Olive oil drizzled over cooked carrots, roasted eggplant, or grilled peppers conjures up images of Mediterranean cooking. Yet it’s as all-American as the founding fathers. Here’s what Thomas Jefferson had to say about the olive tree and olive oil in a letter to William Drayton, a South Carolina lawyer, congressman, and planter: “The olive is a tree the least known in America, and yet the most worthy of being known. Of all the gifts of heaven to man, it is next to the most precious, if it be not the most precious.
Perhaps it may claim a preference even to bread, because there is such an inﬁnitude of vegetables, which it renders a proper and comfortable nourishment.”
Our third president knew something that cooks and chefs are beginning to rediscover—that olive oil can perk up vegetables. Jefferson, a curious naturalist and ardent horticulturalist, repeatedly tried to cultivate olive trees in South Carolina and Georgia, but with little success. He ultimately had to rely on imported olive oil for his table.
Jefferson’s enthusiasm for the marriage between olive oil and vegetables was driven by taste. Follow his example and you, too, may discover intense new ﬂavors and a new appreciation for vegetables. And your heart may silently thank you.
High blood pressure often sets the stage for stroke, heart attack, and other kinds of circulatory problems. Formally known as hypertension, high blood pressure aﬀects more than ﬁfty million Americans and a staggering one billion people worldwide. It’s increasingly common with age, aﬀecting less than 10 percent of U.S. adults between the ages of twenty and thirty-four and more than 75 percent of those over age seventy-ﬁve. Sometimes called the silent killer, high blood pressure causes no real symptoms. That’s one reason at least one-third of people with high blood pressure don’t know they have it. Of those who are well aware they have high blood pressure (also known as hypertension), many have a hard time keeping it under control.
learn more: FAMILY NUTRITION
As a pill-oriented culture, we tend to rely on medications to control blood pressure. But two of the best ways are losing weight, if you are overweight, and increasing your daily physical activity. Eating more fruits and vegetables can also lower blood pressure without the side eﬀects and cost of medications. Even better, eating plenty of fruits and vegetables may help prevent high blood pressure in the ﬁrst place.
An innovative study called DASH, short for Dietary Approaches to Stop Hypertension, clearly showed that eating more fruits and vegetables can substantially lower blood pressure, especially as part of a diet low in animal fat. DASH wasn’t your garden-variety nutrition study but a full-blown clinical trial, much like those done to test a new drug. All 457 of the DASH participants, some with high blood pressure, some without, were randomly assigned to one of three diets: a control diet that mirrored the typical American diet (about three servings of fruits and vegetables a day, nearly 40 percent of calories from fat, and one dairy product daily); a fruit-and-vegetable diet similar to the control diet but with eight servings of fruits and vegetables a day; and a combination diet that included nine servings of fruits and vegetables a day plus three servings of low-fat dairy products. The beauty of the DASH method was that all of the volunteers’ meals during the study were specially prepared in hospital kitchens, a strategy that minimized variation from person to person.
After eight weeks, the combination diet (fruits and vegetables plus three servings of dairy) substantially lowered blood pressure among the volunteers who had high blood pressure. So did the fruit-and-vegetable diet, though not quite as much. For both experimental diets, the reductions were about as large as what drug therapy can do for mild high blood pressure. Both the combination diet and the fruit/vegetable diet also lowered blood pressure in people without hypertension, suggesting that this may be an easy, side-eﬀect-free way to prevent this condition. A second DASH trial showed that a low-salt version of the DASH diet can subtract a few extra points from blood pressure .
Many components of the DASH diet contribute to its ability to lower blood pressure. A follow-up study showed that the single most important factor is the extra potassium provided by the fruits and vegetables.
Cholesterol levels also seem to respond to a diet with plenty of fruits and vegetables. This may be one of the ways that fruits and vegetables reduce the risk of heart disease and stroke. No one knows for sure how fruits and vegetables lower cholesterol. Since eating more plant foods often means eating less meat and dairy products, lower cholesterol levels may come from eating less saturated fat. They could also be due to the ability of soluble ﬁber to block the absorption of cholesterol from food. In spite of what food companies are claiming, though, soluble ﬁber’s eﬀect on cholesterol is relatively small.