The new European research has shown that eating spinach, unwanted in the form of a drink or juice, is the best way to get lutein antioxidant, especially when healthy fats are added to absorb aid.
A new study by researchers at Linzing University, Sweden, reviewed the various ways to prepare spinach to increase the amount of lutein available after cooking.
Lutein is a natural fat-soluble pigment, found in plants. Dark green vegetables contain a particularly high level. However, like many other nutrients, the level of lutein is reduced by cooking.
The researchers chose to study spinach because they contain relatively high levels of lutein and is one of the popular dark green vegetables. To replicate how it is prepared at home, the team bought baby spinach in a supermarket and was fried, steamed or cooked for up to 90 minutes, measuring the content of lutein at different times.
The findings, published in Food Chemistry, have shown that heating and cooking methods are important for retention of lutein.
The longer spinach is cooked, less lutein keeps it, and when spinach is fried at high temperature, a large amount of lutein is lost after only two minutes.
"What is unique to this study is that we used methods for preparation that are often used for cooking food at home, and we compared a few temperatures and heating. We were researching methods for preparation in which spinach is iced cold, such as salads and drinks "says study author Lena Johnson.
The team also reviewed the effect of heating spinach in a microwave oven as part of a packaged lunch, a common practice. They found that microwave heating seems to be partially offset by the previous cooking method, with more lutein released from spinach and made available to the body, as the plant structure decays further with a microwave oven.
However, the researchers concluded that it is best to eat spinach uber.
"It's best not to heat the spinach at all, and it's even better to make a drink and add fat from dairy products such as cream, milk or yogurt. When spinach is chopped into small pieces, more lutein is released from the leaves, and fat increases the solubility of lutein in the fluid, "said Rosana Chung, chief author of the study.
In a previous study, the team found that lutein could reduce inflammation in immune cells from patients with coronary artery disease. The low level of chronic inflammation is associated with an increased risk of heart attack.
They also showed that lutein can be stored in immune cells, which means it is possible to build up lutein reserves in your body.