From the vine to the heart
March 25, 2010 9:00 AM
Have you heard that olive oil is good for you? It seems we are hearing this message frequently, and don’t receive much explanation of what it is about olive oil that brings the variety of health benefits it claims. What makes olive oil so special?
Nutrition recommendations that emphasize the use of olive oil are inspired by the traditional dietary patterns of financially disadvantaged regions of southern Italy, Crete, and Coastal Greece in the 1900’s, in which olive oil is used liberally in cooking.
It was coined the “Mediterranean diet,” presented by Dr. Walter Willett of Harvard University School of Public Health.
Despite its name, the dietary patterns prescribed in the Mediterranean diet are not typical of most Mediterranean cuisine (in which butter and animal fats are used for cooking, while olive oil is reserved for dressing salads and finishing cooked vegetables).
The Mediterranean diet emphasizes eating plant foods, fresh fruits, and raw or lightly cooked vegetables, with a high intake of legumes, whole grains, unrefined cereals, seafood and shellfish. In addition this diet recommends a low intake of red meat and poultry, moderate intake of low-fat dairy (mostly cheese and yogurt), low intake of alcohol (red wine), and abundant and liberal addition of olive oil to food during cooking and serving.
The “Mediterranean diet” came from a study known as the Seven Countries study, which compared death rates from heart disease to the total fat intake of seven countries, and found that the two countries with the highest total fat intake (Finland and Greece) were on opposite side of the heart disease spectrum.
Finland had the highest death rate from cardiovascular disease while Greece had the lowest. In both countries the intake of fat was very high, with over 40 per cent of total caloric intake coming from fat, but the findings of the study made it clear that a high-fat diet was not the problem, and attention was refocused on the type of fat being consumed.
It was later found that death rates from cardiovascular disease are strongly associated with the amount of saturated fat consumed in the diet, but only weakly associated with the total amount of fat in the diet.
Traditionally, intake of fat has been a main dietary concern in preventing the development of heart disease. In many parts of the world, a high fat intake is associated with the development of chronic disease, such as atherosclerosis and type 2 diabetes.
The Seven Countries study, however, indicated that in some areas of the world, such as some areas of the Mediterranean region, a high fat intake is actually associated with lower rates of these conditions, and introduced the possibility of “good” or “healthy” fats and oils.
One of the main explanations of the health benefits of the Mediterranean diet is the health effects of olive oil.
The traditional diets of Greece and other countries in the Mediterranean region offer an excellent example of eating patterns that use “good” fats abundantly in their cuisine, as indicated by their liberal use of olive oil, and low rate of heart disease.
Olive oil is one of the only vegetable oils that can be consumed as it naturally is, freshly pressed from the fruit.
It is prized for its ability to confer excellent flavours and mouthfeel to all foods in which is it used, and more recently, praised for its long list of potential health benefits.
The beneficial health effects of olive oil are mainly attributed to its high content of monounsaturated fatty acids (specifically oleic acid), and its high concentration of phytochemicals with antioxidant properties.
In 2004 the Food and Drug Administration approved a claim for labels on bottles of olive oil that states that olive oil contains a higher amount of monounsaturated fatty acids than any other vegetable oil, and two tablespoons of olive oil consumed each day is an adequate amount to bring about positive health benefits and for reducing the risk of coronary heart disease.
But how is olive oil really healthy for us?
Olive oil can help protect against heart disease by lowering LDL cholesterol in the blood (the “bad” cholesterol) while not affecting the levels of HDL cholesterol (the “good” cholesterol). Antioxidant phytochemicals (such as polyphenols) in olive oil reduce the susceptibility of LDL cholesterol to oxidation. It is when LDL cholesterol becomes oxidized that it sticks to the walls of blood vessels and contributes to atherosclerosis, or “hardening of the arteries.”
Therefore by helping to prevent LDL cholesterol from oxidizing, olive oil helps protect against atherosclerosis), lowering blood clotting factors (preventing the formation of blood clots which can become trapped within narrowed blood vessels and cause a heart attack); and lowering blood pressure.
When we are presented with such a list of potential health benefits as the one above, we may feel compelled to consume these foods and may assume that, “if some is good, more is better.”
This is not the case for olive oil. It is important to remember that olive oil, while rich in nutrients, is not a magic potion, and drizzling it on foods does not necessarily make them healthier foods.
Like any fat, olive oil delivers 9 Calories per gram, and can contribute to weight gain if energy intake is not balanced with energy expenditure.
The role of olive oil in our diets is to replace saturated and trans fats and other less-healthy oils.
Replacing both saturated and trans fats with mono- and polyunsaturated fats is considered among the most effective dietary strategies in preventing cardiovascular disease.
A 2008 article in Clinical Cardiology states that relying on olive oil as your principal source of fat may cut your risk of developing cardiovascular disease in half.
With the emphasis on replacing other fats rather than adding fats to our diet, two ways we may consider incorporating olive oil into our diets include serving olive oil rather than butter at the table for breads, rolls, potatoes, and other vegetables; and using olive oil in cakes and baked products rather than butter or margarine.
“Good oil, like good wine, is a gift from the gods. The grape and the olive are among the priceless benefactions of the soil, and were destined, each in its way, to promote the welfare of man.”
George Ellwanger
