Intervention study

DHEAS decreased by 5.1 To ensure that this does not confound intervention studies, it would be sensible for future studies to utilise diets that are isocalorihc. 

Bray JE, Martin J, Cooper G, Barger B, Bernard S, Bladin C. An interventional study to improve paramedic diagnosis of stroke. Prehosp Emerg Care. 2005 9 297-302. 

Only a few short-term intervention studies have been carried out, principally in postmenopausal women (see Table 6.2). In the first study, the effect of soy... 

Table 6.2 Short-term intervention studies with soy protein containing isoflavones, measurement of BMD...

The mean dietary intake of soy isoflavones in Asian populations consuming soy-based diets ranges from 20-40 mg isoflavones/day, with upper percentile consumer intakes of 70 mg/day (corresponding to around 1 mg/kg body weight). In the six month intervention studies in Western postmenopausal women, the effective dose for improved BMD was around 80-90 mg/day, while in the one year, randomized, double-blind, placebo controlled clinical trial, the effective dose was 54 mg/day. Overall, the dietary recommendation is to consume 50 mg isoflavones/day in combination with standard nutritional requirements for calcium and vitamin D. 

BAIRD D D, UMBACH D M, LANDSDELL L, HUGHES C L, SETCHELL K D R, WEINBERG C R, HANEY A F, WILCOX A J, MCLACHLAN J A (1995) Dietary intervention study to assess estrogenicity of dietary soy amongst postmenopausal women. J Clin Endocinol Metab 80(50, 1685-90. 

Many epidemiological studies have analyzed the correlations between different carotenoids and the various forms of cancer and a lot of conclusions converge toward protective effects of carotenoids. Many studies were carried out with (i-carotene. The SUVIMAX study, a primary intervention trial of the health effects of antioxidant vitamins and minerals, revealed that a supplementation of p-carotene (6 mg/day) was inversely correlated with total cancer risk. Intervention studies investigating the association between carotenoids and different types of cancers and cardiovascular diseases are reported in Table 3.1.2 and Table 3.1.3. 

Intervention Studies Relating Carotenoids and Cardiovascular Diseases... 

Randomized cross-over dietary intervention study... 

Intervention trials confirmed this protective role of lycopene on prostate cancer risk. Three primary intervention studies evaluated the effect of lycopene supplementation on prostate cancer risk or on certain risk markers such as prostate-specific antigen (PSA) plasma concentration or oxidative alterations of leucocyte DNA. - All showed increases of plasma and prostate lycopene levels after diet supplementation with lycopene and inverse correlations between tumor incidence and risk biomarkers. 

Carotenoids and breast cancer — Among seven case-control studies investigating the correlation between different carotenoid plasma levels or dietary intakes and breast cancer risk, five showed significant inverse associations with some carotenoids. - In most cases, this protective effect was due to 3-carotene and lutein. However, one (the Canadian National Breast Screening Study ) showed no association for all studied carotenoids including (I-carotene and lutein. More recently, another study even demonstrated a positive correlation between breast cancer risk and tissue and serum levels of P-carotenes and total carotenes. Nevertheless, these observational results must be confirmed by intervention studies to prove consistent. 

Hercberg, S., The history of beta-carotene and cancers from observational to intervention studies what lessons can be drawn for future research on polyphenols Am. J. Clin. Nutr., 81, 218S, 2005. 

Agarwal, S. and Rao, A.V., Tomato lycopene and low density lipoprotein oxidation a human dietary intervention study. Lipids, 33, 981, 1998. 

Experimental evidence in humans is based upon intervention studies with diets enriched in carotenoids or carotenoid-contaiifing foods. Oxidative stress biomarkers are measured in plasma or urine. The inhibition of low density lipoprotein (LDL) oxidation has been posmlated as one mechanism by which antioxidants may prevent the development of atherosclerosis. Since carotenoids are transported mainly via LDL in blood, testing the susceptibility of carotenoid-loaded LDL to oxidation is a common method of evaluating the antioxidant activities of carotenoids in vivo. This type of smdy is more precisely of the ex vivo type because LDLs are extracted from plasma in order to be tested in vitro for oxidative sensitivity after the subjects are given a special diet. 

Forde, O. H., Knutsen, S.F., Arnesen, E., Thelle, D. S., The Tromso heart study Coffee consumption and serum lipid concentrations in men with hypercholesterolemia A randomized intervention study, BrMedJ, 290, 893, 1985... 

Phytochemicals have been the subject of many studies evaluating their effects in relation to common chronic human illnesses such as cancer and cardiovascular diseases. These studies encounter difficulties in using this information to influence the dietary patterns of consumers because in the past they have used models or experiments with animals. However, in the last decade, researchers have moved away from animal studies in favour of human cell models or human intervention studies. Scientists still need to determine the likely incidence of illness from exposure to known amounts of a given natural compound in the diet and specifically in relation to the complex matrices of whole foods. Therefore, it is inevitable that some animal studies have to be continued for toxicological studies. 

Bioavailability studies need to be performed to evaluate the differences between conventional and organic crops, e.g. human intervention studies. 

IBIS (2002) First results from the international Breast Cancer Intervention Study (IBIS-I) a randomised prevention trial. Lancet 360 817-824... 

McShane R, Keene J, Gedling K et al. (1997) Do neuroleptic drugs hasten cognitive decline in dementia Prospective study with necropsy follow up. BMJ 314(7076) 266-270 Mortimer AM, Shepherd CJ, Rymer M et al. (2005) Primary care use of antipsychotic drugs an audit and intervention study. Ann Gen Psychiatry 4 18 DOI 10.1186/1744-859X-4-18 Mulsant BH, Pollock BG, Kirshner M et al. (2003) Serum anticholinergic activity in a community-based sample of older adults relationship with cognitive performance. Arch Gen Psychiatry 60(2) 198-203... 

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