Eating out of season has been something we never questioned, fresh salad in winter, spinach and fresh strawberries during x’mas. In the northern hemisphere this equates to the unnecessary luxury of imports, science and fossil fuel has also enabled us to grow vegetables in a heated greenhouse out of season for businesses to reap the benefits of economic value from these vegetables when supplies are low and demands is at it’s peak; carbon emission aside what is the true cost of eating food that are grown out of season?
To understand this we need to look at how a plant works. The plant extracts nutrients such as nitrates from the soil and stores this within the plant turning this into protein and sugar used by the plant for growth. For this to happen it requires sunlight for photosynthesis and in winter the hours of sunlight will decrease significantly.
Scientific research carried out in the 60s on spinach and lettuce (Spinach and lettuce are two of the vegetables that has the tendency to hold on to nitrates) has shown that these vegetables while grown in shade contain a higher level of nitrates than those grown in full sun. Imagine the growth of vegetable out of season in a heated greenhouse in just 6 hours of sunlight? The amount of nitrates in the spinach of lettuce may far exceed what has been deemed safe.
The truth to the matter is, consuming excessive amounts of nitrates have been scientifically proven to be one of the major factors that cause cancer; this has also been a huge topic of debate within the EU on the level of nitrates being discharged by the conventional agriculture industry into the water tables of Europe.
We cannot fool nature, trying to grow something that is out of season in a heated greenhouse powered by fossil fuel is a sign of humans excessive demand, we need to respect the forces of nature and live within the seasons and with this understanding and respect we may be duly rewarded by her.
