By Stephen T. Sinatra, M.D., F.A.C.C., F.A.C.N., C.N.S., C.B.T.
I’ve long been an aficionado of olive oil. These days my head is spinning because of a steady outpouring of research showing olive oil’s superb health benefits…
According to Greek mythology, the olive tree was the creation of the goddess Athena, who first planted one out among the rocky grounds of the Acropolis and endowed it with powers to illuminate the darkness, soothe wounds, and provide nourishment.
I don’t know about the veracity of the goddess story, but I do know that few foods can match olive oil’s ability to provide nourishment in the form of a very healthy fat your body needs as well as antioxidants that perform numerous protective functions.
Yes, I’m Italian and have been eating olive oil all my life. But the reason for my bullishness has less to do with that, and more to do with the fact that I am a doctor who preaches good nutrition and optimum health. In this brief article you’ll learn why olive oil fits squarely into my agenda for a healthy lifestyle. And in this follow up article, you’ll learn why you have to be ultra-cautious about the kind of olive oil you buy: not all olive oil is created equally, and some products may be adulterated. The health benefits I describe below relate to extra-virgin olive oil – the preferred form − but unscrupulous suppliers are marketing lesser quality olive oil and calling it extra-virgin. And that’s why you need to read labels carefully. But I diverge….
Benefits of Olive Oil for the Heart, Brain, Body
Goddesses aside, humans have long recognized the healing power of olive oil. Hippocrates, known as “the father of medicine,” was said to have prescribed olive oil for many ailments, including ulcers, cholera, muscular pains, sore gums, and wounds, some 2,500 years ago.
For decades, olive oil has been recognized as an important element in the Mediterranean Diet, the traditional pattern of food eaten by Spaniards, Italians, Greeks, Turks and other peoples living around the Mediterranean basin. The diet (which provides the foundation for my PAMM diet) features fruits, vegetables, fish, olives and olive oil, and a bit of red wine, and is low in meat, sweets, and dairy. Study after study has shown that this diet contributes to heart health and longevity.
Now, it seems research is literally pouring out of the region demonstrating a paramount nutritional and health role for olive oil as an “all-star” in the Mediterranean diet. Studies show that the consumption of olive oil, a fat, is one important reason why Mediterranean populations tend to have much less heart disease than Americans or Northern Europeans; it may also indeed contribute to healthier aging and greater longevity.
In a 2010 review of research, a team of Spanish researchers listed these olive oil benefits:
- Improves blood pressure, an expression of better endothelial function (the endothelium is the critical inner layer of blood vessels that produces nitric oxide, a compound necessary for keeping blood vessels relaxed and dilated);
- Inhibits oxidation of LDL cholesterol;
- Increases protective HDL cholesterol;
- Inhibits abnormal blood clotting;
- Contributes to reduction of cancer risk (mainly breast, colorectal, and prostate); and
- Lowers risk of age-related cognitive decline and Alzheimer’s disease.
In 2014, researchers from Europe and the U.S. discovered that natural compounds in olive oil (called polyphenols) can specifically enhance the ability of HDL cholesterol to strip away and remove excess cholesterol that accumulates in arterial plaque. This function, called “cholesterol efflux capacity,” has attracted major research attention in recent years as a primary anti-atherosclerosis activity of HDL. A higher blood level has long been considered as a protective factor in general, and now lower efflux capacity is being associated with heart failure and coronary artery disease. In the olive oil study, the researchers found that the polyphenols in the oil promote efflux capacity as well as HDL stability.
And here’s more exciting research developments on the olive oil front…
Olive Oil and Genes: More Anti-Inflammatory Action
In a 2010 study, researchers identified nearly a hundred genes related to obesity, diabetes, and blood lipids that were affected in a healthy way by the antioxidant compounds contained in olive oil. Some of those genes, involved intimately in inflammatory processes, were repressed by the olive oil, and that’s a good thing. Keep in mind that uncontrolled inflammation is involved in most common diseases, from cardiovascular disease and diabetes to cancer and auto-immune conditions. So increasing the anti-inflammatory quality of your diet with something like olive oil may be another simple and natural way to protect yourself.
What’s So Special In Olive Oil?
Like any nutritional oil, olive oil has its own particular chemical makeup and this is what makes it indeed so special. First of all, olive oil is rich in a monounsaturated fatty acid called oleic acid that has been linked repeatedly in experiments to beneficial effects against cancer cells as well as to reducing high blood pressure. Next, olive oil contains many compounds with marked physiological benefits. Heading the list are oleuropein and hydroxytyrosol, two highly absorbable and extensively studied antioxidants found to have highly protective actions against several diseases, notably cardiovascular and metabolic disorders. These compounds are multi-taskers. Among other things, they promote arterial dilation and integrity, inhibit cholesterol oxidation and platelet aggregation, and appear to have anti-diabetic properties.
A “Super” Mediterranean Diet?
In 2013, the publication of a large Spanish investigation called the Predimed Study revealed that a Mediterranean diet enhanced with extra-virgin olive oil offered superior protection after nearly five years against heart disease, stroke, and diabetes. Enhancement meant the addition of four tablespoons a day − about 50 grams of fat! Yet there was no weight gain associated with that extra amount of fat intake. The study involved nearly 7,500 men and women at high cardiovascular risk who were free of cardiovascular disease at the time of enrollment, but had either type 2 diabetes or several common risk factors.
Now get this. The participants in the study assigned to eat the olive oil-enhanced diet had a rate of cardiovascular events 28 to 30 percent less than a comparison group eating a standard Western-type low-fat diet! In a further breakdown of non-diabetic but high-risk participants, the olive oil group had a 40 percent less risk of developing diabetes compared to the low-fat dieters. The researchers noted that the Mediterranean diet overall has dietary components beneficial for alleviating inflammation, oxidative stress, and insulin resistance and secretion, all pathogenic factors in the diabetes process. Extra-virgin olive oil, with its potent anti-inflammatory and antioxidant effects, is clearly a major element in this protective activity against diabetes. Another Spanish study found that olive oil reduces triglycerides, a blood fat associated with the metabolic syndrome, diabetes, and cardiovascular disease.
Combined, these results are spectacular. The Predamid study is the first large randomized trial to show that a Mediterranean-type diet can actually – in real life − reduce cardiovascular events and thus serve the purpose of primary cardiovascular prevention. Primary prevention means stopping initial heart attacks or strokes.
Mediterranean Diet Better Than Low-fat Diets
The results from the study were so striking to me that I contacted the lead Spanish researcher, Miguel Martinez-Gonzalez, M.D., Ph.D., an expert in preventive medicine and public health at the University of Navarra in Pamplona, and invited him to serve on an American College of Nutrition panel I moderated in 2013 on the subject of cholesterol, fats, and statins.
Dr. Martinez-Gonzalez strongly believes that the so-called low-fat diet, promoted for decades in the U.S., fails to prevent cardiovascular disease. By comparison, he says, the Mediterranean diet has a great track record for not only effectiveness, but for sustainability, nutritional quality, and taste. Moreover, he says, the protective effects of the traditional Mediterranean diet appear to be even greater when adding extra-virgin olive oil, as his studies indicate.
In an earlier 2013 study, he conducted a review of the medical literature that evaluated the association between overall dietary patterns and the risk of metabolic syndrome, a widespread forerunner to diabetes and cardiovascular disease. The findings showed a clearly higher risk from Westernized diets full of meat and meat products, snacks, baked desserts and sugar-sweetened beverages. The Mediterranean diet, by comparison, had a much lower risk, with its emphasis on olive oil, nuts, and fish with a high mono- and polyunsaturated fatty acid content, dietary fiber, and bioactive natural antioxidant and anti-inflammatory compounds.
- Lopez-Miranda J, et al. Olive oil and health: Summary of the II international conference on olive oil and health consensus report. Nutrition, Metabolism and Cardiovascular Diseases, 2010; 20(4):284-94. Abstract online at http://www.nmcd-journal.com/article/S0939-4753(09)00316-0/abstract
- Camargo A, et al. Gene expression changes in mononuclear cells in patients with metabolic syndrome after acute intake of phenol-rich virgin olive oil. BMC Genomics, 2010; 11:253. Full article online at http://www.biomedcentral.com/1471-2164/11/253
- Khera AV, et al. Cholesterol efflux capacity, high-density lipoprotein function, and atherosclerosis. N Engl J Med, 2011; 364(2):127-135. Full article online at http://www.nejm.org/doi/full/10.1056/NEJMoa1001689#t=articleTop
- Patel PJ, et al. Antioxidative and cholesterol efflux capacities of high-density lipoprotein are reduced in ischaemic cardiomyopathy. Eur J Heart Fail, 2013: 15(11):1215-9. Abstract online at http://www.ncbi.nlm.nih.gov/pubmed/23709232
- Hernáez A, et al. Olive pol polyphenols enhance high-density lipoprotein function in humans: A randomized control trial. Arterioscler Thromb Vasc Biol, 2014. Abstract online at http://atvb.ahajournals.org/content/early/2014/07/24/ATVBAHA.114.303374.abstract
- Carrillo C, et al. Antitumor effect of oleic acid; mechanisms of action. A review. Nutrición Hospitalaria, 2012;27(5):1860-1865. Full article online at http://www.nutricionhospitalaria.com/pdf/6010.pdf
- Houston M. The role of nutrition and nutraceutical supplements in the treatment of hypertension. World J Cardiol, 2014: 6(2):38-66. Full article online at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3935060/
- Estruch R, et al. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet. N Engl J Med, 2013; 368:1279-1290. Full article online at http://www.nejm.org/doi/full/10.1056/NEJMoa1200303#t=article;
- (Retracted and republished June 2018 at https://pubmed.ncbi.nlm.nih.gov/29897866/).
- Salas-Salvadó J. Prevention of Diabetes With Mediterranean Diets: A Subgroup Analysis of a Randomized Trial. Ann Intern Med, 2014;160(1):1-10. Abstract online at http://annals.org/article.aspx?articleid=1811025
- Perez-Martinez P, et al. Consumption of diets with different type of fat influences triacylglycerols-rich lipoproteins particle number and size during the postprandial state. Nutr Metab Cardiovasc Dis, 2011;21(1):39-45. Abstract online at http://www.ncbi.nlm.nih.gov/pubmed/19819118
- Martínez-González MA, Martin-Calvo N. The major European dietary patterns and metabolic syndrome. Reviews Endocrine and Metabolic Disorders, 2013;14(3):265-71. Abstract online at http://link.springer.com/article/10.1007/s11154-013-9264-6
© Stephen Sinatra, MD. All rights reserved.