Newsgroup: it.salute.alimentazione
Titolo: Grassi saturi e malattie cardiache

A quanto pare un altro studio non avrebbe trovato alcuna relazione tra il 
consumo di grassi saturi e le malattie cardiache...
1. Leosdottir M, et al. Dietary fat intake and early mortality patterns - 
data from The Malmo Diet and Cancer Study. Journal of Internal Medicine, 
2005; 258: 153-165.
...almeno secondo la recensione di omnivore
http://www.theomnivore.com/Malmo_Study_2005.html
A. Colpo elenca altri 25 studi che, nella storia, confermerebbero il 
fallimento del tentativo di collegare
il suddetto consumo di grassi saturi e le malattie cardiache...
Qualche esperto potrebbe ribattere all'analisi di Colpo?
Saluti
Gianni 

 on it.salute.alimentazione :

Non mi azzardo a ribattere Colpo su Colpo... ;)
Perņ mi pare interessante lo sguardo d'insieme dello studio di cui riporto
l'Abstract, che fa un bilancio su possibili benefici e controindicazioni
dei diversi tipi di grassi alimentari, anche se spesso questi benefici e
rischi sono ancora contorversi.... 
Probabilmente, credo, non c'č una situazione in bianco e nero, ma ogni
diverso tipo di grasso puņ avere una sua funzione, entro certe dosi e
soprattutto all'interno di una alimentazione e stile di vita equilibrati. 
Lo studio, saggiamente imho, suggerisce in definitiva di *variare* le fonti
per ottenere tutti i nutrienti essenziali e tutti gli elementi benefici... 
"Importance should also be accorded to the consumption of fat from a
variety of sources, both plant and animal. Just as the consumption of a
variety of foods is more likely to provide essential nutrients and other
biologically beneficial components, the consumption of fat from various
foods including fish, nuts, seeds, plant oils and fruits should be
encouraged. These and other dietary guidelines, combined with regular
physical activity, moderate alcohol consumption and abstinence from
smoking, remain the underpinnings of a healthy lifestyle."
===
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15294485&query_hl=10
 Asia Pac J Clin Nutr. 2004 Aug;13(Suppl):S22. 	Related Articles, Links
    Dietary fat quality: a nutritional epidemiologist's view.
    Khor GL.
    Department of Nutrition and Health Sciences, Faculty of Medicine and
Health Sciences, Universiti Putra Malaysia.
    Introduction - Fat intake worldwide has increased substantially, with
East and South-East Asia and China among the foremost, having doubled and
tripled intake (g/capita/day) respectively in the past three decades. The
major dietary source of energy in developing countries is vegetable oils,
but their intake of animal fat is increasing, from 8% of total calories in
the 1960s to 13% in the 1990s. Dietary fat quality - The implications of
dietary fat in the etiology of chronic diseases, including cardiovascular
disease, some types of cancer, type II diabetes, obesity, osteoporosis,
osteoarthritis and other inflammatory disorders, have been extensively
studied. While debate ensues on whether dietary fat is the primary
determinant of excess body fat, the evidence is compelling for the greater
importance of types of fat, rather than total amount of fat, as risk of
chronic disease. 
Total fat, saturated fat - Between-population ecologic studies have
demonstrated an association between intake of fat, specifically saturated
fat and total cholesterol and coronary heart disease (CHD) mortality.
However, results are inconsistent from within-population cohort studies.
Likewise, the association between intake of total fat and saturated fat and
with risk for stroke remains elusive. The paradox of high stroke risk with
low CHD risk among East Asian countries is increasingly attenuated by
lifestyle changes including higher intake of animal fat and protein. As for
the hypothesis that dietary fat is a key cancer risk, particularly with
cancers of the colon, breast and prostate in western countries,
case-control and prospective cohort studies have produced mixed results.
The pooled analysis of several large prospective studies reported weak or
no associations between fat intake and cancer. Probably fat intake in
combination with other concomitant dietary factors, as well as other
confounding factors (e.g. insulin resistance, method of food preparation)
may enhance carcinogenesis. 
Saturated fatty acids (SFA) - In metabolic studies different classes of
saturated fatty acids (SFA) have different effects on plasma lipid and
lipoprotein levels. Specifically, SFA with 12-16 carbon atoms tend to
increase plasma total and LDL-chol levels, whereas stearic acid does not
have a cholesterol-raising effect, but may lower HDL-chol especially in
women, and increase Lp(a) concentration. Among the cholesterol-raising SFA,
myristic acid appears to be more potent than lauric acid or palmitic acid,
but the data are not entirely consistent. 
Monounsaturated fatty acids (MUFA) - Ecological studies indicate an inverse
association between intake of MUFA and CHD mortality. Prospective cohort
studies that adjusted for intake of saturated and trans fatty acids have
found a similar finding. Oleic acid exerts significant beneficial effects
on atherosclerosis and thrombosis. Relatively low CHD mortality rates in
southern Europe is attributed to the traditional Mediterranean diet that is
characterized by, inter alia, high dietary ratio of MUFA/saturated fat. 
Polyunsaturated fatty acids (PUFA) - The North American diet is typically
high in linoleic acid (n-6) (LA), which has been promoted for its
cholesterol-lowering effect. It is now recognized however, that dietary LA
favours oxidative modification of LDL chol, increases platelet response to
aggregation, and suppresses the immune system. In contrast, alpha linolenic
acid (n-3) (ALA) has been found in several studies to exert positive
effects in reducing CHD mortality risk. The major effect of n-3 PUFA
appears to be anti-arrhythmic rather than anti-atherothrombotic. The
emphasis is on the dietary ratio of LA to ALA, rather than the absolute
amounts of ALA, that is critical for disease prevention, due to the
competition between these two essential PUFAs for their entry into the
elongation and desaturation pathways leading to the synthesis of their
respective eicosanoids. Increasingly, attention is focused on the
long-chain n-3 PUFAs in nonhydrogenated fish oils, particularly
eicosapentaenoic acid (EPA) and docosahexaenoic (EPA) and docosahexaenoic
acid (DHA). Studies that have demonstrated the protective effects of fatty
fish intake against myocardial infarction outnumbered those that did not.
Evidence of an inversed association between fatty fish intake and cancer
risk tend to be confined to countries with high fish intake. 
Concluding remarks - The main focus of national recommendations on dietary
fats is on reduced intake of saturated fat and trans fatty acids, and
balanced intake of n-6/n-3 essential fatty acids. Importance should also be
accorded to the consumption of fat from a variety of sources, both plant
and animal. Just as the consumption of a variety of foods is more likely to
provide essential nutrients and other biologically beneficial components,
the consumption of fat from various foods including fish, nuts, seeds,
plant oils and fruits should be encouraged. These and other dietary
guidelines, combined with regular physical activity, moderate alcohol
consumption and abstinence from smoking, remain the underpinnings of a
healthy lifestyle.
    PMID: 15294485 [PubMed - as supplied by publisher]