|
|
Today, we have a very good variety of fruit, and fruit that is better than just edible. On the other hand, fruit consumption has to compete with industrial foods of all kinds, and it doesn't compete well. Fruits are full of antioxidants and cancer suppressing chemicals, they are a valuable energy source, and have fibres, gums and pectins whose health qualities are only just beginning to be discovered.
Some fruits, such as blueberries and cranberries, have proven medicinal qualities.
Many fruit species have not been, and will not be domesticated, for a variety of economic and cultural reasons. For a few of us, where time, space, and inclination allows, home growing some selected fruits can provide valuable adjuncts to the modern industrial diet.
But commercial fruit provide ample vitamin C, so long as they are eaten every day. Jujube, tropical guavas, Kiwifruit, citrus in general, papaya, mangoes and persimmons are especially laden with Vitamin C, in particular. Many other commercial fruit are also very good sources.
By selecting the fruit particularly rich in vitamin C, plus enjoying the particular health qualities of other fruit, we can at least match - and perhaps even surpass - the variety, quality, and quantity of fruit that was available to our ancestors living in the natural world.
"The foundation on the !Kung subsistence diet comprises over 100 species of edible plant. These include...30 species of berries and fruits and an assortment of melons, nuts, leafy greens and edible gums...over the course of a year only 25 species of plants make up 90% of the diet [by] weight and one species, the mongongo nut, accounts for at least half the total"We evolved in the forests and woodlands of Equatorial and subequatorial Africa. Like all the other animals, we knew exactly when the fruiting trees in our tribal territory would be offering their bounty. Fruit supply in the equatorial forests is less seasonal, whereas in the drier areas it is tied partly to temperature, and partly to the seasonality of rains.
-Lee & Devore, 'Kalahari Hunter Gatherers: Studies of the !Kung San and their neighbors'. The !Kung San group studied live in an arid near desert and tree savannah dune land area of north - western Botswana.
Many of the wild fruits that we ate have chemicals in them to dissuade people and other animals from eating them before the seed inside is fully mature. From a fruits 'point of view', the purpose of 'freely' feeding the animal kingdom is to ensure that the fruits 'babies' - its' seeds - are spread across the earth, and hopefully deposited with a 'kick start' dose of manure! If the fruit are eaten before the seeds inside have fully matured, the whole effort of creating and providing a dose of sugars, minerals, vitamins and proteins wrapped in a colorful skin has been a waste of precious resources.
So the tree provides enough sugars and other goodies to be attractive, but only a super abundance where it has to compete against it's own species to draw the fruit eaters.
How important were fruits to our ancestors? Well, it probably depended on the type of fruit. Some fruits are moist, hard to dry, and break down quickly. This is generally typical of tropical fruits. Others are somewhat mealy, almost floury, with much less water, and dry quickly in arid or hot climates. These can be stored for later use.
"Bushmen say ' a man could live on these fruits [Diospyros chaemaethamnus] alone for 3 months, provided that water was available' "- 'Food from the Veldt', Fox & Young.Fruits of the Southern African Mongongo tree, Ricindendron rautaneii, not only provide an astonishingly nutritious nut, but the thin, spongy, rather dry outer flesh is date-like, although not as sweet as a date. Even when the flesh has dried and shriveled up, the now crumbly flesh is nutritious. It's importance was that it could be stored as a kind of dried fruit for many months. And so can the sugary fruit of a small tropical tree, Berchemia discolor, that grows from Ethiopia down to Botswana and parts of Eastern Southern Africa. This fruit has been compared to dates in sweetness it is so full of sugar (chiefly sucrose). Native people sometimes pound the dried pulp to a mealy flour, and mix it with wild grass seeds (Eleusine coracana, Pennisetum typhoides) and then baked it into a sort of biscuit. This way the dried fruit and the grass seeds can be stored in one energy dense, storable 'packet'. The original 'health bar'.
But generally, sweetness was a hard commodity to come by. We have had a long - one sided - relationship with bees, but honey was a rare delight. Our sweet tooth is finely tuned by evolution to find the sweetest and best fruits - a two way relationship with plants. And plants are often happy to oblige, so long as we help distribute their seeds. Sweet fruiting plants are in most ecosystems.
Some African fruits, for example the thorny shrub Carissa edulis, with it's sweet red milky latex suffused pulp are quite widely distributed across the drier areas; others are of fairly local distribution. A close relative of C.edulis, C. macrocarpa, with sweet and delicious fruits, is found only in coastal bush, on sand dunes, and the edges of coastal forests in Southwest Africa. Others, such as the mbungu vine, Landolphia sp, have representative in both tropical and dry grassland areas.
The number of fruits in our ancestral homeland is legion - in Southern
Africa, according to one source, fruits of 200 indigenous trees are eaten
by some peoples, whether raw, dried, or ground and made into a gruel and
cooked. These fruits cover the spectrum from sweet and good, through tasteless,
to actively astringent. Another author counts 200 edible fruits in Zimbabwe
alone!
Such fruits are inevitably seasonal, often erratic, and some would
be eaten only as a last resort.
In more equatorial areas, fruit was probably collected as it was available, and as it was possible - fruiting jungle trees may proffer their fruit 30Metres/100 feet above the ground - generally to birds and fruit eating bats and monkeys.
For our ancestors, fruit contributed to the required 'mix' of energy food, protein, minerals, vitamins, and gums, fibre, and phytochemicals. Most fruit are relatively poor sources of vitamins (other than vitamin C and 'vitamin A') and minerals (other than potassium), but fruit, along with leaves and roots, are most important for supplying protectant phytochemicals and ascorbic acid (vitamin C).
The human animal is one of three kinds of land mammals that are unable to manufacture their own vitamin C. We must get it from plants, as meat is commonly supposed to have little or no vitamin C (except brains, with about 23 mg/100 gram serving).
Nine of the commoner wild fruits of the African Veldt have been analyzed, and all were found to have 'good' amounts of vitamin C. Two other common fruits, the kei apple, Dovyalis caffra, and the baobab, Adansonia digitata, have very good levels. The kei apple, for example, contains around 117 mg ascorbic acid per 100 gms of fruit ( baobab has around 213 mg/100 gms). As each kei apple fruit weighs about 15 grams, each small (about walnut size) fruit provides around 17 grams of vitamin C - four times more than an apricot fruit, a fruit twice the kei apples' weight! The 'recommended adult daily allowance' of vitamin C is 60 mg, and would be satisfied by only 4 of these small fruit. It is more likely that gatherer hunters would have eaten at least double this number every day in the fruiting season.
"In the forests of Transcaucasia the wild [grape] vines twine around the trees of the wild quinces and pears, so that in autumn, when the fruit are ripening, as a Russian scientist Vavilov has said, one might think oneself in the Garden of Paradise."As some of us expanded out of Africa, we moved into a much more strongly seasonal fruit supply than our previous equatorial home. Smaller fruits, often berries such as currant, elder, rowan, wild rose fruits, raspberries, grapes, small vacciniums, and the like, became the fare. Some berries and 'pome' fruits were both small and rather mealy ( some species of mulberry, the various Sorbus species, the jujube), and could be dried to a certain extent for later use, especially in the Mediterranean area and South West Asia. Interestingly, the fruit that best dried naturally on the tree, and that was pleasant eating, and that could be stored for up to a year ( in the same fashion as the Mongongo fruit of Africa) also has astonishingly high levels of vitamin C. This is the jujube fruit, Zizyphus jujuba, whose center of diversity is thought to be in the Eastern Mediterranean, around Syria. Nevertheless, we quite possibly had to turn more to leafy plants to satisfy our vitamin C needs at some times of year.
F. Roach, 'Cultivated Fruits of Britain'
There is a very good range of fruit available to middle class Western people now. People with low disposable incomes can afford little fresh fruit, . There are more or less two types of fruit - fruit that stores well, is moderately priced, and has a fairly long life 'on display' in the retail store - apples, oranges, tangerines, mandarins, grapefruit, pears, kiwifruit, bananas, grapes, and to a lesser degree, stone fruit, such as peaches, plums, and apricots. The other major class are fruits that have a much shorter shelf life, are often air freighted in as luxury items, or have a higher price because they spoil quickly and have a higher 'wastage' factor - mangoes, lychee, papaya, cherimoya.
'Soft fruit' - blackberries, blueberries, raspberries, black currants, loganberries and other brambles - are occasionally available, but are most likely to be bought frozen for use in cooking. Soft fruit have a very short shelf life.
The species of fruit we eat are constrained primarily by their storability. If they won't keep, the in-store losses are too great to be able to offer the fruit to the public. One of the great dilemmas of fruit supply is that fruit have to be very firm to stand handling and transport. Some fruit are simply not as good when picked before they are fully mature; for others, such as bananas and apples it generally makes little or no difference. Nectarines are picked and sold hard, the same with peaches and stone fruit. Stone fruit that is picked when firm very often hasn't developed the level of fruit sugars and flavor components that our sense of taste demands. An older variety of strawberry, altho' too soft to be marketable, is almost a different fruit to modern varieties which are bred to resist handling damage, but which often lack sugars and complex flavors.
Whatever climatic zone you are in , there is always a fairly long list of fruiting plants that you 'could' grow. But most of us are urban dwellers with demanding jobs and lifestyles. There is little spare time, and lot's of attractions competing with gardening, let alone fruit gardening. Besides, lots are much smaller these days, and we are so mobile we may not stay at any one address long enough to harvest fruit from a tree or bush we plant. Add to that the need to protect fruit from birds and other varmints with two legs, the need to spray many fruits against fungal diseases, the need for the right soil, and perhaps pruning, and we soon find something else to do with our time!
The fruiting plants you 'could' grow will often either never or rarely be commercially available - acerola, mountain papaya, kei apple, marula, white sapote, lucuma, many species of passion fruit, casana, american persimmon, jujube, cattley guava, Chilean cranberry - the list goes on and on. Some, as in the wild, are slow to bear. Some don't have a great deal of edible flesh. Some must be perfectly ripe to be edible. Some are very acid. And some are excellent in all respects.
Many of these 'minor fruits' 'could' be bred and improved greatly. But they probably never will be. 'Minor fruits' are by definition non commercial. Perhaps they don't bear heavily enough, perhaps they are adapted only to a very narrow climatic type, perhaps they don't store well, or perhaps they are simply unfamiliar. Breeding programs for trees are very very expensive. No one has the physical space, the long time available, or the money to leave land locked up in a program whose results are not guaranteed to be successful.
So the major commercial fruits we have now are about 'it' with regard to variety of species.
Unlike our ancestors living in the more seasonal temperate areas, or the difficult semi dryland areas, there are no seasons without fruit. Cool storage, controlled atmosphere storage, international shipping, and large scale fruit culture mean that we can chose fruit every day of the year. While vitamin content may decline slowly in storage, and while the species we eat may not have such high concentrations of vitamins, these effects are compensated for by the constant availability of fruit in the urban jungle.
But some of the domesticated fruits have quite exceptional amounts of vitamin C, if we take vitamin C as a key desirable quality for a fruit. The Jujube (Chinese date), tropical guava, and kiwifruit head the list. The recommended daily dietary intake of vitamin C for an adult (not pregnant or lactating) is currently 60 mg. 100 grams of jujube fruit ( at a guesstimate, about 5 or 6 of these small fruits) provides 500 mg of vitamin C! A medium sized tropical guava has 165 mg, and a single medium kiwifruit has 74 mg.
Refer to our 'vitamin C content of fruit' page for a list of more than 50 fruits and their vitamin C content and ranking.
But to look only at the vitamin C content is to tell only part of the story. Fruit are very important sources of vitamin A and various carotenes. The tomato fruit contains lycopene (as does the skin of oriental persimmons), which has the greatest antioxidant capacity of any of the carotenoids, and has shown experimental anti-tumor action.
Study after study demonstrates the protective effect of fruit. Protective against cancers, protective against cardiovascular disease. But again, this cannot be a surprise. We evolved in an environment with fruiting plants. We are an omnivore. We eat everything. We need the vitamins, minerals, phytochemicals, gums, pectins and fibres (only fruit and vegetables are sources of soluble fibre - grains have insoluble fibre) that are in fruit, altho it is fair to say that we are already oversupplied with calories, so the sugars are of lesser importance.
Some fruit have proven medicinal properties. Cranberries and blueberries have been shown to act against the bacilli that can be a cause of cystitis, a painful bladder infection mainly affecting women.
Never before in our evolutionary history have we in the West been so
assured of a rich and diverse supply of the most palatable fruits. The
irony is that in a time of such evolutionarily unprecedented nutritional
wealth, we pay it little value.
Links
African
indigenous fruit - Zambia A brief table of the indigenous fruits
of Zambia (central sub-equatorial Africa)
http://www.agrsci.unibo.it/wchr/wc2/mingochi.html#appendix
Thompson J, 1999 'Evolution of the Apes and the Origin of Human
Beings' in Report on SAGA2/COE Symposium
http://www.pri.kyoto-u.ac.jp/meetings/coe99/report/Thompson.html
accessed 30/05/00
Paper Reading-list
of books & scientific papers to buy or find at the library (links
to internet sources of the book or paper are included where available)
|
|
The author rejects any responsibility
for any decisions about life, diet, or anything else other than his own.
Any action you take after reading the material here is soley your responsibility
- seek advice from others, read critically and widely, don't accept everything
you read here. You have been warned! Question everything.
Form your own opinion on
these matters after reading widely and consulting appropriate professional
advice, including advice of medical practitioners and professional nutritionists.