Linköping [Sweden], May 1 (ANI): When it comes to releasing the antioxidant lutein from spinach in smoothies, different marketed products have extremely variable results. Only four of the 14 common dairy and plant-based products studied by researchers at Linköping University in Sweden increased lutein release. Certain beverages had a negative effect on the lutein content of spinach smoothies compared to water.
Most individuals are aware that spinach is good for one’s health. Lutein, for example, is a chemical found in spinach and kale. Several experimental studies have shown that lutein can suppress inflammation-related processes, and there is now ample evidence that chronic low-grade inflammation is an important risk factor for cardiovascular disease.
“Lutein is a bioactive substance. We investigated lutein in the same way as we would investigate a pharmaceutical medicine. “We looked at lutein release from fresh spinach in this study, explains Rosanna Chung, assistant professor at Linköping University’s Department of Health, Medicine, and Caring Sciences, which led the study published in Nutrients.
Since our bodies cannot produce lutein, the researchers behind the study were interested in finding out how to optimize lutein intake from foods. The research group has previously shown that preparation methods where the spinach is heated breaks down some of the lutein, while mixing it into a smoothie makes more lutein available for absorption.
The type of liquid used in the smoothie can also affect the lutein content. Because lutein dissolves in fat but not in water, it needs gastric juice and/or other food components to be released from the plant material and absorbed by our intestines. The researchers suspected that certain components of our food, such as fat, carbohydrates, proteins and fiber, may affect the amount of lutein available for absorption. The effect of products such as yogurt can also differ due to fermentation. Products that are widely available on the market are rarely examined in scientific studies.
The researchers investigated the effects of different products available from grocery stores on the amount of lutein released in smoothies. Both dairy products and herbal liquids were tested.
The researchers mixed spinach with different products. They then used a method that simulated human digestion in the gastrointestinal tract, by adding digestive enzymes. Finally, the amount of lutein available for the body to absorb in smoothies made with different products was compared to that in smoothies made with just water.
“We could see that only 4 of the 14 products examined increased the release of lutein from spinach compared to water. High-fat cow’s milk as well as coconut milk improved lutein release. In contrast, yogurt, which is considered comparable to cow’s milk and is often used in cafes and the like, did not show much good results,” says Rosanna Chung.
The fact that yogurt is not so good at releasing lutein may have to do with the fermentation process. It also found that plant-based drinks, often made from nuts, legumes or oats, showed significantly different results.
“Plant-based liquids have become increasingly common in smoothies. We saw that soy milk was actually less effective than water in releasing lutein in spinach smoothies. In other words, soy milk had a negative effect on lutein release in our study,” we say. Jan Neelissen, PhD student and one of the researchers behind the study.
The other herbal products in the study did not affect lutein release compared to water. As a general note, smoothies should be consumed as soon as possible, as lutein breaks down quickly.
It is important to note that while the results of this study indicate how much lutein is available for the body to absorb, no conclusions can be drawn about how much lutein is actually absorbed. Therefore, the researchers will conduct a human study in which they will measure the amount of lutein absorbed from smoothies made with different products. (ANI)
Source: sn.dk