SUGAR

Sugar – a preservative, a fermenting agent, a sweetener of food and drink without changing the flavor – has revolutionized the food processing industry; and sugar cane was the most revolutionary of all plants to reach the Americas. Today sugar – actually the chemical sucrose, extracted from the cane – is the world's best-selling food, surpassing even wheat.

This giant grass with stems juicy with a sappy pulp is generally believed to be a native of New Guinea, although India and China are often put forward as alternative cradles because it was cultivated in both places in ancient times. Much later (around 500 bce) the Persians came across sugarcane growing in the Indus Valley and, although humans had doubtless coaxed sweet juice out of bits of cane by chewing on them for eons, the Indus Valley growers may have been the first to use the cane in a more sophisticated fashion by pressing it for its juice, then concentrating that juice by boiling it.

In any event, the Persians quickly adopted cane cultivation and, by the seventh century ad, had refined the process sufficiently to produce a nearly white loaf. Some of these sugar loaves entered Europe through Venice as one more spice called “white salt.”

ANOTHER LARGE and daunting twenty-first century problem involves equal access to food. Today, fertility rates in third-world countries have decreased sharply even as global per capita calorie consumption has risen, the twin phenomena casting doubt on predictions of swelling populations outstripping the globe's food supply. Such predictions were routinely generated by that alarming increase in the number of people occupying planet Earth between 1900 and 1990, which was the equal of four times the sum of all previous increases in the whole of human history. But although we are now 6 billion, with predictions of an increase to 9 billion by 2050, it would seem that agricultural advances have probably resolved concerns about food quantity. There are enough calories for everyone. Yet fully three-quarters of the world's population derive their calories from a diet that is low in high-quality protein compared to the other quarter who consume too much of it in diets that are definitely not tailored for a small planet. And the problem is, as Tony McMichael points out, that if food consumption was somehow made equal in terms of quality, the globe could not currently support our 6 billion; to do so would require two extra planet earths given our current technologies, and to support 10 billion would require four extra earths.

IN THE AMERICAS, Spain and Portugal laid claim to a vast storehouse of strange new plant foods. In the West Indies – the gateway to Spain's Americas – a sampling of the groceries that greeted Columbus and his men included zamia (Zamia integrifolia), manioc (Manihot esculenta), and maize (Zea mays) – these used for breads and gruels. Then there were myriad other mysterious vegetables like sweet potatoes (Ipomoea batatas), yautía (Xanthosoma sagittifolium), beans (genus Phaseolus), and peanuts (Arachis hypogaea). New seasonings were encountered, such as allspice (Pimenta dioica) and chilli peppers (genus Capsicum), along with indigenous West Indies fruits such as guava (Psidium guajava), soursop (Annona muricata), mamey (Mammea americana), custard apple (Annona reticulata), sapodilla (Achras zapota), pawpaw (Carica papaya), and pineapple (Ananas comosus). And these were just a few of the American foods that Europeans had never before laid eyes on nor set tooth to.

Fish and mollusks had provided much of the animal protein for those South American Tainos who had settled in the Greater Antilles and the Bahamas, but sea turtles and their eggs, land crabs (Cardisoma sp.), insects, and small game such as the iguana (family Iguanidae) – which became extinct in the West Indies after the Europeans arrived – also made contributions.

OCEANIA

In the south of Southeast Asia, Alocasia or dryland taro, perhaps originating in India or Burma, has been under cultivation for at least 7,000 years. Wetland (Colocasia) taro, yams, and (probably) dry and wet land rice came along later. Yet, as mentioned earlier, a mystery is why the Austronesian farmer-pioneers, who sailed off to settle the Philippines and the East Indies at about this time (6000 bce), were accompanied by taro, yams, pigs, and dogs, but not rice. The most logical answer is that rice had not yet become a staple in Southeast Asia. But it is not a particularly satisfactory answer because, despite many ensuing waves of Pacific pioneers, when the Europeans first entered the world's largest body of water, rice was absent from the whole of the Pacific, save for the Mariana Islands. Did rice somehow get lost from the horticultural complex? Or were taro and yams just easier to cultivate?

The pioneers originated in Southeast Asia and neighboring New Guinea, and their initial waves fanned out into the Philippines and the East Indies. These were an Austronesian-speaking people whose descendents, with their distinctive Lapita pottery, became the ancestors of the Polynesians. Around 3,500 years ago they launched epic voyages of exploration and colonization, moving swiftly in their double-hulled canoes to establish settlements in Fiji, and then in Samoa and Tonga – the latter two islands becoming jump-off points for the eventual settlement of the rest of Polynesia, ending with Hawaii around 1,500 years ago and New Zealand some 1,000 to 2,000 years ago.

ISLAM

The expansion of Islam began shortly after the Prophet Muhammad died in 632. By 750 the Muslims had conquered an area running from the Indus Valley westward through the Middle East to the Iberian Peninsula, and elites were speaking Arabic from Spain to Central Asia.

The Arabs, like the Romans before them, learned to use the wind systems of the monsoon (the winds reverse themselves seasonally) to sail from the Persian Gulf eastward into the Indian Ocean in November, and then return to port during the summer months. Regular eighth-century trading voyages to China saw wool and iron exchanged for silks and spices. About two centuries later, when trade with China was disrupted by the fall of the Tang Empire (907), the Arabs skipped the middleman and headed directly to the East Indies, capturing the spice trade and spreading Islam as they went.

Christian Europe, an implacable enemy of Islam, nonetheless admired Islamic cuisine and benefited from Islam's commercial activity. That activity ensured that spices reached the Continent on a circuitous path from the East Indies, as well as new foodstuffs such as sugarcane (genus Saccharum), mangos (Mangifera indica), dates, and bananas. Moreover, toward the end of the twelfth century, the wooly merino sheep was introduced to Spain – an animal originally developed by the Romans and later exported to Africa.