials, which are going on at UCLA and elsewhere.”
July 16, 2007
Review finds coQ10 safe and well tolerated by patients with neurodegenerative diseases
A review published in the June, 2007 issue of the journal Mitochondrion concluded that coenzyme Q10 (coQ10) is safe in relatively high doses and may be prove to be an effective treatment for amyotrophic lateral sclerosis (ALS), Huntington's disease, and Parkinson's disease, which are neurodegenerative diseases associated with aging.
Wendy R. Galpern of the National Institute of Neurological Disorders and Stroke in Bethesda, Maryland, and Merit E. Cudkowicz of Massachusetts General Hospital East in Charlestown selected 1 ongoing trial and 1 completed study of ALS, 5 trials of Huntington's disease patients, 7 Parkinson's disease trials, and 1 ongoing trial of Alzheimer's disease and 2 of progressive supranuclear palsy (PSP) for their review.
For ALS patients, 3000 milligrams per day coQ10 was safe and well-tolerated. The ongoing trial included in the review will be evaluating preliminary signs of efficacy for 1800 milligrams or 2700 milligrams coQ10 compared with a placebo.
Among patients with Huntington disease, coenzyme Q10 was discovered to lower brain lactate levels, which are elevated in this disease. Doses of up to 3600 milligrams daily were found to be safe and well tolerated. A phase III trial is being planned to determine whether the compound has the ability to slow the disease's progression.
Coenzyme Q10's benefit in Parkinson's disease has been demonstrated in several studies. Plasma levels of coQ10 have been shown to plateau when between 2400 and 3600 milligrams per day were consumed.
Although lower doses of coQ10 may be helpful for healthy individuals, high doses may be needed to improve symptoms for those with neurodegenerative diseases. The current review has shown that these doses are generally safe and well tolerated, however, more research needs to be conducted in the area of efficacy to confirm laboratory research and preliminary clinical findings.
July 13, 2007
Alternate-day fasting modifies chronic disease risk
A review published in the July, 2007 American Journal of Clinical Nutrition reported that fasting every other day may be as effective as a daily regimen of calorie restriction at providing many benefits seen in animal and human studies. Lowering calorie intake by 15 to 40 percent has been associated with protection from adverse health conditions in many studies, however, many people find it difficult to reduce their calories for a significant length of time.
Krista A. Varady and Mark K. Hellerstein of the University of California, Berkeley selected 12 animal studies and 3 human trials on alternate- day fasting for their analysis, and studied their effects on diabetes, cardiovascular disease, and cancer.
When animal studies were examined, the effects of alternate-day fasting on reducing diabetes incidence, fasting glucose, and insulin concentration were comparable to those achieved by calorie restriction. Fewer improvements in diabetes risk were seen with human studies, however, the authors suggest that longer intervention periods than those used in the trials examined may be required to alter glucose concentrations in humans.
Alternate-day fasting also benefited cardiovascular disease risk in animals, with improvements observed in total cholesterol and triglycerides, heart rate, blood pressure, and cardiac response to myocardial infarction. Human studies found an increase in HDL cholesterol and a reduction in triglycerides, with no decrease in blood pressure associated with the regimen.
Although no human studies have evaluated alternate-day fasting's impact on cancer, animal studies revealed a reduction in lymphoma incidence, longer survival after tumor inoculation, and a reduction in cancer cell proliferation.
"It seems intuitively likely that persons will find it easier to fast or reduce intake on alternative days than to reduce their intake every day," the authors remark. "For this reason, alternate-day fasting regimens may allow better compliance than would calorie restriction regimens and may represent an attractive area for investigation.
July 11, 2007
Type of fat important in reducing colorectal cancer risk
Although high intake of fat has been associated with an increase in cancer risk, a case-control study published in the July 15, 2007 issue of the American Journal of Epidemiology concluded that a greater intake of omega-3 polyunsaturated fatty acids may be protective against colorectal cancer.
Professor Harry Campbell of the College of Medicine and Vet Medicine at the University of Edinburgh in Scotland, and his associates paired 1,455 men and women diagnosed with colorectal cancer with an equal number of healthy control subjects matched for age, gender and region of residence. Lifestyle and food frequency questionnaires regarding the year prior to diagnosis or recruitment to the study were completed by all participants in the current analysis. Total fatty acid, as well as saturated fatty acid, monounsaturated fatty acid, omega-6 polyunsaturated fatty acid, omega-3 polyunsaturated fatty acid, trans-fatty acid, and trans-monounsaturated fatty acid intake was determined. Intake levels of individual fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), were also calculated.
Participants without colorectal cancer reported significantly lower daily calorie intake than those diagnosed with the disease. Although total and trans-monounsaturated fatty acid intake were associated with increased colorectal cancer risk, adjustment for calorie intake negated this effect. Greater intake of omega-3 fatty acids, EPA, and DHA were dose-dependently associated with reduced colorectal cancer risk. Participants whose omega-3 intake was in the top one-fourth of participants experienced a 37 percent lower risk of colorectal cancer than those who intake was in the lowest quarter, while having EPA and DHA in the top fourth was associated with a 41 and 37 percent lower risk.
The authors conclude, "The observed different effects of different types of fatty acids underline the importance of type of fat in the etiology and prevention of colorectal cancer. "
July 9, 2007
Pumpkin extract regenerates pancreatic cells in rats
In the July, 2007 issue of the Journal of the Science of Food and Agriculture, Tao Xia of East China Normal University, and and Qin Wang of Shanghai Jiaotong University, in Shanghai, China reported their discovery that diabetic rats fed an extract of pumpkin had lower blood glucose, increased plasma insulin, and reduced pancreatic lipid peroxidation compared with diabetics that did not receive the extract. Additionally, pumpkin was found to stimulate the regeneration of pancreatic beta-cells responsible for making insulin.
Doctors Xia and Wang divided 12 diabetic rats to receive a diet supplemented with or without pumpkin extract for 30 days. An additional group of 12 healthy, nondiabetic rats were similarly divided and treated. At the end of the study, untreated diabetic rats had lower insulin and higher glucose levels than the healthy controls, however, treatment of the diabetic animals with pumpkin extract significantly elevated insulin, thereby lowering glucose levels. Lipid peroxidation was found to be markedly lowered in the pancreases of diabetic rats that received pumpkin compared with untreated diabetics, and they had just 8 percent fewer beta-cells than healthy animals.
The protective effect of the extract may be due to pumpkin's antioxidants and the presence of D-chiro-inositol, which mediates insulin activity. By boosting insulin levels and lowering blood sugar levels, oxidative damage to beta cells is further reduced which allows for some regeneration. The researchers hope that pumpkin could be useful to treat both type 1 and type 2 diabetes.
"The main finding is that feeding pumpkin extract prevents the progressive destruction of pancreatic beta cells," stated David Bender who is sub-dean at the Royal Free and University College Medical School in London. ‘I think the exciting thing is that this may be a source of medicine to take by mouth (rather than injections)."
July 6, 2007
Apple compounds fight cancer
An article published in the May 30, 2007 issue of the Journal of Agricultural and Food Chemistry described the discovery of Xiangjiu He and Rui Hai Liu of Cornell University in Ithaca, New York that compounds occurring in the peel of apples demonstrate an anticancer effect in human cancer cells.
The duo isolated and identified thirteen triterpenoids in red delicious apple peel and evaluated their ability to inhibit abnormal cell proliferation in cultured liver, breast and colon cancer cell lines. Three of the compounds were newly identified by the team. "We found that several compounds have potent antiproliferative activities against human liver, colon and breast cancer cells and may be partially responsible for the anticancer activities of whole apples," stated Dr Liu, who is an associate professor of food science at Cornell and the study's senior author. "Some compounds were more potent and acted differently against the various cancer cell lines, but they all show very potent anticancer activities and should be studied further."
Previous studies conducted at Cornell found that apples also reduced the size and number of mammary tumors in rats as well as in cell cultures. Drs He and Liu believe that the triterpenoids may be among the compounds responsible for apples' benefits. Additionally, Dr Liu has identified phytochemical compounds known as flavonoids and phenolic acids in apples and other plant foods that appear to have anticancer properties. "We believe that a recommendation that consumers to eat five to 12 servings of a wide variety of fruits and vegetables daily is appropriate to reduce the risks of chronic diseases, including cancer, and to meet nutrient requirements for optimum health," Dr Liu said.
July 2, 2007
Genistein increases bone mineral density
The results of a randomized placebo-controlled trial published in the June 19, 2007 issue of the Annals of Internal Medicine found that women with osteopenia who consumed the soy phytoestrogen genistein, experienced improvements in bone mineral density and markers of bone metabolism compared with those who received a placebo. Osteopenia is a condition in which bone density is reduced that occurs frequently in women following menopause, and while not as severe as osteoporosis, also increases the risk of fracture. The primary female hormone estrogen is commonly used to prevent and treat osteoporosis.
Three university medical centers in Italy enrolled 389 postmenopausal women with a bone mineral density of less than 0.795 grams per cubic centimeter at the femoral neck. The participants were divided to receive 54 milligrams per day genistein with calcium and vitamin D3, or a placebo consisting of calcium and vitamin D3, following a four week stabilization period during which all received a low soy, reduced-fat diet. Bone mineral density of the lumbar spine and femoral neck, and serum and urinary bone metabolism markers were measured at the beginning and conclusion of the study. Ultrasound examination of the uterus measured endometrial thickness. Increased thickness of the endometrium, or uterine lining, is associated with a greater cancer risk, and is a side effect of some hormonal treatments for diminished bone density.
After two years, women who received genistein had an increase in lumbar spine and femoral neck bone density, while those who received a placebo experienced a decline. Treatment with genistein improved serum and urinary bone metabolism factors while not increasing endometrial thickness.
"Twenty-four months of treatment with genistein has positive effects on bone mineral density in osteopenic postmenopausal women," the authors conclude.
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