http___matrixworld-hr.com_2011_08_29_mlijeko-kalcij__1.xml
1.1 2.1 3.1 3.2 3.3 4.1 5.1 5.2 6.1 6.2 7.1 8.1 8.2 9.1 10.1 10.2 11.1 12.1 13.1 14.1 15.1 16.1 17.1
Emphasising the importance of the supplements, researchers from University Hospital Zurich and Dartmouth Medical School in New Hampshire report that the benefits were no longer observed when supplementation was stopped. The results are published in this month's American Journal of Clinical Nutrition. The use of calcium, usually in combination with vitamin D, has long been recommended to reduce the risk of bone fracture for older people, and the use of these supplements is widely accepted by the general public. Calcium is reported to be the biggest seller in the US supplements industry. Annual sales were about $993m (€836m) in 2004, according to the Nutrition Business Journal. The new study adds to this body of evidence, showing that among the 930 healthy participants in the study, fewer fractures were recorded in the group receiving a daily calcium carbonate supplement, than those receiving placebo. Heike Bischoff-Ferrari and co-workers recruited the healthy individuals with an average age of 61, and randomly assigned them to receive the calcium supplement (1,200 mg of elemental calcium) or placebo, for four years. After the supplementation period had ended the participants were followed for a further 10.8 years. Measures of the primary outcomes of all fractures and minimal trauma fractures, showed that people in the calcium group experienced 46 fractures, 15 of which were from minimal trauma, while 54 fractures were documented in the placebo group, 29 of which were from minimal trauma. A minimal trauma fracture is defined as being caused by a falling from a sitting, standing, or walking position and height. Bischoff-Ferrari and co-workers calculated that calcium supplements reduced the risk of fracture by 72 per cent, but no difference between the groups was observed during the follow-up period when no supplements were consumed. "Calcium supplementation reduced the risk of all fractures and of minimal trauma fractures among healthy individuals," concluded the researchers. "The benefit appeared to dissipate after treatment was stopped." Controversy The results are at odds with a meta-analysis published last year in the same journal and authored by Bischoff-Ferrari. According to the meta-analysis of 12 prospective cohort studies and nine clinical trials, no statistically significant benefit for 300 mg per day calcium intakes from seven prospective cohort studies involving 170 991 women and with 2954 documented hip fractures, and five prospective cohort studies involving 68 606 men and with 214 documented hip fractures. Moreover, clinical trials involving supplementation with 800 to 1600 mg per day of calcium did not show any benefits with respect to non-vertebral fractures and hip fracture, compared to placebo. Commenting independently on the meta-analysis, Jeri Nieves and Robert Lindsay from New York's Columbia University and the Clinical Research Center, Helen Hayes Hospital wrote: "Perhaps these data suggest that calcium supplementation, to be effective, requires the addition of vitamin D supplementation. "Bone is not just calcium, and calcium does not function in isolation." Source: American Journal of Clinical Nutrition June 2008, Volume 87, Number 6, Pages 1945-1951 "Effect of calcium supplementation on fracture risk: a double-blind randomized controlled trial" Authors: Heike A Bischoff-Ferrari, Judy R Rees, Maria V Grau, Elizabeth Barry, Jiang Gui, and John A Baron
1.1 1.2 1.3 1.4 2.1 2.2 2.3 3.1 3.2 3.3 4.1 4.2 4.3 4.4 5.1 6.1 6.2 7.1 7.2 8.1 8.2 9.1 9.2 9.3 10.1 10.2
Ako bih pokušao ukratko sažeti ono što ja smatram dobrim prehrambenim savjetom, kazao bih: „Jedite kao špiljski čovjek“. Zamisao je u tome da pokušate oponašati prehranu na kojoj smo mi kao vrsta evoluirali i na koju smo najbolje prilagođeni. Mislim da postoji mnogo studija koje snažno podupiru to kao put kojim treba ići. Iako cijenim to da će biti onih koji odbacuju ideju o prvobitnoj prehrani na temelju neispravnih paradigmi(po mom mišljenju) da su zasićene masnoće loše, a žitarice dobre. Ovdje još jednu anomaliju predstavljaju mliječni proizvodi. Čini se da su dosta nedavno (prije oko 5000 god.) dodani prehrani, tako da u teorji nisu toliko važni za zdravlje. Mnogi prehrambeni komentatori nam ipak govore da su suštinski važni za naše kosti. Ali, zapisi u kostima starim više od 10.000 godina pokazuju da su kosti bile dobrog zdravlja. Kako smo uspjeli preživjeti više od 2 milijuna godina bez kravljeg mlijeka, a da ga sad odjednom trebamo? Možda zato što ga uopće ne trebamo. Odlučio sam ponovno preispitati neka istraživanja u ovom području nedavno. Pronašao sam dosta nedavnih meta-analiza (gomilanje sličnih studija) koje su tražile vezu između konzumacije mlijeka i rizika od prijeloma kuka [1]. Usput, mislim da je rizik od lomova puno bolji kriterij za procjenu vrijednosti mliječnih proizvoda nego što je gustoća kostiju. Navodno je čitav smisao imanja gustih kostiju spriječavanje prijeloma, tako da ima smisla to ispitati (a ne koštani denzitet). Ni kod žena ni kod muškaraca nije utvrđena nikakva veza između konzumacije mlijeka i rizika od lomova (veća potrošnja mlijeka nije bila povezana sa smanjenim rizikom od prijeloma kuka). U jednoj drugoj meta-analizi, ista grupa istraživača je promatrala odnos između unosa kalcija i prijeloma kuka [2]. Rezultati su bili isti – nema smanjenog rizika od lomova povezanog sa višim unosom kalcija. Ova druga meta-analiza također je promatrala interventne studije u kojima su pojedinci tretirani kalcijem. Takve vrste studija potkopavaju epidemiološke studije o kojima smo raspravljali do sada, u tome da u stvari one mogu dokazati “uzročnost”, tj. da, recimo kalcij uzrokuje manje lomova. Gledajući na četiri pokusa u kojima je specifićno rizik od prijeloma kuka procjenjivan, ispostavilo se da oni koji uzimaju kalcij (u usporedbi sa placebom) imaju za 64 posto povećan rizik od lomova. Možda sve ovo s mlijekom i kalcijem, naposlijetku, baš i nije tako dobra ideja. [1] Bischoff-Ferrari HA, et al. Milk intake and risk of hip fracture in men and women: A meta-analysis of prospective cohort studies. J Bone Miner Res, 2010 Oct 14. [2] Bischoff-Ferrari HA, et al. Calcium intake and hip fracture risk in men and women: a meta-analysis of prospective cohort studies and randomized controlled trials.