PMS - B Vitamin-rich food

Source: Am J Clin Nutr, February 23, 2011;[Epub ahead of print]

Research: Thiamine, riboflavin, niacin, vitamin B-6, folate and vitamin B-12 are required to synthesize neurotransmitters that are potentially involved in the pathophysiology of premenstrual syndrome (PMS). In this study, researchers set out to evaluate whether B vitamin intake—from food sources and supplements—is associated with the initial development of PMS. They conducted a case-control study nested within the Nurses’ Health Study II cohort among participants who were free of PMS at baseline (1991). After 10 years of follow up, 1057 women were confirmed as cases and 1968 were confirmed as controls. Dietary information was collected in 1991, 1995 and 1999 by using food-frequency questionnaires.

Results: Intakes of thiamine and riboflavin from food sources were each inversely associated with incident PMS. For example, women in the highest quintile of riboflavin intake 2-4 years before the diagnosis year had a 35% lower risk of developing PMS than did those in the lowest quintile. However, there were no significant associations between incident PMS and dietary intakes of niacin, vitamin B-6, folate, and vitamin B-12. Additionally, intake of B vitamins from supplements was not associated with a lower risk of PMS.

Prostate Cancer - Vitamin E, Soy and Selenium

Source:J Clin Oncol, May 2, 2011. [Epub ahead of print].

Research: High-grade prostatic intraepithelial neoplasia (HGPIN) is a putative precursor of invasive prostate cancer (PCa) and preclinical evidence suggests vitamin E, selenium and soy protein may prevent the progression of HGPIN to PCa. This hypothesis was tested among 300 men in a randomized phase III double-blind study of daily soy (40 grams), vitamin E (800 IUs) and selenium (200 μg) consumption versus placebo. Treatment was administered daily for 3 years. Follow-up prostate biopsies occurred at 6, 12, 24 and 36 months post-randomization.

Results: For all patients, the median age was 63 years. The median baseline prostate-specific antigen (PSA; n = 302) was 5.41 ug/L; total testosterone (n = 291) was 13.4 nmol/L. Invasive PCa developed among 26% of patients. Gleason score distribution was similar in both groups, with 83.5% of cancers graded Gleason sum of 6. Baseline age, weight, PSA and testosterone did not predict for development of PCa. The supplement was well tolerated with flatulence reported more frequently (27% vs. 17%) among men receiving micronutrients. According to researchers, this trial does not support the hypothesis that combination vitamin E, selenium and soy prevents progression from HGPIN to PCa.

Olive Oil and Stroke

Source: Neurology, June 15, 2011;[Epub ahead of print].

Research: Among participants from the Three-City Study with no history of stroke at baseline, researchers examined the association between olive oil consumption (main sample, n=7625) or plasma oleic acid (secondary sample, n=1245) and incidence of stroke (median follow-up 5.25 years), ascertained according to a diagnosis validated by an expert committee.

Results: In the main sample, 148 incident strokes occurred. After adjustment for socio-demographic and dietary variables, physical activity, body mass index, and risk factors for stroke, a lower incidence for stroke with higher olive oil use was observed. Compared to those who never used olive oil, those with intensive use had a 41% lower risk of stroke. In the secondary sample, 27 incident strokes occurred. After full adjustment, higher plasma oleic acid was associated with lower stroke incidence. Compared to those in the first tertile, participants in the third tertile of plasma oleic acid had a 73% reduction of stroke risk.