September/October 2011, Volume 4, Issue 5
“The regular intake of specific plant foods [grains, nuts and vegetables] may prevent overweight among children and adolescents.”

FEATURED ARTICLES:

Editor’s Log: Chiropractic Identity:
Charting Our Future Roles »

Chiropractic in an Integrative Cancer
Center: Interview with Jeff Sklar, DC »

Yoga and Health: Interview with
Sandra McLanahan, MD »

Risks of Acetaminophen »

Chiropractic and Manual Therapies
Research »

Nutrition Update

Exercise and Fitness Report »

CAM in Review »

Mind-Body News »

Health News

The Daily HIT Blog

NUTRITION UPDATE
When reading reports on new research, it is important to remember that no single study should be seen as providing the whole truth. The following reports offer helpful clues but in most cases further research is needed before firm conclusions can be drawn.
Dairy Products Associated with Childhood Obesity, While Grains, Nuts and Vegetables Help Keep Young People Thin

Matthews VL, Wien M, Sabate J. The risk of child and adolescent overweight is related to types of food consumed. Nutrition Journal. 2011;10:71

ABSTRACT: BACKGROUND/AIMS: To investigate the association between the risk of overweight and the consumption of food groups in children and adolescents. METHODS: We studied 1764 healthy children and adolescents (age 6-19y) attending 16 Seventh-Day Adventist schools and 13 public schools using a 106-item non-quantitative food frequency questionnaire from the late 1980 Child-Adolescent Blood Pressure Study. Logistic regression models were used to compute the risk of overweight according to consumption of grains, nuts, vegetables, fruits, meats/fish/eggs, dairy, and, low nutrient-dense foods (LNDF). RESULTS: The frequency of consumption of grains, nuts, vegetables and LNDF were inversely related to the risk of being overweight and dairy increased the risk. Specifically, the odds ratio (95% CI) for children in the highest quartile or tertile of consumption compared with the lowest quartile or tertile were as follows: grains 0.59(0.41-0.83); nuts 0.60(0.43-0.85); vegetables 0.67(0.48-0.94); LNDF 0.43(0.29-0.63); and, dairy 1.36(0.97, 1.92). CONCLUSION: The regular intake of specific plant foods may prevent overweight among children and adolescents.

Review Finds Soy and Fish Components Lower Arterial Stiffness

Pase MP, Grima NA, Sarris J. The effects of dietary and nutrient interventions on arterial stiffness: a systematic review. The American Journal of Clinical Nutrition. Feb 2011;93(2):446-454.

Background: Although dietary and nutrient interventions have been extensively studied as a means of improving arterial stiffness, to our knowledge no systematic analysis of the data has been conducted. Objective: The aim of the current study was to systematically review the human clinical trial data and qualitatively examine the efficacy of dietary and nutrient interventions in the treatment of arterial stiffness. Design: We systematically searched multiple databases until July 2010 for relevant randomized controlled human clinical trials of common dietary and nutrient interventions in the treatment of arterial stiffness. Located studies were subject to strict inclusion criteria and objectively assessed for scientific quality. Results: Of the 75 relevant studies located, we considered 38 studies to be appropriate for review. Results revealed support for intakes of omega-3 (n−3) fish oils (Cohen’s d = 0.21–0.81) and soy isoflavones (Cohen’s d = 0.35–0.39) in the treatment of arterial stiffness. There was limited but consistent evidence to suggest that salt restriction (Cohen’s d = 0.28–0.37) as well as consumption of fermented-milk products (Cohen’s d = 0.15–0.33) that contain bioactive peptides improved arterial stiffness. The evidentiary support for intakes of vitamins, micronutrients, and herbal medicines was insufficient. Limited but consistent evidence suggested that caffeine intake acutely increased arterial stiffness (Cohen’s d = 0.34–0.51). Conclusions: Current evidence from several small studies suggests that omega-3 and soy isoflavone supplementation provides an effective means of reducing arterial stiffness. There was little research that explored intakes of herbal medicines or micronutrients in the treatment of arterial stiffness, and this remains an area of potential research.

Above a Required Minimum of 750 Mg/Day, Extra Calcium Intake Provides No Protection Against Bone Loss or Fracture

Warensjo E, Byberg L, Melhus H, et al. Dietary calcium intake and risk of fracture and osteoporosis: prospective longitudinal cohort study. BMJ. 2011;342:d1473

OBJECTIVE: To investigate associations between long term dietary intake of calcium and risk of fracture of any type, hip fractures, and osteoporosis. DESIGN: A longitudinal and prospective cohort study, based on the Swedish Mammography Cohort, including a subcohort, the Swedish Mammography Cohort Clinical. SETTING: A population based cohort in Sweden established in 1987. PARTICIPANTS: 61 433 women (born between 1914 and 1948) were followed up for 19 years. 5022 of these women participated in the subcohort. MAIN OUTCOME MEASURES: Primary outcome measures were incident fractures of any type and hip fractures, which were identified from registry data. Secondary outcome was osteoporosis diagnosed by dual energy x ray absorptiometry in the subcohort. Diet was assessed by repeated food frequency questionnaires. RESULTS: During follow-up, 14 738 women (24%) experienced a first fracture of any type and among them 3871 (6%) a first hip fracture. Of the 5022 women in the subcohort, 1012 (20%) were measured as osteoporotic. The risk patterns with dietary calcium were non-linear. The crude rate of a first fracture of any type was 17.2/1000 person years at risk in the lowest quintile of calcium intake, and 14.0/1000 person years at risk in the third quintile, corresponding to a multivariable adjusted hazard ratio of 1.18 (95% confidence interval 1.12 to 1.25). The hazard ratio for a first hip fracture was 1.29 (1.17 to 1.43) and the odds ratio for osteoporosis was 1.47 (1.09 to 2.00). With a low vitamin D intake, the rate of fracture in the first calcium quintile was more pronounced. The highest quintile of calcium intake did not further reduce the risk of fractures of any type, or of osteoporosis, but was associated with a higher rate of hip fracture, hazard ratio 1.19 (1.06 to 1.32). CONCLUSION: Gradual increases in dietary calcium intake above the first quintile in our female population were not associated with further reductions in fracture risk or osteoporosis.

Commentary: The first quintile in the study above was for calcium intake under 751 mg/day. The highest quintile was for calcium intake above 1137 mg/day.

Plant Foods and Their Fiber Help Prevent Diverticular Disease

Crowe FL, Appleby PN, Allen NE, Key TJ. Diet and risk of diverticular disease in Oxford cohort of European Prospective Investigation into Cancer and Nutrition (EPIC): prospective study of British vegetarians and non-vegetarians. BMJ. July 19, 2011 2011;343.

Objective: To examine the associations of a vegetarian diet and dietary fibre intake with risk of diverticular disease. Design Prospective cohort study. Setting: The EPIC-Oxford study, a cohort of mainly health conscious participants recruited from around the United Kingdom. Participants: 47 033 men and women living in England or Scotland of whom 15 459 (33%) reported consuming a vegetarian diet. Main outcome measures: Diet group was assessed at baseline; intake of dietary fibre was estimated from a 130 item validated food frequency questionnaire. Cases of diverticular disease were identified through linkage with hospital records and death certificates. Hazard ratios and 95% confidence intervals for the risk of diverticular disease by diet group and fifths of intake of dietary fibre were estimated with multivariate Cox proportional hazards regression models. Results: After a mean follow-up time of 11.6 years, there were 812 cases of diverticular disease (806 admissions to hospital and six deaths). After adjustment for confounding variables, vegetarians had a 31% lower risk (relative risk 0.69, 95% confidence interval 0.55 to 0.86) of diverticular disease compared with meat eaters. The cumulative probability of admission to hospital or death from diverticular disease between the ages of 50 and 70 for meat eaters was 4.4% compared with 3.0% for vegetarians. There was also an inverse association with dietary fibre intake; participants in the highest fifth (≥25.5 g/day for women and ≥26.1 g/day for men) had a 41% lower risk (0.59, 0.46 to 0.78; P<0.001 trend) compared with those in the lowest fifth (<14 g/day for both women and men). After mutual adjustment, both a vegetarian diet and a higher intake of fibre were significantly associated with a lower risk of diverticular disease. Conclusions: Consuming a vegetarian diet and a high intake of dietary fibre were both associated with a lower risk of admission to hospital or death from diverticular disease.

Vitamin D Status Associated with Diabetes Risk

Mitri J, Muraru MD, Pittas AG. Vitamin D and type 2 diabetes: a systematic review. European Journal of Clinical Nutrition. Jul 6 2011.

Background/Objectives: Vitamin D may modify the risk of type 2 diabetes mellitus. The aim of this review was to examine the association between vitamin D status and incident type 2 diabetes, and the effect of vitamin D supplementation on glycemic outcomes. Methods: We performed a systematic review of English-language studies using MEDLINE through February 2011. Longitudinal cohort studies reporting associations between vitamin D status and incident type 2 diabetes, and randomized controlled trials (RCTs) of vitamin D supplementation, were included. Study characteristics and results were extracted, and study quality was assessed. Results: A total of 8 observational cohort studies and 11 RCTs were included. In meta-analyses of observational studies, vitamin D intake >500 international units (IU)/day decreased the risk of type 2 diabetes by 13% compared with vitamin D intake <200 IU/day. Individuals with the highest vitamin D status (>25 ng/ml) had a 43% lower risk of developing type 2 diabetes (95% confidence interval 24, 57%) compared with those in the lowest group (<14 ng/ml). In post hoc analyses from eight trials among participants with normal glucose tolerance at baseline and in three small underpowered (n=32-62) trials of patients with established type 2 diabetes, there was no effect of vitamin D supplementation on glycemic outcomes. In two trials among patients with baseline glucose intolerance, vitamin D supplementation improved insulin resistance. Conclusions: Vitamin D may play a role in type 2 diabetes; however, to better define the role of vitamin D in the development and progression of type 2 diabetes, high-quality observational studies and RCTs that measure blood 25-hydroxyvitamin D concentration and clinically relevant glycemic outcomes are needed.

Low Blood Levels of Vitamin D Correlate with Some
Heart Disease Risk Markers

Chacko SA, Song Y, Manson JE, et al. Serum 25-hydroxyvitamin D concentrations in relation to cardiometabolic risk factors and metabolic syndrome in postmenopausal women. The American Journal of Clinical Nutrition. July 1, 2011 2011;94(1):209-217.

Background: Low concentrations of serum 25-hydroxyvitamin D [25(OH)D] may be associated with cardiometabolic disorders; however, little is known about their relation to intermediate metabolic and lipid markers. Objective: We investigated the relation of serum 25(OH)D concentrations to fasting insulin, glucose, dyslipidemia, adiposity, and prevalent metabolic syndrome. Design: We conducted this cross-sectional analysis in 292 postmenopausal women aged 50–79 y in the Women’s Health Initiative Calcium–Vitamin D (WHI-CaD) trial. Data were collected from 3 nested case-control studies that measured baseline serum 25(OH)D concentrations. Inverse probability weighting was used to approximate parameter estimates for the WHI-CaD population.Results: In weighted linear regression models adjusted for age, race-ethnicity, month of blood draw, region, case-control status, smoking, alcohol, physical activity, and history of cardiometabolic risk factors, there was an inverse association of serum 25(OH)D with adiposity [body mass index (BMI): β = −1.12 ± 0.30, P = 0.0002; waist circumference: β = −3.57 ± 0.49, P < 0.0001; waist-hip ratio: β = −0.01 ± 0.002, P < 0.0001], triglycerides (β = −0.10 ± 0.02, P < 0.0001), and triglyceride:HDL-cholesterol ratio (β = −0.11 ± 0.03, P = 0.0003). The multivariable-adjusted odds ratio for metabolic syndrome for the highest (≥52 nmol/L) compared with the lowest (<35 nmol/L) tertile of serum 25(OH)D concentrations was 0.28 (95% CI: 0.14, 0.56). Significant associations remained after adjustment for BMI. We observed no significant associations with LDL cholesterol, HDL cholesterol, insulin, glucose, homeostatic model assessment of insulin resistance (HOMA-IR), or homeostatic model assessment of β cell function (HOMA-β).Conclusion: Higher serum 25(OH)D concentrations may be inversely associated with adiposity, triglycerides, triglyceride:HDL-cholesterol ratio, and metabolic syndrome but are not associated with LDL and HDL cholesterol, insulin, glucose, HOMA-IR, or HOMA-β in postmenopausal women.