Multivitamin supplements unrelated to breast cancer risk in large U.S. study

A recent Harvard Medical School study followed more than 37,000 U.S. women for 10 years and found no correlation between multivitamin use and breast cancer risk.

Researchers from Harvard Medical School and Brigham and Women’s Hospital recently evaluated possible associations between multivitamin supplements and risk of breast cancer. At the beginning of the study, 37,920 cancer-free U.S. women aged 45 and older provided detailed information on multivitamin supplement use. Throughout an average of 10 years of follow-up, 1,171 cases of breast cancer were documented.

The use of multivitamin supplements was not associated with an overall risk of breast cancer in this large study group. High frequency of use (at least 6 times per week) and duration of supplementation (current use for at least 20 years) were not associated with an increase in risk compared to non-users. A small reduction in breast cancer risk was seen in multivitamin users who consumed 10 grams/day of alcohol or more. There was also a slight decrease in risk of estrogen receptor negative-progesterone receptor negative breast cancer among multivitamin users.

The researchers stated that although there was no overall statistically significant association between multivitamin use and breast cancer, multivitamins may reduce the risk for women consuming alcohol and in certain estrogen receptor negative cancers.

Source: A Prospective Study of Multivitamin Supplement Use and Risk of Breast Cancer, Ishitani K, Lin J, Mason JE, Buring JE, Zhang SM, Am J Epidemiol 167(10):1197-206

Source: USANA Health Sciences

Researchers recommend pregnant women take 4,000 IU Vitamin D a day

VANCOUVER, BRITISH COLUMBIA – Taking vitamin D supplements during pregnancy is not only safe for mother and baby, but also can prevent preterm labour/births and infections, according to results of a randomized controlled study to be presented at the Pediatric Academic Societies (PAS) annual meeting in Vancouver, British Columbia, Canada.

In the 1950s and ’60s, people were concerned that vitamin D could cause birth defects, according to Carol L. Wagner, MD, lead author of the study and a pediatric researcher at Medical University of South Carolina. It now is known that vitamin D is important for maternal and infant health, including bone health and immune function.

Recent studies have shown that vitamin D deficiency during pregnancy is a serious public health issue.

“Diet doesn’t provide enough vitamin D, and we don’t go in the sun as much as we need,” Dr. Wagner said.

Therefore, she and her colleagues, including Bruce W. Hollis, PhD, who has worked in the field of vitamin D research for the last 30 years, set out to determine the optimal dose of vitamin D supplements for pregnant women without doing harm.

Researchers randomized 494 pregnant women at 12-16 weeks’ gestation into three treatment groups. Group one received 400 International Units (IU) of vitamin D a day until delivery; group two received 2,000 IU and group three received 4,000 IU. The women were evaluated monthly to ensure safety.

“No adverse events related to vitamin D dosing were found in any of the three arms of the study,” Dr. Wagner said.

Investigators also looked at the effects of vitamin D supplementation on complications during pregnancy, including preeclampsia, gestational diabetes, infections, and preterm labor and birth.

“The spectacular part of the study was it showed women replete in vitamin D had lower rates of preterm labor and preterm birth, and lower rates of infection,” Dr. Wagner said.

The greatest effects were seen among women taking 4,000 IU of vitamin D per day. Therefore, the researchers recommend this daily regimen for all pregnant women.

Dr. Wagner will discuss the two parts of the study in separate presentations. The outcomes of vitamin D supplementation during pregnancy will be presented on Saturday, May 1, and the safety of vitamin D supplementation will be presented on Sunday, May 2.

Reporters wanting to interview any of the speakers should call the PAS Press Office at 778-331-7694. Reporters who wish to attend the session must first check in with the PAS Press Office at the Vancouver Convention & Exhibition Centre to receive press credentials.

To view part 1 of the study on safety, go to

http://www.abstracts2view.com/pas/view.php?nu=PAS10L1_2450&terms.

To view part 2 of the study on outcomes, go to

http://www.abstracts2view.com/pas/view.php?nu=PAS10L1_2481&terms.

Diets high in B-vitamins reduce risk of death from cardiovascular disease

New research out of Japan reports an inverse association between a diet rich in B-vitamins and risk of death from cardiovascular disease.

Begun in 1988, the Japan Collaborative Cohort Study (JCCS) examined the dietary patterns of 130,000 Japanese adults over nearly ten years. Analyses continue to be performed on the enormous dataset generated by this long-term, large-scale study.

In the latest JCSS analysis (published in the journal Stroke in April 2010), researchers compiled information on dietary levels of folate, vitamin B6, and vitamin B12 as reported in JCSS food frequency questionnaires. They then examined possible correlations between dietary intake of these nutrients and risk of death from common cardiovascular diseases. Data from 23,119 men and 35,611 women (age 40-79 years) met the study criteria, making this one of the largest sample sizes to date for this type of analysis.

Based on the available data, dietary folate and vitamin B6 intakes were inversely associated with mortality from heart failure for men. (Inverse association means that higher dietary levels of folate and vitamin B6 are connected with lower risk of disease.) For women, folate and vitamin B6 intakes were inversely associated with mortality from stroke and coronary heart disease, as well as total cardiovascular disease incidence. Interestingly, these associations remained statistically significant even after adjusting for common cardiovascular disease factors. A statistically significant association could not be determined for vitamin B12 intake and risk of death from cardiovascular disease.

This large-scale collaborative study from Japanese researchers correlates with similar results from the National Health and Nutrition Examination Surveys (NHANES) performed in the United States, further confirming the benefits of a diet high in certain B-vitamins.

Source: Dietary folate and vitamin b6 and B12 intake in relation to mortality from cardiovascular diseases: Japan collaborative cohort study, Cui et al, Stroke, ePub ahead of print, doi: 10.1161/STROKEAHA.110.578906, 2010

Source: USANA Health Sciences

The benefits of exercise in postmenopausal women

A new study out of Australia shows significant benefits to bone mineral density among postmenopausal women who participate in a twice-weekly exercise program.

A February 2010 research study from the University of New South Wales examined the effect of an aerobic weight-bearing exercise program on bone mineral density (BMD) in postmenopausal women. The purpose of the study was to examine what specific role - if any - regular exercise had on BMD.

30 postmenopausal women were divided into two groups for the study. The first group (19 women, mean age 66.4 years) was assigned a two-year exercise program consisting of twice-weekly aerobic weight-bearing exercises. The second group (11 women, mean age 65.4 years) did not participate in an exercise program. Before and after the two-year study period, bone density measurements were taken at the spine and hip of each study participant.

At the end of the study, women in the exercise group experienced less than one-fourth the spinal BMD loss compared to the control group (-0.8 compared to -3.8, 95% CI 0.3-5.7% difference.) Results were even more impressive for the hip measurement, where the exercise group saw a 9.6% improvement compared to a 4.4% loss in the controls (14.0% difference, 95% CI 4.6-23.5.)

The authors of the study concluded: “this study adds strong evidence that twice-weekly weight-bearing aerobic exercise has a protective effect on bone density in postmenopausal women as well as being associated with other measurable benefits."

Source: The benefits of exercise in postmenopausal women, Caplan GA, Ward JA, Lord SR, Australian Journal of Public Health 17(1):23-6 2010.

Source: USANA Health Sciences

Inadequate DHA intake in infants is related to decreased visual acuity

New research shows that infants receiving milk or formula with adequate docosahaxaenoic acid (DHA) have improved visual acuity compared to infants receiving the lowest levels. Higher dietary intakes of DHA (a fat contained in highest amounts in fish oil) can positively affect levels in milk.

The range of human milk docosahexaenoic acid (DHA) concentrations can vary considerably since maternal diet can greatly influence breast milk fatty acid composition. In one study, average DHA levels in human milk ranged from 0.17% to 0.99%, with U.S. and Canadian women among those with the lowest levels.

New research published in the American Journal of Clinical Nutrition sought to determine the effect of 4 amounts of DHA supplementation on the visual acuity of formula-fed infants. Other objectives were evaluated, including visual acuity maturation, red blood cell fatty acids, tolerance, anthropometric measures, and adverse events.

This double-blind randomized trial included 343 healthy, term, formula-fed infants. The infants were enrolled at 1-9 days of age and randomly assigned to be fed one of four infant formulas containing differing levels of DHA (0%, 0.32%, 0.64% and 0.96%). All other nutrients were equivalent between the formulas. Visual acuity of the infants was measured at the completion of the study at 12 months.

Infants fed control formula (0% DHA) had significantly poorer visual acuity at 12 mo of age than did infants who received any of the DHA-supplemented formulas. There were no significant differences in the visual acuity of the infants fed any of the other DHA-supplemented formulas.

DHA supplementation of infant formula at 0.32% of total fatty acids improves visual acuity. Higher amounts of DHA supplementation do not appear to provide additional improvements to visual acuity.

Source: The DIAMOND (DHA Intake And Measurement Of Neural Development) Study: a double-masked, randomized controlled clinical trial of the maturation of infant visual acuity as a function of the dietary level of docosahexaenoic acid, Birch EE, Carlson SE, Hoffman DR, Fitzgerald-Gustafson KM, Fu VLN, Drover JR, Castañeda YS, Minns L, Wheaton DKH, Mundy D, Marunycz J, Diersen-Schade DA, AJCN 91(4):848-59 2010.

Source: USANA Health Sciences