Edible nuts deliver polyphenols and their transformation products to the large intestine: An in vitro fermentation model combining targeted/untargeted metabolomics.
The fate of polyphenols from edible tree nuts was investigated using a simulated in vitro intestinal fermentation system. The digested food matrix was fermented for 48 h and the changes in the phenolic profiles were evaluated by both untargeted UHPLC-QTOF and targeted UHPLC-Orbitrap mass spectrometry. The untargeted metabolomics approach allowed us to monitor the comprehensive changes in phenolic profiles from 0 up to 48 h of in vitro fermentation. Multivariate statistics (i.e., orthogonal projection to latent structures discriminant analysis) applied to this untargeted data allowed us to identify the most discriminating phenolic metabolites and to further understand the colonic transformation pathways involved. In particular, 13 putatively identified compounds derived from flavonoids, lignans and phenolic acids were found to have the highest discrimination potential. Six phenolic metabolites were then quantified by means of targeted metabolomics (using a UHPLC-Orbitrap). These metabolites included 3,4-dihydroxyphenylacetic acid, 4-hydroxybenzoic acid, hippuric acid, caffeic acid, protocatechuic acid and protocatechuic aldehyde. Using the targeted data, a clear matrix effect was observed over time, with an increase of some phenolic metabolites moving from 8 to 48 h of in vitro fermentation. Based on these data, catabolic pathways for colonic microbial degradation of flavonoids, hydroxycinnamic acids, tyrosols and lignans are proposed. Our findings show that edible tree nuts deliver polyphenols to the colon, where several microbial transformations occur that lead to smaller phenolic metabolites being observed. Furthermore, we found that the combined use of targeted and untargeted metabolomics can be particularly effective for investigating the fate of polyphenols in the large intestine.
The Type of Dietary Fat in an Isocaloric Breakfast Meal Does Not Modify Postprandial Metabolism in Overweight/Obese Pregnant Women.
Abstract: Almonds provide a satiating, healthy source of fat and fiber. The postprandial metabolic and satiety response to 2 ounces of nuts or dairy was assessed in 18 overweight/obese women during late pregnancy. Serum glucose, triglycerides, insulin, c-peptide, leptin, ghrelin, and lipoprotein particles were measured prior to and during a 5-h postprandial period following the consumption of an isocaloric breakfast meal with equivalent amounts of fat from either nuts or dairy on two separate mornings. Satiety was assessed by visual analogue scale (VAS) questionnaires and ad libitum food intake at the end of the study. At 33 weeks gestation, the women had gained an average of 7.0 ± 4.4 kg during gestation. Body fat averaged 41.9 ± 5.5% and hemoglobin A1c levels were elevated, (7.2 ± 0.6%). Fasting glucose levels were normal, but hyperinsulinemia was evident. The two test meals did not affect the postprandial metabolic response, but glucose, triglyceride, and ghrelin concentrations changed with time during the postprandial period (p < 0.001, p = 0.0008, p = 0.006). Satiety measures did not differ between the two test meals. Consuming an isocaloric breakfast meal with equivalent amounts of fat from nuts or dairy did not alter postprandial levels of blood lipids, glucose, hormones, or measures of satiety in overweight/obese, pregnant women.
Lower Depression Scores among Walnut Consumers in NHANES.
Background: Multiple studies have shown a Mediterranean diet, characterized by their olive oil and nut consumption, to be correlated with lower depression risk. Objective: To examine whether part of this reduced risk in the United States is attributable to walnut consumption, we analyzed data on walnut consumption and depression scores from the National Health and Nutrition Examination Survey (NHANES). Methods: NHANES survey data for 2005 through 2014 was pooled for adults with 24 h recall dietary data. Depression scores were based on PHQ-9 self-report responses. A total of 26,656 participants were characterized as reporting the consumption of walnuts with high certainty, walnuts with other nuts, other nuts, or no nuts. Results: After an adjustment for covariates, walnut consumers showed lower depression scores compared to non-nut consumers. The least square mean for total depression score was 26% lower for walnut with high certainty consumers than for non-nut consumers (p < 0.0001), and the association was stronger among women (32%, p< 0.0001) than men (21%, p = 0.05). The significant contributors to this difference were due to walnut consumers reporting greater interest in doing things (p = 0.003), less hopelessness (p = 0.02), and feeling more energetic (p = 0.05) than non-nut consumers. Non-nut consumers were more likely to have trouble concentrating (p = 0.02), to feel they were moving or speaking abnormally (p = 0.03), and to have thought they were better off dead (p = 0.002). Conclusions: Depression scores were significantly lower among nut consumers and particularly walnut consumers as compared to non-nut consumers. After controlling for potential covariates, walnut users had scores significantly lower than other nut consumers. The difference was strongest among women, who are more likely than men to report higher depression scores.
Relationship Between Nut Consumption and Metabolic Syndrome: A Meta-Analysis of Observational Studies.
Objective: Our aim was to examine the relationship between nut consumption and metabolic syndrome (MetS). Methods: The electronic databases of PubMed, Web of Science, and Embase were searched up to November 2018 for observational studies on the relationship between nut consumption and MetS. The pooled relative risk (RR) of MetS for the highest versus lowest category of nut consumption, as well as their corresponding 95% confidence intervals (CIs) were calculated. Results: A total of 11 observational studies (6 cross-sectional and 5 prospective cohort studies), which involved a total of 89,224 participants, were identified for this meta-analysis. The overall multivariable adjusted RR showed that nut consumption was negatively associated with MetS (RR = 0.84; 95% CI, 0.76–0.92; p < 0.001). Of interest, subgroup analysis confirmed that such findings existed in tree nuts (RR = 0.97; 95% CI, 0.94–1.00; p = 0.04), but not in peanuts (RR = 1.01; 95% CI, 0.96–1.06; p = 0.68). Conclusions: The existing evidence suggested that nut consumption was negatively associated with MetS. However, such an inverse relationship only existed in tree nuts, not in peanuts. More well-designed studies with detailed specifications of nut varieties are needed to further elaborate the issues examined in this study.
The effect of nuts on markers of glycemic control: a systematic review and meta-analysis of randomized controlled trials.
BACKGROUND: Observational evidence suggests higher nut consumption is associated with better glycemic control; however, it is unclear if this association is causal. OBJECTIVES: We aimed to conduct a systematic review and meta-analysis of randomized controlled trials to examine the effect of tree nuts and peanuts on markers of glycemic control in adults. METHODS: A systematic review and meta-analysis of randomized controlled trials was conducted. A total of 1063 potentially eligible articles were screened in duplicate. From these articles, 40 were eligible for inclusion and data from these articles were extracted in duplicate. The weighted mean difference (WMD) between the nut intervention and control arms was determined for fasting glucose, fasting insulin, glycated hemoglobin (HbA1c), and homeostasis model assessment of insulin resistance (HOMA-IR) using the DerSimonian and Laird random-effects method. For outcomes where a limited number of studies were published, a qualitative synthesis was presented. RESULTS: A total of 40 randomized controlled trials including 2832 unique participants, with a median duration of 3 mo (range: 1-12 mo), were included. Overall consumption of tree nuts or peanuts had a favorable effect on HOMA-IR (WMD: -0.23; 95% CI: -0.40, -0.06; I2 = 51.7%) and fasting insulin (WMD: -0.40 μIU/mL; 95% CI: -0.73, -0.07 μIU/mL; I2 = 49.4%). There was no significant effect of nut consumption on fasting blood glucose (WMD: -0.52 mg/dL; 95% CI: -1.43, 0.38 mg/dL; I2 = 53.4%) or HbA1c (WMD: 0.02%; 95% CI: -0.01%, 0.04%; I2 = 51.0%). CONCLUSIONS: Consumption of peanuts or tree nuts significantly decreased HOMA-IR and fasting insulin; there was no effect of nut consumption on HbA1c or fasting glucose. The results suggest that nut consumption may improve insulin sensitivity. In the future, well-designed clinical trials are required to elucidate the mechanisms that account for these observed effects.
Nut Consumption in Relation to Cardiovascular Disease Incidence and Mortality among Patients with Diabetes Mellitus.
RATIONALE: The evidence regarding the potential health benefits of nut consumption among individuals with type 2 diabetes is limited. OBJECTIVE: To examine intake of total and specific types of nuts, including tree nuts and peanuts, in relation to subsequent risk of cardiovascular disease (CVD), including coronary heart disease (CHD) and stroke, and all-cause and cause-specific mortality among individuals with diabetes. METHODS AND RESULTS: This prospective analysis included 16,217 men and women with diabetes at baseline or diagnosed during follow-up (Nurses' Health Study: 1980-2014, Health Professionals Follow-Up Study: 1986-2014). Nut consumption was assessed using a validated food frequency questionnaire and updated every 2-4 years. During 223,682 and 254,923 person-years of follow-up, there were 3,336 incident CVD cases and 5,682 deaths. Higher total nut consumption was associated with a lower risk of CVD incidence and mortality. The multivariate-adjusted hazard ratios (95% confidence intervals) for participants who consumed 5 or more servings of total nuts per week (1 serving=28g), compared with those who consumed less than 1 serving per month, were 0.83 (0.71-0.98; P trend=0.01) for total CVD incidence, 0.80 (0.67-0.96; P trend=0.005) for CHD incidence, 0.66 (0.52-0.84; P trend<0.001) for CVD mortality, and 0.69 (0.61-0.77; P trend<0.001) for all-cause mortality. Total nut consumption was not significantly associated with risk of stroke incidence or cancer mortality. For specific types of nuts, higher tree nut consumption was associated with lower risk of total CVD, CHD incidence, and mortality due to CVD, cancer, and all causes, while peanut consumption was associated with lower all-cause mortality only (all P trend<0.001). In addition, compared with participants who did not change the consumption of total nuts from pre- to post-diabetes diagnosis, participants who increased consumption of total nuts after diabetes diagnosis had an 11% lower risk of CVD, a 15% lower CHD risk, a 25% lower CVD mortality, and a 27% lower all-cause mortality. The associations persisted in subgroup analyses stratified by sex/cohort, body mass index at diabetes diagnosis, smoking status, diabetes duration, nut consumption before diabetes diagnosis, or diet quality. CONCLUSIONS: Higher consumption of nuts, especially tree nuts, is associated with lower CVD incidence and mortality among participants with diabetes. These data provide novel evidence that supports the recommendation of incorporating nuts into healthy dietary patterns for the prevention of CVD complications and premature deaths among individuals with diabetes.
Consumption of cashew nuts does not influence blood lipids or other markers of cardiovascular disease in humans: a randomized controlled trial.
BACKGROUND: The US Food and Drug Administration (FDA) approved a qualified health claim for tree nuts and reduction of cardiovascular disease. However, cashews are excluded from that claim due to their content of saturated fats, which is predominantly stearic acid. Because stearic acid is neutral with respect to blood lipids, several studies have been conducted to test the effect of cashew nuts on blood lipids, and these studies have produced conflicting results. OBJECTIVES: The aim of this study was to conduct a highly controlled intervention to determine the effect of cashews fed at the amount specified in the health claim on risk factors for cardiovascular disease. METHODS: A total of 42 adults participated in a controlled-feeding study conducted as a randomized crossover trial with 2 treatment phases. The volunteers were provided the same base diet in both treatment phases, with no additions during the control phase and with the addition of 1.5 servings (42 g) of cashews/d for the cashew nut phase. During the cashew nut phase, the amount of all foods was decreased proportionally to achieve isocaloric overall diets in the 2 phases. After 4 wk of intervention, assessments included blood lipids, blood pressure, central (aortic) pressure, augmentation index, blood glucose, endothelin, proprotein convertase subtilisin/kexin type 9 (PCSK9), adhesion molecules, and clotting and inflammatory factors. RESULTS: There were no significant differences in blood lipids, blood pressure, augmentation index, blood glucose, endothelin, adhesion molecules, or clotting factors in this weight-stable cohort. PCSK9 was significantly decreased after cashew consumption, although there was no change in LDL cholesterol. CONCLUSIONS: Consumption of 1.5 servings of cashew nuts/d, the amount associated with the FDA qualified health claim for tree nuts and cardiovascular disease, did not positively or adversely affect any of the primary risk factors for cardiovascular disease. This trial was registered at clinicaltrials.gov as NCT02628171.
UK-Eastern and Southern Africa: Trade Continuity Agreement
It replicates the effects of the existing EU Economic Partnership Agreement with Eastern and Southern Africa allowing tariff-free imports and removing the majority of tariffs over the coming years. In signing this Agreement, both countries ensure certainty for businesses, consumers and investors when the UK ceases to be bound by EU deals.
UK signs Eastern and Southern Africa trade continuity agreement
Thailand: Contaminants and Toxins in Food
The Draft details the limits of contaminants and mycotoxins in foods. As for total aflatoxin in nuts and dried fruits, the Draft sets the following maximum limits:
| Product | Description | Aflatoxin, total (mg/kg) |
| Brazil nuts | Whole commodity (ready to eat) | 10 |
| shelled Brazil nuts intended for further processing | 15 | |
| Pistachios | Whole commodity (ready to eat) | 10 |
| pistachios intended for further processing | 15 | |
| Dried figs | Whole commodity (ready to eat) | 10 |
| Peanuts | Unless specified, seed or kernels, after removal of shell or husk and intended for further processing | 20 |
| Almonds | Whole commodity after remove shell (ready to eat) | 10 |
| Whole commodity after remove shell (intended for further processing) | 15 | |
| Hazelnuts | Whole commodity after removal of shell (ready to eat) | 10 |
| Whole commodity after remove shell (intended for further processing) | 15 | |
| Other nuts and dried fruits | Other than the above lists | 20 |
The final date for comments is April 15, 2019.
For further information, please contact us at inc@nutfruit.org.
Saudi Arabia: Contaminants and Toxins
This Draft contains maximum levels of contaminants and toxicants in food and feed. As for nuts and dried fruits, the maximum levels (ML) of mycotoxins are proposed as follows:
| Commodity/Product Name | Maximum level of aflatoxins (μg/kg) (B1+B2+G1+G2) |
|
| RTE | FP | |
| Almonds (whole commodity after removal of shell) | 10 | 15 |
| Brazil nuts (whole commodity) | 10 | 15 |
| Hazelnuts (whole commodity after removal of shell) | 10 | 15 |
| Peanuts (unless specified, seed or kernels, after removal of shell or husk) | - | 15 |
| Pistachios (whole commodity after removal of shell) | 10 | 15 |
| Dried figs (whole commodity) | 10 | - |
| Nuts with exception mentioned (whole commodity) | 4 | 10 |
| Dried fruit, other than dried figs (whole commodity) | 4 | 10 |
| Ochratoxin A (μg/kg) | ||
| Dried vine fruit | 10 | |
| Lead (mg/kg) | ||
| Cranberry (Whole commodity after removal of caps and stems) | 0.2 | |
RTE: ready-to-eat means not intended to undergo an additional processing/treatment that has proven to reduce levels of aflatoxins before being used as ingredient in foodstuffs, otherwise processed or offered for human consumption.
PF: intended for further processing means intended to undergo an additional processing/treatment that has proven to reduce levels of aflatoxins before being used as an ingredient in foodstuffs, otherwise processed or offered for human consumption. Processes that have proven to reduce levels of aflatoxins are shelling, blanching followed by color sorting, and sorting by specific gravity and color (damage). There is some evidence that roasting reduces aflatoxins in pistachios but for other nuts the evidence is still to be supplied.
The deadline for comments is April 9, 2018.
For further information, please contact us at inc@nutfruit.org.