DOWN TO EARTH – How nutritious are our crops?

I recently received two interesting emails relating to the nutritional value of foods.
The first noted that the Ministry of Agriculture was about to produce and distribute charts showing the nutritional value of local produce to schools and others. The email also quoted from Ins and Outs of Barbados a list of our Top 10 healthiest Foods:
1. Fish, 2. Ground provisions 3. Local herbs and spices, 4. Honey, 5. Barbados fruit 6. Goat’s milk, 7. Local vegetables, 8. Pork and Black Belly lamb,  9. Molasses and local yellow crystal sugar, 10. Water
The second compared the nutritional value of  local fruits and vegetables with imports. It noted that one guava has four times the fibre, slightly more potassium and 19 times the vitamin C as an American apple, 25 times more vitamin C, four times more fibre and about the same potassium as a bunch of grapes.  Likewise, it would take 15 American apples to supply the vitamin C content of only one West Indian cherry.
It noted that the same beneficial effect on the bladder can be had from coconut water as from cranberry juice at less than half the calories and with appreciably more potassium.
For those concerned about the sodium content of coconut water, a single glass will provide only 60mg sodium compared to the 700 mg in V8 canned vegetable juice.
A tablespoon of coconut milk has only 38 calories and 4g fat compared to 111 calories in the same amount of margarine and 11.5 g fat.
Broccoli, cauliflower and brussels sprouts, like other vegetables will provide vitamin C, minerals, flavonoids and other phytochemicals but they are no match for our local callaloo (amaranth) which has more than four times the calcium, two or more times the iron with more than twice the vitamin A as the American vegetables.
The Irish potato, brown rice and whole kernel corn provide the least fibre per serving. Those of better value are green banana and sweet potato providing 1.5 g per serving of about 70 calories. Topping the list is breadfruit at 2.45 for a serving of two slices.
But on reflection, the issue of nutritional value of foods is not that simple. This became even clearer to me after reading The End of Food – How the food industry is destroying our food and what we can do about it by Thomas F. Pawlick.
He notes that using official food tables, a comparison  for the years 1963 and 2002 shows that 100gm of today’s average red ripe, whole tomato contains 22.7 per cent less protein than a tomato in 1963, 30.7 per cent less vitamin A and 16.9 per cent less vitamin C.  It also has 61.5 per cent less calcium, 11.1 per cent less phosphorus, nine per cent less potassium and ten per cent less iron.  Furthermore,  if we compare with the 1950 figures, the difference is even greater i.e 25 per cent less iron.
On the other hand, two elements have increased considerably – fat has climbed by 65 per cent and sodium by 200 per cent. 
With the breeding of vegetables in particular, it could be that much more attention is paid to yield, fruit size, firmness, resistance to disease, heat tolerance, uniformity and so on than to flavour and nutritional content.
It could also be changes in farming methods which put less emphasis on soil organic matter content, less use of animal manures and more inorganic fertilisers or perhaps the wrong ones, poor rotation of crops and so on.
A member of the Diabetes Association has expressed  concern about this issue and  I have in fact discussed with BNSI the possibility of a project  to actually test vegetable and food crop varieties  under various growing conditions to see if this cause for concern is valid. Of course, many of our  local fruits like guava, cherry, golden apple and breadfruit have not been genetically changed over the years.
These could possibly be affected by a degradation in soils and we would be advised to confirm that nutritional values are what we have come to expect.
 
 
The Agro-doc has  over 40 years experience in agriculture in Barbados, operating at different levels of the sector. Send any questions or comments to: The Agro-doc, C/o Nation Publishing Co. Ltd., Fontabelle, St Michael.