Etudes Compléments alimentaires : page 83.6

Stévia : bon pour le santé ?

16/03/2010 | Etudes Compléments alimentaires et Etudes Perte de poids et Etudes Anti-âge


Stevioside inhibits atherosclerosis by improving insulin signaling and antioxidant defense in obese insulin-resistant mice
International Journal of Obesity (2010) 34, 569–577

B Geeraert, F Crombé, M Hulsmans

Objective: Stevioside is a non-caloric natural sweetener that does not induce a glycemic response, making it attractive as sweetener to diabetics and others on carbohydrate-controlled diets. Obesity is frequently associated with insulin resistance and increased inflammation and oxidative stress. Therefore, we investigated its effects on insulin resistance, inflammation and oxidative stress related to atherosclerosis in obese insulin-resistant mice.

Research design: Twelve-week-old mice were treated with stevioside (10 mg kg−1, n=14) or placebo (n=20) for 12 weeks.

Results: Stevioside had no effect on weight and triglycerides, but lowered glucose and insulin. Stevioside treatment improved adipose tissue maturation, and increased glucose transport, insulin signaling and antioxidant defense in white visceral adipose tissues. Together, these increases were associated with a twofold increase of adiponectin. In addition, stevioside reduced plaque volume in the aortic arch by decreasing the macrophage, lipid and oxidized low-density lipoprotein (ox-LDL) content of the plaque. The higher smooth muscle cell-to-macrophage ratio was indicative for a more stable plaque phenotype. The decrease in ox-LDL in the plaque was likely due to an increase in the antioxidant defense in the vascular wall, as evidenced by increased Sod1, Sod2 and Sod3. Circulating adiponectin was associated with improved insulin signaling and antioxidant defense in both the adipose tissue and the aorta of stevioside-treated mice.

Conclusion: Stevioside treatment was associated with improved insulin signaling and antioxidant defense in both the adipose tissue and the vascular wall, leading to inhibition of atherosclerotic plaque development and inducing plaque stabilization.

Du fructose pour tomber malade rapidement

16/03/2010 | Etudes Compléments alimentaires et Etudes Perte de poids et Etudes Anti-âge


Excessive fructose intake induces the features of metabolic syndrome in healthy adult men: role of uric acid in the hypertensive response
International Journal of Obesity (2010) 34, 454–461; doi:10.1038/ijo.2009.259; published online 22 December 2009

S E Perez-Pozo, J Schold, T Nakagawa

Background: Excessive fructose intake causes metabolic syndrome in animals and can be partially prevented by lowering the uric acid level. We tested the hypothesis that fructose might induce features of metabolic syndrome in adult men and whether this is protected by allopurinol. Methods: A randomized, controlled trial of 74 adult men who were administered 200 g fructose daily for 2 weeks with or without allopurinol. Primary measures included changes in ambulatory blood pressure (BP), fasting lipids, glucose and insulin, homeostatic model assessment (HOMA) index, body mass index and criteria for metabolic syndrome. Results: The ingestion of fructose resulted in an increase in ambulatory BP (7±2 and 5±2 mm Hg for systolic (SBP) and diastolic BP (DBP), P<0.004 and P<0.007, respectively). Mean fasting triglycerides increased by 0.62±0.23 mmol l−1 (55±20 mg per 100 ml), whereas high-density lipoprotein cholesterol decreased by 0.06±0.02 mmol l−1 (2.5±0.7 mg per 100 ml), P<0.002 and P<0.001, respectively. Fasting insulin and HOMA indices increased significantly, whereas plasma glucose level did not change. All liver function tests showed an increase in values. The metabolic syndrome increased by 25–33% depending on the criteria. Allopurinol lowered the serum uric acid level (P<0.0001) and prevented the increase in 24-h ambulatory DBP and daytime SBP and DBP. Allopurinol treatment did not reduce HOMA or fasting plasma triglyceride levels, but lowered low-density lipoprotein cholesterol relative to control (P<0.02) and also prevented the increase in newly diagnosed metabolic syndrome (0–2%, P=0.009). Conclusions: High doses of fructose raise the BP and cause the features of metabolic syndrome. Lowering the uric acid level prevents the increase in mean arterial blood pressure. Excessive intake of fructose may have a role in the current epidemics of obesity and diabetes.

Huile d’olive, il faudrait m’expliquer

12/03/2010 | Etudes Compléments alimentaires et Etudes Anti-âge


Beaucoup rajoutent de l’huile d’olive dans leur alimentation. Il faudrait m’expliquer pourquoi si ce n’est pour faire plaisir aux marchants d’huile.
Dans cette étude, l’huile d’olive fait autant grossir que les “mauvaises” graisses et n’augmente pas la durée de vie.

Dietary extra-virgin olive oil rich in phenolic antioxidants and the aging process: long-term effects in the rat
The Journal of Nutritional Biochemistry Volume 21, Issue 4, April 2010, Pages 290-296

Michela Jacomelli, Vanessa Pitozz

The aim of the present work was to verify whether extra-virgin olive oil, a food naturally containing phenolic antioxidants, has the potential to protect from the pro-aging effects of a high-calorie diet. Male rats were fed from age 12 months to senescence a high-calorie diet containing either corn oil (CO), or extra-virgin olive oil with high (H-EVOO) or low (L-EVOO) amounts of phenols. The prolonged high fat intake led to obesity, liver lipid degeneration and insulin resistance, which were not counteracted by high phenol intake. No difference in overall survival was found at the end of the experiment in the animals treated with H-EVOO compared to the other groups. However, we did detect a protective effect of olive oil on some age-related pathologies and on blood pressure, of which the former was associated with the antioxidant content. Concomitantly, a decrease in DNA oxidative damage in blood cells and plasma TBARS and an increase in liver superoxide dismutase were detected following H-EVOO consumption. Thus, although olive oil phenols cannot reverse the detrimental effects of a prolonged intake of high amounts of fat, improving the quality of olive oil in terms of antioxidant content can be beneficial.

Vitamines et humidité ne font pas bon ménage

09/03/2010 | Etudes Compléments alimentaires et Etudes Perte de poids et Etudes Anti-âge


Don’t store vitamins in the bathroom

A U.S. food scientist warns humidity—storing vitamins in the bathroom or kitchen—may eliminate the benefits of some vitamins. Lisa Mauer of Purdue University in West Lafayette, Ind., says subjecting some vitamins to humidity can chemically change their composition—even if the lids are on tight. “Opening and closing a package will change the atmosphere in it,” Mauer says in statement. “If you open and close a package in a bathroom, you add a little bit of humidity and moisture each time.” Mauer said crystalline substances—including vitamin C, some forms of vitamin B and other dietary supplements—may undergo deliquescence, a process in which humidity causes the water-soluble solid to dissolve similar to how sugar cakes in the summer. Once humidity or temperature is brought back down, the product will solidify, Mauer says, but the damage has been done. Depending on how long a person takes for a shower, the humidity of the bathroom can go as high as 98 percent, Mauer says. Mauer’s findings were published in the early online version of the Journal of Agricultural and Food Chemistry.


Le Pycnogénol protége les reins

05/03/2010 | Livres Compléments alimentaires et Etudes Compléments alimentaires et Etudes Anti-âge


L’hypertension affecte de nombreux sportifs de force. Le Pycnogénol contribue à les protéger.

Kidney flow and function in hypertension: protective effects of pycnogenol in hypertensive participants—a controlled study.
J Cardiovasc Pharmacol Ther. 2010 Mar;15(1):41-6. Cesarone MR, Belcaro G, Stuard S, Schönlau F, Di Renzo A, Grossi MG, Dugall M, Cornelli U, Cacchio M, Gizzi G, Pellegrini L.

This study evaluated the effects of Pycnogenol as an adjunct to angiotensin-converting enzyme (ACE)-inhibitor ramipril treatment of hypertensive patients presenting with early signs of renal function problems. One group of 26 patients was medicated with 10 mg ramipril per day only; a second group of 29 patients took Pycnogenol in addition to the ACE inhibitor over a period of 6 months. At trial end, a lowered systolic and diastolic blood pressure was found in both groups, with a significant further reduction of diastolic pressure in the group given Pycnogenol in addition to ramipril. The major aim of this study was the investigation of kidney-protective effects of Pycnogenol. Urinary albumin decreased from 87 +/- 23 to 64 +/- 16 mg/d with ramipril only. Additional Pycnogenol lowered albumin significantly better from 91 +/- 25 to 39 +/- 13 mg/day (P

< .05). In both groups, serum creatinine was lowered; however, only in the combination treatment group did the effect reached statistical significance. In both groups, CRP levels decreased from 2.1 to 1.8 with ramipril and from 2.2 to 1.1 with the ramipril-Pycnogenol combination; the latter reached statistical significance. Kidney cortical flow velocity was investigated by Doppler color duplex ultrasonography. Both systolic and diastolic flow velocities increased significantly after 6 months medication with ramipril. The addition of Pycnogenol to the regimen statistically significantly further enhanced kidney cortical flow velocities, by 8% for diastolic flow and 12% for systolic flow, relative to values found for the group taking ramipril only. The

protective effects of Pycnogenol for initial kidney damage found in this study warrant further research with a larger number of patients and over a longer period of time.

Les oméga-3 protègent les reins

04/03/2010 | Livres Compléments alimentaires et Etudes Compléments alimentaires et Etudes Anti-âge


La musculation abaisse temporairement la fonction rénale. Les oméga-3 produisent l’effet inverse sur la protéinurie.

The effect of n–3 long-chain polyunsaturated fatty acid supplementation on urine protein excretion and kidney function: meta-analysis of clinical trials
Am J Clin Nutr 2009;89:1937–45.

Edgar R Miller III, Stephen P Juraschek, Lawrence J Appel, Madhavi Madala, Cheryl AM Anderson, Joachim Bleys, and Background: Chronic kidney disease is a major worldwide problem. Although epidemiologic and experimental studies suggest that n–3 long-chain polyunsaturated fatty acid (n–3 LCPUFA) supplementation may prevent or slow the progression of kidney disease, evidence from clinical trials is inconsistent.

Objective: The objective was to combine evidence from controlled clinical trials to assess the effect of n–3 LCPUFA supplementation on the change in urine protein excretion (UPE) and on glomerular filtration rate (GFR).

Design: We performed a meta-analysis of clinical trials that tested the effect of n–3 LCPUFA supplementation on UPE, a marker of kidney damage, and on GFR, a marker of kidney function. A randomeffects model was used to pool SD effect size (Cohen’s d) across studies.

Results: Seventeen trials with 626 participants were included in the meta-analysis. Most trials focused on patients with a single underlying diagnosis: IgA nephropathy (n ¼ 5), diabetes (n ¼ 7), or lupus nephritis (n ¼ 1). The dose of n–3 LCPUFAs ranged from 0.7 to 5.1 g/d, and the median follow-up was 9 mo. In the pooled analysis, there was a greater reduction in UPE in the n–3 LCPUFA group than in the control group: Cohen’s d for all trials was 20.19 (95% CI: 20.34, 20.04; P ¼ 0.01). In a patient with 1 g UPE/d , this corresponds to a reduction of 190 mg/d. Effects on GFR were reported in 12 trials. The decline in GFR was slower in the n–3 LCPUFA group than in the control group, but this effect was not significant (0.11; 95% CI: 20.07, 0.29; P ¼ 0.24).

Conclusions: In our meta-analysis, use of n–3 LCPUFA supplements reduced UPE but not the decline in GFR. However, small numbers of participants in trials, different methods of assessing proteinuria and GFR, and inconsistent data reporting limit the strength of these conclusions. Large, high-quality trials with clinical outcomes are warranted.

Les vitamines allongent les télomères

04/03/2010 | Etudes Compléments alimentaires et Etudes Anti-âge


Chez la femme, ce qui est associé avec une augmentation de la longévité.

Multivitamin use and telomere length in women
Am J Clin Nutr 2009;89:1857–63.  Qun Xu, Christine G Parks, Lisa A DeRoo, Richard M Cawthon, Dale P Sandler, and Honglei Chen

Background: Telomere length may be a marker of biological aging. Multivitamin supplements represent a major source of micronutrients, which may affect telomere length by modulating oxidative stress and chronic inflammation. Objective: The objective was to examine whether multivitamin use is associated with longer telomeres in women. Design: We performed a cross-sectional analysis of data from 586 early participants (age 35–74 y) in the Sister Study. Multivitamin use and nutrient intakes were assessed with a 146-item food-frequency questionnaire, and relative telomere length of leukocyte DNA was measured by quantitative polymerase chain reaction. Results: After age and other potential confounders were adjusted for, multivitamin use was associated with longer telomeres. Compared with nonusers, the relative telomere length of leukocyte DNA was on average 5.1% longer among daily multivitamin users.

In the analysis of micronutrients, higher intakes of vitamins C and E from foods were each associated with longer telomeres, even after adjustment for multivitamin use. Furthermore, intakes of both nutrients were associated with telomere length among women who did not take multivitamins. Conclusion: This study provides the first epidemiologic evidence that multivitamin use is associated with longer telomere length among women.

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