In The News: February 2011

Greater dietary intake of magnesium and higher plasma magnesium levels are associated with a reduced risk of sudden cardiac death in women, according to a study published in the American Journal of Clinical Nutrition.* Long known for its anti-arrhythmic properties in cellular and experimental models, magnesium’s relation to sudden cardiac death has been unclear.

Scientists examined dietary intake data collected from more than 88,000 women enrolled in the Nurses’ Health Study. During 26 years of follow-up, 505 cases of sudden cardiac death occurred. In a case-control analysis, the scientists compared plasma magnesium levels between 99 sudden cardiac death cases and 291 control patients.

Higher dietary intake of magnesium and higher plasma magnesium levels were associated with lower risks of sudden cardiac death.

These findings suggest that increasing magnesium intake and plasma levels may protect women against sudden cardiac death by preventing abnormal heart rhythms.

—E. Wagner, ND

An article published in the journal Cancer Research reveals an association between higher levels of serum vitamin D and a lower risk of bladder cancer in men.*

The study involved 500 participants in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study of Finnish male smokers conducted to determine the effects of alpha-tocopherol and beta-carotene supplementation on cancer risk.

The researchers compared 250 subjects who were diagnosed with bladder cancer through April 2005 with an equal number of participants who did not have the disease. Men whose vitamin D level was less than 25 nanomoles per liter experienced a 73% greater adjusted risk of the disease than those whose levels were at least 50 nanomoles per liter.

“These findings are consistent with previous cell culture, in vivo, and genetic evidence suggesting that greater exposure to vitamin D could have a role in protecting against bladder cancer,” Alison M. Mondul and coauthors write.

Editor’s note: The finding adds another cancer to the list of those for which vitamin D appears to have a protective benefit.

—D. Dye

Researchers writing in Bio-Med Central’s open access journal Nutrition and Metabolism discovered that when rats were exposed to a moderately toxic herbicide, ingestion of olive oil partially protected them against liver damage.* The herbicide is known to deplete antioxidants and cause oxidative stress.

The experiments were carried out on a group of 80 rats by Mohamed Hammami and his teams from the University of Monastir, Tunisia, and King Saud University, Riyadh, Saudi Arabia. The researchers divided the rats into a control group, an olive oil group, and 6 groups that were exposed to the herbicide ‘2,4-Dichlorophenoxyacetic acid’ with or without either whole olive oil, or one of two oil extracts—the hydrophilic fraction or the lipophilic fraction.

The results were interesting. Every rat given the herbicide showed signs of significant liver damage, but the rats that ingested extra virgin olive oil and hydrophilic fraction showed a significant increase in antioxidant enzyme activity and a decrease in markers of liver damage.

—J. Finkel

A report published in the journal Blood reveals an increased risk of rapid disease progression and earlier mortality in chronic lymphocytic leukemia (CLL) patients who had insufficient vitamin D levels.*

Tait Shanafelt, MD, and his colleagues evaluated the blood of 390 newly diagnosed chronic lymphocytic leukemia patients for plasma 25-hydroxyvitamin D. After a median follow-up of three years, an association was observed between decreasing vitamin D levels and shorter intervals between diagnosis and cancer progression, as well as reduced survival. Participants whose vitamin D levels were insufficient had a 66% greater risk of disease progression necessitating chemotherapy and more than double the risk of dying than those with sufficient levels.

“Vitamin D insufficiency is associated with inferior time to treatment and overall survival in CLL patients,” the authors conclude. “Whether normalizing vitamin D levels in deficient CLL patients would improve outcome merits clinical testing.”

Editor’s note: “It is simple for patients to have their vitamin D levels checked by their physicians with a blood test,” Dr. Shanafelt remarked. “And if they are deficient, vitamin D supplements are widely available and have minimal side effects.”

—D. Dye

A recent article in the San Antonio Business Journal describes a device being developed by a team of researchers in San Antonio that utilizes cutting-edge technology to cool the kidney to aid in surgery.* The device is being developed by South Texas Technology Management, which is in charge of taking the medical inventions developed at the University of Texas Health and Science Center at San Antonio and commercializing them.

Between 20,000 and 30,000 partial nephrectomy (kidney) surgeries are performed a year in the United States. A typical nephrectomy with a cancerous growth involves clamping off blood flow to the organ, which gives surgeons roughly 15 minutes to perform the operation before kidney failure is likely. Because of this enormous time constraint, many doctors will choose to simply remove the kidney instead.

The new device may double the amount of time a surgeon has to work with. The device cools the kidney by laproscopically inserting tubes that wrap around the kidney and pump cold fluid to lower the temperature of the organ.

“We think this device will encourage more doctors to offer this type of surgery rather than removing the entire kidney,” Dr. Dipen Parekh, a surgeon and associate professor of urology at the Health Science Center, says.

—J. Finkel

In a study reported in a recent issue of Nutrition and Cancer, researchers in Milan uncovered an association between a lower risk of several types of cancer and an increased intake of flavonoids and proanthocyanidins.*

Carlo La Vecchia of the Università degli Studi di Milano and colleagues evaluated data in a network of case-control studies conducted at multiple Italian centers since the early 1990s. The studies included a total of 9,622 cases of cancer and 16,050 controls. The participants’ diets were analyzed for 6 classes of flavonoids, including isoflavones, anthocyanidins, flavanols, flavanones, flavones and flavonols, and 6 classes of proanthocyanidins.

“The findings from this large network of Italian case-control studies have provided support for an apparent protective role of flavanones on upper aerodigestive tract cancers; flavonols, anthocyanidins, and proanthocyanidins on colorectal cancer; flavonols and flavones on breast cancer; isoflavones on ovarian cancer; and flavonols on renal cancer,” the authors conclude.

Editor’s note: These polyphenolic compounds are found in fruit, vegetables, and plant-sourced beverages, and may be responsible for the protective effects observed for plant foods against a number of chronic diseases.

—D. Dye

A team of researchers from Sao Paulo State University, Brazil, recently published a study in Nutrition Journal that tested the effectiveness of olive oil and its minor constituents as important dietary therapeutic interventions in preventive medicine in regards to obesity-induced cardiac metabolic changes.*

The study involved two groups of rats receiving hypercaloric-chow. Halfway through the study, each group was divided into subgroups, with one group receiving standard food and saline, another group receiving standard food and olive oil, a third group receiving standard food and oleuropein, a fourth group receiving standard food and cafeic acid, and several more groups involving rats receiving some combination of hypercaloric food, olive oil, oleuropein, and cafeic acid.

The results were conclusive, as the study demonstrated for the first time that olive-oil, oleuropein, and cafeic-acid enhanced fat-oxidation and optimized cardiac energy metabolism in obesity conditions. Olive oil and its phenolic compounds improved myocardial oxidative stress in standard-fed conditions.

—J. Finkel

A new study performed at Saint Louis University suggests that curcumin may have some promise in preventing or treating liver damage from an advanced form of a condition known as fatty liver disease.* Curcumin is contained in the plant turmeric, which has been used by the Chinese for thousands of years and is the chemical that gives curry its spicy nature.

The research specifically points to curcumin’s use as a potential weapon in the battle against a type of fatty liver disease called non-alcoholic steatohepatitis (NASH). NASH is commonly linked to obesity and weight gain.

“While research in an animal model and human clinical trials are needed, our study suggests that curcumin may be an effective therapy to treat and prevent liver fibrosis, which is associated with NASH,” said Anping Chen, PhD, director of research in the pathology department of Saint Louis University.

—J. Finkel

According to new studies led by US Department of Agriculture (USDA) chemist Richard Anderson, a water-soluble extract of cinnamon could help reduce risk factors long associated with diabetes and heart disease.* Cinnamon extract has antioxidant compounds, which may be what is responsible for this data.

The study involved twenty-two obese participants with impaired glucose values, or “prediabetes.” Prediabetes occurs when cells show resistance to the higher-than-normal levels of insulin produced by the pancreas. The members of the study were divided into two random groups and either given a placebo or 250 milligrams of dried, water-soluble cinnamon extract twice daily with their diets. The results were measured through blood samples that were collected at the beginning of the study, after six weeks, and after 12 weeks. The study showed that water-soluble cinnamon extract improved several antioxidant variables by as much as 13% to 23%. These numbers led to decreases in fasting glucose.

—J. Finkel

A recent study published in the Journal of Nutritional Biochemistry points to the use of fish oils as a weapon in the fight against diabetes.* Specifically, fish oils activate the transcription factor PPAR-gamma, which increases the regulation of adipocytes and helps to maintain glucose homeostasis.

The mice in the study that were fed the diabetes drug rosiglitazone, brand name Avandia®, had a significantly lower feed intake but showed no major effect on body weight or fat pad weight. The mice fed fish oil did not significantly decrease feed intake, but they did show significantly decreased body and fat pad weight.

These results suggest that there was increased glucose utilization and, therefore, a reduced blood glucose concentration in the transgenic mice. Also, the plasma adiponectin was elevated by fish oil treatment, suggesting a role of adiponectin in mediating the polyunsaturated fatty acids (PUFA) effect. These results suggest that PUFA may serve as a natural regulator of glucose uptake in vivo and these effects are mainly through PPAR-gamma function.

—J. Finkel

An article in Translational Stroke Research reports a neuroprotective effect for DHA given after ischemic stroke.*

Dr. Nicolas Bazan and his associates induced stroke in rats by occluding the middle cerebral artery. In a preliminary experiment, the animals received DHA intravenously following cerebral artery occlusion. A second experiment involved the administration of DHA post-stroke and the assessment of brain damage by MRI. In a third experiment, rats were given DHA or saline after stroke onset, after which their brains were examined for NPD1, a substance for which DHA is a precursor that has cell-protective effects.

The first experiment found a reduction in neurologic deficits in rats that received DHA compared with controls, even when DHA was administered 5 hours after the onset of stroke. In the study involving MRI, DHA treatment was associated with smaller infarcts. The third experiment revealed increased NPD1 synthesis in the DHA treated group.

Editor’s note: The findings identify a possible treatment for strokes and quantify the time limit of DHA’s effectiveness.

—D. Dye