Can nuts mitigate malnutrition in older adults? A conceptual framework

The proportion of adults aged over 60 years in the world is expected to reach 20% by the year 2050. Ageing is associated with several physiological changes that increase the risk of malnutrition among this population. Malnutrition is characterized by deficiencies or insufficiencies of macro- and micronutrients. Malnutrition has detrimental effects on the health, wellbeing, and quality of life in older adults. Nuts are rich in energy, unsaturated fats, and protein, as well as other nutrients that provide a range of health benefits. While the effects of nuts on overnutrition have been studied extensively, very few studies have been specifically designed to understand the role of nuts in mitigating undernutrition in the elderly. Therefore, this review explores the potential role of nuts in improving the nutritional status of older adults who are at risk of undernutrition. Several properties of whole nuts, some of which appear important for addressing overnutrition, (e.g., hardness, lower-than-expected nutrient availability, satiety-enhancing effects) may limit their effectiveness as a food to combat undernutrition. However, we propose that modifications such as transforming the physical form of nuts, addressing the timing of nut ingestion, and introducing variety may overcome these barriers. This review also discusses the feasibility of using nuts to prevent and reverse undernutrition among older adults. We conclude with a recommendation to conduct clinical studies in the future to test this conceptual framework

Application of a high density adsorbent in expanded bed adsorption of lipase from Burkholderia pseudomallei

The application of STREAMLINE Direct HST adsorbent in expanded bed adsorption of lipase from Burkholderia pseudomallei was explored in this study. Scouting of optimum binding and elution condition was performed in batch binding mode. Theaddition of 0.2 M salt in acetate buffer (pH 5) during adsorption has increased thespecificity and quantity of lipase binding onto the adsorbent. The addition of 0.4 M salt in phosphate buffer (pH 7) achieved the highest purification fold (2.5) in elution. The high density of the adsorbent allowed the EBA to be operated at linear velocityas high as 657 cm/h with feedstock containing 4.5% (w/v) wet biomass. The Richardson-Zaki correlation obtained for this EBA system at the presence of 4.5% (w/v) wet biomass is 5.14, a value closed to the laminar flow regime of 4.8, demonstrated that a stable bed is achieved under this operating condition.Meanwhile, a flow velocity of 343 cm/h with bed expansion of 3.2 gave highest dynamic binding capacity (4979.28 U/ml) and productivity (61.52 U/ml.min) for this EBA operation. It also demonstrated that biomass concentration up to 4.5% (w/v) wet weight showed slightly drop of sorption efficiency (0.82) compared to lower biomass concentration (0.94). Further increase of biomass concentration above 4.5% (w/v) wet weight has greatly decreased the equilibrium and dynamic capacity. Application of high density adsorbent tolerated to high density and biomass has reduced the processing time and increased the productivity

In-band pumped conical refraction Nd:KGW laser

We have demonstrated an in-band pumped conical refraction (CR) Nd: KGW laser. The CR laser was diode-pumped at 910 nm and produced an output power of 1.15 W at 1069 nm

A comparison of perceptions of nuts between the general public, dietitians, general practitioners, and nurses

Background Nut consumption at the population level remains low despite the well-documented benefits of their consumption, including their cardioprotective effects. Studies have suggested that advice from health professionals may be a means to increase nut consumption levels. Understanding how nuts are perceived by the public and health professionals, along with understanding the public’s perceptions of motivators of and deterrents to consuming nuts, may inform the development of initiatives to improve on these low levels of consumption. The aim of this cross-sectional study was to compare perceptions of nuts among three groups of health professionals (dietitians, general practioners, and practice nurses) and the general public in New Zealand (NZ), along with motivators of and deterrents to consuming nuts amongst the general public and their experiences of receiving advice around nut consumption. Methods The NZ electoral roll was used to identify dietitians, general practitioners (GPs), and practice nurses, based on their free-text occupation descriptions, who were then invited to complete a questionnaire with 318, 292, and 149 respondents respectively. 1,600 members of the general public were randomly selected from the roll with 710 respondents. Analyses were performed using chi-squared tests to look at differences in categorical variables and linear regression for differences in other variables between the four survey groups. Results Although there were significant differences between the four groups regarding the perceptions of nuts, in general there was agreement that nuts are healthy, high in protein and fat, are filling, and some nuts are high in selenium. We noted frequent agreement that the general public participants would consume more if nuts: improved health (67%), were more affordable (60%), or improved the nutrient content (59%) and balance of fats (58%) within their diets. Over half the respondents reported they would eat more nuts if they were advised to do so by a dietitian or doctor, despite less than 4% reporting they had received such advice. The most frequently selected deterrents to increasing nut consumption were: cost (67%), potential weight gain (66%), and leading to eating too much fat (63%). Discussion It is concerning that so few among the general public report receiving advice to consume more nuts from health professionals, especially given their apparent responsiveness to such advice. Health professionals could exploit the motivators of nut consumption, while also addressing the deterrents, to promote nut intake. These factors should also be addressed in public health messages to encourage regular nut consumption among the public. Educational initiatives could also be used to improve the nutritional knowledge of GPs and practice nurses with regard to nuts, although even dietitians were unsure of their knowledge in some cases

Effects of hazelnut consumption on cardiovascular disease risk factors, energy balance, sensory-specific satiety, and acceptance

Nuts are rich sources of cis-unsaturated fatty acids, vegetable protein, dietary fibre, phytochemicals, and essential vitamins and minerals. Epidemiological studies have consistently demonstrated an inverse association between frequent nut consumption and the risk of cardiovascular disease (CVD). Randomised controlled trials (RCTs) have shown a significant improvement in blood lipid profiles when following a diet enriched in different types of nuts. Interestingly, although nuts are high in fat and energy, several studies report that nut consumption is not associated with adverse weight gain. This raises the question as to whether nuts have unique properties that protect against unwanted weight gain. No studies to date have been designed to determine whether regular nut consumption is different to the frequent ingestion of other energy-dense foods in terms of body weight regulation. Recent evidence suggests that frequent nut consumption may have beneficial effects above and beyond their cholesterol-lowering effect. For instance, nut consumption may also improve novel risk factors for CVD such as oxidative stress, inflammatory markers, and endothelial dysfunction. The current recommended daily serving of nuts (30 g) is largely based on their lipid-lowering properties. The dose of nuts required to influence the aforementioned novel risk factors is unknown. To achieve optimal health benefits, nuts must be consumed regularly and in sufficient quantity. Sensory-specific satiety (SSS) and acceptance (‘desire’ and ‘liking’) have been shown to influence intake both acutely and over the long-term. For example, an increase in SSS may result in early termination of consumption, which may compromise adherence to dietary guidelines. Furthermore, a decline in acceptance over time is likely to reduce compliance to consume nuts on a regular basis. The overall aims of this thesis were: (i) to examine the effects of regular nut consumption on body weight and SSS in comparison to other energy-dense snack foods; (ii) to determine the effects of consuming nuts at different doses on novel risk factors for CVD; and (iii) to assess the effects of long-term nut consumption on acceptance. To achieve these overall aims, two randomised, controlled, parallel studies were conducted. In part one of the first study (Chapter 3), 118 healthy normocholesterolaemic individuals were randomly allocated to receive daily portions of ~1100 kJ/d of hazelnuts (42 g), chocolate (50 g), potato crisps (50 g), or no snack food (control group) for 12 weeks. Body composition, resting metabolic rate (RMR), blood lipid profiles, and diet quality were measured at baseline and at week 12. The results showed no statistically significant differences in changes in body composition, RMR, and blood lipid profiles from baseline to week 12 between the groups, after adjusting for baseline value, sex, baseline age, and baseline body mass index (BMI) (all P ≥ 0.106). However, diet quality improved significantly in the nut group. Compared to all other groups, the percentage of total energy derived from saturated fatty acids (SFA) (all P ≤ 0.045) and carbohydrate (all P ≤ 0.006) was significantly lower whereas vitamin E intake (all P ≤ 0.007), the percentage of energy derived from monounsaturated fatty acids (MUFA) (all P ≤ 0.001) and polyunsaturated fatty acids (PUFA) (all P ≤ 0.011) was significantly higher in the nut group at week 12. In part two of this study (Chapter 4), SSS and ad libitum intake for the snack foods were measured during a tasting session at baseline and at week 12. In addition, ‘desire to consume’ and ‘overall liking’ for the snack foods were also assessed at daily intervals during the 12-week exposure period. Twelve-week consumption of snack foods resulted in a statistically significant reduction in SSS in all three snack groups (P = 0.015). However no such changes were seen in the control group (P = 0.608). Ad libitum energy intake for the snack food increased over the study across all groups including the control group (P = 0.039). Daily exposure to chocolate and potato crisps for 12 weeks caused a significant decline in ‘liking’ (P = 0.002, P = 0.031 respectively). However, nuts were found to be resistant to such an effect, and ‘liking’ for nuts was stable throughout the exposure period. Two important findings of this first study were that regular consumption of 42 g of nuts on a daily basis did not adversely affect body weight, and acceptance of the nuts remained high over 12 weeks. Whether the consumption of higher doses of nuts elicits similar results is unknown. Although 30 g of nuts is recommended to reduce blood lipid and lipoprotein concentrations, the dose of nuts required to influence novel risk factors for CVD may be higher. Therefore, a second study was conducted to investigate whether there was a dose-response effect of nut consumption on markers of inflammation and endothelial function. Importantly, body composition and acceptance were also assessed given the higher dose was in excess of current recommendations. In the second study (Chapter 5), 107 overweight and obese individuals were randomly allocated to one of the three treatment arms: no nuts (control group), 30 g/d of hazelnuts or 60 g/d of hazelnuts for 12 weeks. These individuals were chosen as previous research demonstrates that chronic inflammation and impaired endothelial function is more pronounced among overweight and obese individuals. Body composition, blood lipid profiles, markers of inflammation and endothelial function were assessed at baseline, week 6, and week 12. In addition, ‘desire to consume’ and ‘liking’ for nuts were assessed at weekly intervals during the twelve-week exposure period. The results showed no statistically significant change in body composition from baseline to week 12 in both nut groups. Although 30 g/d and 60 g/d of hazelnuts significantly improved blood lipid profiles and endothelial function compared with baseline, these changes were not statistically significantly different from the control group after adjusting for baseline value, sex, baseline age, and baseline BMI (all P ≥ 0.065). However, hazelnut consumption significantly improved diet quality in a dose-response manner. Compared to the control group, both hazelnut-enriched diets significantly reduced carbohydrate intake (overall P < 0.001) whereas the intakes of MUFA (overall P < 0.001), vitamin E (overall P < 0.001), and potassium (overall P = 0.038) increased significantly. The ‘desire’ and ‘liking’ for nuts remained stable throughout the exposure period in the 30 g/d nut group, whereas both measures declined significantly in the 60 g/d nut group (both P < 0.001). Unlike previous literature, hazelnut consumption had little influence on blood lipid profiles in both studies reported in this thesis. It is important to note that the participants in the first study were normocholesterolaemic while the second study was comprised of overweight and obese individuals. Recent evidence suggests that the response to a cholesterol-lowering diet is less pronounced in weight-stable individuals with high BMI and among those with low baseline cholesterol concentrations. Our study disagrees with previous nut studies, which have shown significant improvements in novel risk factors such as endothelial function. An important difference between the current study and previous research is that our study simply added nuts to participants’ habitual diet. All other studies have not only included nuts, but have also altered the background diet or provided additional dietary advice. An important finding of this thesis is that moderate nut consumption (up to 60 g/d) does not adversely affect body composition. In addition, nut consumption significantly improves diet quality in a way that would be expected to improve CVD risk. On the basis of SSS and acceptance data, the current guideline to consume one serving (30 to 42 g/d) of nuts regularly appears to be an achievable and sustainable behaviour. However, higher intakes (i.e. 60 g/d) compromised participants’ ‘desire’ and ‘liking’ for them. Therefore, this thesis reinforces the recommendation to consume a moderate serving (30 to 42 g/d) of nuts regularly as part of the heart-healthy diet

Effects of hazelnut consumption on cardiovascular disease risk factors, energy balance, sensory-specific satiety, and acceptance

Nuts are rich sources of cis-unsaturated fatty acids, vegetable protein, dietary fibre, phytochemicals, and essential vitamins and minerals. Epidemiological studies have consistently demonstrated an inverse association between frequent nut consumption and the risk of cardiovascular disease (CVD). Randomised controlled trials (RCTs) have shown a significant improvement in blood lipid profiles when following a diet enriched in different types of nuts. Interestingly, although nuts are high in fat and energy, several studies report that nut consumption is not associated with adverse weight gain. This raises the question as to whether nuts have unique properties that protect against unwanted weight gain. No studies to date have been designed to determine whether regular nut consumption is different to the frequent ingestion of other energy-dense foods in terms of body weight regulation. Recent evidence suggests that frequent nut consumption may have beneficial effects above and beyond their cholesterol-lowering effect. For instance, nut consumption may also improve novel risk factors for CVD such as oxidative stress, inflammatory markers, and endothelial dysfunction. The current recommended daily serving of nuts (30 g) is largely based on their lipid-lowering properties. The dose of nuts required to influence the aforementioned novel risk factors is unknown. To achieve optimal health benefits, nuts must be consumed regularly and in sufficient quantity. Sensory-specific satiety (SSS) and acceptance (‘desire’ and ‘liking’) have been shown to influence intake both acutely and over the long-term. For example, an increase in SSS may result in early termination of consumption, which may compromise adherence to dietary guidelines. Furthermore, a decline in acceptance over time is likely to reduce compliance to consume nuts on a regular basis. The overall aims of this thesis were: (i) to examine the effects of regular nut consumption on body weight and SSS in comparison to other energy-dense snack foods; (ii) to determine the effects of consuming nuts at different doses on novel risk factors for CVD; and (iii) to assess the effects of long-term nut consumption on acceptance. To achieve these overall aims, two randomised, controlled, parallel studies were conducted. In part one of the first study (Chapter 3), 118 healthy normocholesterolaemic individuals were randomly allocated to receive daily portions of ~1100 kJ/d of hazelnuts (42 g), chocolate (50 g), potato crisps (50 g), or no snack food (control group) for 12 weeks. Body composition, resting metabolic rate (RMR), blood lipid profiles, and diet quality were measured at baseline and at week 12. The results showed no statistically significant differences in changes in body composition, RMR, and blood lipid profiles from baseline to week 12 between the groups, after adjusting for baseline value, sex, baseline age, and baseline body mass index (BMI) (all P ≥ 0.106). However, diet quality improved significantly in the nut group. Compared to all other groups, the percentage of total energy derived from saturated fatty acids (SFA) (all P ≤ 0.045) and carbohydrate (all P ≤ 0.006) was significantly lower whereas vitamin E intake (all P ≤ 0.007), the percentage of energy derived from monounsaturated fatty acids (MUFA) (all P ≤ 0.001) and polyunsaturated fatty acids (PUFA) (all P ≤ 0.011) was significantly higher in the nut group at week 12. In part two of this study (Chapter 4), SSS and ad libitum intake for the snack foods were measured during a tasting session at baseline and at week 12. In addition, ‘desire to consume’ and ‘overall liking’ for the snack foods were also assessed at daily intervals during the 12-week exposure period. Twelve-week consumption of snack foods resulted in a statistically significant reduction in SSS in all three snack groups (P = 0.015). However no such changes were seen in the control group (P = 0.608). Ad libitum energy intake for the snack food increased over the study across all groups including the control group (P = 0.039). Daily exposure to chocolate and potato crisps for 12 weeks caused a significant decline in ‘liking’ (P = 0.002, P = 0.031 respectively). However, nuts were found to be resistant to such an effect, and ‘liking’ for nuts was stable throughout the exposure period. Two important findings of this first study were that regular consumption of 42 g of nuts on a daily basis did not adversely affect body weight, and acceptance of the nuts remained high over 12 weeks. Whether the consumption of higher doses of nuts elicits similar results is unknown. Although 30 g of nuts is recommended to reduce blood lipid and lipoprotein concentrations, the dose of nuts required to influence novel risk factors for CVD may be higher. Therefore, a second study was conducted to investigate whether there was a dose-response effect of nut consumption on markers of inflammation and endothelial function. Importantly, body composition and acceptance were also assessed given the higher dose was in excess of current recommendations. In the second study (Chapter 5), 107 overweight and obese individuals were randomly allocated to one of the three treatment arms: no nuts (control group), 30 g/d of hazelnuts or 60 g/d of hazelnuts for 12 weeks. These individuals were chosen as previous research demonstrates that chronic inflammation and impaired endothelial function is more pronounced among overweight and obese individuals. Body composition, blood lipid profiles, markers of inflammation and endothelial function were assessed at baseline, week 6, and week 12. In addition, ‘desire to consume’ and ‘liking’ for nuts were assessed at weekly intervals during the twelve-week exposure period. The results showed no statistically significant change in body composition from baseline to week 12 in both nut groups. Although 30 g/d and 60 g/d of hazelnuts significantly improved blood lipid profiles and endothelial function compared with baseline, these changes were not statistically significantly different from the control group after adjusting for baseline value, sex, baseline age, and baseline BMI (all P ≥ 0.065). However, hazelnut consumption significantly improved diet quality in a dose-response manner. Compared to the control group, both hazelnut-enriched diets significantly reduced carbohydrate intake (overall P < 0.001) whereas the intakes of MUFA (overall P < 0.001), vitamin E (overall P < 0.001), and potassium (overall P = 0.038) increased significantly. The ‘desire’ and ‘liking’ for nuts remained stable throughout the exposure period in the 30 g/d nut group, whereas both measures declined significantly in the 60 g/d nut group (both P < 0.001). Unlike previous literature, hazelnut consumption had little influence on blood lipid profiles in both studies reported in this thesis. It is important to note that the participants in the first study were normocholesterolaemic while the second study was comprised of overweight and obese individuals. Recent evidence suggests that the response to a cholesterol-lowering diet is less pronounced in weight-stable individuals with high BMI and among those with low baseline cholesterol concentrations. Our study disagrees with previous nut studies, which have shown significant improvements in novel risk factors such as endothelial function. An important difference between the current study and previous research is that our study simply added nuts to participants’ habitual diet. All other studies have not only included nuts, but have also altered the background diet or provided additional dietary advice. An important finding of this thesis is that moderate nut consumption (up to 60 g/d) does not adversely affect body composition. In addition, nut consumption significantly improves diet quality in a way that would be expected to improve CVD risk. On the basis of SSS and acceptance data, the current guideline to consume one serving (30 to 42 g/d) of nuts regularly appears to be an achievable and sustainable behaviour. However, higher intakes (i.e. 60 g/d) compromised participants’ ‘desire’ and ‘liking’ for them. Therefore, this thesis reinforces the recommendation to consume a moderate serving (30 to 42 g/d) of nuts regularly as part of the heart-healthy diet

Effects of Hazelnut Consumption on Cardiometabolic Risk Factors and Acceptance: A Systematic Review

Despite being rich sources of monounsaturated fat and a number of vitamins, minerals, and phytonutrients, hazelnuts have received less attention than some other nut types. A qualitative systematic review was carried out to determine the effects of hazelnut consumption on acceptance and markers of cardiometabolic health, including blood lipids and lipoproteins, apolipoproteins A1 and B100, body weight and composition, blood pressure, glycemia, antioxidant status, oxidative stress, inflammation, and endothelial function. In total, 22 intervention studies (25 publications) met our inclusion criteria. The findings indicate some improvements in cardiometabolic risk factors; however, limitations in study design mean interpretation is problematic. The inclusion of hazelnuts in the diet did not adversely affect body weight and composition. Acceptance of hazelnuts remained stable over time confirming nut consumption guidelines are feasible and sustainable. Future studies using more robust study designs in a variety of populations are required to draw more definitive conclusions on the health benefits of hazelnut consumption

Impact of dose-response calorie reduction or supplementation of a covertly manipulated lunchtime meal on energy compensation

Numerous studies have examined energy compensation following overfeeding regimes whereas much less is known about the impact of acute underfeeding on energy compensation and fewer still have compared energy reduction and addition in the same group of individuals. This study compared the effects of consuming lunches with varying energy content (7.2-fold difference) on subsequent energy intake. A total of 27 healthy males took part in this randomized, crossover study with five treatments: 163 kcal (very low energy meal, VLEM), 302 kcal (low energy meal, LEM), 605 kcal (control), 889 kcal (high energy meal, HEM), and 1176 kcal (very high energy meal, VHEM) served as a noodle soup. Participants were instructed to consume a standardized breakfast in the morning and they were provided with one of the five treatments for lunch on non-consecutive test day. Test lunches were matched for palatability, sensory properties, and volume. Participants were provided with an afternoon snack and ad libitum dinner on each test day and recorded food intake for the rest of the day. Appetite ratings were measured at regular intervals. As the energy content of treatments increased, participants' hunger, desire to eat, and prospective consumption decreased significantly whereas fullness increased significantly. However, no significant difference in subsequent meal intake was found between the treatments (P = 0.458): 1003 kcal VLEM, 1010 kcal LEM, 1011 kcal control, 940 kcal HEM, and 919 kcal VHEM. Total daily energy intake was statistically significantly different between the treatments (P < 0.001) and was varied directly with the energy content of the lunchtime meal. Despite the large difference in energy content between the treatments, participants did not compensate for the “missing calories” or “additional calories” at subsequent meals. These results suggest that covertly manipulated, equally palatable, sensory and volume matched meals have the potential to promote either positive or negative energy balance if the effects seen in this single meal study are sustained

Effects of Consuming Preloads with Different Energy Density and Taste Quality on Energy Intake and Postprandial Blood Glucose

Consumption of reduced energy dense foods and drink has the potential to reduce energy intake and postprandial blood glucose concentrations. In addition, the taste quality of a meal (e.g., sweet or savoury) may play a role in satiation and food intake. The objective of this randomised crossover study was to examine whether energy density and taste quality has an impact on energy intake and postprandial blood glucose response. Using a preload design, participants were asked to consume a sweet (“Cheng Teng”) or a savoury (broth) preload soup in high energy density (HED; around 0.50 kcal/g; 250 kcal) or low energy density (LED; around 0.12 kcal/g; 50 kcal) in mid-morning and an ad libitum lunch was provided an hour after the preload. Participants recorded their food intake for the rest of the day after they left the study site. Energy compensation and postprandial blood glucose response were measured in 32 healthy lean males (mean age = 28.9 years, mean BMI = 22.1 kg/m2). There was a significant difference in ad libitum lunch intake between treatments (p = 0.012), with higher intake in sweet LED and savoury LED compared to sweet HED and savoury HED. Energy intake at subsequent meals and total daily energy intake did not differ between the four treatments (both p ≥ 0.214). Consumption of HED preloads resulted in a larger spike in postprandial blood glucose response compared with LED preloads, irrespective of taste quality (p &lt; 0.001). Energy density rather than taste quality plays an important role in energy compensation and postprandial blood glucose response. This suggests that regular consumption of low energy-dense foods has the potential to reduce overall energy intake and to improve glycemic control

Nuts Improve Diet Quality Compared to Other Energy-Dense Snacks While Maintaining Body Weight

Previous studies have reported that regular nut consumption reduces cardiovascular disease (CVD) risk and does not promote weight gain despite the fact that nuts are energy-dense. However, no studies have investigated the body composition of those regularly consuming nuts compared to similar intakes of other snacks of equal energy density. This parallel study (n = 118) examined the effects of providing daily portions (~1100 kJ/d) of hazelnuts, chocolate, or potato crisps compared to a control group receiving no snacks for twelve weeks. Effects on body weight and composition, blood lipids and lipoproteins, resting metabolic rate (RMR), appetite indices, and dietary quality were compared. At week 12, there was no significant difference in any of the outcome measurements between the groups except for dietary quality, which improved significantly in the nut group. Nuts can be incorporated into the diet without adversely affecting body weight and can improve diet quality