Nutrition

AJCN June, 2007

[Why Nutrition Investigator reviews AJCN and J. Nutr ] Summing up by retiring Editor-in-Chief ” my overall goal was for the AJCN to be the primary vehicle for advancing the significance of nutritional science to clinical medicine, while promoting the Journal as the repository for the best science in our field… while ensuring that nutrition be regarded as ‘the cornerstone of preventive medicine, the handmaiden of curative disease, and the responsibility of every physician’…The impact factor…places the AJCN in the forefront of all peer-reviewed nutrition journals and in the top one-half of all medical specialty journals.”

[whole grains key to heart health] Dietary prevention of atherosclerosis: go with whole grains ” In the 1970s, Burkitt and Trowell (2) pioneered the link between chronic disease and refined grain consumption by observing that African natives who consumed large quantities of whole-plant foods had a lower prevalence of coronary heart disease, diabetes, and cancer than did refined-grain consumers of the West. To date, a number of epidemiologic studies have found a protective effect of whole-grain consumption against chronic disease, including various cancers (3), cardiovascular disease (4), and type 2 diabetes (5). In contrast, positive associations have been reported between the consumption of refined grains and risk of chronic diseases (6). Whole grains are composed of germ, bran, and endosperm. In contrast, refined grains lack both the germ and bran, which are removed during processing and results in the loss of fiber, vitamins, minerals, lignans, phenolic compounds, and phytochemicals (7). It is this unique constellation of constituents that are thought to confer the beneficial effects of whole grain on chronic disease risk… a prospective cohort study reported a significant reduction in atherosclerotic progression in postmenopausal women with preexisting heart disease who consumed 6 servings/wk of whole grains compared with those with lower intakes over 3 y … On average, Americans eat less than one serving per day of whole grains.”

[Whole grains help heart by opening arteries] Whole-grain intake and carotid artery atherosclerosis in a multiethnic cohort: the Insulin Resistance Atherosclerosis Study “Conclusions: Whole-grain intake is inversely associated with common carotid artery carotid intimal medial thickness, and this relation is not attributable to individual risk intermediates, single nutrient constituents, or larger dietary patterns.

[Whole grain reduces inflammation] Whole-grain consumption is associated with a reduced risk of noncardiovascular, noncancer death attributed to inflammatory diseases in the Iowa Women’s Health Study “Background: It has recently been shown that oxidative stress, infection, and inflammation are predominant pathophysiologic factors for several major diseases…Conclusions: The reduction in inflammatory mortality associated with habitual whole-grain intake was larger than that previously reported for coronary heart disease and diabetes. Because a variety of phytochemicals are found in whole grains that may directly or indirectly inhibit oxidative stress, and because oxidative stress is an inevitable consequence of inflammation, we suggest that oxidative stress reduction by constituents of whole grain is a likely mechanism for the protective effect.”

[Low energy density food choices reduce your weight] Dietary energy density in the treatment of obesity: a year-long trial comparing 2 weight-loss diets “Objective: The effects on weight loss of 2 strategies for reducing the energy density of the diet were compared over 1 y…No goals for energy or fat intake were assigned; the subjects were instructed to eat ad libitum…Conclusion: Reducing dietary energy density, particularly by combining increased fruit and vegetable intakes with decreased fat intake, is an effective strategy for managing body weight while controlling hunger.”

[One or two drinks of alcohol a day is good for health] Effect of alcoholic beverages on postprandial glycemia and insulinemia in lean, young, healthy adults “Conclusion:In realistic settings, alcoholic beverage consumption lowers postprandial glycemia by 16–37%, which represents an unrecognized mechanism by which alcohol may reduce the risk of chronic disease.”

[Cinnamon is great for health] Effect of cinnamon on postprandial blood glucose, gastric emptying, and satiety in healthy subjects “Background: Previous studies of patients with type 2 diabetes showed that cinnamon lowers fasting serum glucose, triacylglycerol, and LDL- and total cholesterol concentrations. ..Conclusions: The intake of 6 g cinnamon with rice pudding reduces postprandial blood glucose and delays gastric emptying without affecting satiety.”

[High dose vitamin D is safe and healthy] Efficacy of daily and monthly high-dose calciferol in vitamin D–deficient nulliparous and lactating women “Conclusions: Oral vitamin D2 supplementation with 2000 IU/d or 60 000 IU/mo for 3 mo was safe, and it increased serum 25(OH)D concentrations significantly; however, only a small proportion of the women studied achieved concentrations of 50 nmol/L. ” [The most advantageous serum concentrations of 25(OH)D begin at 75 nmol/L (30 ng/mL), and the best range from 90 to 100 nmol/L (Am J Clin Nutr. 2006;84:18-28)] [vitamin D reduces cancer risk] Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial ” Conclusions: Improving calcium and vitamin D nutritional status [by 1,100 IU per day] substantially reduces all-cancer risk in postmenopausal women.

[Fish oil essential for optimal child health/brain] Maternal consumption of a docosahexaenoic acid–containing functional food during pregnancy: benefit for infant performance on problem-solving but not on recognition memory tasks at age 9 mo ” Conclusion: These data point to a benefit for problem solving but not for recognition memory at age 9 mo in infants of mothers who consumed a DHA-containing functional food [with 300 mg DHA 5 times per week] during pregnancy.”

[Breastfeeding may prevent obesity in your child] Infant feeding method and obesity: body mass index and dual-energy X-ray absorptiometry measurements at 9–10 y of age from the Avon Longitudinal Study of Parents and Children (ALSPAC) “Breastfeeding may protect against obesity if maintained for 6 mo.”

[Feeding babies too much protein risks obesity] Protein intake during the period of complementary feeding and early childhood and the association with body mass index and percentage body fat at 7 y of age ” Objective: We analyzed the association of different protein intakes during 6–24 mo with body mass index …and percentage body fat… at 7 y of age. Conclusions: High protein intakes during the period of complementary feeding and the transition to the family diet are associated with an unfavorable body composition at the age of 7 y. ”

[Antioxidant vitamins are one main key to fruit/vegetable benefits ] Fruit and vegetable intakes, dietary antioxidant nutrients, and total mortality in Spanish adults: findings from the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Spain) “Objective: We aimed to assess the relation of mortality to the consumption of fruit, vegetables, and other plant foods and to the dietary intake of vitamin C, vitamin E, and carotenoids…Conclusions: A high intake of fresh fruit, root vegetables, and fruiting vegetables is associated with reduced mortality, probably as a result of their high content of vitamin C, provitamin A carotenoids, and lycopene. Antioxidant capacity could partly explain the effect of ascorbic acid and provitamin A but not the association with lycopene.”

[Fruits and vegetables reduce Blood Pressure] Dietary patterns and blood pressure change over 5-y follow-up in the SU.VI.MAX cohort “Conclusion: These results suggest that high fruit and vegetable intakes may be associated with a lower increase in BP with aging. “