Wibisono,C., Y. Probst, E. Neale, L. Tapsell, 2017. Changes in diet quality during a 12 month weight loss randomised controlled trial. BMC Nutrition. 3:38 Doi: 10.1186/s40795-017-0157-z.
Abstract: Background: Reductions in energy intake are seen in weight loss trials, but whether this occurs with improvements to diet quality (DQ) is less established. The aim of this study was to evaluate changes in diet quality in a sample of volunteers in a weight loss trial. Methods This was a secondary analysis of dietary data from a lifestyle intervention trial (the HealthTrack study) which advised on dietary guidelines. The trial ran for 12 months with three treatment groups: control (general advice C), intervention (individualised advice, I), and intervention plus a supplement of walnuts (IW). Both the published a priori diet quality score (APDQS, maximum score 164) and a study specific Diet Quality Tracker (DQT, maximum score 44) indicated compliance to dietary advice. DQ scores calculated at 0, 3months and 12months were evaluated using two-way RMANOVA, one-way ANOVA and one-way RMANOVA. Changes in intakes of food groups and nutrients were analysed using Kruskal-Wallis and Friedman’s tests. Results There were no differences between groups at baseline, but at 3months IW recorded higher DQ scores (APDQS:96 ± 10; DQT:22 ± 5, P < 1 × 10−3 for both) compared to I (APDQS:91 ± 13, P < 1 × 10−3; DQT:21 ± 4, P < 1 × 10−2) and C (APDQS:87 ± 12, P < 5 × 10−2; DQT:19 ± 4, P > 5 × 10−2), and a higher consumption of nuts at 3 months (P < 1 × 10−3), and 12months (P < 1 × 10−2). All groups reported decreased intakes of discretionary foods/beverages assessed by the DQT (P < 1 × 10−3 for IW and I; P < 1 × 10−2 for C). The APDQS showed this as reduced intakes of grain-based desserts (P < 1 × 10−3 at 3 and 12months), and salty snacks at 12months (P < 1 × 10−3 for IW and I; P < 5 × 10−2 for C). Intakes of monounsaturated and saturated fatty acids were lowest, and polyunsaturated fatty acids highest for IW (P < 1 × 10−3), resulting in a higher dietary polyunsaturated:saturated fat ratio (P < 1 × 10−3). Conclusions: Lifestyle intervention addressing dietary guidelines can lead to significant reductions in consumption of discretionary foods and saturated fat, but individualised advice may have a greater impact on improving overall DQ regardless of DQI used. Providing a healthy food supplement may help assure higher DQ and where the food is walnuts, produce commensurate differences in dietary fatty acid profiles.
Tapsell, L.C., M. Lonergan, M.J. Batterham, E.P. Neale, A. Martin, R. Thorne, F. Deane, G. Peoples, 2017. Effect of interdisciplinary care on weight loss: a randomized controlled trial. BMJ Open. 7:e014533. doi:10.1136/ bmjopen-2016-014533.
Objective: To determine the effectiveness of a novel interdisciplinary treatment compared with usual care on weight loss in overweight and obese adult volunteers. Design Single blinded controlled trial. Participants randomly assigned to usual care (C, general guideline based diet and exercise advice), intervention (I, interdisciplinary protocol) or intervention + a healthy food supplement (30 g walnuts/day) (IW). Setting Community based study, Illawarra region, south of Sydney, Australia. Participants: Generally well volunteer adult residents, 25-54 years, body mass index (BMI) 25-40kg/m2 were eligible. At baseline 439 were assessed, 377 were randomised, 298 completed the 3-month intensive phase and 178 completed the 12-month follow-up. Interventions Treatment was provided at clinic visits intensively (0 months, 1 month, 2 months, 3 months) then quarterly to 12 months. Support phone calls were quarterly. All participants underwent blinded assessments for diet, exercise and psychological status. Primary and secondary measures: The primary outcome was difference in weight loss between baseline and 12 months (clinically relevant target 5% loss). Secondary outcomes were changes in blood pressure, fasting blood glucose and lipids, and changes in diet, exercise and psychological parameters. Results At 12 months, differences in weight loss were identified (p<0.001). The I group lost more than controls at 3 months (91.11 (92.23,90.00), p<0.05) and the IW more than controls at 3 months (91.25 (92.35,90.15), p<0.05) and 6 months (92.20 (93.90,90.49), p<0.01). The proportion achieving 5% weight loss was significantly different at 3 months, 6 months and months (p=0.04, p=0.03, p=0.03), due to fewer controls on target at 3 months, 6 months and 9 months and more IW participants at 6 months. Reductions in secondary outcomes (systolic blood pressure, blood glucose/lipid parameters and lifestyle measures) followed the pattern of weight loss. Conclusions An interdisciplinary intervention produced greater and more clinically significant and sustained weight loss compared with usual care. The intensive phase was sufficient to reach clinically relevant targets, but long-term management plans may be required.
Vitolins, M.Z., C.S. Blackwell, J.D. Williamson, C.G. Foy, S. Wilmoth, K.M. Sink, L.M. Reynolds, R.P. Byington, D.M. Reboussin, 2017. The feasibility of walnut and extra virgin olive oil supplementation in older adults. J Food Nutr Sci. 4(1):1-6.
Researchers in Spain provided randomized, controlled trial evidence that adding extra virgin olive oil (EVOO) and nuts to diets of older adults lowered cardiovascular disease risk. Supplementing these foods may represent a simple and straightforward approach to favourable dietary change with potential for dissemination to the broader public. This was an 8-week feasibility trial in which all participants were asked to supplement their ad libitum diets with both walnuts and EVOO to determine their interest in participating and to assess retention and adherence once enrolled. Inclusion criteria were broad: Adults ≥ 55 years old treated for hypertension with medication; exclusions included walnuts/EVOO allergies, homebound or diagnosis of dementia. Recruitment was assessed as number of weeks to accrue 25 participants. Adherence was assessed by participant self-report using a daily diary. Blood pressure (BP), body weight, and HDL cholesterol were measured to estimate the variability of outcomes. Results: Twenty- seven participants were recruited in 2 ½ weeks; 26 of the 27 participants remained in the study for a retention rate of 96% (95% CI: 78% – 100%). Of 216 possible diaries, 185 were returned (86%). On average, weight increased over 8 weeks by 0.8 pounds. Mean systolic BP dropped by 0.25 mmHg while mean diastolic BP decreased by 1.0 mmHg. Mean HDL increased by 1.96 mg/dL. A full-scale walnut/EVOO trial in older adults with hypertension seems realistic given our high rates of recruitment, retention, and adherence, coupled with minimal weight gain and favorable trends in BP and HDL.
Stevenson, J.L., C.M. Paton, J.A. Cooper, 2017. Hunger and satiety responses to high-fat meals after a high-polyunsaturated fat diet: A randomized trial. Nutrition. 41:1-10.
Objective Previous studies have shown that polyunsaturated fats (PUFAs) elicit a greater response in satiety after a single-meal challenge compared with other types of fats. The long-term effects of PUFAs on satiety, however, remain unknown. The aim of this study was to determine subjective and physiological hunger and satiety responses to high-fat (HF) meals before and after a 7-d PUFA-rich diet. Methods Twenty-six, healthy weight (body mass index 18–24.9 kg/m2), sedentary adults were randomly assigned to either a 7-d PUFA-rich diet (n = 8 men and n = 8 women) or a 7-d control diet (n = 5 men and n = 5 women). After a 3-d lead-in diet, participants reported for the baseline visit where anthropometrics, fasting visual analog scale (VAS) measurements, and a fasting blood sample were collected. Then, two HF meals (breakfast and lunch) were consumed. Postprandial blood draws and VAS measures were collected approximately every 30 min for 4 h after each meal, for a total of 8 h. Results From pre- to post-PUFA–rich diet, there was a decrease in fasting ghrelin (P < 0.05) and an increase in fasting peptide YY (PYY; P < 0.05); however, there were no changes in fasting insulin or leptin concentrations. The postprandial response for PYY was higher after the PUFA-rich diet visit compared to baseline (P < 0.01). However, there were no differences in the postprandial response for ghrelin, insulin, leptin, or VAS measures from pre- to post-diet in either the PUFA-rich diet or control (ns). Conclusion A PUFA-rich diet consumed for 7 d favorably altered fasting and postprandial physiological markers of hunger and satiety; yet, did not alter subjective ratings of hunger or fullness.
Rana, B.K., S.W. Flatt, D.D. Health, B. Pakiz, E.L. Quintana, L. Natarajan, C.L. Rock, 2017. The IL-6 gene promoter SNP and plasma IL-6 in response to diet intervention. Nutrients. 9, 552; Doi:10.3390/nu9060552
We recently reported that interleukin-6 (IL-6), an inflammatory marker associated with breast pathology and the development of breast cancer, decreases with diet intervention and weight loss in both insulin-sensitive and insulin-resistant obese women. Here, we tested whether an individual’s genotype at an IL6 SNP, rs1800795, which has previously been associated with circulating IL-6 levels, contributes to changes in IL-6 levels or modifies the effect of diet composition on IL-6 in these women. We genotyped rs1800795 in overweight/obese women (N = 242) who were randomly assigned to a lower fat (20% energy), higher carbohydrate (65% energy) diet; a lower carbohydrate (45% energy), higher fat (35% energy) diet; or a walnut-rich (18% energy), higher fat (35% energy), lower carbohydrate (45% energy) diet in a 1-year weight loss intervention study of obesity-related biomarkers for breast cancer incidence and mortality. Plasma IL-6 levels were measured at baseline, 6 and 12 months. At baseline, individuals with a CC genotype had significantly lower IL-6 levels than individuals with either a GC or GG genotype (p < 0.03; 2.72 pg/mL vs. 2.04 pg/mL), but this result was not significant when body mass index (BMI) was accounted for; the CC genotype group had lower BMI (p = 0.03; 32.5 kg/m² vs. 33.6 kg/m²). We did not observe a 2-way interaction of time*rs1800795 genotype or diet*rs1800795 genotype. Our findings provide evidence that rs1800795 is associated with IL-6 levels, but do not support a differential interaction effect of rs1800795 and diet composition or time on changes in circulating IL-6 levels. Diet intervention and weight loss are an important strategy for reducing plasma IL-6, a risk factor of breast cancer in women, regardless of their rs1800795 genotype.
Rock, C.L., S.W. Flatt, H.S. Barkai, B. Pakiz, D.D. Heath, 2017. A walnut-containing meal had similar effects on early satiety, CCK, and PYY, but attenuated the postprandial GLP-1 and insulin response compared to a nut-free control meal. Appetite. 117:51-57.
Regular nut consumption is associated with lower adiposity and reduced weight gain in adulthood. Walnut feeding studies have observed minimal effect on body weight despite potential additional energy intake. Several mechanisms may explain why consuming nuts promotes weight control, including increased early phase satiety, possibly reflected in postprandial response of gastrointestinal and pancreatic peptides hypothesized to affect appetite. The purpose of this study was to compare postprandial insulin, glucagon and gastrointestinal peptide response and satiety following a meal with ∼54% of energy from walnuts or cream cheese, using a within-subject crossover study design in overweight/obese adults (N = 28). Sixty minutes after the walnut-containing meal, glucagon-like peptide-1 was lower than after the reference meal (p=0.0433), and peptide YY, cholecystokinin and ghrelin did not differ after the two meals. Sixty and 120 min after the walnut-containing meal, pancreatic polypeptide (p = 0.0014 and p = 0.0002) and glucose-dependent insulinotropic peptide (p < 0.0001 and p = 0.0079) were lower than after the reference meal, and 120 min after the walnut-containing meal, glucagon was higher (p=0.0069). Insulin and C-peptide increased at 60 min in response to both meals but were lower at 120 min after the walnut-containing meal (p=0.0349 and 0.0237, respectively). Satiety measures were similar after both meals. These findings fail to support the hypothesis that acute postprandial gastrointestinal peptide response to a walnut-containing meal contributes to increased satiety. However, inclusion of walnuts attenuated the postprandial insulin response, which may contribute to the more favorable lipid profile observed in association with regular walnut consumption.
Rajaram, S., C. Valls-Pedret, M. Cofán, J. Sabaté, M. Serra-Mir, A.M. Pérez-Heras, A. Arechiga, R.P. Casaroli-Marano, S. Alforja, A. Sala-Vila, M. Doménech, I. Roth, T.M. Freitas-Simoes, C. Calvo, A. López-Illamola, E. Haddad, E. Bitok, N. Kazzi, L. Huey, J. Fan, E. Ros, 2017. The Walnuts and Healthy Aging Study (WAHA): Protocol for a nutritional intervention trial with walnuts on brain aging.Front. Aging Neurosci. 2017 Jan 10;8:333.
Introduction: An unwanted consequence of population aging is the growing number of elderly at risk of neurodegenerative disorders, including dementia and macular degeneration. As nutritional and behavioral changes can delay disease progression, we designed the Walnuts and Healthy Aging (WAHA) study, a two-center, randomized, 2-year clinical trial conducted in free-living, cognitively healthy elderly men and women. Our interest in exploring the role of walnuts in maintaining cognitive and retinal health is based on extensive evidence supporting their cardio-protective and vascular health effects, which are linked to bioactive components such as n-3 fatty acids and polyphenols. Methods: The primary aim of WAHA is to examine the effects of ingesting walnuts daily for 2 years on cognitive function and retinal health, assessed with a battery of neuropsychological tests and optical coherence tomography, respectively. All participants followed their habitual diet, adding walnuts at 15% of energy (~30-60 g/d) (walnut group) or abstaining from walnuts (control group). Secondary outcomes include changes in adiposity, blood pressure, and serum and urinary biomarkers in all participants and brain magnetic resonance imaging in a subset. Results: From May 2012 to May 2014, 708 participants (mean age 69 years, 68% women) were randomized. The study ended in May 2016 with a 90% retention rate. Discussion: The results of WAHA might provide high-level evidence of the benefit of regular walnut consumption in delaying the onset of age-related cognitive impairment and retinal pathology. The findings should translate into public health policy and sound recommendations to the general population.
Farr, O.M., D. Tuccinardi, J. Upadhyay, S.M. Oussaada, C.S. Mantzoros, 2017. Walnut consumption increases activation of the insula to highly desirable food cues: A randomized, double-blind, placebo-controlled, cross-over fMRI study. Diabetes Obes Metab. 2017 Jul 17. doi: 10.1111/dom.13060. [Epub ahead of print]
Aims: The use of walnuts is recommended for obesity and type 2 diabetes, although the mechanisms through which walnuts may improve appetite and/or glycemic control remain largely unknown. Materials and Methods: To determine whether short-term walnut consumption could alter the neural control of appetite using functional magnetic resonance imaging, we performed a randomized, placebo-controlled, double-blind, cross-over trial of 10 patients who received, while living in the controlled environment of a clinical research center, either walnuts or placebo (using a validated smoothie delivery system) for 5 days each, separated by a wash-out period of one month. Results: Walnut consumption decreased feelings of hunger and appetite assessed using visual analog scales and increased the activation of the right insula to highly desirable food cues. Conclusions: These findings suggest that walnut consumption may increase salience and cognitive control processing of highly desirable food cues, leading to the beneficial metabolic effects observed.
Ndanuko, R.N., L.C. Tapsell, K.E. Charlton, E.P. Neale, M.J. Batterham, 2017. Associations between dietary patterns and blood pressure in a clinical sample of overweight adults. J Acad Nutr Diet. 7(2):228-239.
Background: Dietary pattern analysis provides important evidence revealing diet-disease relationships. It may be especially useful in areas less well researched, such as diet and hypertension in clinical populations. Objective: The aim of this study was to identify the association between dietary patterns and blood pressure (BP) in a sample of overweight adults volunteering for a clinical trial for weight loss. Design: This cross-sectional analysis used baseline data from the HealthTrack study, a 12-month randomized controlled trial. Dietary intake was evaluated with 4-day food records. Participants/Setting: Participants were 328 adults recruited from the Illawarra region of New South Wales, Australia, between May 2014 and April 2015. Main Outcome Measures: Resting BP and 24-hour urine sodium and potassium were measured. Statistical Analysis: Dietary patterns were derived by principal component analysis from 21 food groups. Multiple regression analysis was performed to assess the association between the extracted dietary patterns and BP. Results: The participants’ mean age was 43.6±8.0 years, mean body mass index was 32.4±4.2, and mean systolic BP/diastolic BP was 124.9±14.5/73.3±9.9 mm Hg. Six major dietary patterns were identified: “nuts, seeds, fruit, and fish,” “milk and meat,” “breads, cereals, and snacks,” “cereal-based products, fats, and oils,” “alcohol, eggs, and legumes,” and “savoury sauces, condiments, and meat.” The “nuts, seeds, fruit, and fish” dietary pattern was significantly and inversely associated with systolic BP (F [7,320]=15.248; P<0.0005; adjusted R2=0.234 and diastolic BP (F [7,320]=17.351; P<0.0005; adjusted R2=0.259) and sodium-to-potassium ratio (F [7,320]=6.210; P<0.0005; adjusted R2=0.100). Conclusions: A dietary pattern rich in nuts, seeds, fruit, and fish was inversely associated with blood pressure in this clinical sample. The findings suggest that current dietary guidelines are relevant to an overweight clinical population and support the value of dietary pattern analysis when exploring the diet-disease relationship.
Schwingshackl, L., G. Hoffmann, B. Missbach, M. Stelmach-Mardas, H. Boeing, 2017. An umbrella review of nuts intake and risk of cardiovascular disease. Current Pharmaceutical Design. 23:1016-1027.
Background: Nuts have been an indispensable component of the human diet for hundreds because of their unique nutrient composition and are thought to play a beneficial part in the prevention of cardiovascular diseases. Objective: To evaluate the extent, validity and presence of evidence for studies investigating the impact of nuts intake on biomarkers of cardiovascular disease and cardiovascular events, we performed an umbrella review of all published meta-analyses synthesizing data from both observational studies and randomized controlled trials. Method: PubMed (between 1966 and April 2016) was searched for systematic reviews and meta-analyses. Methodological quality was assessed by applying the AMSTAR score (0-11 points), and the meta-evidence by applying NutriGrade, our recently developed scoring system (0-10 points). Results: In total, 14 meta-analyses were included in the umbrella review. Only 4 out of 14 reported an AMSTAR score ≥8 (high methodological quality), whereas NutriGrade meta-evidence score varied between 2 (very low meta-evidence) and 7.9 (moderate meta-evidence). There is consistent evidence from intervention trials, reporting significant reductions for total cholesterol, and from observational studies that higher intakes of nuts were associated with reduced risk of cardiovascular disease and hypertension. On the other side no effect could be observed for stroke, HDL-cholesterol, and blood pressure in the normal range. Conclusion: In summary, the present umbrella review showed that nuts intake was associated with reduced risk of cardiovascular disease and hypertension, and lower levels of total cholesterol. The observed evidence is limited by the moderate methodological quality and very low to moderate quality of evidence.
