The Effect of Walnut Consumption on n-3 Fatty Acid Profile of Healthy People Living in a Non-Mediterranean West Balkan Country, a Small Scale Randomized Study

Abstract

People living in non-Mediterranean West Balkan countries have diets with a low n-3 polyunsaturated fatty acid (PUFA) content. Walnuts, a traditional Serbian food, could be an excellent source of n-3 PUFA. The first sub-study evaluated the fatty acid and mineral content of Serbian walnuts, demonstrating that walnuts had the high content of linolenic acid (C18:3, n-3 ALA). The second sub-study assessed the consumption of walnuts (Juglans regia L.) and total n-3-fatty acid intake in apparently healthy Serbian residents, using 24-h dietary recalls (n = 352). An inadequate intake of n-3 fatty acids and a low consumption of walnuts was seen. Additionally, we evaluated the fatty acid profile of healthy Serbian adults (n = 110) and finally, via a randomized intervention 4-weeks study, we assessed the effects of walnut consumption on n-3 fatty acid profile of participants (n = 18). The plasma content of n-3 PUFA was low and the n-6/n-3 ratio was high in our study participants. The n-3 plasma fatty acid profile was improved after 4 weeks of walnut consumption, meaning that ALA, eicosapentaenoic acid, and total n-3 were significantly increased. The results of our study pointed out the potential health benefits of walnuts consumption on amelioration of the n-3 fatty acid profile that should be taken into account in preventive management programs. The higher conversion of ALA to EPA (>10%) in examined study participants, suggests the importance of a moderate walnut consumption.

Fructose‐rich diet and walnut supplementation differently regulate rat hypothalamic and hippocampal glucose transporters expression

“…The observed tendency of the brain linoleic acid content increase upon walnut consumption might have resulted from increased plasma levels of this fatty acid 18 originating from the ingested walnuts. 22 These results are in the line with the findings that brain uptake of these fatty acids is quite low in the rats 53 and that they are being largely metabolized through peroxisomal pathways in the astrocytes. 54…”

“…The walnut kernels used in our study are rich in PUFA, as documented by Petrović-Oggiano and coworkers. 22 Moreover, animals fed with walnuts, used in our study, exhibited increased plasma levels of n-3 PUFA. 18 Hence documented trend of an increase in hypothalamic GLUT1 content upon walnut consumption could partly be due to the elevated plasma levels of n-3 PUFA originating from the ingested walnuts.…”

“…The importance of diet on brain function has been previously described, 25 although limited information is available regarding the effects of dietary nutrients on the major brain glucose transporters. 26,27 Based on this, we hypothesize that walnut kernels, which are an excellent source of n-3 PUFA, 22 can affect brain fatty acid composition and exert beneficial effects on brain glucose utilization in healthy and metabolically challenged animals. We previously investigated the impact of walnut intake and fructose-rich diet on feeding behavior and metabolic parameters of animals used in this study and demonstrated that both individual and combined dietary regimes increased total calorie intake, body weight and adiposity.…”

“…21 Previously we characterized walnuts used in the current study. 22 Briefly, the mean macronutrient composition of walnuts was as follows: carbohydrate 81 g kg −1 , protein 162.1 g kg −1 , fat 683.8 g kg −1 and fiber 18.6 g kg −1 . The most abundant fatty acids were linoleic with 63.2%, oleic with 14.5% and ⊍-linolenic with 11.2% total fatty acids.…”

Walnut Supplementation Restores the SIRT1-FoxO3a-MnSOD/Catalase Axis in the Heart, Promotes an Anti-Inflammatory Fatty Acid Profile in Plasma, and Lowers Blood Pressure on Fructose-Rich Diet

“…Walnuts ( Juglans regia ) used in this study were purchased from a local market. A recent study described the complete fatty acid, macronutrient, and mineral composition of the walnuts [ 34 ]. In terms of fatty acid content, the most abundant n-3 fatty acid in the walnuts was ALA (C18:3 n -3, 11.2%), while linoleic acid (C18:2 n -6, 63.2%) was the most abundant n-6 fatty acid identified by gas chromatography, similar to the data reported in the European Food Information Resource [ 35 ].…”