Study confirms spinach strengthens muscles

Swedish researchers confirm: make spinach strong

02/02/2011

Who has not heard as a child that spinach makes you big and strong? What the popular saying long ago, Swedish researchers have now confirmed in a comprehensive study: The contained in spinach and other leafy vegetables nitrates improve muscle performance.

Even comic hero Popeye knew the strengthening effect of spinach. Where this comes from Swedish researchers have now found out. As part of their study, scientists were able to show that nitrates contained in vegetables improve muscle efficiency, allowing them to perform the same with less oxygen. Accordingly, spinach actually makes strong. The results of their study have been researched by Filip Larsen from the Karolinska Institute in Stockholm in the current issue of the journal „Cell metabolism“ released.

Nitrates have many positive health effects
In their study, the Swedish researchers looked more closely at the health effects of nitrate intake and found that nitrates in leafy vegetables are partially unfounded. The researchers from the Karolinska Institute subjected 14 volunteers to a three-day nitrate cure. Before and after the volunteers tissue from the thigh muscles were removed and performed a performance test on a bicycle ergometer. The Swedish researchers found that the nitrates considered to be harmful to health or even carcinogenic apparently also bring a variety of positive effects on health. A condition for this, however, is a healthy oral flora, because for the processing of nitrate, humans need bacteria that live in the saliva, so the statement of the Swedish scientists

Carcinogenic nitrosamines responsible for the bad reputation
During food intake, part of the nitrate is already converted into nitrite by the bacteria in the oral cavity, which subsequently enters the gastrointestinal tract when swallowed. There, the nitrite is then converted to nitric oxide (NO), which is used by the body as an important messenger, or there are the so-called carcinogenic nitrosamines. The nitrosamines are one of the main reasons why nitrates have a relatively bad reputation in terms of health consequences today. Various studies have also observed many positive effects of nitrate intake, Larsen and colleagues report. For example, NO increases blood vessels and can lower blood pressure. In addition, it appears that positive effects on the blood sugar level are observed and the body is armed against the negative consequences of a local oxygen deficiency, said the Swedish scientists.

Nitrates increase muscle efficiency
Participants in their study had seen a significant improvement in muscle efficiency after the three-day nitrate regimen - with an amount equivalent to about two or three beetroot balls or a large portion of spinach, said Karolinska researchers. Institute. The subjects had consumed significantly less oxygen at the same muscle power after the nitrate cure in the power measurement on a bicycle ergometer, the scientists continue. The additional tissue samples taken from the thigh muscle also indicated increased muscle efficiency, explained Larsen and colleagues. According to the researchers, the increased muscle performance is probably due to nitrate-enhanced mitochondrial efficiency in the muscle cells. When examining the tissue samples, there would have been evidence that the nitrates closed a kind of leak in the tiny cell power plants and the mitochondria could thus generate more energy per oxygen unit. According to the Swedish scientists, the rapid effect of the nitrate treatment in their study was also impressive. Immediately after consuming nitrate-containing foods, the performance-enhancing effects are triggered, explain Larsen and his team. Like Popeye, after a can of spinach.

Further studies necessary
However, the Swedish researchers also point out that there are still some questions left open. Because the negative effects of nitrosamines continue to exist. According to the scientists, for example, in further investigations it should be clarified, for example, which amount of nitrate is optimal, whether regular, sustained nitrate intake also has predominantly positive effects and whether chronically ill patients can also benefit from the nitrates. Overall, nitrates have their bad reputation but in any case wrongly, judged Larsen and colleagues.

How healthy is spinach?
Not only does spinach contain a great deal of muscle-efficiency-enhancing nitrates, but it also contains a host of other minerals and vitamins such as carotenoids, vitamin C, vitamin E, calcium, and magnesium. In addition, spinach contains iron and a high protein content. Overall, spinach is described by nutritionists as extremely healthy, but this should be consumed fresh, since the nitrate contained is converted over time bacterial to nitrite and then to the carcinogenic nitrosamines. It is also to be considered that spinach can not only absorb a particularly large amount of nutrients but also, if necessary, a particularly large number of pollutants from the cultivation soil. As with all types of vegetables, the type of cultivation here has a significant influence on the desired health-promoting effect of spinach. (Fp)

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Image: Dieter Schütz