22 mars 2011 kl 21:01
@Claes Wikdahl
Det är rimligt att efterfråga studier som du gör.
Den vetenskapliga artikeln "Efficacy of Dietary Behavior Modification for Preserving Cardiovascular Health and Longevity" summerar forskningsresultat och gör en grundlig genomgång av kostråd. Rapporten släpptes 2011 och bör därför vara i linje med aktuell forskning.
Här finns artikeln:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3021873/?tool=pubmedFöljande konstateras kring mättat fett:
"People have been advised to avoid eating saturated fats to preserve CVD health for 60 years or more. However, there has been little evidence from research to substantiate this recommendation. The food industry and the general public have reduced saturated fat over the years, but have often replaced them with harmful trans fats and refined carbohydrates. A recent study by the Harvard School of Public Health has produced the first conclusive evidence that reducing saturated fat with polyunsaturated fat substitution reduces CHD risk by 19%. The meta-analyses of 8 randomized trials revealed that for every 5% increase in polyunsaturated fat consumed, the risk of CVD decreased by 10%. The Institute of Medicine recommends that 5%–10% of energy intake should come from polyunsaturated fats. Other trials have advised an intake of 15%"
Med andra ord - det verkar vettigt att byta ut mättat fett mot fleromättat fett.
Man diskuterar vidare rött (och processat) kött:
"A study of the relationship between white, red, and processed meat with mortality in half a million middle-aged participants of the NIH-AARP Diet & Health Study was recently reported by Sinha et al. Consumption of processed and red meats was found to increase total deaths, cancer, and CVD deaths, whereas white meat protected against total mortality and cancer mortality. Red meat appeared to increase all the specified mortalities more than the processed meats. Red meat increased overall mortality 31% in men and 35% in women, whilst processed meat increased it 15% and 25% in men and women, respectively. For cancer mortality there was a 27% increase for red meat for men and 50% increase for women, whereas processed meat conferred a lesser 12% increase in men and 11% in women. For CVD, red meat imposed a 27% increase in men and 50% in women, while for processed meat the increases were 9% in men and 38% in women."
Verkar finnas en del negativt med rött kött.
En annan färsk studie vid Harvard undersökte kopplingen rött/processat kött och diabetes:
http://www.ncbi.nlm.nih.gov/pubmed/21310828"A score representing a low-carbohydrate diet high in animal protein and fat was positively associated with the risk of T2D [Type 2 Diabetes] in men. Low-carbohydrate diets should obtain protein and fat from foods other than red and processed meat."
En aktuell summering av forskningsläget kring mättat fett finns i "The role of reducing intakes of saturated fat in the prevention of cardiovascular disease: where does the evidence stand in 2010":
http://www.ajcn.org/content/93/4/684.long" In populations who consume a Western diet, the replacement of 1% of energy from SFAs [mättat fett] with PUFAs [fleromättat fett] lowers LDL cholesterol and is likely to produce a reduction in CHD incidence of =2–3%."
Eller en sammanfattning från mars 2011 ("Dietary fats and cardiovascular health"):
http://www.ncbi.nlm.nih.gov/pubmed/21392857"...Thus, saturated and trans fats have been found to increase the risk of atherogenic disease. This is why it is recommended to substitute complex carbohydrates or unsaturated fat for unsaturated and trans fats with the aim of reducing saturated and trans fat intake to <10% and <1%, respectively, of the total calorie intake. Recent population studies, particularly that conducted in Kuopio, Finland, and those on Mediterranean diet, stress the important role of monounsaturated and polyunsaturated fats as key nutrients in preventing cardiovascular disease in modern societies"
Samma slutsats - ät lite mindre av mättat fett och lite mer av fleromättat fett.