As maravilhas do óleo de coco. I- Perfil lipidico

Marina gostaria de saber se há embasamento científico para o grande sucesso atual do óleo de coco: “A moda da galera fitness/wellness é o óleo de coco. A fama é que emagrece e parece que tem dois estudos (Universidade de Columbia) que mostram que reduz a circunferência da cintura e o colesterol em obesos.” 

Mais um alimento milagroso?

The following are additional benefits from coconut oil:

1. Provides a nutritional source of quick energy.
2. Boosts energy and endurance, enhancing physical and athletic performance.
3. Improves digestion and absorption of other nutrients including vitamins, minerals, and amino acids.
4. Improves insulin secretion and utilization of blood glucose.
5. Helps protect against osteoporosis.
6. Reduces inflammation.
7. Supports tissue healing and repair
8. Supports the natural chemical balance of the skin.
9. Softens skin and helps relieve dryness and flaking.
10. Prevents wrinkles, sagging skin, and age spots.
11. Promotes healthy looking hair and complexion.

segundo um artigo do Examiner.

Será verdade tudo isto? Para começar a posição oficial das associações, segundo indicado na Wikipedia:

“The United States Food and Drug Administration, World Health Organization,[3] International College of Nutrition,[4] the United States Department of Health and Human Services,[5] American Dietetic Association,[6] American Heart Association,[7] British National Health Service,[8] and Dietitians of Canada[6] recommend against the consumption of significant amounts of coconut oil due to its high levels of saturated fat.”

Contudo, o óleo de coco contem uma grande proporção de ácido laurico, uma gordura saturada mas que eleva o HDL (lipoproteina de alta densidade)-colesterol (Mensink RP, Zock PL, Kester AD, Katan MB (May 2003). "Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials". Am. J. Clin. Nutr. 77 (5): 1146–55.) e o HDL-colesterol está relacionado com a redução do risco de infarto do miocárdio (embora não para todos - aguarde post relacionado a sair em breve). Poder-se-ia imaginar que o óleo de coco cria um perfil lipídico mais favorável (doi:10.1016/j.tifs.2009.06.003). Além disto, o óleo de coco é composto de triglicéridas de cadeia média, que não tem os mesmos riscos de outras gorduras saturadas (Kaunitz, H. (1986). "Medium chain triglycerides (MCT) in aging and arteriosclerosis". Journal of Environmental Pathology, Toxicology and Oncology 6 (3–4): 115–121). 

Ou seja, a posição oficial parece ser muito conservadora. Cadê o embasamento experimental para ser contra?

Há um estudo que afirma:

“The results demonstrated the potential beneficiary effect of virgin coconut oil in lowering lipid levels in serum and tissues and LDL oxidation by physiological oxidants.”

mas é realizado em ratos! (doi: 10.1016/j.clinbiochem.2004.04.010).

Um estudo antigo, no homem, não mostra vantagens do óleo de coco no perfil lipidico (Reiser, R., Probstfield, J. L., Silvers, A., Scott, L. W., Shorney, M. L., Wood, R. D., O'Brien, B. C., et al. (1985). Plasma lipid and lipoprotein response of humans to beef fat, coconut oil and safflower oil The American journal of clinical nutrition, 42(2), 190–197.).

O artigo de Connor (Connor, W. E. (2000). Importance of n-3 fatty acids in health and disease The American journal of clinical nutrition, 71(1 Suppl), 171S–5S.) é citado num post pró-coco (Can coconut oil help you lose weight?) como “According to studies by William E. Connor of the Division of Endocrinology at Oregon Health Sciences University, fatty acids found in coconut oil can "favorably affect atherosclerosis, coronary heart disease, inflammatory disease, and perhaps even behavioral disorders."” mas o artigo é voltado para apresentar as vantagens do óleo de peixe e até comenta negativamente sobre o óleo de coco, embora em outro contexto: 

“In rhesus monkeys, n-3 fatty acid–deficient diets fed to pregnant animals and then continued after birth induce profound functional changes such as reduced vision, abnormal electroretinograms, impaired visual evoked potential, polydipsia, more stereotypic behavior (eg, pacing), and, perhaps, disturbances of cognition (31, 32). Some of these find- ings have been replicated in infants fed formulas deficient in n-3 fatty acids (eg, corn- and coconut-oil formulas).”

e 

“A typical corn- and coconut-oil formula has a plethora of linoleic acid and little of ALA. Such formulas were still being marketed up to several years ago in Mexico (32). In the United States, such formulas were changed in the 1980s and soybean oil, which has a good ratio of linoleic acid to ALA (7:1), was introduced. The use of soybean oil has greatly improved the n-3 fatty acid status of currently marketed formulas.”

Ou seja, não há evidência para recomendar o uso do óleo de coco como benéfico para a área cardiovascular.

Chega de colesterol e a perda de peso?  

Como este post ficou longo, a parte de perda de peso fica para um outro post.

Imagem acima do post obtida do Examiner.