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Visa fullständig version : Dietärt fett och sjukdomsprevention ur ett evolutionärt och historiskt perspektiv


mikaelj
2009-10-18, 08:41
Dietary Fat Quality and Coronary Heart Disease Prevention: A Unified Theory Based on Evolutionary, Historical, Global, and Modern Perspectives (http://thepaleodiet.com/articles/Dietary%20Fat%20Quality%20%20CHD%20August%202009.p df)


Saturated fatty acids
In the Nurses’ Health Study, a large prospective cohort study, a weak but significant positive association between SFA intake and CHD risk was initially seen [41]. With long-term follow-up, this association was no longer significant [40]. Any association between SFAs and CHD appears to be a small fraction of that observed for TFAs [41]. Other observational studies and dietary trials have been unconvincing or even contradictory [50]. In general, experimental evidence does not support a robust link between SFA intake and CHD risk [51].

Replacement of SFAs, especially palmitate, with MUFAs may provide moderate cardiometabolic benefits, and is unlikely to do harm. However, SFA reduction does not appear to be the most important dietary modification for CHD risk reduction.

Monounsaturated fatty acids
Mediterranean populations consuming diets rich in MUFAs have among the lowest CHD rates in the world [3,4].

Modern pasture-fed meats have a fatty acid composition similar to that of wild meats [48].

Medium-chain omega-3 PUFAs: ALA
Several, but not all, large epidemiologic studies have observed an inverse association between ALA intake and CHD risk [66,74].

Consumption of moderate quantities of n-3 ALA may have considerable cardiometabolic benefits and is unlikely to do harm. ALA is most effective in the context of low-LA diets.

Medium-chain omega-6: LA
Traditional Mediterranean, rural Japanese, and other populations with very low CHD risk have uniformly low LA intakes [26,32]. Two US prospective cohort studies have reported inverse associations between LA intake and CHD risk [41,66] (...) The only long-term trial that reduced n-6 LA intake to resemble a traditional Mediterranean diet (but still higher than preindustrial LA intake) reduced CHD events and mortality by 70% [31]. Although this does not prove that LA intake has adverse consequences, it clearly indicates that high LA intake is not necessary for profound CHD risk reduction.

Long-chain omega-6 PUFAs: AA
Mean population tissue proportions of AA and other long-chain n-6 PUFAs have a marked positive correlation with CHD mortality [79].

Long-chain omega-3 PUFas: EPA and DHA
Populations with high intakes of EPA+DHA–rich foods generally have low CHD risk [32,79]

Increased consumption of n-3 EPA+DHA provides significant cardiometabolic benefit and is unlikely to do harm. A long-term increase in EPA+DHA intake is perhaps the most beneficial isolated dietary modification for reducing CHD events and mortality.


Current Treatment Options in Cardiovascular Medicine 2009, 11:289–301

Sverker
2009-10-18, 17:37
Verkar var lite Populärvetenskapligt stuk på texten.

However, in the two decades before the study began, Oslo males had a
sevenfold increase in incidence of fi rst MI (from 9.0 per 10,000 in 1945
to 65 per 10,000 in 1961) [38]. This rapid rise coincided with the widespread
use of partially hydrogenated fi sh and vegetable oil margarines,
which accounted for 65 g/d per person (25% of energy). Importantly,
experimental dieters replaced margarines with nonhydrogenated LArich
oils, whereas the control diet was unchanged. Hence, the historical
context of dietary trials must be taken into consideration; failure to do so
may lead to fl awed recommendations.

Norge var ockuperat 1940 - 1945. Kanske inte relevant att använda resultat från 1945 i en undersökning.:confused: Mindre mat pga ransonering och mer motion pga brist på bensin.


Till sak.
Hur vill du att vi ska tolka informationen. Allt fett verkar vara bra utom arakidonsyra. Enda källorna som innehåller mycket arakidonsyra, vad jag vet, är lever från gris och kyckling. För att krångla till det ytterligare finns ett visst intresse av arakidonsyra på Kollozzeum pga misstänkt possitiv effekt på proteinsyntesen:D

mikaelj
2009-10-18, 18:00
Hur vill du att vi ska tolka informationen. Allt fett verkar vara bra utom arakidonsyra.

Det låter som en bra början! Jag tänker mig i att diverse kostråd borde ställas i relation till fynden.

Snorkelfarsan
2009-10-18, 20:33
linolsyra är alltså mellan-långa n-6-kedjor och sånt som det finns mycket av i vegetabiliska oljor som solrosolja inte sant? Den är inte "dålig" på samma sätt som arakidonsyra som är långa n-6-kedjor? (Skippa leverpastejen?)
Däremot nämner dom väl inget om n-3/n-6 ratio, har det någon betydelse för CHD?

Sverker
2009-10-19, 06:02
Författaren till artikeln har valt att kalla linolsyran Medium-chain n-6. Där n-6 just betyder Omega-6. Förväxla inte detta med mellanlånga fettsyror de sk MCFA.

Antagligen vill författaren skilja ut linolsyran från arakidonsyran som författaren kallar Long-chain n-6.


Självklart har förhållandet mellan Omega-3 och Omega-6 betydelse eftersom de båda grupperna aktivt påverkar blodtryck och stelningstider för blodet.