Fruits, vegetables and their polyphenols protect dietary lipids from oxidation during gastric digestion

Abstract

Previous studies indicate that the ingestion of oxidized vegetable oils leads to the incorporation of chemically reactive molecules issued from the decomposition of the initial lipid hydroperoxides into lipoproteins. The aim of the present study is to investigate the oxidation of dietary lipids in the gastric compartment and their inhibition by plant polyphenols provided either as fruit and vegetables (F&V) or an extract. Six minipigs received a standard Western diet containing primarily sunflower oil, ground beef meat, and starch. Polyphenols in different matrix forms were ingested either as cubed F&V or as the corresponding hydroacetonic extract. Sampling of the gastric digesta allowed the kinetic investigation of pH, heme and non-heme iron forms, total lipids, lipid-derived conjugated dienes (CD) and TBARS. F&V and the corresponding polyphenol extract delayed the gastric digestion process as shown for total lipid and heme iron contents. This study also demonstrated the occurrence of in vivo oxidation of dietary lipids in the presence of meat iron. Interestingly, F&V played a protective role by totally inhibiting the accumulation of CD while largely decreasing the formation of TBARS. The polyphenol extract similarly slowed down the TBARS formation although it had no effect on the CD accumulation.

Antioxidant activity of olive phenols and other dietary phenols in model gastric conditions: Scavenging of the free radical DPPH and inhibition of the haem-induced peroxidation of linoleic acid

“…In this work, the ability of olive phenols to inhibit the metmyoglobin-induced peroxidation of linoleic acid in Brij35 micelles was investigated at pH 5.8 in the presence or absence of α-tocopherol, the typical endogenous antioxidant protecting PUFA chains in oils, emulsions and membranes. It is believed that the combination of metmyoglobin (the main form of dietary iron), linoleic acid (possibly released from dietary triglycerides by the gastric lipase) and a mildly acidic medium corresponding to the first hour of gastric digestion (Gobert et al, 2014;Tyssandier et al, 2003) provides a simple but relevant model of lipid oxidation in the stomach.…”

“…By contrast, upstream antioxidant effects during food processing, storage and digestion remain important issues involving native phenolic compounds. In particular, postprandial oxidative stress may occur as early as in the stomach itself where combinations of dietary (haem) iron, polyunsaturated lipids (inevitably contaminated by a fraction of lipid hydroperoxides), acidity and dioxygen in non-limiting concentration can create favourable conditions for polyunsaturated lipid peroxidation, itself responsible for a lower nutritional value of the dietary bolus and an accumulation of potentially toxic lipid oxidation products (Kanner et al, 2012;Gobert et al, 2014). Owing to their abundance in plant food, electron-donating phenolic compounds could be important micronutrients for fighting oxidative stress in the stomach (Dangles, 2012).…”

Current Level of Fish Consumption is Associated with Mortality in Chinese but not US Adults: New Findings From Two Nationwide Cohort Studies With 14 and 9.8 Years of Follow‐Up

“…Notably, we found a strong and significant interaction between fish consumption and fruit consumption, which showed stronger inverse associations of fish intake with total mortality among those with higher fruit consumption. A possible reason is that http://fruit-based natural antioxidants like polyphenols may protect essential fatty acids of fish against oxidation during gastric digestion . A large region difference was also observed between rural and urban residents in CHNS, indicating more pronounced inverse associations of fish intake with mortality among rural residents than among urban residents.…”

Effect of rosemary extract on lipid oxidation of cooked pork during simulated gastric digestion

“…In addition to the lipid content, unsaturation degree, and initial oxidative status of food lipids, the dietary patterns also affect the rate and/or extent of lipid oxidation under digestive conditions . Previous studies have shown that antioxidant‐rich fruits, vegetable, plant extracts, and beverages can effectively inhibit lipid oxidation during ex vivo or in vivo digestion . Recently, scientific interest in the field of natural plant extracts has increased because of their varied bioactivities and higher safety.…”