ייעוץ חלב- למה? כמה? בריא?

[Enforcer]

ראיתי יותר מפעם אחת המלצות על צריכת חלב מרובה.

• האם למישהו יש הסבר \ כתבה \ מחקר שמסביר מדוע החלב כל כך תורם?
• האם למישהו יש הסבר \ כתבה \ מחקר עם קביעה ודאית שאין שום סכנה בצריכת חלב מעבר לצרכים היום יומיים (2-3 כוסות קפה עם קצת חלב, גבינה על הסנדוויץ' בבוקר ובערב)
• איך אני יודע כמה חלב אני אמור לצרוך אם אני שוקל 70 קילו?

אני באמת לא מחפש תשובות כמו "לא מתאים לך, אל תשתה".
לא באתי להציע כאן משקאות משקה מתחרה, אלא ללמוד על החלב.

 

[Mike Bikov]

בקשר לפותח האשכול קח:

Med Sci Sports Exerc. 2009 Dec 9. [Epub ahead of print]
Body Composition and Strength Changes in Women with Milk and Resistance Exercise.

Josse AR, Tang JE, Tarnopolsky MA, Phillips SM.

1 Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON, CANADA; 2 Pediatrics and Medicine, McMaster University Medical Centre, Hamilton, ON, CANADA.

PURPOSE:: We aimed to determine whether women consuming fat free milk versus isoenergetic carbohydrate after resistance exercise would see augmented gains in lean mass and reductions in fat mass similar to what we observed in young men. METHODS:: Young women were randomized to drink either fat-free milk (MILK: n=10; age=23.2+/-2.8y; BMI=26.2+/-4.2kg/m [mean+/-SD]) or isoenergetic carbohydrate (CON: n=10; age=22.4+/-2.4y; BMI=25.2+/-3.8kg/m) immediately post and 1h post-exercise (2 x 500ml). Subjects exercised 5d/wk for 12 wks. Body composition changes were measured by DXA, and subjects' strength and fasting blood were measured pre- and post-training. RESULTS:: CON gained weight post-training (CON: +0.86+/-0.4kg, P<0.05; MILK: +0.50+/-0.4kg, P=0.29). Lean mass increased with training in both groups (P< 0.01), with a greater net gain in MILK versus CON (1.9+/-0.2kg vs. 1.1 +/-0.2kg, respectively; P<0.01). Fat mass decreased with training in MILK only (-1.6+/- 0.4kg, P<0.01; CON: -0.3+/-0.3kg, P=0.41). Isotonic strength increased more in MILK than CON (P<0.05) for some exercises. Serum 25-hydroxyvitamin D increased in both groups but to a greater extent in MILK than CON (+6.5+/-1.1nM vs. +2.8+/-1.3nM, respectively; P<0.05), and parathyroid hormone decreased only in MILK (-1.2+/-0.2pM; P<0.01). CONCLUSION:: Heavy, whole-body resistance exercise with the consumption of milk versus carbohydrate in the early post-exercise period resulted in greater muscle mass accretion, strength gains, fat mass loss, and a possible reduction in bone turnover in women after 12 wks. Our results, similar to those in men, highlight that milk is an effective drink to support favourable body composition changes in women with resistance training.
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Appl Physiol Nutr Metab. 2009 Dec;34(6):1017-22.
Acute effects of chocolate milk and a commercial recovery beverage on postexercise recovery indices and endurance cycling performance.

Pritchett K, Bishop P, Pritchett R, Green M, Katica C.

Department of Health, Human Performance, and Nutrition, Central Washington University, Ellensburg, WA 98926, USA.

To maximize training quality, athletes have sought nutritional supplements that optimize recovery. This study compared chocolate milk (CHOC) with a carbohydrate replacement beverage (CRB) as a recovery aid after intense exercise, regarding performance and muscle damage markers in trained cyclists. Ten regional-level cyclists and triathletes (maximal oxygen uptake 55.2 +/- 7.2 mL.kg-1.min-1) completed a high-intensity intermittent exercise protocol, then 15-18 h later performed a performance trial at 85% of maximal oxygen uptake to exhaustion. Participants consumed 1.0 g carbohydrate.kg-1.h-1 of a randomly assigned isocaloric beverage (CHOC or CRB) after the first high-intensity intermittent exercise session. The same protocol was repeated 1 week later with the other beverage. A 1-way repeated measures analysis of variance revealed no significant difference (p = 0.91) between trials for time to exhaustion at 85% of maximal oxygen uptake (CHOC 13 +/- 10.2 min, CRB 13.5 +/- 8.9 min). The change in creatine kinase (CK) was significantly (p < 0.05) greater in the CRB trial than in the CHOC trial (increase CHOC 27.9 +/- 134.8 U.L-1, CRB 211.9 +/- 192.5 U.L-1), with differences not significant for CK levels before the second exercise session (CHOC 394.8 +/- 166.1 U.L-1, CRB 489.1 +/- 264.4 U.L-1) between the 2 trials. These findings indicate no difference between CHOC and this commercial beverage as potential recovery aids for cyclists between intense workouts.
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זה מחקר מגניב:

Br J Nutr. 2009 Sep 22:1-5. [Epub ahead of print]
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Short-term effects of replacing milk with cola beverages on insulin-like growth factor-I and insulin-glucose metabolism: a 10 d interventional study in young men.

Hoppe C, Kristensen M, Boiesen M, Kudsk J, Fleischer Michaelsen K, Mølgaard C.

Department of Human Nutrition, University of Copenhagen, Rolighedsvej 30, DK-1958 Fredericksberg, Denmark.

In the Western world, a trend towards increased consumption of carbonated soft drinks combined with a decreasing intake of milk is observed. This may affect circulating insulin-like growth factor I (IGF-I) and fasting insulin, as seen in pre-pubertal children. The present study was designed to reflect the trend of replacing milk with carbonated beverages in young men and to study the effects of this replacement on IGF-I, IGF-binding protein 3 (IGFBP-3), IGF-I:IGFBP-3 and glucose-insulin metabolism. A randomised, controlled crossover intervention study, in which eleven men aged 22-29 years were given a low-Ca diet in two 10 d periods with 10 d washout in between. In one period, they drank 2.5 litres of Coca Cola(R) per day and the other period 2.5 litres of semi-skimmed milk. Serum IGF-I, IGFBP-3 (RIA), insulin (fluoro immunoassay) and glucose (Cobas) were determined at baseline and end point of each intervention period. Insulin resistance and beta-cell function were calculated with the homeostasis model assessment. A decrease in serum IGF-I was observed in the cola period compared with the milk period (P < 0.05). No effects of treatment were observed on IGFBP-3, IGF-I:IGFBP-3, insulin, glucose, insulin resistance or beta-cell function. The present study demonstrates that high intake of cola over a 10 d period decreases total IGF-I compared with a high intake of milk, with no effect on glucose-insulin metabolism in adult men. It is unknown whether this is a transient phenomenon or whether it has long-term consequences.
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Fuck Stupid People

J Int Soc Sports Nutr. 2008 Oct 2;5(1):15. [Epub ahead of print]

Milk: the new sports drink? A Review.

Roy BD.

ABSTRACT: There has been growing interest in the potential use of bovine milk as an exercise beverage, especially during recovery from resistance training and endurance sports. Based on the limited research, milk appears to be an effective post-resistance exercise beverage that results in favourable acute alterations in protein metabolism. Milk consumption acutely increases muscle protein synthesis, leading to an improved net muscle protein balance. Furthermore, when post-exercise milk consumption is combined with resistance training (12 weeks minimum), greater increases in muscle hypertrophy and lean mass have been observed. Although research with milk is limited, there is some evidence to suggest that milk may be an effective post-exercise beverage for endurance activities. Low-fat milk has been shown to be as effective, if not more effective, than commercially available sports drinks as a rehydration beverage. Milk represents a more nutrient dense beverage choice for individuals who partake in strength and endurance activities, compared to traditional sports drinks. Bovine low-fat fluid milk is a safe and effective post exercise beverage for most individuals, except for those who are lactose intolerant. Further research is warranted to better delineate the possible applications and efficacy of bovine milk in the field of sports nutrition.
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Improved endurance capacity following chocolate milk consumption compared with 2 commercially available sport drinks.
Thomas K, Morris P, Stevenson E.
Appl Physiol Nutr Metab. 2009 Feb;34(1):78-82.
PMID: 19234590

This study examined the effects of 3 recovery drinks on endurance performance following glycogen-depleting exercise. Nine trained male cyclists performed 3 experimental trials, in a randomized counter-balanced order, consisting of a glycogen-depleting trial, a 4-h recovery period, and a cycle to exhaustion at 70% power at maximal oxygen uptake. At 0 and 2 h into the recovery period, participants consumed chocolate milk (CM), a carbohydrate replacement drink (CR), or a fluid replacement drink (FR). Participants cycled 51% and 43% longer after ingesting CM (32 +/- 11 min) than after ingesting CR (21 +/- 8 min) or FR (23 +/- 8 min). CM is an effective recovery aid after prolonged endurance exercise for subsequent exercise at low-moderate intensities.
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Folia Microbiol (Praha). 2008;53(5):378-94. Epub 2008 Dec 16.Links
Beneficial health effects of milk and fermented dairy products - Review.
Ebringer L, Ferencík M, Krajcovic J.

Institute of Cell Biology, Faculty of Science, Comenius University, 842 15, Bratislava, Slovakia, [email protected].

Milk is a complex physiological liquid that simultaneously provides nutrients and bioactive components that facilitate the successful postnatal adaptation of the newborn infant by stimulating cellular growth and digestive maturation, the establishment of symbiotic microflora, and the development of gut-associated lymphoid tissues. The number, the potency, and the importance of bioactive compounds in milk and especially in fermented milk products are probably greater than previously thought. They include certain vitamins, specific proteins, bioactive peptides, oligosaccharides, organic (including fatty) acids. Some of them are normal milk components, others emerge during digestive or fermentation processes. Fermented dairy products and probiotic bacteria decrease the absorption of cholesterol. Whey proteins, medium-chain fatty acids and in particular calcium and other minerals may contribute to the beneficial effect of dairy food on body fat and body mass. There has been growing evidence of the role that dairy proteins play in the regulation of satiety, food intake and obesity-related metabolic disorders. Milk proteins, peptides, probiotic lactic acid bacteria, calcium and other minerals can significantly reduce blood pressure. Milk fat contains a number of components having functional properties. Sphingolipids and their active metabolites may exert antimicrobial effects either directly or upon digestion.
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Cereal and nonfat milk support muscle recovery following exercise

Lynne Kammer email, Zhenping Ding email, Bei Wang email, Daiske Hara email, Yi-Hung Liao email and John L. Ivy email

Journal of the International Society of Sports Nutrition 2009, 6:11doi:10.1186/1550-2783-6-11
Published: 14 May 2009
Abstract (provisional)

Background

This study compared the effects of ingesting cereal and nonfat milk (Cereal) and a carbohydrate-electrolyte sports drink (Drink) immediately following endurance exercise on muscle glycogen synthesis and the phosphorylation state of proteins controlling protein synthesis: Akt, mTOR, rpS6 and eIF4E.
Methods

Trained cyclists or triathletes (8 male: 28.0+/-1.6 yrs, 1.8+/-0.0 m, 75.4+/-3.2 kg, 61.0+/-1.6 ml O2 * kg-1 * min-1; 4 female: 25.3+/-1.7 yrs, 1.7+/-0.0 m, 66.9+/-4.6 kg, 46.4+/-1.2 mlO2 * kg-1 * min-1) completed two randomly-ordered trials serving as their own controls. After 2 hours of cycling at 60-65% VO2MAX, a biopsy from the vastus lateralis was obtained (Post0), then subjects consumed either Drink (78.5 g carbohydrate) or Cereal (77 g carbohydrate, 19.5 g protein and 2.7 g fat). Blood was drawn before and at the end of exercise, and at 15, 30 and 60 minutes after treatment. A second biopsy was taken 60 minutes after supplementation (Post60). Differences within and between treatments were tested using repeated measures ANOVA.
Results

At Post60, blood glucose was similar between treatments (Drink 6.1+/-0.3, Cereal 5.6+/-0.2 mmol/L, p<.05), but after Cereal, plasma insulin was significantly higher (Drink 123.1+/-11.8, Cereal 191.0+/-12.3 pmol/L, p<.05), and plasma lactate significantly lower (Drink 1.4+/-0.1, Cereal 1.00+/-0.1 mmol/L, p<.05). Except for higher phosphorylation of mTOR after Cereal, glycogen and muscle proteins were not statistically different between treatments. Significant Post0 to Post60 changes occurred in glycogen (Drink 52.4+/-7.0 to 58.6+/-6.9, Cereal 58.7+/-9.6 to 66.0+/-10.0 mumol/g, p<.05) and rpS6 (Drink 17.9+/-2.5 to 35.2+/-4.9, Cereal 18.6+/-2.2 to 35.4+/-4.4 %Std, p<.05) for each treatment, but only Cereal significantly affected glycogen synthase (Drink 66.6+/-6.9 to 64.9+/-6.9, Cereal 61.1+/-8.0 to 54.2+/-7.2%Std, p<.05), Akt (Drink 57.9+/-3.2 to 55.7+/-3.1, Cereal 53.2+/-4.1 to 60.5+/-3.7 %Std, p<.05) and mTOR (Drink 28.7+/-4.4 to 35.4+/-4.5, Cereal 23.0+/-3.1 to 42.2+/-2.5 %Std, p<.05). eIF4E was unchanged after both treatments.
Conclusion

These results suggest that Cereal is as good as a commercially-available sports drink in initiating post-exercise muscle recovery.
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Med Sci Sports Exerc. 2006 Apr;38(4):667-74.

Milk ingestion stimulates net muscle protein synthesis following resistance exercise.

Elliot TA, Cree MG, Sanford AP, Wolfe RR, Tipton KD.

Metabolism Unit, Shriners Hospitals for Children and Department of Surgery, The University of Texas Medical Branch, Galveston, TX, USA.

PURPOSE: Previous studies have examined the response of muscle protein to resistance exercise and nutrient ingestion. Net muscle protein synthesis results from the combination of resistance exercise and amino acid intake. No study has examined the response of muscle protein to ingestion of protein in the context of a food. This study was designed to determine the response of net muscle protein balance following resistance exercise to ingestion of nutrients as components of milk. METHOD: Three groups of volunteers ingested one of three milk drinks each: 237 g of fat-free milk (FM), 237 g of whole milk (WM), and 393 g of fat-free milk isocaloric with the WM (IM). Milk was ingested 1 h following a leg resistance exercise routine. Net muscle protein balance was determined by measuring amino acid balance across the leg. RESULTS: Arterial concentrations of representative amino acids increased in response to milk ingestion. Threonine balance and phenylalanine balance were both > 0 following milk ingestion. Net amino acid uptake for threonine was 2.8-fold greater (P < 0.05) for WM than for FM. Mean uptake of phenylalanine was 80 and 85% greater for WM and IM, respectively, than for FM, but not statistically different. Threonine uptake relative to ingested was significantly (P < 0.05) higher for WM (21 +/- 6%) than FM (11 +/- 5%), but not IM (12 +/- 3%). Mean phenylalanine uptake/ingested also was greatest for WM, but not significantly. CONCLUSIONS: Ingestion of milk following resistance exercise results in phenylalanine and threonine uptake, representative of net muscle protein synthesis. These results suggest that whole milk may have increased utilization of available amino acids for protein synthesis.
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Eur J Appl Physiol. 2008 Jul 10. [Epub ahead of print]
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A comparison of the effects of milk and a carbohydrate-electrolyte drink on the restoration of fluid balance and exercise capacity in a hot, humid environment.

Watson P, Love TD, Maughan RJ, Shirreffs SM.

School of Sport and Exercise Sciences, Loughborough University, Leicestershire, LE11 3TU, UK.

Following a 2.0 +/- 0.1% body mass loss induced by intermittent exercise in the heat, seven male volunteers ingested either a carbohydrate-electrolyte solution (CE) or skimmed milk (M) in a volume equal to 150% of body mass loss. At the end of the 3 h recovery period, subjects were essentially in positive fluid balance on trial M (191 +/- 162 mL), and euhydrated on trial CE (-135 +/- 392 mL) despite being in negative sodium balance on both trials and negative potassium balance on trial CE. This difference of 326 +/- 354 mL or 0.4% body mass approached significance (P = 0.051). Subjects ingested 137 +/- 15 and 113 +/- 12 g of CHO during the CE and M trials, respectively, as well as 75 +/- 8 g of protein during the M trial. At the end of the 3 h recovery period, an exercise capacity test was completed at 61% VO(2peak) in warm (35.3 +/- 0.5 degrees C), humid (63 +/- 2%) conditions. HR (P = 0.020) and rectal temperature (P = 0.045) were higher on trial M, but no difference in exercise time to exhaustion was observed between trials (39.6 +/- 7.3 min vs. 39.7 +/- 8.1 min on trials CE and M, respectively). The results of the present study suggest that milk can be an effective post-exercise rehydration drink, with subjects remaining in net positive fluid balance throughout the recovery period. Despite the effect on fluid retention, exercise capacity was not different between skimmed milk and a commercially available carbohydrate-electrolyte drink 4 h following exercise/heat-induced body mass loss.
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American Journal of Clinical Nutrition, Vol. 86, No. 2, 373-381, August 2007

Consumption of fat-free fluid milk after resistance exercise promotes greater lean mass accretion than does consumption of soy or carbohydrate in young, novice, male weightlifters
Joseph W Hartman, Jason E Tang, Sarah B Wilkinson, Mark A Tarnopolsky, Randa L Lawrence, Amy V Fullerton and Stuart M Phillips

1 From the Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON, Canada (JWH, JET, SBW, RLL, AVF, and SMP), and Pediatrics and Medicine, McMaster University Medical Centre, Hamilton, ON, Canada (MAT)

Background: Acute consumption of fat-free fluid milk after resistance exercise promotes a greater positive protein balance than does soy protein.

Objective: We aimed to determine the long-term consequences of milk or soy protein or equivalent energy consumption on training-induced lean mass accretion.

Design: We recruited 56 healthy young men who trained 5 d/wk for 12 wk on a rotating split-body resistance exercise program in a parallel 3-group longitudinal design. Subjects were randomly assigned to consume drinks immediately and again 1 h after exercise: fat-free milk (Milk; n = 18); fat-free soy protein (Soy; n = 19) that was isoenergetic, isonitrogenous, and macronutrient ratio matched to Milk; or maltodextrin that was isoenergetic with Milk and Soy (control group; n = 19).

Results: Muscle fiber size, maximal strength, and body composition by dual-energy X-ray absorptiometry (DXA) were measured before and after training. No between-group differences were seen in strength. Type II muscle fiber area increased in all groups with training, but with greater increases in the Milk group than in both the Soy and control groups (P < 0.05). Type I muscle fiber area increased after training only in the Milk and Soy groups, with the increase in the Milk group being greater than that in the control group (P < 0.05). DXA-measured fat- and bone-free mass increased in all groups, with a greater increase in the Milk group than in both the Soy and control groups (P < 0.05).

Conclusion: We conclude that chronic postexercise consumption of milk promotes greater hypertrophy during the early stages of resistance training in novice weightlifters when compared with isoenergetic soy or carbohydrate consumption.
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Am J Clin Nutr. 2006 Nov;84(5):1070-9.

Compared with casein or total milk protein, digestion of milk soluble proteins is too rapid to sustain the anabolic postprandial amino acid requirement.

Lacroix M, Bos C, Leonil J, Airinei G, Luengo C, Dare S, Benamouzig R, Fouillet H, Fauquant J, Tome D, Gaudichon C.

UMR INRA 914, Physiology of Nutrition and Feeding Control Unit, Institut National Agronomique Paris-Grignon, Paris, France.

BACKGROUND: The in vivo quality of milk protein fractions has seldom been studied in humans. OBJECTIVE: Our objective was to compare the postprandial utilization of dietary nitrogen from 3 [(15)N]-labeled milk products: micellar caseins (MC), milk soluble protein isolate (MSPI), and total milk protein (TMP). DESIGN: The macronutrient intakes of 23 healthy volunteers were standardized for 1 wk, after which time the subjects ingested a meal containing MC (n = 8), MSPI (n = 7), or TMP (n = 8). [(15)N] was measured for an 8-h period in plasma amino acids, proteins, and urea and in urinary urea. RESULTS: The transfer of dietary nitrogen to urea occurred earlier after MSPI ingestion than after MC and TMP ingestion, and concentrations remained high for 8 h, concomitantly with higher but transient hyperaminoacidemia and a higher incorporation of dietary nitrogen into plasma amino acids. In contrast, deamination, postprandial hyperaminoacidemia, and the incorporation of dietary nitrogen into plasma amino acids were lower in the MC and TMP groups. Finally, total postprandial deamination values were 18.5 +/- 2.9%, 21.1 +/- 2.8%, and 28.2 +/- 2.9% of ingested nitrogen in the TMP, MC, and MSPI groups, respectively. CONCLUSIONS: Our results confirm the major role of kinetics in dietary nitrogen postprandial utilization and highlight the paradox of MSPI, which, despite its high Protein Digestibility Corrected Amino Acid Score, ensures a rate of amino acid delivery that is too rapid to sustain the anabolic requirement during the postprandial period. Milk proteins had the best nutritional quality, which suggested a synergistic effect between soluble proteins and caseins.
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