If you are one of those people who are tired of hearing about how good fruits and vegetables are for you, this may finally get your attention: A certain nutrient found in them reduces the risk of cardiovascular disease and early death.

In a large study, researchers noted that high levels of vitamin C in the blood are associated with a decreased risk of cardiovascular disease and early death. And fruits and vegetables are the best way to raise those levels of vitamin C.

Citrus fruits are the most well-known source of the vitamin, but cantaloupe, watermelon, kiwi, strawberries, and blueberries are also good sources. Vegetable sources include broccoli, potatoes, red and green peppers, tomatoes, and leafy greens.

Researchers looked at the fruit and vegetable intake, as well as the DNA, of over 100,000 Danish people who were part of the Copenhagen General Population Study. Those people who had diets high in fruits and vegetables had a 15% lower risk of developing cardiovascular disease and a 20% lower risk of early death compared with those who very rarely ate fruit and vegetables.

Looking deeper, the team found that the protective properties of fruits and vegetables are related to high vitamin C concentrations in the blood from the fruit and vegetables, according to researcher Camilla Kobylecki, a medical doctor and PhD student in the clinical biochemistry department of Herlev and Gentofte Hospital in Denmark.

Vitamin C serves many functions in the body. It is vital for the growth and repair of body tissues. It is necessary to heal wounds and form scar tissue, and it aids in the formation of collagen that is needed to make skin, tendons, and ligaments. It is also an important antioxidant that blocks some of the harm caused by free radicals in the body. These destructive molecules are believed to play a role in the aging progress and are suspect in the cause of cancer and heart disease.

“We know that fruit and vegetables are healthy, but now our research is pinpointing more precisely why this is so. Eating a lot of fruit and vegetables is a natural way of increasing vitamin C blood levels, which in the long term may contribute to reducing the risk of cardiovascular disease and early death,” Boerge Nordestgaard, a clinical professor at the Faculty of Health and Medical Sciences, University of Copenhagen, and a consultant at Herlev and Gentofte Hospital, said in a statement.

Getting the vitamin from food is preferable to supplements he adds. Not only is it more likely to help people develop a healthier lifestyle, food sources contain other nutrients that contribute to health and that may work best in conjunction with vitamin C.

Our bodies cannot make vitamin C, so we must obtain it from the foods we eat. All fruits and vegetables contain vitamin C, but some are better sources than others.

Citrus fruits are the most well-known source of the vitamin, but cantaloupe, watermelon, kiwi, strawberries, and blueberries are also good sources. Vegetable sources include broccoli, potatoes, red and green peppers, tomatoes, and leafy greens. All it takes is five servings (generally a half cup each) to meet your quota for the day.

The researchers plan to look further for other factors which, when combined with vitamin C, may play a role in the development of cardiovascular disease and early death.

The study is published in the American Journal of Clinical Nutrition.