In The News: May 2012

An article published online in the Archives of Ophthalmology describes the discovery of Harvard researchers of a benefit for omega-3 fatty acids in combination with vitamin A for individuals with retinitis pigmentosa.*

Eliot L. Berson, MD, of Harvard Medical School and his associates analyzed data from 357 adults with retinitis pigmentosa who participated in one of three randomized clinical trials that were conducted from 1984 to 1991, 1996 to 2001 and 2003 to 2008. All subjects were receiving 15,000 international units vitamin A for four to six years. Dietary questionnaires completed upon enrollment and at yearly follow-up visits were analyzed for the intake of omega-3 fatty acids.

Among those whose intake of omega-3 fatty acids was classified as high, a 40% reduction in the average yearly rate of decline of distance visual acuity was observed in comparison with those who consumed lower levels.

Editor’s note: Retinitis pigmentosa is a disease that begins with night blindness in adolescence and progresses to side vision loss, tunnel vision, and eventual blindness in some men and women.

A recent issue of Arteriosclerosis, Thrombosis and Vascular Biology reports the finding of Danish researchers of a link between short telomeres and an increased risk of heart disease and early death.*

University of Copenhagen Clinical Professor of Genetic Epidemiology Borge Nordestgaard and his colleagues measured white blood cell telomere length in blood samples from 19,838 participants in the Copenhagen City Heart Study and the Copenhagen General Population Study. The subjects were followed for up to 19 years, during which time 2,038 cases of ischemic heart disease, 929 heart attacks, and 4,342 deaths occurred.

Telomere length was found to decrease with age in both men and women. Shortened telomeres were detected in 25% of the participants, and were associated with a 49% adjusted increase in heart attack risk, a 24% increased risk of heart disease, and a 25% greater risk of early mortality.

Editor’s note: Telomeres cap and protect the ends of chromosomes and shorten with the passage of time, which makes them useful as a marker of cellular aging. While accelerated telomere shortening has been associated with obesity, smoking, and other factors; multivitamin use, exercise, and high levels of omega-3 fatty acids have been found to have a protective effect on their maintenance.

In the journal BMC Medicine, researchers from Texas Tech University Health Sciences report the discovery of a mechanism for diindolylmethane (DIM), an active metabolite of indole-3-carbinol found in cruciferous vegetables, to induce programmed cell death (apoptosis) in cultured ovarian cancer cells.*

The current study explored the effects of DIM in several ovarian cancer lines. It was found that DIM induces apoptosis, and that it exerts its effects by blocking the production and activation of STAT3, a transcription factor that is associated with the growth and survival of cells which is over-expressed in cases of resistance to the chemotherapy cisplatin.

In further experimentation, the researchers pretreated ovarian cancer cells with DIM, followed by the administration of cisplatin for 24 hours. The combination resulted in a 50 to 70% reduction in cell survival, in contrast with a 28% reduction in cells treated with cisplatin alone.

Editor’s note: Furthermore, mice treated with DIM alone or DIM and cisplatin experienced retarded growth of implanted ovarian tumors compared to untreated mice or animals that received cisplatin alone.

An article published in the journal Appetite reports the finding of researchers from the University of Copenhagen of an appetite-suppressing effect for flaxseed in healthy young men and women.*

In a crossover study, 24 men and women underwent an overnight fast after which they were assigned to a drink containing 2.5 grams soluble flaxseed fibers or no fiber. Appetite was assessed every 30 minutes for two hours. A meal was then served to the participants and food consumption measured. A second crossover study involved 20 participants, and compared the effects of the same flax-containing drink to flax fiber tablets taken with the control beverage.

While the flax drink decreased hunger and food intake in comparison with the control beverage, no significant differences were observed between the effects of the flax drink and flax tablets. Calorie intake was 9% less after consuming the flax drink in comparison with that of subjects who consumed the control beverage.

Editor’s note: While a diet that contains foods that are naturally high in fiber may help control appetite, “The advantage of flaxseed fibers over other dietary fibers is that a dose of 2.5 grams is sufficient to impact appetite,” the authors write. “This is a considerably smaller amount than in most other studies, which administered dietary fiber doses ranging from 5 to 12 grams.”

A study described in the Journals of Gerontology Series A revealed that the addition of coenzyme Q10 (CoQ10) to a Mediterranean diet lowers a number of indicators of inflammation in older men and women.*

Spanish researchers enrolled ten men and ten women who were not being treated for inflammation or elevated lipids. The regimens consisted of a Mediterranean diet, a Mediterranean diet supplemented with 200 milligrams per day of coenzyme Q10, and a Western diet containing high amounts of saturated fat.

Consumption of the Mediterranean diet was found to be associated with a reduction in the expression of a number of genes involved in the inflammatory process. The addition of coenzyme Q10 to the diet further reduced the expression of three significant genes.

Editor’s note: Authors Jose Lopez-Miranda and colleagues write that, “In healthy humans, plasma oxidative damage may be partially prevented by CoQ10 supplementa­tion, which has been replicated in other populations, like psoriasis or coronary heart disease patients.”

A study proposed by the University of Zurich will evaluate the effects of an exercise program and/or supplementation with omega-3 polyunsaturated fatty acids or vitamin D on the risk of age-related diseases, including arthritis, cardiovascular disease, dementia and osteoporosis, in a senior population.*

The DO-HEALTH trial will recruit over 2,000 men and women aged 70 and older residing in five European countries beginning in May of this year. Professor Heike Bischoff-Ferrari and her associates will assess the safety and efficacy of the regimens on the risk of age-related conditions as well as on the ability to perform activities of daily living. “DO-HEALTH hopes to provide definitive evidence that the three interventions, alone or combined, are able to reduce the number of fractures, the functional and cognitive decline, the risk of hypertension, and the risk of infections in the senior population,” Dr. Bischoff-Ferrari stated.

Editor’s note: “Various studies have shown that vitamin D and simple targeted exercise programs can significantly improve functional mobility and reduce falls and fractures in seniors, even by up to 30%,” Dr. Bischoff-Ferrari noted.

A report published in the American Journal of Clinical Nutrition reveals an association between lower risk of incident functional disability, such as that caused by cognitive impairment, osteoporosis, and stroke, and increased intake of green tea in older men and women.*

The researchers analyzed data from 13,988 Japanese men and women aged 65 and older. Questionnaires completed upon enrollment were analyzed for the frequency of green, oolong, and black tea intake. Over a three year follow-up period, incident functional disability was documented in 1,316 men and women.

For subjects who consumed one to two cups green tea per day, the risk of becoming disabled was 10% lower than those who reported drinking less than a cup per day. The probability of disability declined with greater green tea consumption to a 33% lower risk for those whose intake was five cups per day or more.

Editor’s note: Previous studies have uncovered associations between green tea consumption and a lower risk of stroke, dementia, fracture, and depression, all of which can contribute to disability. Green tea polyphenol intake has also been associated with improved leg strength, thereby reducing frailty, a major disability risk factor.

An article published in Science Translational Medicine reveals the discovery of a significant reduction in the growth of cancerous tumors subjected to short cycles of fasting. The regimen was found to improve the effect of chemotherapy but also worked well without drug treatment in cultured cancer cell lines and in mice.*

The researchers initially determined that glucose and growth factor restriction sensitized 15 of 17 cancer cell lines to chemotherapy drugs. In studies with live mice that received implanted human and animal cancer tumors, animals that had access to only water for 48 to 60 hours experienced benefits that, in some cases, were comparable to chemotherapy. However, the greatest benefits were observed in animals that underwent both chemotherapy and fasting. In two experiments with mice injected with neuroblastoma cells, approximately 25 and 42% of fasted animals that received chemotherapy achieved long term survival, in contrast with zero chemotherapy-treated animals that consumed a normal diet.

Editor’s note: The proposed mechanism behind the protective action of fasting centers around the allocation of cellular energy resources. In the fasting state when available energy nutrients are low, a normal cell utilizes available cellular energy towards its basic maintenance needs and away from reproductive and growth processes. Cancer cells lack this same capability because their oncogenes (often mutated genes that cause rapid replication of tumor cells) block this response and by allocating cellular energy towards replication, there is not enough left to support basic processes and the cell dies.

A recent issue of Anticancer Research reports a lower risk for colorectal cancer in association with increased intake of calcium, vitamin C, vitamin D, riboflavin, and folate.*

Researchers matched 1,760 men and women with colorectal cancer with 2,481 control subjects. Questionnaire responses were used to quantify the intake of calcium, iron, folate, and vitamins A, B1, B2, B6, B12, C, D, and E from food and supplements.

The team observed diminishing odds of having colorectal cancer in association with increased intake of calcium, vitamin C, vitamin D, riboflavin, and folate from dietary and supplemental sources. Those whose intake of calcium from supplements and food was among the top one-fifth of participants had a 41% lower adjusted risk of colorectal cancer compared to those whose intake was among the lowest fifth, and for riboflavin, the risk was 39% lower for subjects in the highest fifth.

Editor’s note: A reduction in risk was also observed for increased consumption of these nutrients when derived from food alone, although the decrease was not as great as that observed for food plus supplemental sources.

The FDA recently announced that a counterfeit version of the anti-cancer drug Avastin^® may have been purchased and used in a number of medical facilities in the United States.* Nineteen medical practices known to have purchased unapproved cancer medications were contacted to warn them about use of the possible counterfeit drug. The fake version of Avastin^® that is being peddled lacks the medicine’s key ingredient, bevacizumab, which may endanger patients who take the drug believing it to be the real thing. Roche, who manufactures Avastin^®, conducted laboratory tests confirming the presence of the counterfeit version.

“The counterfeit product is not safe or effective and should not be used,” Roche member company Genentech said in a written statement. Genentech is responsible for marketing Avastin^®. The unapproved cancer medications—potentially including the counterfeit version of Avastin^®—were purchased from a foreign supplier known as Quality Specialty Products, which may also be known as Montana Health Care Solutions, according to the FDA. “It sounds like the key issue with that ... is that the counterfeit vials don’t have Genentech labels on them,” said Donald Harvey, president of the Hematology and Oncology Pharmacists Association.

Scientists at the Salk Institute for Biological Studies have reported in the journal Science that they have discovered that long-lived proteins (ELLPs) in the brains of rats can persist for more than one year—a result that suggests the proteins, also found in human brains, last an entire lifetime.*

“Most cells, but not neurons, combat functional deterioration of their protein components through the process of protein turnover, in which the potentially impaired parts of the proteins are replaced with new functional copies,” said senior author Martin Hetzer, of Salk’s Molecular and Cell Biology Laboratory, in a statement. “Our results also suggest that nuclear pore deterioration might be a general aging mechanism leading to age-related defects in nuclear function, such as the loss of youthful gene expression programs.”

The hope is that in addition to providing data on brain aging, the information gathered may give insight into the development of neurodegenerative diseases like Parkinson’s and Alzheimer’s.