HEALTHWATCH : A Refresher Course on Benefits of Vegetables : Local residents have access to fresh, home-grown produce through farmers’ markets and roadside stands.

Local nutritionists agree with mom--eat your veggies. No big surprise there. But in the highly agricultural Ventura County, it’s saying a lot.

Though much of the local stuff ends up in supermarkets outside the county, residents do have access to fresh, home-grown produce through farmers’ markets and roadside stands.

So we thought we’d give you a refresher course, a little follow-up on mom’s lessons, on the benefits of some vegetables now being, or soon to be, harvested in local fields. We’re talking, specifically, tomatoes, lettuce, celery and corn.

Let’s start with lettuce, second only to the potato in popularity in the United States, said Cindy DeMotte, director of nutrition services at Los Robles Regional Medical Center in Thousand Oaks. The average American, she said, consumes 30 pounds of the stuff annually.

DeMotte said the nutritional value of lettuce depends on the type of lettuce in question.

“Loose-leaf and romaine lettuce have six times the vitamin C and five to 10 times the beta carotene as iceberg lettuce,” she said. “The darker the leaves, the more nutritious it is as far as beta carotene content.”

Beta carotene is an anti-oxidant, which recent studies indicate may have a role in the prevention of heart disease, strokes and some forms of cancer.

Vickie Doss, chief clinical dietitian at Simi Valley Hospital, was less enthusiastic about the leafy greens. “Lettuce is not so great,” she said. “It’s part of a balanced diet, but compared to other vegetables it’s mostly water.”

Doss had far more flattering things to say about the low-calorie celery.

“It’s high-fiber and there are many benefits,” she said. “Different types of fiber lower the blood lipids, including triglycerides and cholesterol, and they help lower the blood sugar.”

High-fiber foods are healthy for the intestines because they remove particles and debris, Doss said. “They also move carcinogens through the body,” she said, “so they are less likely to be in the body so long and less likely to affect us.”

Doss said the average American consumes 12 grams of fiber daily, less than half the 25 to 40 grams recommended.

The tomato, ranked number three in consumption in this country, is another food loaded with fiber. It is also high in vitamins A and C, which help reduce the risk of cancer, and has significant amounts of beta carotene and lycotene. Lycotene is an anti-oxidant that helps absorb beta carotene.

Well, we’ve hit green and red produce, how about some yellow?

Both DeMotte and Doss said corn contains a lot of certain nutrients, but is insufficient as a main part of one’s diet.

Corn is high in carbohydrates and protein, and depending on the particular variety, may have a substantial vitamin C content. DeMotte said sweet corn, which is harvested before reaching maturity, is higher in vitamin C than mature corn. Yellow corn is higher in beta carotene than white corn.

To maintain the vitamin C in corn, “it is important to cook it as soon as possible after it has been picked,” said DeMotte. “The benefit in this area is that you can go to a farmers’ market or roadside stand for corn that has been picked that day.”

When produce is eaten soon after it is plucked from the tree, stalk or vine, it tastes wonderful, and there is the added bonus that it is healthful.

“Fruits and vegetables provide only 1% of the fat in our food supply,” she said, “but 90% of the vitamin C and beta carotene.”