Lack of exercise is an immense health problem that is on the increase. Even if their life literally depends on it, most people still refuse to start becoming more active. Nutritionists at the University of South Australia may have found an answer to this: lutein supplementation induces people to move more whether they like it or not, and thus reduces the amount of time they spend sitting.
Lutein and physical exercise
If we are to believe animal studies, a diet containing 15-20 mg lutein each day can make you fitter. Lutein – a compound related to beta-carotene, which is found in carrots, broccoli, pumpkin and leafy green vegetables – stimulates the activity of the enzyme AMPK in muscle cells during a period of intensive training. This implies that lutein strengthens and speeds up the adaptation processes in muscle cells that enable these cells to adapt to frequent intensive exercise.
Several epidemiological studies have shown that people move more, more often and more intensively the more lutein they consume. The figure below comes from an article published in September 2015 in Nutrients. [Nutrients 2015, 7(9), 8058-8071.]
The correlation coefficients show the relationship between the consumption of vegetables high in lutein and the amount of physical exercise found in two different studies. The higher the correlation coefficients, the more an increase in the amount of lutein seemed to increase the amount of exercise.
Epidemiological studies can reveal relationships, but not causalities. Perhaps people who get lots of exercise also just lead healthier lives. Not only do they exercise more, but they also eat more vegetables – and therefore also consume more lutein. This might be the case.
The nutritionist Rebecca Thomson, at the University of South Australia, did an experiment with 39 healthy but inactive adults aged 55-80 to try and determine whether a higher lutein intake does actually lead to more physical exercise. Thomson gave half of her subjects a placebo every day for a month, and the other half capsules containing lutein.
The subjects in the experimental group ingested a daily total of 21 mg lutein and 0.9 mg zeaxanthin, which is related to lutein. They consumed this dose via three capsules, taken over the course of the day, together with a glass of full fat milk. The body absorbs lutein better when combined with fat.
In the experimental group the amount of light physical activity increased by twenty minutes; in the placebo group the amount decreased by fifteen minutes.
The greater the increase in the concentration of lutein in the bloodstream, the greater the increase in daily physical activity – and the greater the decrease in the amount of minutes the subjects spent sitting each day.
“The current study provides preliminary evidence that the consumption of lutein increases plasma lutein concentrations, and that this increase is associated with increases in activity and reductions in time spent engaged in sedentary activities”, the researchers concluded.
“Further evaluation of the potential for lutein to increase physical activity and reduce sedentary activity in older adults should be undertaken in larger, longer-term studies which evaluate the potential health benefits associated with these changes in physical activity and sedentary behaviours.”
What would happen if you gave athletes 20 mg lutein every day?
Increases in Plasma Lutein through Supplementation Are Correlated with Increases in Physical Activity and Reductions in Sedentary Time in Older Adults
Cross-sectional studies have reported positive relationships between serum lutein concentrations and higher physical activity levels. The purpose of the study was to determine whether increasing plasma lutein levels increases physical activity. Forty-four older adults (BMI, 25.3 ± 2.6 kg/m2; age, 68.8 ± 6.4 year) not meeting Australian physical activity guidelines (150 min/week of moderate to vigorous activity) were randomized to consume capsules containing 21 mg of lutein or placebo with 250 mL of full-cream milk per day for 4 weeks and encouraged to increase physical activity. Physical activity was assessed by self-report, pedometry and accelerometry (daily activity counts and sedentary time). Exercise self-efficacy was assessed by questionnaire. Thirty-nine participants competed the study (Lutein = 19, Placebo = 20). Lutein increased plasma lutein concentrations compared with placebo (p < 0.001). Absolute and percentage changes in plasma lutein were inversely associated with absolute (r = ?0.36, p = 0.03) and percentage changes (r = ?0.39, p = 0.02) in sedentary time. Percentage change in plasma lutein was positively associated with the percentage change in average daily activity counts (r = 0.36, p = 0.03). Exercise self-efficacy did not change (p = 0.16). Lutein increased plasma lutein, which was associated with increased physical activity and reduced sedentary time in older adults. Larger trials should evaluate whether Lutein can provide health benefits over the longer term. Source: http://www.mdpi.com/2072-6643/6/3/974