Carrots are not only good for your eyes. People who eat plenty of vegetables have a reduced risk of dying from cardiovascular disease.
The reduced mortality is correlated with the consumption of the orange pigment beta-carotene, an antioxidant that is present primarily in carrots and leafy vegetables. However, previous studies have shown that vitamin supplements that contain only beta-carotene do not lead to a reduced risk. This was the conclusion of the doctoral thesis that Brian Buijsse defended on 11 June at Wageningen University.
In his PhD research, Buijsse conducted three different studies using a group of European elderly subjects and a group of older men in Zutphen. The same group of men in Zutphen was also compared with a group of men on Crete.
In the data from the large-scale, 10-year European study, Buijsse discovered that high concentrations of carotene in the blood were correlated with a reduced risk of mortality from cardiovascular disease. This study used the data from 1168 men and women. After 10 years, it turned out that 148 of them had died as a result of cardiovascular disease
In the Zutphen population of 559 men, it turned out that 197 had died of cardiovascular disease after 15 years. In this study, men who consumed large amounts of beta-carotene in their food had a lower risk of mortality due to cardiovascular disease. For the Zutphen subjects, carrots were the most important source of beta-carotene. Eating carrots was also correlated with a lower mortality risk due to cardiovascular disease. A study on Crete also showed that low mortality from cardiovascular disease was correlated with higher levels of beta-carotene in the blood.
The Wageningen study showed that the concentrations of beta-carotene in the blood of men on Crete were clearly higher than the men in Zutphen. Moreover, there is virtually no heart disease on the island, while in Zutphen it is one of the most important causes of death. The research results support the assumption that a diet rich in beta-carotene can prevent cardiovascular disease.
Carotene is especially known as the substance that gives carrots their orange colour. Carotene is also abundantly present in many leafy vegetables, but the orange colour is not expressed. The more carotene-rich vegetables that are eaten, the lower the risk of cardiovascular disease.
Nevertheless, it is questionable whether beta-carotene by itself is responsible for the lower risk of mortality. Previous large-scale studies, where people took a daily pill containing large amounts of beta-carotene, indicated that there was no reduced risk of cardiovascular disease. This paradox, known as the anti-oxidant paradox, has not yet been clarified. It is possible that a high intake of beta-carotene from food reflects a diet that is rich in plant-based nutrients with many antioxidants and bioactive components, which together with beta-carotene, lead to a reduced risk of mortality.