Here are a mixed bag of six recent research papers on diet, vitamin D, IBS and yoga (all details & abstracts to these studies are listed further down this blog post).  The first three papers highlight the toxic effects on psychological health, physical health, and society of our processed, high sugar diets.  Sanchez-Villegas et al map a bit more clearly the potential link between diet and depression.  They conclude "Our results suggest a potential protective role of the MDP (Mediterranean dietary pattern) with regard to the prevention of depressive disorders; additional longitudinal studies and trials are needed to confirm these findings."  Fiorito et al show that intake of sweetened drinks in 5 year old girls predicts overweight over subsequent childhood and adolescence, and - rather scarily - Moore & colleagues show a link between confectionary consumption at age 10 and subsequent violence in adulthood.  They concluded "Children who ate confectionery daily at age 10 years were significantly more likely to have been convicted for violence at age 34 years, a relationship that was robust when controlling for ecological and individual factors."

Regular readers of this blog will know that I'm a vitamin D fan (see results from clicking the tag vitamin D).  Here's another in a long line of studies showing benefit - Bischoff-Ferrari et al's meta-analysis of fall prevention in older adults showed "Supplemental vitamin D in a dose of 700-1000 IU a day reduced the risk of falling among older individuals by 19% and to a similar degree as active forms of vitamin D. Doses of supplemental vitamin D of less than 700 IU or serum 25-hydroxyvitamin D concentrations of less than 60 nmol/l may not reduce the risk of falling among older individuals." 

Lee & colleagues surveyed over 2,000 people to assess overlaps between irritable bowel syndrome (IBS) and generalized anxiety disorder (GAD).  They found "The current prevalence of IBS was 5.4% and the 12-month prevalence of GAD was 4%. GAD was five times more common among IBS respondents than non-IBS respondents, whereas IBS was 4.7 times more common among GAD respondents than among non-GAD respondents."

Finally, in the sixth paper in this collection, Shelov et al explored the effects of an 8-week yoga intervention on mindfulness.  Mindfulness training - typically in the form of mindfulness-based cognitive therapy - has been shown to reduce the risk of relapse in recurrent depression sufferers.  The researchers concluded "Results indicate that the yoga group experienced a significant increase in Overall mindfulness, and in three mindfulness subscales; Attention to the present moment, Accepting and open attitudes toward experience, and Insightful understanding ... Findings suggest that a yoga intervention may be a viable method for increasing levels of trait mindfulness in a healthy population, potentially implicating yoga as a preventive method for the later development of negative emotional mood states (i.e. anxiety and depression)."

Sanchez-Villegas, A., M. Delgado-Rodriguez, et al. (2009). "Association of the Mediterranean Dietary Pattern With the Incidence of Depression: The Seguimiento Universidad de Navarra/University of Navarra Follow-up (SUN) Cohort." Arch Gen Psychiatry 66(10): 1090-1098.  [Abstract/Full Text]  
Context Adherence to the Mediterranean dietary pattern (MDP) is thought to reduce inflammatory, vascular, and metabolic processes that may be involved in the risk of clinical depression. Objective To assess the association between adherence to the MDP and the incidence of clinical depression. Design Prospective study that uses a validated 136-item food frequency questionnaire to assess adherence to the MDP. The MDP score positively weighted the consumption of vegetables, fruit and nuts, cereal, legumes, and fish; the monounsaturated- to saturated-fatty-acids ratio; and moderate alcohol consumption, whereas meat or meat products and whole-fat dairy were negatively weighted. Setting A dynamic cohort of university graduates (Seguimiento Universidad de Navarra/University of Navarra Follow-up [SUN] Project). Participants A total of 10,094 initially healthy Spanish participants from the SUN Project participated in the study. Recruitment began on December 21, 1999, and is ongoing. Main Outcome Measure Participants were classified as having incident depression if they were free of depression and antidepressant medication at baseline and reported a physician-made diagnosis of clinical depression and/or antidepressant medication use during follow-up. Results After a median follow-up of 4.4 years, 480 new cases of depression were identified. The multiple adjusted hazard ratios (95% confidence intervals) of depression for the 4 upper successive categories of adherence to the MDP (taking the category of lowest adherence as reference) were 0.74 (0.57-0.98), 0.66 (0.50-0.86), 0.49 (0.36-0.67), and 0.58 (0.44-0.77) (P for trend <.001). Inverse dose-response relationships were found for fruit and nuts, the monounsaturated- to saturated-fatty-acids ratio, and legumes. Conclusions Our results suggest a potential protective role of the MDP with regard to the prevention of depressive disorders; additional longitudinal studies and trials are needed to confirm these findings.

Fiorito, L. M., M. Marini, et al. (2009). "Beverage intake of girls at age 5 y predicts adiposity and weight status in childhood and adolescence." Am J Clin Nutr 90(4): 935-942.  [Abstract/Full Text] 
Background: Increased consumption of sweetened beverage has been linked to higher energy intake and adiposity in childhood. Objective: The objective was to assess whether beverage intake at age 5 y predicted energy intake, adiposity, and weight status across childhood and adolescence. Design: Participants were part of a longitudinal study of non-Hispanic white girls and their parents (n = 170) who were assessed biennially from age 5 to 15 y. At each assessment, beverage intake (milk, fruit juice, and sweetened beverages) and energy intake were assessed by using three 24-h recalls. Percentage body fat and waist circumference were measured. Height and weight were measured and used to calculate body mass index. Multiple regression analyses were used to predict the girls' adiposity. In addition, at age 5 y, girls were categorized as consuming <1, > or = 1 and <2, or > or = 2 servings of sweetened beverages. A mixed modeling approach was used to assess longitudinal differences and patterns of change in sweetened beverage and energy intake, adiposity, and weight status by frequency of sweetened beverage intake. Results: Sweetened beverage intake at age 5 y, but not milk or fruit juice intake, was positively associated with adiposity from age 5 to 15 y. Greater consumption of sweetened beverages at age 5 y (> or = 2 servings/d) was associated with a higher percentage body fat, waist circumference, and weight status from age 5 to 15 y. Conclusion: These findings provide new longitudinal evidence that early intake of sweetened beverages predicts adiposity and weight status across childhood and adolescence.

Moore, S. C., L. M. Carter, et al. (2009). "Confectionery consumption in childhood and adult violence." British Journal of Psychiatry 195(4): 366-367.  [Abstract/Full Text] 
Diet has been associated with behavioural problems, including aggression, but the long-term effects of childhood diet on adult violence have not been studied. We tested the hypothesis that excessive consumption of confectionery at age 10 years predicts convictions for violence in adulthood (age 34 years). Data from age 5, 10 and 34 years were used. Children who ate confectionery daily at age 10 years were significantly more likely to have been convicted for violence at age 34 years, a relationship that was robust when controlling for ecological and individual factors.

Bischoff-Ferrari, H. A., B. Dawson-Hughes, et al. (2009). "Fall prevention with supplemental and active forms of vitamin D: a meta-analysis of randomised controlled trials." BMJ 339(oct01_1): b3692-.  [Free Full Text] 
Objective To test the efficacy of supplemental vitamin D and active forms of vitamin D with or without calcium in preventing falls among older individuals. Data sources We searched Medline, the Cochrane central register of controlled trials, BIOSIS, and Embase up to August 2008 for relevant articles. Further studies were identified by consulting clinical experts, bibliographies, and abstracts. We contacted authors for additional data when necessary. Review methods Only double blind randomised controlled trials of older individuals (mean age 65 years or older) receiving a defined oral dose of supplemental vitamin D (vitamin D3 (cholecalciferol) or vitamin D2 (ergocalciferol)) or an active form of vitamin D (1{alpha}-hydroxyvitamin D3 (1{alpha}-hydroxycalciferol) or 1,25-dihydroxyvitamin D3 (1,25-dihydroxycholecalciferol)) and with sufficiently specified fall assessment were considered for inclusion. Results Eight randomised controlled trials (n=2426) of supplemental vitamin D met our inclusion criteria. Heterogeneity among trials was observed for dose of vitamin D (700-1000 IU/day v 200-600 IU/day; P=0.02) and achieved 25-hydroxyvitamin D3 concentration (25(OH)D concentration: <60 nmol/l v > or =60 nmol/l; P=0.005). High dose supplemental vitamin D reduced fall risk by 19% (pooled relative risk (RR) 0.81, 95% CI 0.71 to 0.92; n=1921 from seven trials), whereas achieved serum 25(OH)D concentrations of 60 nmol/l or more resulted in a 23% fall reduction (pooled RR 0.77, 95% CI 0.65 to 0.90). Falls were not notably reduced by low dose supplemental vitamin D (pooled RR 1.10, 95% CI 0.89 to 1.35; n=505 from two trials) or by achieved serum 25-hydroxyvitamin D concentrations of less than 60 nmol/l (pooled RR 1.35, 95% CI 0.98 to 1.84). Two randomised controlled trials (n=624) of active forms of vitamin D met our inclusion criteria. Active forms of vitamin D reduced fall risk by 22% (pooled RR 0.78, 95% CI 0.64 to 0.94). Conclusions Supplemental vitamin D in a dose of 700-1000 IU a day reduced the risk of falling among older individuals by 19% and to a similar degree as active forms of vitamin D. Doses of supplemental vitamin D of less than 700 IU or serum 25-hydroxyvitamin D concentrations of less than 60 nmol/l may not reduce the risk of falling among older individuals.

Lee, S., J. Wu, et al. (2009). "Irritable bowel syndrome is strongly associated with generalized anxiety disorder: a community study." Alimentary Pharmacology & Therapeutics 30(6): 643-651.  [Abstract/Full Text] 
Background No previous study has examined the comorbidity of Irritable Bowel Syndrome (IBS) and Generalized Anxiety Disorder (GAD) in a general population using standardized diagnostic methods.  Aim  To examine the prevalence, comorbidity and risk correlates of IBS and GAD in a general population.  Methods  A random community-based telephone survey was conducted. The questionnaire covered symptoms of IBS, GAD, core depressive symptoms, help-seeking behaviour and functional impairment on the Sheehan Disability Scale.  Results  A total of 2005 participants completed the interview. The current prevalence of IBS was 5.4% and the 12-month prevalence of GAD was 4%. GAD was five times more common among IBS respondents than non-IBS respondents (OR: 5.84, P<0.001), whereas IBS was 4.7 times more common among GAD respondents than among non-GAD respondents (OR: 6.32, P<0.001). Core depressive symptoms (OR: 6.25, P<0.01) and education level (OR: 5.918, P = 0.021) were risk correlates of GAD among IBS respondents. Comorbid respondents were more impaired than respondents having either disorder alone, but were not more likely to seek professional help than IBS-only respondents.  Conclusion  Irritable Bowel Syndrome and GAD comorbidity was common and added to impairment in the community. The strong association between psychiatric morbidity and IBS observed in referral centres was not a consequence of increased help-seeking behaviour.

Shelov, D. V., S. Suchday, et al. (2009). "A Pilot Study Measuring the Impact of Yoga on the Trait of Mindfulness." Behavioural and Cognitive Psychotherapy 37(05): 595-598.  [Abstract/Full Text] 
Background: The current study examined whether yoga would increase levels of mindfulness in a healthy population. Method: Forty-six participants were randomly assigned to an 8-week yoga intervention group or a wait-list control group. Mindfulness was assessed pre and post yoga, using the Freiburg Mindfulness Inventory (FMI). Results: Results indicate that the yoga group experienced a significant increase in Overall mindfulness, and in three mindfulness subscales; Attention to the present moment, Accepting and open attitudes toward experience, and Insightful understanding (p<.01). The control group experienced a significant increase in overall mindfulness (p<.02) and insightful understanding (p<.01). Findings suggest that a yoga intervention may be a viable method for increasing levels of trait mindfulness in a healthy population, potentially implicating yoga as a preventive method for the later development of negative emotional mood states (i.e. anxiety and depression). The control group also experienced moderate elevations of mindfulness at the second assessment.