Vadivel, V., C.N. Kunyanga, H.K. Biesalski, 2012. Health benefits of nut consumption with special reference to body weight control. Nutrition. 28:1089–1097.
Nuts are an integral part of the Mediterranean food patterns, and their incorporation into the regular diets of human beings is believed to provide many health benefits. The recent recognition of nuts as “heart-healthy” foods by the U.S. Food and Drug Administration has given a major boost to the positive image of nuts. Nut consumption has been associated with several health benefits, such as antioxidant, hypocholesterolemic, cardioprotective, anticancer, anti-inflammatory, and antidiabetic benefits, among other functional properties. However, although nuts possess these many health benefits, their consumption has been hampered by a lack of adequate information regarding those benefits. In addition, because nuts are energy-dense foods with high-fat content, there is a misconception among consumers that increased consumption may lead to unwanted gain in body weight with the risk of developing overweight/obesity. Nonetheless, available epidemiologic studies and short-term controlled feeding trials have supported the theory that the inclusion of nuts in the typical diet does not induce weight gain, despite an expected increase in total caloric intake. To address the misperception about nuts and body weight gain, the present review focuses mainly on the relation between nut consumption and body weight gain, in the context of the many health benefits of nuts.
Mullie, M., P. Clarys, 2012. Nut consumption is associated with a healthy dietary pattern in military men. Food and Nutrition Sciences. 3:1048-1054.
The objective of the research was to determine the relation between nut consumption and dietary patterns described by Healthy Eating Index, Mediterranean Diet Score and principal component analysis. In a cross-sectional study, 1852 military men were contacted by mail. Using food-frequency questionnaires, nut consumption was recorded and stratified in weekly versus less than weekly. Three dietary indices were calculated and stratified in quintiles. For principal component analysis, the healthiest dietary pattern rich in fruits and vegetables was selected as Healthy Dietary Pattern. The highest quintiles of Healthy Eating Index, Mediterranean Diet Score and Healthy Dietary Pattern were systematically associated with the highest weekly consumption of nuts. The highest quintiles were also associated with the lowest intake of saturated fat, i.e. between 10 and 12 energy-percent compared with 17 to 19 energy-percent for the lowest quintiles. The mean daily nut consumption was less than 6 g a day, which is beneath the recommended quantity for cardiovascular protection. Nut consumption was associated with the healthiest dietary pattern, independently of the used method to determine the dietary pattern. Regular nut consumption seems to be a component of a cluster of several healthy behaviors.
Tulipani, S., M. Urpi-Sarda, R. Garcıá -Villalba, M. Rabassa, P. López-Uriarte, M. Bulló, O. Jáuregui, F. Tomás-Barberán, J. Salas-Salvado,́ J. Carlos Espıń, C. Andrés-Lacueva, 2012. Urolithins are the main urinary microbial-derived phenolic metabolites discriminating a moderate consumption of nuts in free-living subjects with diagnosed metabolic syndrome. J. Agric. Food Chem. doi.org/10.1021/jf301509w.
Walnuts (Juglans regia L.), hazelnuts (Corylus avellana L.), and almonds (Prunus dulcis Mill.) are rich sources of ellagitannins and proanthocyanidins. Gut microbiota plays a crucial role in modulating the bioavailability of these high molecular weight polyphenols. However, to date there are no studies evaluating the capacity to produce nut phenolic metabolites in subjects with metabolic syndrome (MetS), a pathology associated with an altered gut bacterial diversity. This study applied a LC-MS targeted approach to analyze the urinary excretion of nut phenolic metabolites in MetS subjects following 12 weeks of nut consumption, compared to sex- and age-matched individuals given a nut-free control diet. Metabolites were targeted in both hydrolyzed and nonhydrolyzed urine by LC-PDA-QqQ-MS/MS analysis, and identification of metabolites lacking available standards was confirmed by LC-ESI-ITD-FT-MS. Ellagitannin-derived urolithins A and B significantly increased after the nutenriched-diet, urolithins C and D were also detected, and a complex combination of urolithin-conjugated forms was observed in nonhydrolyzed urine, confirming an extensive phase II metabolism after absorption. In contrast, no significant increases in proanthocyanidin microbial metabolites were observed in urine following nut consumption. Because the intestinal microbiota of the subjects in this study could catabolize ellagitannins into a wide range of urolithins, further research is strongly warranted on the in vivo potential of these microbial metabolites in reducing cardiometabolic risk.
Pribis P., R.N. Bailey, A.A. Russell, M.A. Kilsby, M. Hernandez, W.J. Craig, T. Grajales, D.J. Shavlik, J. Sabatè, 2011. Effects of walnut consumption on cognitive performance in young adults. Br J Nutr. 107(9):1393-1401.
Walnuts contain a number of potentially neuroprotective compounds like vitamin E, folate, melatonin, several antioxidative polyphenols and significant amounts of n-3 α-linolenic fatty acid. The present study sought to determine the effect of walnuts on verbal and non-verbal reasoning, memory and mood. A total of sixty-four college students were randomly assigned to two treatment sequences in a crossover fashion: walnuts-placebo or placebo-walnuts. Baseline data were collected for non-verbal reasoning, verbal reasoning, memory and mood states. Data were collected again after 8 weeks of intervention. After 6 weeks of washout, the intervention groups followed the diets in reverse order. Data were collected once more at the end of the 8-week intervention period. No significant increases were detected for mood, non-verbal reasoning or memory on the walnut-supplemented diet. However, inferential verbal reasoning increased significantly by 11.2 %, indicating a medium effect size (P = 0.009; d = 0.567). In young, healthy, normal adults, walnuts do not appear to improve memory, mood or non-verbal reasoning abilities. However, walnuts may have the ability to increase inferential reasoning.
Kamil, A., C.-Y. O. Chen, 2012. Nuts for diabetes prevention and management. Journal of Food and Drug Analysis. 20(Suppl.1): 323-327.
Type 2 diabetes mellitus is an important preventable disease and a growing public health problem. Epidemiologic and clinical studies suggest that healthy eating, physical activity, and BW control are the main driving forces to reduce diabetes risk. Owing to their low available carbohydrate content, favorable fat and protein profile as well as phytonutrient content, nut consumption has been associated with a reduced risk of development and management of diabetes. Nuts, by virtue of its cardioprotective actions, have also been shown to reduce biomarkers of risk factors for diabetic complications. Although more studies are warranted, the emerging picture is that nut consumption beneficially influences diabetes risk and management beyond blood glucose control.
Zhang, J., P.M. Kris-Etherton, J.T. Thompson, D.B. Hannon, P.J. Gillies, J.P. Vanden Heuvel, 2012. Alpha-linolenic acid increases cholesterol efflux in macrophage-derived foam cells by decreasing stearoyl CoA desaturase 1 expression: evidence for a farnesoid-X-receptor mechanism of action. J Nutr Biochem. 23(4):400-9.
Increased cholesterol efflux from macrophage-derived foam cells (MDFCs) is an important protective mechanism to decrease lipid load in the atherosclerotic plaque. Dietary alpha-linolenic acid (ALA), an omega-3 polyunsaturated fatty acid (PUFA), decreases circulating cholesterol, but its role in cholesterol efflux has not been extensively studied. Stearoyl CoA desaturase 1 (SCD1) is the rate-limiting enzyme in the synthesis of monounsaturated fatty acids (MUFAs). Endogenous MUFAs are preferentially incorporated into triglycerides, phospholipids and cholesteryl ester, which are abundant in atherosclerotic plaque. This study investigated the mechanisms by which ALA regulated SCD1 and subsequent effect on cholesterol storage and transport in MDFCs. Small interfering RNA (siRNA) also was applied to modify SCD1 expression in foam cells. Alpha-linolenic acid treatment and SCD1 siRNA significantly decreased SCD1 expression in MDFCs. The reduction of SCD1 was accompanied with increased cholesterol efflux and decreased intracellular cholesterol storage within these cells. Alphalinolenic acid activated the nuclear receptor farnesoid-X-receptor, which in turn increased its target gene small heterodimer partner (SHP) expression, and decreased liver-X-receptor dependent sterol regulatory element binding protein 1c transcription, ultimately resulting in repressed SCD1 expression. In conclusion, repression of SCD1 by ALA favorably increased cholesterol efflux and decreased cholesterol accumulation in foam cells. This may be one mechanism by which dietary omega-3 PUFAs promote atherosclerosis regressio
Moon, H.-S., X. Liu, J.M. Nagel, J.P. Chamberland, K.N. Diakopoulos, M.T. Brinkoetter, M. Hatziapostolou, Y. Wu, S.C. Robson, D. Iliopoulos, C.S. Mantzoros, 2012. Salutary effects of adiponectin on colon cancer: in vivo and in vitro studies in mice. Gut. doi:10.1136/gutjnl-2012-302092.
Background: Obesity and a high-fat diet are associated with the risk and progression of colon cancer. Low adiponectin levels may play an important role in the development of colon and other obesity-related malignancies. No previous studies have directly investigated the mechanistic effects of adiponectin on colon cancer in the settings of obesity, a high-fat diet and/or adiponectin deficiency. Objective: To investigate the effects of adiponectin on the growth of colorectal cancer in adiponectin-deficient or wild-type-C57BL/6 mice fed a low-fat or high-fat diet. Results: Mice fed a high-fat-diet gained more weight and had larger tumours than mice fed a low-fat-diet. Adiponectin administration suppressed implanted tumour growth, causing larger central necrotic areas. Adiponectin treatment also suppressed angiogenesis assessed by CD31 staining and VEGFb and VEGFd mRNA expression in tumours obtained from mice fed a high-fat diet and from adiponectin-deficient mice. Adiponectin treatment decreased serum insulin levels in mice on a high-fat-diet and increased serum-interleukin (IL)-12 levels in adiponectin-deficient mice. In vitro, it was found that adiponectin directly controls malignant potential (cell proliferation, adhesion, invasion and colony formation) and regulates metabolic (AMPK/S6), inflammatory (STAT3/VEGF) and cell cycle (p21/p27/p53/cyclins) signalling pathways in both mouse MCA38 and human HT29, HCT116 and LoVo colon cancer cell lines in a LKB1-dependent way. Conclusion: These new mechanistic and pathophysiology studies provide evidence for an important role of adiponectin in colon cancer. The data indicate that adiponectin or analogues might be useful agents in the management or chemoprevention of colon cancer.
Davis, P.A., V.T. Vasu, K. Gohil, H. Kim, I.H. Khan, C.E. Cross, W. Yokoyama, 2012. A high-fat diet containing whole walnuts (Juglans regia) reduces tumour size and growth along with plasma insulin-like growth factor 1 in the transgenic adenocarcinoma of the mouse prostate model. British Journal of Nutrition. doi:10.1017/S0007114511007288
Prostate cancer (PCa) has been linked to fat intake, but the effects of both different dietary fat levels and types remain inconsistent and incompletely characterised. The effects on PCa in the transgenic adenocarcinoma of the mouse prostate (TRAMP) cancer model of an elevated fat (20% of energy as fat) diet containing 155 g of whole walnuts were compared to those of an elevated fat (20% of energy as soyabean oil) diet with matched macronutrients, tocopherols as well as a low-fat (8% of energy as soyabean oil) diet. Mice, starting at 8 weeks of age, consumed one of the three different diets ad libitum; and prostates, livers and blood were obtained after 9, 18 or 24 weeks of feeding. No differences were observed in whole animal growth rates in either high-fat (HF) diet group, but prostate tumour weight and growth rate were reduced in the walnut diet group. Walnut diet group prostate weight, plasma insulin-like growth factor 1, resistin and LDL were lower at 18 weeks, while no statistically significant prostate weight differences by diet were seen at 9 or 24 weeks. Multiple metabolites in the livers differed by diet at 9 and 18 weeks. The walnut diet’s beneficial effects probably represent the effects of whole walnuts’ multiple constituents and not via a specific fatty acid or tocopherols. Moreover, as the two HF diets had dissimilar effects on prostate tumour growth rate and size, and yet had the same total fat and tocopherol composition and content, this suggests that these are not strongly linked to PCa growth.
Robbins, W.A., L. Xun, L.Z. FitzGerald, S. Esguerra, S.M. Henning, C.L. Carpenter, 2012. Walnuts improve semen quality in men consuming a western-style diet: randomized control dietary intervention trial. Biol Reprod. doi:10.1095/biolreprod.112.101634
Purpose: We tested the hypothesis that 75 gm of whole-shelled walnuts/day added to a Westernstyle diet of healthy young men would beneficially affect semen quality. Methods: A randomized, parallel two-group, dietary intervention trial with single-blind masking of outcome assessors, was conducted with 117 healthy men, age 21 – 35 years, who routinely consumed a Western-style diet. Primary outcome evaluated was improvement from baseline to 12 weeks in conventional semen parameters and sperm aneuploidy. Secondary endpoints included blood serum and sperm fatty acid (FA) profiles, sex hormones, and serum folate. Conclusions: The group consuming walnuts (n=59) experienced improvement in sperm vitality, motility, and morphology and the group continuing their usual diet but avoiding tree nuts (n=58) saw no change. Comparing differences from baseline between the groups, significance was found for vitality p=0.003, motility p=0.009, and morphology (normal forms) p=0.04. Serum FA profiles improved in the walnut group with increases in omega-6 (p=0.0004) and omega-3 p=0.0007) but not the control group. Only the plant source of omega-3, α-linolenic acid (ALA), increased (p=0.0001). Sperm aneuploidy was inversely correlated with sperm ALA, particularly sex chromosome nullisomy (-0.41, p=0.002). Findings demonstrated that walnuts added to a Western-style diet improved sperm vitality, motility and morphology.
Dalamaga, M., K.N. Diakopoulos, C.S. Mantzoros, 2012. The role of adiponectin in cancer: A review of current evidence. Endocrine Reviews. 33(4):547-94.
Excess body weight is associated not only with an increased risk of type 2 diabetes and cardiovascular disease (CVD) but also with various types of malignancies. Adiponectin, the most abundant protein secreted by adipose tissue, exhibits insulin-sensitizing, antiinflammatory, antiatherogenic, proapoptotic, and antiproliferative properties. Circulating adiponectin levels, which are determined predominantly by genetic factors, diet, physical activity, and abdominal adiposity, are decreased in patients with diabetes, CVD, and several obesity-associated cancers. Also, adiponectin levels are inversely associated with the risk of developing diabetes, CVD, and several malignancies later in life. Many cancer cell lines express adiponectin receptors, and adiponectin in vitro limits cell proliferation and induces apoptosis. Recent in vitro studies demonstrate the antiangiogenic and tumor growth-limiting properties of adiponectin. Studies in both animals and humans have investigated adiponectin and adiponectin receptor regulation and expression in several cancers. Current evidence supports a role of adiponectin as a novel risk factor and potential diagnostic and prognostic biomarker in cancer. In addition, either adiponectin per se or medications that increase adiponectin levels or up-regulate signaling pathways downstream of adiponectin may prove to be useful anticancer agents. This review presents the role of adiponectin in carcinogenesis and cancer progression and examines the pathophysiological mechanisms that underlie the association between adiponectin and malignancy in the context of a dysfunctional adipose tissue in obesity. Understanding of these mechanisms may be important for the development of preventive and therapeutic strategies against obesity-associated malignancies.
