He has done well on it, since he first appeared in 1929 and seems to have maintained his muscle strength in his maturity.
The reason why seems to be because the spinach is rich in nitrates.
A new study recently published in the Journal of Nutrition indicates that eating just one cup of leafy green vegetables like spinach every day can significantly boost the muscle function of the lower limbs.
In this study of almost four thousand Australians, over a twelve-year period they found that those people with the highest regular nitrate consumption had over ten per cent stronger lower limb strength than those with the lowest nitrate intake.
They also walked faster.
The conclusion was that diets high in nitrate-rich vegetables boost muscle strength, independent of physical activity.
There is a great deal of research carried out on nitrate high diets.
Nitrates are chemicals that include nitrogen and oxygen molecules.
The nitrates in food are either natural or added.
Cured and processed meats and green, leafy vegetables are all rich in nitrates.
But there is a big difference in diets that have the bulk of their nitrates from cured meats, as opposed to those that have them from natural nitrates in leafy green vegetables.
The nitrates in cured meats help to preserve and improve the colour of meats.
Cured ham has the most nitrates, followed by bacon, then deli meats and then hot dogs.
The intense pink is due to the nitrates.
Too much of these sources, however, are not good for health.
Nitrates in processed foods are not broken down by stomach acid but are broken down into ‘nitrites’ by the bowel microflora.
It is these ‘nitrites’ that cause the problems.
On the other hand, nitrates in vegetables get broken down into nitric oxide, which is good and healthy.
It is an antioxidant which counters free radicals.
The researchers found that nitrate-rich vegetables, such as lettuce, spinach, kale and even beetroot, provided the greatest health benefits.
A cupful a day of one of them, taken as one of your five fruit and veg a day, would be a good aim.