The triacylglycerol structures are key factors influencing lipid digestion in preterm formulas during in vitro digestion.

Preterm formulas are usually supplemented with medium-chain triacylglycerols (MCT) whereas breast milk contains more medium and long-chain triacylglycerols (MLCT). Different types of triacylglycerol (TAG) containing medium-chain fatty acids may influence lipid digestion. In this study, the digestive characteristics of breast milk and preterm formulas with different MCT contents were evaluated using a dynamic in vitro system simulating the gastrointestinal tract of preterm infants. The lipolysis products, including diacylglycerols, monoacylglycerols (MAGs), free fatty acids, and undigested TAGs, were analyzed. Formulas with MCT addition has significantly (P < 0.05) lower lipolysis degree (LD, 69.35%-71.28%) than breast milk (76.93%). Higher amounts of C8:0 and C10:0 were released in the formulas with MCT addition. Breast milk released more C18:1n-9, C18:2n-6, and MAG containing C16:0, whereas formulas released more free C16:0. The Pearson correlation heatmap showed that the LD value was significantly and positively (P < 0.05) related to the MLCT and sn-2 C16:0 content.

Effects of omega-3, omega-6, and total dietary polyunsaturated fatty acid supplementation in patients with atherosclerotic cardiovascular disease: a systematic review and meta-analysis.

Background: Uncertainty exists about the link between omega-3 fatty acid, omega-6 fatty acid, and total polyunsaturated fatty acid (PUFA) intake and mortality in atherosclerotic cardiovascular disease (ASCVD) patients, and no meta-analyses summarize the relationship between these various types of PUFAs and ASCVD. Methods: Web of Science, PubMed, EBSCO and Cochrane Library up to November 30, 2022 were searched for prospective randomized controlled studies investigating the relationships among omega-3, omega-6, and PUFA intake and mortality and cardiovascular events in ASCVD patients. This study has been registered at PROSPERO (No. CRD42023407566). Results: This meta-analysis included 21 publications from 17 studies involving 40 861 participants published between 1965 and 2022. In ASCVD patients, omega-3 may lower all-cause mortality (RR: 0.90, 95% CI [0.83, 0.98], I2 = 8%), CVD mortality (RR: 0.82, 95% CI [0.73, 0.91], I2 = 34%) and CVD events (RR: 0.90, 95% CI [0.86, 0.93], I2 = 79%). Subgroup analyses showed that EPA or EPA ethyl ester supplementation reduced CVD events, while the mixture of EPA and DHA had no significant impact. Long-chain omega-3 consumption of 1.0-4.0 g per d reduced death risk by 3.5% for each 1 g per d increase. Omega-6 and PUFA had no significant effect on mortality or CVD events, with low-quality evidence and significant heterogeneity. Conclusions: omega-3 intake is associated with a reduced risk of all-cause mortality, CVD mortality, and CVD events in ASCVD patients, while omega-6 or total PUFA intake showed no significant association. Increasing the omega-3 intake by 1 g per d resulted in a 3.5% decrease in the risk of death. These findings support the recommendation of supplements with omega-3 fatty acids for the secondary prevention of ASCVD.

Reassessing the Effects of Dietary Fat on Cardiovascular Disease in China: A Review of the Last Three Decades.

Cardiovascular disease (CVD) is a leading cause of global mortality, and is considered one of diseases with the most rapid growth rate in China. Numerous studies have indicated a closed relationship between an increased incidence of CVD and dietary factors. Dietary fat is one of the three primary nutrients of consumption; however, high fat dietary in causing CVD has been neglected in some official dietary guidelines. Our present review has analyzed the relationship between dietary fat consumption and CVD in China over the past 30 years (from 1990 to 2019). There is a significant correlation between CVD incidence and mortality for consumption of both vegetable oils and animal fats, per capita consumption, and the relative weight of dietary fat exceeding that of other food ingredients (e.g., salt, fruit, and marine food). For fatty acid species, the proportion of ω6 fatty acid consumption increased, causing a significant increase in the ratios of ω6/ω3 fatty acids, whereas the proportion of monounsaturated fatty acid consumption decreased. Such changes have been considered a characteristic of dietary fat consumption in Chinese residents over the past 30 years, and are closely related to the incidence of CVD. Therefore, we suggest that the government should spread awareness regarding the consumption of dietary fat intake to prevent CVD and related health disorders. The public should be educated to avoid high fat diet and increase the intake of monounsaturated fatty acids and ω3 fatty acids.

Sensory Features of Partially Hydrogenated Oil and Their Connection with Melting and Crystalline Characteristics.

Although partially hydrogenated oil (PHO) provides foods with outstanding thick tastes and pronounced "creamy" flavor, the high level of artificial trans-fatty acids (TFA; about 30%) limits its usages around the world in the near future. It is necessary to produce trans-free alternatives with similar tastes to PHO. The relationship between sensory attributes and physicochemical characteristics of PHO and four typical specialty fats were therefore analyzed in the present study. PHO exhibited the highest greasiness score (8.19), accompanying by mild creaminess and aftertaste as well as a weak coolness during swallow, which were resulted from the close-packed arrangements of TFA, its cis-counterparts and other long chain fatty acids. None of artificial trans-fats, mainly anhydrous milk fat, cocoa butter, and coconut oil and its fully hydrogenated counterpart, were similar to PHO in terms of these sensory attributes. The unique fatty acid species of PHO and their arrangements contributed to the relatively smooth solid fat content profile and melting-crystallization curve, as well as forming uniform and dense ß' crystal-structures (Db=1.80). The Pearson correlation analyses relevelled that long chain fatty acids, e.g., t-C18:1 and C18:1, and melting final temperatures were generally positive correlated with greasiness, creaminess and aftertaste; whereas these indices were negatively correlated with coolness. The melting enthalpy was highly connected with coolness, which reflected the endothermic effectiveness during the melting process of fats in the mouth. These indices screened by correlation analyses that were strongly correlated with sensory attributes could provide references for producing trans-free alternatives.

A comparative study on flavor trapping techniques from the viewpoint of odorants of hot-pressed rapeseed oil.

Rapeseed oil, as one of the three major vegetable oils in the world, its matrix effect makes the decoding flavor a challenge. Solid-phase microextraction (SPME), SPME-Arrow, headspace stir bar sorptive extraction (HSSE), direct thermal desorption (DTD), and solvent-assisted flavor evaporation (SAFE) were compared based on the odorants in hot-pressed rapeseed oil. Besides, methodological validation for 31 aroma standards was conducted to compare reliability and robustness of these approaches. DTD showed the largest proportion of acids, while the other techniques extracted a majority of nitriles. The highest number of odorants was detected by SAFE (31), followed by HSSE (30), SPME-Arrow (30), SPME (24), and DTD (14). SPME-Arrow showed the best performance in linearity, recovery, and reproducibility followed by SPME, HSSE, DTD, and SAFE. Results reveal the advantages and limitations of diverse methodologies and provide valuable insights for the selection of extraction methods in an oil matrix and flavor decoding.

Characteristics of Cephalotaxus fortunei kernel oil and its digestion behaviors.

Cephalotaxus fortunei, a potential underutilized oil resource, contains various active ingredients that exert positive effects on human health. In the present study, characteristics of C. fortunei kernel oil and its digestion properties were systematically investigated. Results indicated that C. fortunei kernels contained high oil content (64.59%), of which over 90% was triacylglycerols (TAGs). The kernel oil was rich in oleic acid (C18:1n-9, 42.88%), linoleic acid (C18:2n-6, 31.05%), and sciadonic acid (C20:3n-6, 10.78%). The kernel oil also contained some beneficial fat-soluble nutrients, such as tocopherols (143 mg/kg) and phytosterols (1474 mg/kg). Thirty-five kinds of TAGs were identified, among which O-O-L (17.96%), O-O-O (12.12%), L-L-O (11.79%), O-L-Et (8.59%), and O-O-Et (8.76%) were the most abundant. In vitro digestion experiments showed that after 120 min of small intestine digestion, the maximum FFAs release level of the kernel oil was 75.02%, which was lower than that of soybean oil (89.63%).

Comparison of lipid structure and composition in human or cow's milk with different fat globules by homogenization.

Homogenization is used in human milk to add supplements for premature infants and in cow's milk to make it more uniform and stable for commercial purposes. However, it may destroy the milk fat globule (MFG) structure and composition, affecting its functional characteristics. This study aims to compare human and cow's milk with particle size ranges of 4-6 µm (large-sized), 1-2 µm (medium-sized), and 0.3-0.5 µm (small-sized) before and after homogenization at different pressure levels. CLSM and SDS-PAGE were used to perform the structural characterization. The lipid compositions were analyzed using GC and LC-MS. The results showed that homogenization obviously changed the MFG structure and its lipid composition. After homogenization, more caseins and whey proteins were adsorbed on both the human and cow's milk fat globule interface, while the proteins observed in human milk were dispersed. This could be attributed to the different types and contents of proteins initially. The influence of homogenization on milk phospholipids was higher than triacylglycerols and fatty acids, which was highly correlated with their initial distributions in MFGs. These results provide new information about the interfacial composition of human and cow's milk fat globules upon homogenization and establish the scientific basis for homogenization application in human and cow's milk to help explore their potential functions.

Fatty acids and their sn-2 positional distribution in breast milk and their association with edible oils in maternal diet: a study of five regions in China.

This study analyzed total fatty acids (FAs) and their sn-2 positional distribution in triacylglycerol (TAG) in breast milk (n = 300) from three lactational stages in five regions of China, and further investigated their association with the effect of the type of edible oil consumed by lactating mothers. A total of 33 FAs including 12 saturated fatty acids (SFAs), 8 monounsaturated fatty acids (MUFAs), and 13 polyunsaturated fatty acids (PUFAs) were determined using GC. Breast milk from different regions showed significant differences in MUFAs, sn-2 MUFAs, and PUFAs (P < 0.01, P < 0.001, and P < 0.001). The results showed that 10 : 0, 18 : 0, 18 : 1 n-9, 18 : 2 n-6 (LA), and 18 : 3 n-3 (ALA) were mainly esterified at the sn-1 and sn-3 positions; 20 : 4 n-6 (ARA) seemed homogeneously esterified at all sn-positions in TAG, while 14 : 0, 16 : 0, and 22 : 6 n-3 (DHA) were primarily esterified at the sn-2 position. In breast milk, major FAs (16 : 0, 18 : 1 n-9, LA, and ALA) and the ratio of PUFAs (LA/ALA and n-6/n-3) were obviously influenced by maternal edible oils. Breast milk from mothers consuming rapeseed oil had the lowest LA (∼19%) and the highest ALA (∼1.9%). The MUFAs, especially 18 : 1 n-9, in breast milk from mothers consuming high oleic acid oils were significantly higher than those in breast milk from mothers consuming other types of edible oils. These results provide a potential nutritional strategy for better breastfeeding by specifically adjusting maternal edible oils despite other fat sources being part of the diet of lactating women.

Highly Valuable Fish Oil: Formation Process, Enrichment, Subsequent Utilization, and Storage of Eicosapentaenoic Acid Ethyl Esters.

In recent years, as the demand for precision nutrition is continuously increasing, scientific studies have shown that high-purity eicosapentaenoic acid ethyl ester (EPA-EE) functions more efficiently than mixed omega-3 polyunsaturated fatty acid preparations in diseases such as hyperlipidemia, heart disease, major depression, and heart disease; therefore, the market demand for EPA-EE is growing by the day. In this paper, we attempt to review EPA-EE from a whole-manufacturing-chain perspective. First, the extraction, refining, and ethanolysis processes (fish oil and ethanol undergo transesterification) of EPA-EE are described, emphasizing the potential of green substitute technologies. Then, the method of EPA enrichment is thoroughly detailed, the pros and cons of different methods are compared, and current developments in monomer production techniques are addressed. Finally, a summary of current advanced strategies for dealing with the low oxidative stability and low bioavailability of EPA-EE is presented. In conclusion, understanding the entire production process of EPA-EE will enable us to govern each step from a macro perspective and accomplish the best use of EPA-EE in a more cost-effective and environmentally friendly way.

Comparative characterization of key odorants and aroma profiles of fragrant rapeseed oil under different roasting conditions.

Fragrant rapeseed oil (FRO) produced by typical roasting process is popular for its characteristic aroma. Accordingly, key aroma-active compounds were characterized in FRO by the Sensomics approach and then correlated to the crucial roasting parameters revealed by aroma profile analysis and hierarchical cluster analysis. Nineteen key odorants in FRO were identified and quantified, among which dimethyl trisulfide (OAV, odor active value, 323, cabbage-like, sulfury) and 4-isothiocyanato-1-butene (OAV, 88, pungent) were the most important aroma-active compounds in FRO and showed first rising and then decline trends as the increased roasting temperature and time. The oil under high-temperature-short time and low-temperature-long time conditions imparted similar aroma profiles. On the basis of sensory evaluation, roasting at 160, 170, 180, 190, and 200 °C should not exceed 50, 40, 30, 30, and 30 min, respectively to satisfy consumer preference. All findings provide a reference on industrial FRO production in terms of not only aroma but also sustainability.

Does omega-3 PUFA-enriched oral nutritional intervention benefit cancer patients receiving chemo (radio) therapy? A systematic review and meta-analysis of randomized controlled trials.

Although data indicate omega-3 polyunsaturated fatty acids are beneficial nutrients in cancer therapy, the evidences for efficacy of nutritional interventions during chemo (radio) therapy are still limited. The leading goal of the present meta-analysis was to summarize randomized controlled trials involving the administration of ω-3 PUFA-enriched oral nutritional supplements during chemo (radio) therapy, and evaluate the effects on nutritional status and clinical outcomes in patients. We systematically searched PubMed, Embase, Web of Science, Cochrane databases to identify interventions assessing body weight, BMI, immune and inflammatory indicators, plasma omega-3 fatty acids and adverse events, with subgroup analyses for region, types of ω-3 fatty acids, dose, duration and dosage form. In total, 22 studies including 1155 participants met the inclusion criteria. Meta-analysis showed a significant increase in body weight (BW) (WMD = 0.59 kg, 95% CI: 0.06, 1.13, P = 0.03), body mass index (BMI) (WMD = 0.43 kg/m2, 95% CI: 0.07, 0.79, P = 0.02), and plasma total ω-3 fatty acids (SMD = 2.52, 95% CI: 1.27, 3.78, P<0.0001), and a significant reduction in plasma levels of C-reactive protein (CRP) (SMD= -0.53, 95% CI: -0.80, -0.25, P = 0.0001), tumor necrosis factor-α (TNF-α) (WMD = -0.40 pg/mL, 95% CI: -0.80, -0.01, P = 0.05), interleukin 6 (IL-6) (WMD = -1.25 pg/mL, 95% CI: -2.41, -0.10, P = 0.03) and the incidence of adverse events (RR= 0.72, 95% CI: 0.54, 0.95, P = 0.02). However, plasma albumin levels (WMD = 0.02 mg/dL, 95% CI: -0.13, 0.18, P = 0.75) was remained unaffected. Overall, our meta-analysis provides evidences that the consumption of ω-3 PUFA-enriched oral nutritional supplements exert beneficial effects on nutritional status and clinical outcomes in patients undergoing chemo (radio) therapy.

Associations of Region and Lactation Stage with Odd-Chain Fatty Acid Profile in Triglycerides of Breast Milk in China.

Odd-chain fatty acids (OCFAs), with potential value for growing infants, have been reported in breast milk. The association of location and lactation stage with the profile and content of OCFAs in breast milk was studied. We analyzed 1487 breast milk samples collected from 12 areas in China, and 102 infant formulas from different brands were purchased from the local supermarket. The content of sn-2 C15:0 significantly decreased from the colostrum to the mature stage, while that of C17:0 was not significantly increased by the lactation stage (p > 0.05). The content of C15:0 and C17:0 significantly decreased dramatically after the colostrum period, while the content of C13:0 was highest in the mature stage. The level of C15:0 and C17:0 in human milk from Gansu and Xinjiang was significantly higher than that from other areas. Similar trends were observed on the level of sn-2 C15:0 and C17:0, whereas the content of sn-2 C11:0 and C13:0 was significantly higher in breast milk from Shandong. Based on the PDS-LA analysis, the difference among infant formulas, each stage of human milk and human milk from different locations were different. Research is needed to determine if there are health benefits associated with OCFAs.

Effect of olive polyphenols on lipid oxidation of high-fat beef during digestion.

Olive oil is one of the most important ingredients in the Mediterranean diet, in which its polyphenols adversely affect dietary lipid oxidation. In this study, the effect of olive oil polyphenols on lipid oxidation of high-fat beef during digestion was determined. Thirty-three phenolic compounds were tentatively identified, and the contents of 3,4-dihydroxyphenylethanol-elenolic acid dialdehyde (3,4-DHPEA-EDA), 3,4-dihydroxyphenylethanol-elenolic acid (3,4-DHPEA-EA), p-hydroxyphenylethanol elenolic acid (p-HPEA-EA) and hydroxytyrosol were higher than those of other compounds. In an in vitro model, the production of lipid oxidation products, including hydroperoxides, malondialdehyde, 4-hydroxy-2-hexenal and 4-hydroxy-2-nominal, were significantly inhibited by olive polyphenol in the gastrointestinal digests. Compared with the other four groups, the inhibition was better when the polyphenol content reached 600 mg GAE/kg. The 3,4-DHPEA-EDA and 3,4-DHPEA-EA played a better antioxidant role in the stomach stage, while hydroxytyrosol showed the more potent antioxidant activity in the intestinal phase. Electron spin resonance technology showed that two main free radicals, including alkyl radical and alkoxy radical, were detected during the high-fat beef digestion, and olive polyphenols could significantly reduce their formation. All these results showed that the lipid oxidation could be significantly inhibited by olive oil with higher polyphenol content, indicating that the consumption of olive oil with abundant levels of polyphenols could reduce lipid oxidation of high-fat meat during digestion.

Triacylglycerol regioisomers containing palmitic acid analyzed by ultra-performance supercritical fluid chromatography and quadrupole time-of-flight mass spectrometry: Comparison of standard curve calibration and calculation equation.

Triacylglycerol (TAG) regioisomers containing palmitic acid (16:0) was identified using ultra-performance supercritical fluid chromatography and quadrupole time-of-flight mass spectrometry (UPSFC-Q-TOF-MS) and quantified using calibration curve method and calculation equation method. There were negative linear correlation between [RA-A]+/[RA-A]++[RA-B]+ and content of sn-A-B-A (%) for AAB/ABA type TAGs, [Rsn-1 FA-sn-3 FA]+/[RB-C]++[RA-C]++[RA-B]+ and content of fatty acid (FA) at sn-2 position (%) for BAC/ABC/ACB type TAGs. The difference between calculation equation and standard curve method was acceptable. The TAG regioisomers in human milk, mammalian milk, lard and fish oil were identified and quantified using the developed methods. This study provided a reliable and facile method for analysis of the TAG regioisomers, which was capable of the selection of oil materials for infant formula production.

Effect of microwave pretreatment of perilla seeds on minor bioactive components content and oxidative stability of oil.

This study investigated the effects of different microwave power (380 W, 540 W, 700 W) and time (0-10 min) on the minor bioactive components content and oxidative stability of perilla oil. The results indicated that fatty acids in perilla oil were slightly affected by microwave treatment. The oxidative stability of perilla oil increased with increasing microwave treatment intensity and the oil from perilla seeds treated at 700 W for 10 min had the highest oxidative stability. Compared with other microwave treatments, treatment with 700 W for 10 min resulted in significant increases in the total phytosterols content, Maillard reaction products and DPPH radical scavenging activity of perilla oil, while showed dramatic reductions in the total tocopherol content, phenolic compounds content and lipase activity. These results proved that microwave treatment of perilla seeds was an effective way to improve the quality of perilla oil.

Reviews of medium- and long-chain triglyceride with respect to nutritional benefits and digestion and absorption behavior.

With the progress in the study of functional lipid, interest has turned recently to the medium- and long-chain triglyceride (MLCT) obtained by modification of natural oil. From a health perspective, MLCT not only provides us with the essential fatty acids, but,moreimportantly,it also reduces body fat accumulation, improves insulin resistance and plays an important role in clinical nutritional treatment. The potential effectiveness of MLCT in the human body is influenced mainly byits digestion and absorption in thegastrointestinaltract. However, the current understanding of the digestion and absorption mechanism of MLCT is still not comprehensive. Thisreview first presents the nutritional properties, digestion and absorption of MLCT. Then it will focus on the effects of MLCT compositions and structures (eg, fatty acid chain length, saturation, and location distribution) on its digestion and absorption process for a better understanding of its nutritional properties. This review also presents the synthesis methods and current application status of MLCT. Finally, the advantages, challenges and future prospects of MLCT are discussed. With its potential health benefits, MLCT is widely being used as nutraceutical in food and pharmaceutical sectors. In the future, the purpose of modifying the digestion and absorption of MLCT can be realized by structural design and other means, to achieve nutritional supplement and precise therapy.

Digestion of Medium- and Long-Chain Triacylglycerol and sn-2 Palmitate in Infant Formula: A Study Based on Dynamic In Vitro Simulation of Infant Gastrointestinal Lipolysis.

In this study, lipolysis of triacylglycerols (TAGs) in infant formula (IF) composed of different oils and supplied with different structured TAGs, including medium- and long-chain triacylglycerol (MLCT) and sn-2 palmitate, was studied using a dynamic digestion model simulating the infant gastrointestinal tract. The molecular species of digestion products released during digestion, including diacylglycerols, monoacylglycerols (MAGs), and free fatty acids, as well as undigested TAGs, were identified and quantified using liquid chromatography-mass spectrometry. We observed clearly different lipolysis degrees (LDs), with diversity in digestion products of different IFs. IFs supplied with MLCT showed moderate medium-chain fatty acid release during gastric digestion and higher LD after intestinal digestion. The presence of sn-2 palmitate in IF was associated with higher content of MAG-16:0 in digestion products. The species and contents of digestion products in IF were highly influenced by structured TAGs.

Effects of temperature and ferric ion on the formation of glycerol core aldehydes during simulated frying.

Glycerol core aldehydes (GCAs) are toxins widely formed in oils at high temperature. This study investigated the effects of frying time, temperature, and Fe3+ content on the GCAs formation in high-oleic sunflower oil. The results showed that the GCAs (8-oxo, 9-oxo, 10-oxo-8, 11-oxo-9) concentrations increased with time following the pseudo-first-order kinetics. Frying at 160 °C without Fe3+ and at 180 °C with 0.0005 mol·L-1 Fe3+ yielded the lowest and highest total GCA content. The concentrations of GCAs (8-oxo) and GCAs (9-oxo) or GCAs (10-oxo-8) and GCAs (11-oxo-9) changed similarly with different frying temperature and Fe3+ concentration. The major GCAs was GCAs (9-oxo) (40-70%), which also had the highest formation rate (5.42 × 10-4 mg·g-1·h-1). However, GCA (10-oxo-8) and GCAs (11-oxo-9) with similar proportion (ca. 10-20%) and GCAs (8-oxo) made up the least proportions (<10%).

The enzymatic synthesis of EPA-rich medium- and long-chain triacylglycerol improves the digestion behavior of MCFA and EPA: evidence on in vitro digestion.

Medium-chain triglyceride (MCT) and eicosapentaenoic acid (EPA) have been widely applied in nutritional supplementation. However, when administered individually or mixed, they were unable to maximize their nutritional value. Hence, EPA-rich medium- and long-chain triacylglycerol (MLCT) was synthesized from MCT and EPA-rich fish oil (FO) by enzymatic transesterification. The fatty acids in triglyceride (TAG) were rearranged which resulted in significant changes in TAG profiles compared to the physical mixture of MCT and FO (PM). EPA-containing MML (MML, MLM and LMM) and LLM (LLM, LML and MLL) type TAGs account for 70.21%. The fate of different oils (MCT, FO, PM, and MLCT) across the gastrointestinal tract was subsequently simulated using an in vitro digestion model. The results showed that the physical and structural characteristics of different oils during digestion depended upon the oil type and the microenvironment they were in. After 120 min of small intestine digestion, the degree of hydrolysis for MLCT was higher than that for the other three oils. The final FFA release level was in the following order: MLCT (102.79%) > MCT (95.20%) > PM (85.81%) > FO (74.18%). This can be attributed to the composition and positional distribution of fatty acids in TAGs. What's more, LCFAs (EPA) in MLCT mainly existed in the form of sn-2 MAG, which was conducive to their subsequent absorption and transport. These results may aid in the future rational design of structural lipids, thereby regulating lipid digestion and maximizing the nutritional value of oils.

Dietary oleic acid supplementation and blood inflammatory markers: a systematic review and meta-analysis of randomized controlled trials.

The aim of this systematic review and meta-analysis was to analyze data from randomized controlled trials (RCTs) assessing the effects of oleic acid (OA) supplementation on blood inflammatory markers in adults. PubMed, EMBASE and Cochrane Library databases were systematically searched from 1950 to 2019, with adults and a minimum intervention duration of 4 weeks. The effect size was estimated, adopting standardized mean difference (SMD) and 95% confidence interval (CI). Of the 719 identified studies, thirty-one RCTs involving 1634 subjects were eligible. The results of this study revealed that increasing OA supplementation significantly reduced C-reactive protein (CRP) (SMD: -0.11, 95% CI: -0.21, -0.01, P = 0.038). However, dietary OA consumption did not significantly affect tumor necrosis factor (TNF) (SMD: -0.05, 95% CI: -0.19, 0.10, P = 0.534), interleukin 6 (IL-6) (SMD: 0.01, 95% CI: -0.10, 0.13, P = 0.849), fibrinogen (SMD: 0.08, 95% CI: -0.16, 0.31, P = 0.520), plasminogen activator inhibitor type 1 (PAI-1) activity (SMD: -0.11, 95% CI: -0.34, 0.12, P = 0.355), soluble intercellular adhesion molecule-1 (sICAM-1) (SMD: -0.06, 95% CI: -0.26, 0.13, P = 0.595) or soluble vascular cell adhesion molecule-1 (sVCAM-1) (SMD: -0.04, 95% CI: -0.27, 0.18, P = 0.701). Overall, the meta-analysis demonstrated that dietary OA supplementation significantly reduced CRP, yet did not affect other inflammatory markers including TNF, IL-6, fibrinogen, PAI-1 activity, sICAM-1or sVCAM-1.