VITAMIN K AND CARDIOVASCULAR DISEASE
Beulens JW, Bots ML, Atsma F, Bartelink ML, Prokop M, Geleijnse JM, Witteman JC, Grobbee DE, van der Schouw YT. High dietary menaquinone intake is associated with reduced coronary calcification. Atherosclerosis. Published online ahead of print: doi:10.1016/j.atherosclerosis.2008.07.010
An appreciation for the significance of dietary vitamin K in the prevention of various diseases is growing. Vitamin K, widely known for its role in blood coagulation, is also important for bone health and may be important in the prevention of cardiovascular disease through reduction of coronary calcification. Findings on the relationship between vitamin K intake and cardiovascular disease are mixed, perhaps through different effects of the active forms of vitamin K: phylloquinone (vitamin K1) and menaquinone (vitamin K2). Phylloquinone is found primarily in leafy greens, whereas menaquinone is found primarily in meat, eggs, and cheese. The present study by Beulens et al. examined the relationship between dietary intake of both forms of vitamin K and coronary calcification.
Data on 564 Dutch women were selected from a cohort enrolled in the European Prospective Investigation into Cancer and Nutrition (EPIC). Participants were between the ages of 49 and 70 years, post-menopausal, and did not take hormone replacement therapy. Dietary intake of phylloquinone and menaquinone was derived from food-frequency questionnaire data and intake levels were categorized into quartiles. Coronary calcification was determined using a multi-detector computed tomography (MDCT) examination, and calcification was quantified according to the Agatston calcium score. Three hundred and sixty (62%) of the participants had coronary calcification. Coronary calcification was not related to phylloquinone intake. Intake of menaquinone in the highest quartile was associated with lower coronary calcification relative to the lowest quartile of menaquinone intake. The authors acknowledge that there are limitations in interpreting the findings from an observational cross-sectional study, but they also suggest that maintaining adequate levels of menaquinone intake may be useful in preventing heart disease.
MICRONUTRIENT DEFICIENCY IN PATIENTS WITH QUIESCENT INFLAMMATORY BOWEL DISEASE
Valentini L, Schaper L, Buning C, Hengstermann S, Koernicke T, Tillinger W, Guglielmi FW, Norman K, Buhner S, Ockenga J, Pirlich M, Lochs H. Malnutrition and impaired muscle strength in patients with Crohn's disease and ulcerative colitis in remission. Nutrition 2008;24:694–702.
Individuals with active inflammatory bowel disease (IBD), specifically Crohn's disease and ulcerative colitis, are at risk for malnourishment and loss of lean muscle mass due to both nutrient malabsorption and dietary restrictions. However, little is known about the nutrient status of these individuals during periods of remission. In a prospective, multicenter study, Valentini et al. addressed this issue by comparing the nutrient status and muscle function of patients with IBD in clinical remission, either Crohn's (CD) or ulcerative colitis (UC), with those of controls.
One hundred and forty-four participants (CD: n = 94; UC: n = 50) with quiescent IBD were enrolled. Remission was defined as a Crohn's Disease Activity Index <150 or an Ulcerative Colitis Activity Index <5. Disease duration in participants was ∼7.8 years in CD and ∼9.0 years in UC; the specific duration of remission for all participants was not reported. Sixty-one healthy control participants were used for comparison. A subset of 47 well-nourished IBD patients who had been in remission for more than 3 months were pair-matched according to BMI with a subset of 47 control participants. Primary measures included BMI, SGA (subjective global assessment), C-reactive protein level, blood levels of selected micronutrients, handgrip strength, food intake, and quality of life. Approximately 23% of CD patients and 33% of UC patients showed some level of malnutrition, as determined using SGA, BMI, and plasma albumin levels. Body cell mass was significantly decreased in both patient populations in comparison with controls and was correlated with handgrip strength. Handgrip strength was significantly decreased in patient populations relative to controls. Quality-of-life scores were significantly lower in individuals with IBD in comparison to controls. With respect to food intake, participants with IBD consumed lower amounts of fruits and vegetables, dairy products, fish, and alcoholic beverages relative to controls, but intakes of meat, fats, sweets, and fast foods did not vary with disease condition. The present study shows nutritional deficits and body composition changes in individuals with quiescent IBD. The authors indicate that these deficiencies and compromised muscle strength may not be detected in standard malnutrition screening and assessment. They also suggest that while micronutrient supplementation may be of benefit, dietary eating patterns in patients were suboptimal and can be improved within the parameters of dietary restrictions imposed by IBD.
PROTECTIVE ROLE OF VITAMIN C FOR BONE LOSS IN MEN
Sahni S, Hannan MT, Gagnon D, Blumberg J, Cupples LA, Kiel DP, Tucker KL. High vitamin C intake is associated with lower 4-year bone loss in elderly men. J Nutr. 2008; 138:1931–1938.
Bone loss and bone thinning continues to be a major public health concern for older individuals. Bone mineral status is linked not only to intake of calcium, but also to intakes of fruits and vegetables. Vitamin C, in particular, is needed for collagen formation and bone development. Animal studies have shown a link between vitamin C deficiency and impaired bone mass, but studies in humans show mixed findings that may be related to interactions between dietary and supplemental vitamin C. In the present report, Sahni et al. measured cross-sectional and longitudinal changes in bone mineral density at the hip, spine, and radial shaft and compared these changes with vitamin C intake from all sources.
Participants (mean age, 75 years) in the Framingham Heart Study were enrolled in the ancillary Framingham Osteoporosis Study. A subset (334 men; 540 women) of the ancillary participants was included in the present analyses. Vitamin C intakes were quantified using food-frequency questionnaires, and supplement intakes were categorized into non-supplement users, <75 mg/d (women) or <90 mg/d (men), and ≥75 mg/d (women) or ≥90 mg/d (men). Bone mineral density was assessed using dual-photon or dual X-ray absorptiometry. There were no associations between total vitamin C intake and bone mineral density in women. In male non-smokers, total intake of vitamin C was associated with higher femoral bone mineral density and tended to be associated with lower bone mineral loss. In smokers, there was a negative relationship between total vitamin C intake and bone mineral density, suggesting that smokers with low bone mineral density may be using more vitamin C supplements. The dietary effects of vitamin C were more strongly protective of bone mineral density loss in comparison to vitamin C from supplements. Finally, when the findings were adjusted for potassium intake, the relationships were lessened, but remained significant, indicating that the effects of vitamin C alone may not be discriminated from the overall protective effects of fruits and vegetables in the diet.
LONG-TERM EFFECTS OF MATERNAL n-3 PUFA SUPPLEMENTATION ON OFFSPRING COGNITION
Helland IB, Smith L, Blomén B, Saarem K, Saugstad OD, Drevon CA. Effect of supplementing pregnant and lactating mothers with n-3 very-long-chain fatty acids on children's IQ and body mass index at 7 years of age. Pediatrics. 2008;122:e472–479.
The long-chain fatty acids arachidonic acid (AHA) and docosahexaenoic acid (DHA) are essential for proper brain growth and cognitive development in children. In a previous report by this group, maternal supplementation of 10 ml cod liver oil from week 18 of pregnancy until 3 months after delivery resulted in significantly greater mental processing scores for children at 4 years of age relative to children from mothers given corn oil (control). The present paper from Helland et al. reports the follow-up performed in the same children at age 7 years.
Children whose mothers had been given 10 ml/d cod liver oil (n = 82) or corn oil (n = 61) were tested using the Kaufman Assessment Battery for Children at age 4 years (previously reported: Helland et al., Pediatrics. 2003;111:e39–44) and at age 7 years, and their BMIs were measured. Maternal supplementation condition was compared with cognitive test scores. There were no associations between neonatal fatty acid status and BMI. In contrast with observations from testing at the age of 4 years, at age 7 years overall cognitive scores were not related to the maternal supplementation condition. Maternal DHA and alpha-linolenic acid levels were positively correlated with sequential processing scores at age 7 years. The authors suggest the findings at age 7 years may be related to several factors, including dilution from other variables such as dietary status, social interactions, test sensitivity, and illness or drugs. Still, the authors maintain that the present data support the utility of long-chain fatty acid supplementation in aspects of later cognitive function.
MODERATE RESVERATROL INTAKE AND PLATELET NITRIC OXIDE PRODUCTION
Gresele P, Pignatelli P, Guglielmini G, Carnevale R, Mezzasoma AM, Ghiselli A, Momi S, Violi F. Resveratrol, at concentrations attainable with moderate wine consumption, stimulates human platelet nitric oxide production. J Nutr. 2008;138:1602–1608.
Moderate wine consumption is associated with reduced cardiovascular and cerebrovascular ischemic events. Wine, de-alcoholized wine, and grape juice provide a myriad of polyphenolic compounds including resveratrol, quercetin, epicatechin, and proanthocyanidins. Studies using grape extracts show increases in nitric oxide production and associated decreases in reactive oxygen species, suggesting one mechanism by which wine intake may produce benefits in offsetting oxidative stress. Many studies, however, have used high doses of resveratrol, or other polyphenols, which may not be comparable to current guidelines for moderate wine consumption. Gresele et al. determined the effects of moderate amounts of resveratrol, levels comparable to moderate wine intake, on platelet nitric oxide production.
Participants were randomized into red or white wine conditions (300 ml/d). Red wine (n = 10; 4 males, 6 females) contained 1.8 g/L total polyphenol and white wine (n = 10; 5 males, 5 females) contained 0.25 g/L polyphenol. Wine was consumed daily at the evening meal for 15 d. Baseline and day 15 blood samples were taken and platelet-rich plasma was isolated, platelets were washed and incubated with resveratrol. Wine intake increased plasma resveratrol and platelet nitric oxide release relative to baseline. Platelets incubated with low levels of resveratrol had significantly increased nitric oxide production and increased nitric oxide synthase activity. The observed actions of resveratrol at doses relevant to human intake indicate one mechanism by which moderate wine intake may exert beneficial effects on cardiovascular health.