The spinach-eating cartoon character Popeye has much to teach us according to new research from the Swedish medical university Karolinska Institutet.
The muscles’ cellular power plants – the mitochondria – are boosted by nitrate, a substance found in abundance in vegetables such as lettuce, spinach and beetroot but for half a century, inorganic nitrate was associated with negative health effects, until this new evidence to the contrary emerged.
In this latest study, researchers asked healthy people take nitrate equivalent to 200-300g of spinach or lettuce for three days, after which they were given a cycling task to perform.
They then analysed samples taken from the thigh muscles of the volunteers and compared them with similar samples from the same subjects when they had taken a placebo instead.
After nitrate ingestion, a significant improvement was seen in the efficiency of the mitochondria, which consumed less oxygen and produced more of the energy-rich substance ATP per consumed oxygen molecule.