In The News: July 2010

In one of several noteworthy presentations at the 101st Annual Meeting of the American Association for Cancer Research, it was reported that a higher intake of vitamin K is associated with a reduced risk of non-Hodgkin lymphoma.*

James Cerhan, MD, PhD and his colleagues at the Mayo Comprehensive Cancer Center compared 603 non-Hodgkin lymphoma patients to 1,007 men and women who did not have cancer. The investigators found an association between a lower risk of non-Hodgkin lymphoma and increased consumption of vitamin K. For those whose intake of the vitamin was among the top 25% of participants at over 108 micrograms per day, the risk of the disease was 45% lower compared with those whose intake was among the lowest fourth at less than 39 micrograms per day.

“As with all new findings, this will need to be replicated in other studies,” Dr. Cerhan noted.

Editor’s note: This study adds evidence to previous research that associates vitamin K intake with cancer protection.

—Dayna Dye

The American Association for Cancer Research 101st Annual Meeting 2010 was the site of a presentation concerning the finding of a protective effect of vitamin and calcium supplements against breast cancer.*

Jaime Matta, PhD of the Ponce School of Medicine in Puerto Rico and his colleagues compared 268 Puerto Rican women with breast cancer to 457 healthy control subjects. Participants who consumed vitamin supplements were found to have a 30% lower risk of breast cancer compared to those who did not have a history of vitamin supplementation, and those who consumed calcium supplements had a 40% lower risk.

“It is not an immediate effect,” Dr. Matta noted. “You don’t take a vitamin today and your breast cancer risk is reduced tomorrow. However, we did see a long-term effect in terms of breast cancer reduction.”

Editor’s note: Since cancer takes years to develop, long-term protective measures are essential.

—Dayna Dye

The International Journal of Gynecologic Cancer reports the finding of Korean researchers of a lower risk of cervical intraepithelial neoplasia (also known as cervical dysplasia) among human papilloma virus-positive women who consumed vitamin supplements. Human papilloma virus has been identified as the agent responsible for cervical cancer, for which cervical dysplasia is a precursor. The condition is detected by a pap smear and graded according to stage as 1, 2, or 3.*

Ninety women with cervical dysplasia 1 and 72 with cervical dysplasia 2/3 were compared with 166 control subjects. Women who used multivitamins had a 79% lower risk of cervical dysplasia 2/3 than those who did not use them. Similar reductions in cervical dysplasia 2/3 risk were observed for vitamins A, C, and E, and calcium use.

“Larger studies are needed for confirmation of these findings before the results can be generalized to a broader population,” the authors write.

Editor’s note: The researchers involved in this study previously uncovered a link between a lower risk of cervical cancer and increased antioxidant intake from diet and supplements.

—Dayna Dye

A study published online in the journal Environmental Health Perspectives suggest that increased vitamin D from sunlight exposure could have a protective effect against rheumatoid arthritis, a chronic autoimmune disease with unknown causes.*

For the current investigation, Boston University School of Public Health associate professor Verónica Vieira, MS, DSc and her colleagues analyzed data from the Nurses’ Health Study, which enrolled female nurses in the United States beginning in 1976. Four hundred sixty-one participants diagnosed with rheumatoid arthritis between 1988 and 2002 were compared to 9,220 control subjects who did not have the disease. The researchers examined the association between rheumatoid arthritis risk and residential address.

The team found a higher risk of rheumatoid arthritis among women living in the northeastern United States, suggesting that less sunlight exposure, and, consequently, decreased vitamin D production, could be a factor in the development of the disease.

Editor’s note: The authors remark that an association with northern latitudes has also been observed for multiple sclerosis, Crohn’s disease, and other autoimmune diseases.

—Dayna Dye

A recent study published in the American Journal of Clinical Nutrition suggests that “sleep restriction could be one of the environmental factors that contribute to the obesity epidemic.”* In particular, the study discovered that normal-weight young men ate several hundred extra calories a day when they’d gotten just four hours of sleep compared to when they slept for a full eight hours.

The study, led by Dr. Laurent Brondel of the European Centre for Taste Sciences in Dijon, France, followed the sleep, eating, and energy expenditure in 12 healthy young men across two 48-hour periods. Two days served as a control period, where the men in the study adhered to their normal routines but wrote down their sleep, eating, and activities in a diary. During the second 48-hour period, the men went to bed at 12 am and woke up at 8 am on one day, and on the other day they went to bed at 2 am and woke up at 6 am. There were no eating restrictions during each period.

Researchers found that after the short night sleep, the men consumed 22% more calories, on average, than when they were allowed to sleep eight hours. This accounted for nearly 560 extra calories a day per person.

Editor’s note: Getting adequate sleep may be beneficial when trying to follow a low-calorie or calorie restricted diet.

—Jon Finkel

A study published by the British Journal of Nutrition states that inadequate levels of vitamin B6 may increase the risk of Parkinson’s disease by 50%.* According to the American Parkinson’s Disease Association, over two million Americans currently suffer from PD. While searching for optimal vitamin levels to combat Parkinson’s, researchers from Japan conducted a hospital-based case-control study involving 249 people with Parkinson’s disease and 368 people without any neurodegenerative condition.

In order to quantify the intake of B vitamins, the subjects filled out a self-administered, semi-quantitative, diet questionnaire. They observed that there was no link between riboflavin, folate, and vitamin B12, but low intake of vitamin B6 was linked to an increased risk of the disease, independent of other factors.

These findings agree with a previous study done by researchers from the Erasmus Medical Center in Rotterdam, England, that also linked increased B6 intake with Parkinson’s disease risk.

Editor’s note: These low levels of B6 intake would only occur in those who do not take vitamin supplements.

—Jon Finkel

An article published in the American Journal of Clinical Nutrition reports the finding of German researchers of an association between reduced vitamin K2 intake and an increased risk of dying from cancer.*

The researchers analyzed data from 24,340 participants in the EPIC-Heidelberg study who were aged 35 to 64 upon enrollment between 1994 and 1998. Participants were followed through 2008. Over the follow up period, there were 1,755 cases of cancer, including 458 fatalities. While those whose intake of vitamin K2 was among the top 25% of participants had a 14% reduction in cancer incidence compared with those whose intake was among the lowest fourth, the group with the highest intake experienced a 28% lower risk of dying of the disease. The reduction occurred mainly in men.

“This study showed inverse associations between the dietary intake of menaquinones and both overall cancer incidence and mortality,” the authors conclude.

Editor’s note: The authors explain the difference in vitamin K2’s effects on men and women by the fact that the men in the study had cancer sites (prostate, lung) that were likelier to be influenced by vitamin K2.

—Dayna Dye

The outcome of a study appearing in the Journal of Gerontology: Medical Sciences contradicts concerns raised by previous studies that deliberate weight loss among older individuals could increase the risk of death.*

Researchers at Wake Forest University Baptist Medical Center analyzed data from 318 arthritic men and women over the age of 60 who participated in a randomized trial that evaluated the effects of dieting and/or exercise on physical function. Those assigned to a weight loss diet lost an average of 10.5 pounds over 18.5 months.

Within 8 years after the trial’s conclusion, 15 deaths occurred among those assigned to weight loss diet interventions, compared with 30 in the remainder of the participants. “This study puts to rest a lot of unfounded concerns about how to address the epidemic of obesity among our older adults,” coauthor Stephen B. Kritchevsky, PhD concluded.

Editor’s note: The current findings are in agreement with numerous animal studies that have associated increased life span with calorie restriction.

—Dayna Dye

According to a WebMD Health News article, women who walk two or more hours per week or who walk at a brisk pace can significantly reduce their risk of suffering a stroke.* Based on a study of the exercising habits of 39,315 female health professionals whose average age was 54, the findings showed that women who walked at a pace of 3 miles per hour or faster had a 37% lower risk of suffering any type of stroke. Women who walked two or more hours a week had a 30% reduced risk of any type of stroke.

Jacob R. Sattelmair, MSc, of the Harvard School of Public Health was interviewed for the feature and concluded that “physical activity, including regular walking, is an important modifiable behavior for stroke prevention. Physical activity is essential to promoting cardiovascular health and reducing risk of cardiovascular disease, and walking is one way of achieving physical activity.”

—Jon Finkel

A research team headed by Dr. Amanda Adler from the MRC Epidemiology Unit at the Institute of Metabolic Science in Cambridge (UK), published findings in Diabetes Care stating that kidney function was improved in type-1 diabetics with the highest average intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), compared with people with the lowest intakes of the fatty acids.*

They culled their results from data made available to them in the Diabetes Control and Complications Trial, which involved 1,436 participants who were between the ages of 13 and 39. The researchers measured the excretion of the protein albumin in urine. People who have kidney problems often experience a leakage of the protein albumin from the kidney into the urine. According to the study, people with a higher average intake of omega-3s had albumin excretion levels 22.7 mg per 24 hours lower than people with the lowest average intakes of omega-3s.

—Jon Finkel

A new team of researchers from Japan suspect that antimicrobial molecules contained within green tea helps preserve teeth, as long as you don’t add sugar.* An article posted to discoverynews.com describes the findings, noting that catechins, found heavily in green tea, may be the protecting component.

Yasushi Koyama, the lead researcher on the project from the Tohuku University Graduate School of Medicine, and his colleagues examined more than 25,000 Japanese men and women between the ages of 40 and 64. They discovered that men who consumed at least one cup of tea a day were 19% less likely to have fewer than 20 teeth than those who did not drink green tea. Women had 13% lower odds.

The researchers concluded that catechins, which have been shown to kill mouth bacteria associated with tooth decay and gum disease, most likely give green tea its dental benefits.

Editor’s note: The authors remark that an association with northern latitudes has also been observed for multiple sclerosis, Crohn’s disease, and other autoimmune diseases.

—Jon Finkel