Here is an essay on ‘Walnut’ for class 8, 9, 10, 11 and 12. Find paragraphs, long and short essays on ‘Walnut’ especially written for school and college students.
Essay on Walnut
1. Essay on Walnut (Anti-Cognitive Impairment):
Walnuts contain a number of potentially neuro-protective compounds like vitamin E, folate, melatonin, several anti-oxidative polyphenols. Walnuts are well known for their high levels of PUFAs, specifically the ω-6 fatty acid linoleic acid (LA) and the ω-3 fatty acid α-linolenic acid (ALA). LA and ALA can either exist as membrane components or can be metabolized via the arachidonic acid cascade to generate numerous lipid messengers including prostaglandins, eicosapentaenoic acid (EPA), and docosahaenoic acid (DHA).
High-anti-oxidant foods such as berries, concord grapes, and walnuts may increase “health span” and enhance cognitive and motor function in ageing. Though no significant increases were detected for mood, non-verbal reasoning or memory on the walnut-supplemented diet in young healthy normal adults, inferential verbal reasoning increased significantly by 112 per cent.
A significant improvement in learning and memory of walnut treated rats compared to controls was observed. Analysis of brain monoamines exhibited enhanced serotonergic levels in rat brain fed walnuts suggesting that walnut may exert its hypophagic and no tropic actions via an enhancement of brain 5-HT metabolism. Recently, Poulose et al (2013) demonstrated the effectiveness of a walnut-supplemented diet in activating the autophagy function in brain beyond its traditionally known anti-oxidant and anti-inflammatory benefits.
Willis et al (2009) reported that the 2 per cent walnut diet improved performance on rod walking, while the 6 per cent walnut diet improved performance on the medium plank walk; the higher dose of the 9 per cent walnut diet did not improve psychomotor performance and on the large plank actually impaired performance. All of the walnut diets improved working memory in the Morris water maze and showed that moderate dietary walnut supplementation can improve cognitive and motor performance in aged rats.
Walnut extract induced a decrease in tumor necrosis-alpha production, internalization of the lipo-polysaccharide receptor and toll-like receptor 4. The anti-inflammatory effects of walnut were dependent on functional activation of phospholipase D2.
Thus Willis et al. (2010) were the first ones to describe the anti-inflammatory effects of walnuts in microglia, which could lead to nutritional interventions in the prevention and treatment of neuro-degeneration. Shabani et al. (2012) observed walnut consumption to improve memory and motor abilities in cisplatin treated rats. Cisplatin increased latency of response to nociception, and walnut reversed this effect of cisplatin.
2. Essay on Walnuts (Anti-Hyperlipidemic Foods):
Nut consumption, particularly walnut intake, has been inversely related to incident coronary heart disease (CHD) in observational studies and to improved lipid profiles with a decrease in total and LDL cholesterol as well as triglycerides and an increase in HDL cholesterol and apo-lipoprotein A1 in short-term feeding trials. The walnut extracts exhibited a Trolox equivalent activity greater than that of alpha-tocopherol.
LC-ELSD/MS analysis of the walnut extracts identified ellagic acid monomers, polymeric ellagitannins and other phenolics, principally non-flavonoid compounds. Walnut poly-phenolics are effective inhibitors of in vitro plasma and LDL oxidation. Therefore, Anderson et al (2001) recommended that the poly-phenolic content of walnuts should be considered when evaluating their anti-atherogenic potential.
Papoutsi et al (2008) reported that the walnut extract has a high anti-atherogenic potential and a remarkable osteoblastic activity, an effect mediated, at least in part, by its major component ellagic acid. Such findings implicate the beneficial effect of a walnut-enriched diet on cardio-protection and bone loss.
The restructured meat products with added walnuts supplied can be considered functional foods for subjects at high risk for CVD, as their regular consumption provokes a reduction in total cholesterol of 4.5 per cent with respect to baseline values (mixed diet) and 3 per cent with respect to the restructured meat without walnuts. Rajaram et al (2009) through a randomized cross-over study confirmed that including walnuts and fatty fish in a healthy diet lowered serum cholesterol and triglyceride concentrations, respectively, and thus decreased CHD risk considerably.
Canales et al. (2009) also demonstrated that meat enriched with walnut paste and low-fat meat consumptions reduced plasma thromboxane A2 (TXB2) levels most (P = 0.050) in obese individuals, while the prostacyclin I2 and the thrombogenic (TXB2/6-keto-PGF1alpha) ratio decreased most (P = 0.066) in volunteers whose serum cholesterol levels were > or = 220 mg/dl.
3. Essay on Walnuts (Anti-Obesity Foods):
Studies consistently show the beneficial effects of eating nuts, but as high-energy foods, their regular consumption may lead to weight gain. Epidemiologic studies indicate an inverse association between frequency of nut consumption and body mass index. In well-controlled nut-feeding trials, no changes in body weight were observed. Some studies on free-living subjects in which no constraints on body weight were imposed showed a non-significant tendency to lower weight while subjects are on the nut diets.
The weight gain from incorporating walnuts into the diet (control walnut sequence) was less than the weight loss from withdrawing walnuts from the diet (walnut control sequence). Sabaté et al. (2005) showed that regular walnut intake resulted in weight gain much lower than expected but the gain became non-significant after controlling for differences in energy intake. Despite its high energy content, it appears that in overweight and obese people it did not exert negative effect upon body weight.
4. Essay on Walnuts (Anti-Oxidant Foods):
Walnuts are ranked second only to rose hips (Rosa canina) in their anti-oxidant activity, as determined by the ferric reducing antioxidant power (FRAP) assay. Most of this anti-oxidant activity can be attributed to the polyphenolic constituents present primarily in the pellicle. Polyphenols isolated from walnuts, including ellagic acid monomers, polymeric tannins, and other phenolic compounds, are potent inhibitors of plasma and LDL oxidation in vitro and have been found to decrease biomarkers of oxidative stress in diabetic mice.
Melatonin, another antioxidant constituent present in walnuts, has been positively correlated with increased plasma antioxidant capacity in rats. A limited number of human feeding trials, conducted in subjects at high risk for CVD, indicate that walnuts improve endothelial function, and affect some measures of antioxidant status.
Walnuts contain even more anti-oxidants than do pomegranates. The high antioxidant content of walnuts may be related to the high monounsaturated fatty acids and polyunsaturated fatty acids n-6 (linoleate) and n-3 (linolenate) content unlike fish that also contain high amount of unsaturated fatty acids but low anti-oxidant value. \