Polyfenoler från äpple skyddar mot muskelskador

[King Grub]

We examined whether polyphenols from dietary apple have protective effects against exercise-induced muscle strain injury. Sixteen male Wistar rats were randomly assigned into the apple polyphenol (APP; N=8) and control (CON; N=8) groups. The APP and the CON groups were fed diets with and without 5% APP, respectively. After a 3-wk feeding period, the gastrocnemii of the animals were subject to lengthening contractions with electrical stimulation and forced ankle dorsiflexion. Isometric torques were measured before and after the lengthening contractions and on days 1, 2, 3, 5, and 7 after the contractions. On day 7, the animals were sacrificed and the gastrocnemii harvested. Thiobarbituric-acid-reactive substances, protein carbonyl, and mRNA of antioxidative proteins in the muscles were quantified. The APP group had significantly lower torque deficits than the CON group on days 3, 5, and 7 after the eccentric contractions. The thiobarbituric-acid-reactive substances and protein carbonyl levels in the case of the APP group were significantly lower than those in the case of the CON group. The APP group had significantly higher glutathione-S-transferase alpha1 mRNA levels than the CON group. Therefore, we conclude that dietary APPs have protective effects against lengthening contraction-induced muscle injury.

Mol Nutr Food Res. 2009 Oct 28. Dietary apple polyphenols have preventive effects against lengthening contraction-induced muscle injuries.

[the Wire]

Snygg timing också att publicera mitt i äppelsäsongen :)

[-Englund]

Synd att man inte kan äta äpplen då. Aja!

[the Wire]

Apples are a major source of flavonoids in the Western diet, and flavonoid-rich foods may help protect against chronic diseases by antioxidant mechanisms. In the present study we investigated: (1) the antioxidant capacity of representative apple polyphenols and their contribution to the total antioxidant capacity of apple extracts; (2) the effects of adding apple extract to human plasma in vitro on oxidation of endogenous antioxidants and lipids; and (3) the effects of apple consumption by humans on ex vivo oxidation of plasma antioxidants and lipids. We found that the apple-contained flavonols and flavanols, quercetin, rutin, (−)-epicatechin, and (+)-catechin, had a higher antioxidant capacity than the dihydrochalcones, phloridzin and phloretin, and the hydroxycinnamate, chlorogenic acid. However, together these apple polyphenols contributed less than 20% to the total antioxidant capacity of aqueous apple extracts. When human plasma was exposed to a constant flux of aqueous peroxyl radicals, endogenous ascorbate (70.0 ± 10.3 μM) was oxidized within 45 min of incubation, while endogenous urate (375 ± 40 μM) and α-tocopherol (24.7 ± 1.2 μM) were oxidized after ascorbate. Addition of 7.1 or 14.3 μg/ml total phenols of apple extract did not protect ascorbate from oxidation, but increased the half-life (t1/2) of urate from 136 ± 15 to 192 ± 16 and 208 ± 23 min, respectively (p < 0.05 each), and t1/2 of α-tocopherol from 141 ± 18 to 164 ± 8 min (p = ns) and 188 ± 8 min (p < 0.05). Lipid peroxidation started after ascorbate depletion, and addition of apple extract increased the lag time preceding detectable lipid peroxidation from 36.3 ± 3.7 to 50.9 ± 2.7 min (p < 0.05) and 70.4 ± 4.2 min (p < 0.001). However, when six healthy volunteers ate five apples and plasma was obtained up to 4 h after apple consumption, no significant increases in the resistance to oxidation of endogenous urate, α-tocopherol, and lipids were found. Thus, despite the high antioxidant capacity of individual apple polyphenols and apple extracts and the significant antioxidant effects of apple extract added to human plasma in vitro, ingestion of large amounts of apples by humans does not appear to result in equivalent in vivo antioxidant effects of apple polyphenols.

Free Radic Biol Med. 2004 Jan 15;36(2):201-11.

Enligt den här studien så hjälper inte polyphenolerna om man får i sig dem på "normalt" sätt, genom att äta mycket äpplen, synd...

[Morty]

Äpple är i princip enda frukten jag äter. Billig, god och mättande, precis det jag vill ha av en frukt. Såna här grejer gör bara att man kan dra lite extra i opti-tasken, enligt mig.

[Scratch89]

Äpple är i princip enda frukten jag äter. Billig, god och mättande, precis det jag vill ha av en frukt. Såna här grejer gör bara att man kan dra lite extra i opti-tasken, enligt mig.

Dra inte för mycket, då minskar testot... :D