Nedavni sistematični pregled in metaanaliza ugotavljata, da klinična preskušanja ne potrjujejo pozitivnega stališča javnosti o kokosovem olju. Študija, objavljena v reviji Circulation, je pokazala, da kokosovo olje v primerjavi z drugimi rastlinskimi olji zvišuje raven holesterola lipoproteinov nizke gostote (LDL-C) - "slabega" holesterola, ki povečuje tveganje za srčno-žilne bolezni -, medtem ko ne izboljšuje telesne teže, glukoze v krvi ali vnetnih markerjev.
Zakaj je to pomembno
Nasičene maščobe zvišujejo raven LDL-C. Kljub svoji visoki vsebnosti nasičenih maščob je kokosovo olje v preteklem desetletju pridobilo neke vrste kultni status med domačimi kuharji. V anketi iz leta 2016, ki jo je izvedel New York Times, je 72 % sodelujočih trdilo, da je kokosovo olje zdravo živilo. Z njimi se je strinjalo le 37 % strokovnjakov za prehrano, ki so sodelovali v anketi.
"To predstavlja izreden uspeh oglaševanja kokosovega olja in sorodnih industrij, ki kokosovo olje označujejo za naraven, zdrav izdelek, čeprav je znano, da zvišuje holesterol LDL, ki je dokazan vzrok ateroskleroze in srčno-žilnih dogodkov," je v uvodniku nove analize zapisal Frank M. Sacks, doktor medicine, s Harvard T.H. Chan School of Public Health.
Če raba kokosovega olja namesto ostalih rastlinskih olj zvišuje raven ‘slabega’ holesterola, bi lahko pogosta zamenjava slednjih olj za kokosovo lahko postavila javno kardiovaskularno zdravje pred tveganje.
Kaj smo že vedeli
Po navedbah avtorjev pregleda so klinične raziskave, v katerih so primerjali učinke kokosovega olja in netropskih rastlinskih olj na holesterol v krvi, pokazale mešane rezultate. V nekaterih študijah je kokosovo olje znižalo raven LDL-C, medtem ko so druge študije pokazale nasprotno. Nekatere raziskave tudi kažejo, da bi lahko rastlinska maščoba blažila vnetja, nadzorovala glukozo v krvi in celo pomagala ljudem pri hujšanju.
Pred dvema letoma so evropski raziskovalci objavili pregled 54 raziskav, v katerih so primerjali učinke različnih prehranskih maščob na krvne lipide. Ugotovili so, da kokosovo olje ne zvišuje LDL-C nič bolj kot druga rastlinska olja. Vendar je analiza vključevala le 6 raziskav s kokosovim oljem in ni bila namenjena ocenjevanju njegovih drugih domnevnih koristi.
Tropska prehrana je drugačna
Avtorji prav tako razpravljajo o ostalih pogostih argumentih: določeno domorodno prebivalstvo ima nizko stopnjo obolelosti za srčnimi boleznimi ne glede na obilno uživanje kokosa. Raziskovalci so izpostavili, da imajo te skupine drugačne prehrambene vzorce glede na povprečno zahodno prehrano, saj vsebuje več rib, ki pozitivno vplivajo na zdravje srca, in manj predelane hrane. Poleg tega je za to tradicionalno prehrano značilno surovo kokosovo meso ali kokosova smetana, kar vsebuje manj nasičenih maščob kot kokosovo olje.
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Bistvo
Avtorji trdijo: "Kljub vse večji priljubljenosti kokosovega olja zaradi njegovih domnevnih koristi za zdravje so naši rezultati zaskrbljujoči glede velikega uživanja kokosovega olja. Kokosovega olja ne smemo obravnavati kot zdravega olja za zmanjševanje tveganja za srčno-žilne bolezni, zato je upravičeno omejiti uživanje kokosovega olja zaradi visoke vsebnosti nasičenih maščob."
Iz Grenlandije: "V svetu lipidov je bilo to vprašanje že zdavnaj rešeno. Pomirjujoče je videti, da tudi ko se je nabralo več podatkov, splošno sporočilo ostaja nespremenjeno. Kokosovo olje v primerjavi z drugimi jedilnimi olji nima dokazanih koristi za zdravje in se zdi škodljivo za pomembne krvne lipide. Zato bi bilo preudarno, če bi se mu v primerjavi z drugimi jedilnimi olji, ki nimajo teh učinkov, izogibali."
Abbasi J. Coconut Oil’s Health Halo a Mirage, Clinical Trials Suggest. JAMA. 2020;323(16):1540–1541. doi:10.1001/jama.2020.5186
Diet myth busted- Coconut Oil does not improve health
Clinical trials don’t support the public’s positive perception of coconut oil, a recent systematic review and meta-analysis suggests. The study, published in Circulation, found that compared with other vegetable oils, coconut oil increases low-density lipoprotein cholesterol (LDL-C)—the “bad” kind that ups cardiovascular disease risk—while offering no improvements to weight, blood glucose, or inflammation markers.
Why This Matters
Saturated fat raises LDL-C levels. Despite its high saturated fat content, coconut oil has attained a sort of cult status among home chefs over the past decade. In a 2016 New York Times–commissioned survey, 72% of the public said coconut oil is a healthful food. Tellingly, only 37% of nutritionists in the survey agreed.
“This represents a remarkable success in marketing by the coconut oil and related industries calling coconut oil a natural, healthful product, despite its known action to increase LDL cholesterol, an established cause of atherosclerosis and cardiovascular events,” Frank M. Sacks, MD, of the Harvard T.H. Chan School of Public Health, wrote in an editorial on the new analysis.
If using coconut oil instead of other vegetable oils increases “bad” cholesterol, frequently swapping it in for them could put the public’s heart health at risk.
What We Already Knew
According to the review’s authors, clinical trials comparing the blood cholesterol effects of coconut oil and nontropical vegetable oils have had mixed results. Coconut oil appeared to lower LDL-C levels in some of the studies, while other trials showed the opposite. Some research also suggests that the plant fat might quell inflammation, control blood glucose, and even help people to lose weight.
Two years ago, European researchers published a review of 54 trials comparing different dietary fats’ effects on blood lipids. They concluded that coconut oil did not raise LDL-C more than other vegetable oils. The analysis included only 6 coconut oil trials, though, and wasn’t designed to assess its other purported benefits.
Tropical Diets Are Different
The authors also discussed another common argument: certain indigenous populations have low heart disease rates despite plentiful coconut consumption. Researchers have pointed out that these groups have different eating patterns than the average Western diet, with more heart-healthy fish and less processed food. Plus, these traditional diets feature raw coconut flesh or pressed coconut cream, which are lower in saturated fat than coconut oil.
The Bottom Line
From the authors: “Despite the rising popularity of coconut oil because of its purported health benefits, our results raise concerns about high coconut oil consumption. Coconut oil should not be viewed as healthy oil for cardiovascular disease risk reduction and limiting coconut oil consumption because of its high saturated fat content is warranted.”
From Greenland: “In the lipid world, this issue has been thought to be settled a long time ago. It is reassuring to see that even as more data accumulated, the overall message really remains unchanged. Coconut oil offers no proven health benefits compared to other cooking oils and seems detrimental on important blood lipids. As such, the prudent approach would be to avoid it in comparison to other cooking oils that do not have these effects.”
Reference:
Abbasi J. Coconut Oil’s Health Halo a Mirage, Clinical Trials Suggest. JAMA. 2020;323(16):1540–1541. doi:10.1001/jama.2020.5186
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