Take in your spinach in the form of a juice smoothie or juice — this is the best way to obtain the antioxidant lutein, according to research from Linköping University, Laxa, sweden. High levels of lutein are found in darker green vegetables, and scientists at the university have compared different ways of preparing fresh spinach in order to increase the levels of lutein in done food. The findings are published in the record Food Chemistry.
Many individuals with atherosclerosis (narrowing of the arteries) have low-grade, long-term inflammation that can be measured in the blood vessels. This inflammation is associated to an increased likelihood of myocardial infarction. A research group at Linköping College previously studied the role of the antioxidant lutein. It is a natural fat-soluble pigment present in plants, particularly in dark green vegetables. The experts showed in their final study that lutein can dampen inflammation in defense cells from patients with coronary artery disease. They also demonstrated that lutein can be stored in immune tissues, which means it is possible to develop a reserve of lutein within your body. This directed the researchers to question whether it is possible to influence the degree of lutein in the blood by increasing lutein nutritional intake.
In the new study, the researchers have investigated which method of preparation is the greatest way of obtaining lutein. They selected to study spinach, which contains comparatively high levels of lutein and is eaten by many people. Just as a number of other nutrition, lutein is degraded by heat.
“What is unique about this study is that we now have used preparation methods that are often used when preparing food at home, and we have in comparison several temperatures and heating system times. We have also investigated methods of planning where the spinach is consumed cold, such as in salads and smoothies, inch states Lena Jonasson, teacher in the Department of Medical and Health Sciences and consultant in cardiology.
In order to replicate methods of preparation that are often used in everyday living, the researchers purchased baby spinach at a supermarket. They subjected the spinach to, for example, frying, steaming, or cooking for up to ninety minutes, and measured the lutein content at different times.
Spinach cooked in a soup or stew is not heated to as high a heat or for as long as spinach in a lasagne, for example. This particular is why the experts compared different heating times. It turned out that the heating system time is important when spinach is boiled. The particular longer it is boiled, the less lutein the spinach retains. The cooking food method is also important: when spinach is fried at high temperature a big portion of the lutein is degraded after only two minutes.
Reheating lunch containers in a microwave stove is a very common practice in modern life. The researchers found that reheating the food in a microwave to some extent compensated for losing lutein in cooked food. More lutein is released from the spinach since the plant structure is divided further by the micro wave. “Best is not to heat the spinach at all. And also better is to make a juice smoothie and add fat from dairy food, such as ointment, milk or yoghurt. Any time the spinach is sliced into small pieces, more lutein is released from the leaves, and the fat increases the solubility of the lutein in the fluid, ” claims postdoc Rosanna Chung, main author of the article.