Coconut milk is the plant-based milk that works best at releasing the antioxidant lutein from green spinach, according to a new study recently published in the journal Scientific Reports. nutrients.
Lutein is a powerful antioxidant that is abundant in dark leafy greens such as spinach and kale and is known to benefit eye health. Several experimental studies have also shown that lutein can suppress processes associated with inflammation, an important risk factor for cardiovascular disease. And since smoothies are commonly used by consumers as a way to increase fruit and/or vegetable consumption, researchers at Linköping University in Sweden wanted to determine which milk is best for absorption.
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The research team previously showed that preparation methods in which spinach is heated break down some of the lutein, making more lutein available for absorption when blended into a smoothie.
“Lutein is a bioactive compound,” study lead author and assistant professor Rosanna Chung of Linköping University’s Department of Health, Medicine and Caring Sciences said in a statement. “We studied lutein in a similar way to pharmaceutical drug studies. In this study, we looked at the release of lutein from fresh spinach.”
For the study, researchers tested 14 common dairy and plant-based milk products and found that only four of them increased the release of lutein. Compared to water, some mixers had a negative effect on the lutein content of spinach smoothies.
Researchers suspected that certain components of our diet, such as fat, carbohydrates, protein and fiber, could affect the amount of lutein available for absorption. The effects of products such as yogurt may also differ due to fermentation. However, products widely available in the market are rarely tested in scientific studies.
For the study, researchers tested both dairy and plant-based liquids by mixing spinach with different products. They then used a method to mimic human digestion in the gastrointestinal tract by adding digestive enzymes. Finally, the amount of lutein available to the body in a smoothie made with different products was compared to a smoothie made with just water.
Which milk is best for smoothies?
Compared to mixing spinach with water alone, the study found that coconut milk without additives significantly improved lutein release by 42 percent and coconut milk with additives by 25 percent. In comparison, high-fat and medium-fat cow’s milk were found to improve lutein release by 36 percent and 30 percent, respectively. Consistency models suggested that the effects of coconut milk and cow’s milk arose from fat and protein, respectively.
“We found that only four of the 14 products tested increased the release of lutein from spinach compared to water,” Chung said. “Cow’s milk with a high fat content as well as coconut milk release enhanced lutein. Yogurt, however, which is considered comparable to cow’s milk and is often used in cafes and the like, has not shown particularly good results.”
Dairy yogurt is not so good at releasing lutein that may be related to the fermentation process. It also found that plant-based drinks, often made from nuts, legumes or oats, showed significantly different results.
Among plant-based milks, the researchers also found that soymilk was less effective than water when it came to releasing lutein. “Plant-based liquids are becoming increasingly common in smoothies,” Jan Nilissen, a doctoral student and one of the researchers behind the study, said in a statement.
“We found that soymilk was actually less effective than water at releasing lutein in spinach smoothies,” Nilisen said. “In other words, soymilk had a negative effect on lutein release in our study.”
Other plant-based products in the study did not affect lutein release compared to water. As a general piece of information, the researchers also noted that smoothies should be consumed as soon as possible, as lutein breaks down quickly.
Now that researchers have discovered how much lutein is available for the body to absorb, they will conduct further studies to measure the amount of lutein actually absorbed by the body from smoothies made with different milk products.