Dietary intervention studies

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. 

Randomized cross-over dietary intervention study... 

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

Three dietary intervention studies reported the effects of soy or soy phytoestrogen consumption on reproductive hormones in men and very modest alterations of doubtful clinical significance were found (Habito et al., 2000 Nagata et al., 2001). None of these studies evaluated the prostate itself, and it is possible that soy consumption alters local hormone metabolism and action within the gland. 

It has been shown that fish oil can not only suppress proinflammatory mediators but also can increase the anti-inflammatory ones such as adiponectin (Duda et al., 2009 Kalupahana et al., 2010b). Increased adipo-nectin levels can reduce inflammation and beneficially improve the metabolism. Specifically, the increased levels of adiponectin can significantly reduce the insulin resistance. Oster et al. (2010) showed that DHA increases cellular adiponectin mRNA and secreted adiponectin protein in 3T3-L1 adipocytes, possibly by a mechanism involving PPARy. A recent dietary intervention study conducted on healthy Japanese female subjects by Kondo et al. (2010) showed that a fish-based diet intervention increased the serum adiponectin concentration in young, nonobese, healthy Japanese female subjects. Also, the same study indicated that the increment in serum -3 PUFA may regulate the serum adiponectin concentration (Kondo et al., 2010). 

Setchell KD, Lydeking-Olsen E. 2003. Dietary phytoestrogens and their effect on bone Evidence from in vitro and in vivo, human observational, and dietary intervention studies. Am J Clin Nutr 78 593S-609S. 

FIG. 12 Effect of dietary lycopene supplements on serum LDL oxidation (SS, spaghetti sauce TJ, tomato juice TO, tomato oleoresin). Bars with different letters are statistically different (p < 0.05). (Tomato lycopene and low density lipoprotein oxidation A human dietary intervention study. Reprinted from Lipids. 1988 33, pp. 981-984 by permission of AOCS Press.)... 

Even though milk fat contains some fatty acids that may elevate plasma total and LDL-cholesterol levels, which are risk factors for CHD, this effect is balanced by concurrent increases in levels of anti-atherogenic HDL-choles-terol. In addition, saturated fatty acids reduce plasma levels of atherogenic Lp[a] and produce a less atherogenic LDL particle size. Dietary intervention studies, where there was a substantial reduction in saturated fat intake and plasma cholesterol levels, did not produce an improvement in CHD or total mortality. Prospective epidemiological studies provide no evidence that saturated fatty acids are a risk factor for CHD. Indeed, in two large studies, saturated fatty acids were inversely associated with risk. 

Dyerberg J, Eskesen DC, Andersen PW, Astrup A, Buermann B, Christensen JH, Clausen P, Rasmussen BF, Schmidt EB, Thol-strup T, et al. Effects of trans- and n-3 unsaturated fatty acids on cardiovascular risk markers in healfliy males an 8 weeks dietary intervention study. Eur. J. CUn. Nutr. 2004 58 1062-1070. 

The compositional characteristics of almond oil show that it is rich in several health-promoting nutrients, many of which may be responsible for the observed benehcial effects of dietary almond consumption in cardiovascular diseases (11) and in weight management (12), however, few investigations have explored this topic. Hyson et al. (13) conducted a dietary intervention study to determine whether the consumption of whole almonds or almond oil for 6 weeks would result in similar or different effects on plasma lipids and ex vivo LDL oxidation. Both groups consumed diets with identical almond oil and total fat levels. This study showed that both whole almond and almond oil consumption caused similar reductions in plasma cholesterol and LDL (4% and 6%, respectively) as well as a 14%... 

Obarzanek E, Hunsberger SA, Van Horn L, et al. Safety of a fat-reduced diet The Dietary Intervention Study in Children (DISC). Pediatrics 1997 99 687-694. 

The Lyon Heart Study was a dietary intervention study in which a modified diet of Crete (the experimental diet) was compared with the prudent diet, or Step I American Heart Association Diet (the control diet). The experimental diet provided a ratio of LA to ALA of 4/1. This ratio was achieved by substituting olive oil and canola (oil) margarine for com oil. Since olive oil is low in LA, whereas com oil is high (8% and 61%, respectively) the ALA incorporation into cell membranes was increased. Cleland et al. have shown that olive oil increases the ineorporation of omega-3 fatty acids, whereas the LA from com oil competes. The ratio of 4/1 of LA/ALA led to a 70% decrease in total mortality at the end of two years. ... 

Isoflavonoids also have been reported to have physiological activity in animal and human studies. Besides acting as an estro n mimic, it was reported that the isoflavones found in soybean seeds possess antihemolytic, antifungal, tumorsuppressing, and serum cholesterol-lowering effects. In addition, both epidemiological and dietary-intervention studies indicate that when isoflavones in soybean seeds and in subsequent protein products prepared from the seeds are part of the human dietary intake, those products provide many significant health benefits. - ... 

A recent development, especially useful for conducting long-term studies of the effect of diet on metabolism, is to administer extremely low levels of long-lived radioisotopes, e.g., " Ca, that are then measured by AMS. Because the activity of the radioisotope is extremely low (typically <10 " of annual background radiation dose), it is considered to be safe for human use. AMS opens up the exciting possibility of conducting long-term metabolic and dietary intervention studies where required for example, in studies of bone metabolism. 

R457 F. Puiggros, R. Sola, C. Blade, M.-J. Salvado and L. Arola, Nutritional Biomarkers and Foodomic Methodologies for Qualitative and Quantitative Analysis of Bioactive Ingredients in Dietary Intervention Studies , J. Chro-matogr.. A, [online computer file], 2011,1218, 7399. 

Stumpf K, Pietinen P, Puska P, Adlercreutz H. Changes in serum enterolactone, genistein, and daidzein in a dietary intervention study in Finland. Cancer Epidemiol Biomarkers Preu. 2000 9 1369-1372. 

It is proposed that polyphenols and fiber are the main contributors to the observed effects, either individually or in a synergistic interaction. However, bioavailability and metabolism of the numerous apple polyphenols is not completely understood. Moreover, limited data are available for the characterization of apple fiber, in particular pectin, in the different apple varieties and the impact of the physicochemical properties and structure on the degree of effect. Suitably powered randomly controlled, human dietary intervention studies with long intervention periods are required to clarify the protective effects of apples and juice consumption. Further in vivo animal models are also necessary to explore the potential multiple mechanisms of actions. 

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