The Land of Israel is described as “A land of wheat, and barley, and vines, and fig trees, and pomegranates; a land of olive oil and honey." These seven species were the staple foods consumed by the Jewish people in the Land of Israel during biblical times. They contain special holiness, as reflected by the unique blessing recited after eating them, thanking G-d for the goodness of the land.
The praise of the land of Israel for its fruit-trees is a deep environmental lesson in itself, testifying to the importance of nature and trees in Judaism. The Bible paints the shade of the grape vine and fig tree as a metaphor for the idyllic world-peace we await. Our ultimate trust in G-d is expressed through the serene environment where “Judah and Israel will sit securely , each person under his vine and fig tree…” As we munch on juicy grapes we are reminded that there is no greater sign of the coming redemption than when the Land of Israel produces fruits in abundance.
Moreover, the offerings of the bikkurim (first fruits) brought to the Temple in Jerusalem on Shavuot were only from these seven species. On what merit are these fruits selected? Nogah Hareuveni  explains that the flowering and fruiting of the seven species take place during the period between Pesach and Shavuot, a season depending on the delicate balance between contradictory forces of nature. It is characterized by climatic contrasts between extreme dryness and heat on the one hand and cold storms on the other, which could easily be misconceived as battles between opposing deities. Therefore, the seven species are selected to reaffirm our pure faith in G-d through our expressing thanks to the One and only G-d specifically for the fruits of the Land.
The flowering and fruiting of the seven species parallel our own spiritual development during the season between Pesach and Shavuot, characterized by self-improvement and preparation for receiving the Torah. As we count the Omer during the 49 days between Pesach and Shavuot,  we turn to G-din repentance and prayer. Since the fruiting of the seven fruits is linked to our own spiritual achievement, it is not surprising that these seven kinds comprise a wealth of spiritual attributes, nutrients and medicinal properties.
The special significance of the seven species is accentuated by the great Kabbalist Arizal,  who attributes the spiritual energies of each fruit to one of the seven lower sefirot (spiritual emanations) that we count during each week of the Omer., Their correspondence is according to the order they occur in the Torah verse. It is interesting to note how the medical properties of the seven species are synchronized with their spiritual energies.
Wheat corresponds to chesed (kindness), the first of the seven lower sefirot. The characteristic of chesed is expansion, to reach out and extend oneself toward others. Wheat likewise reflects the nourishing food of kindness and to this day remains our main sustaining food staple. According to the renowned rabbi and physician Maimonidesm, wheat strengthens the body and increases mothers’ milk, the ultimate nourishment and expression of chesed. 
Barley corresponds to gevura (restraint). Its characteristic is contraction, reduction and setting boundaries. This is reflected by each barley seed being enclosed in a strong hull (boundary) which remains intact even during threshing. Due to its contracting quality, barley is highly effective in reducing liquid when added to soup. A recent study by the FDA evidenced that barley reduces cholesterol and risk of coronary disease. 
Grapes grow in beautiful clusters and correspond to tiferet (beauty). This trait is characterized by the balance between its different and sometimes contrary components. Since tiferet is the perfect balance between chesed and gevura, grapes include both nourishing and eliminating qualities. Grape-seed oil nourishes the skin, while also containing a very high content of antioxidants that help in eliminating free radicals.  Grapes possess a diuretic quality, yet they are very nutritive replete with vitamins A, B, and C, while also treating blood and energy deficiency. 
Figs correspond to netzach (endurance), which engenders longevity. The fig-tree reflects everlasting fruitfulness as it has one of the longest periods of ripening, spanning more than three months. The Malbim explains that we need to watch the fig-tree very carefully by picking its figs daily, since they ripen one after the other; likewise we need to observe our teachers daily in order to glean the fruits of their wisdom. According to Maimonides, “Figs, grapes and almonds are always the best fruits whether fresh or dried.” Maimonides also taught that figs alleviate constipation,  which is one of the main tenets of longevity and health.  Figs may benefit the elderly  by strengthening the blood and arousing a person’s vitality. 
Modern science affirms the nutritional benefits of figs: they are very rich in minerals, especially potassium, iron and calcium, and they contain omega-3 and omega-6 fatty acids. Figs also contain phytosterols, which inhibit the absorption of dietary cholesterol, thus decreasing the total levels of cholesterol. Moreover, they may help prevent certain types of cancers. 
Pomegranate, a very beautiful and majestic fruit, even has a crown. It corresponds to hod which means majesty and glory. Hod is also related to the Hebrew word toda which means thanks and recognition. According to Rav Yitzchak Ginsburgh,  hod corresponds to our immune system.  A healthy immune-system is able to recognize our friends from our foes, and pomegranates boost our immune system. Pomegranate seed oil causes cancer cells to self-destruct; the juice of the fruit is toxic to most breast cancer cells, yet has almost no effect on healthy cells. Pomegranate juice has also been proven to decrease heart disease by decreasing LDL ("bad cholesterol") and increased HDL ("good cholesterol"). 
Olive oil corresponds to yesod (foundation). Olive oil is the foundation of most Mediterranean foods. Maimonides explains that olive oil cleanses the liver and loosens stools.  It is helpful against stones in the urinary tract to drink a teaspoon of olive oil every morning before eating.  Olive oil protects against heart disease by lowering the blood pressure, and has strong anti-bacterial properties. It also contains several antioxidants to help fight cancer. Thus olive oil can truly be called the foundation (“yesod”) of life.
Dates correspond to malchut (kingdom). Malchut is the channel that allows everything to manifest below. Therefore malchut is connected with the digestive system. The Talmud teaches that dates heal intestinal illnesses. The palm tree has no waste, its lulavs (hearts) are used for prayer, its fronds for shade, its fibers for ropes, its twigs for a sieve, and its beams for houses. Likewise the people of Israel have no waste: they each master their own particular part of Torah learning or perform mitzvoth and charitable deeds. 
The Torah's mention of the seven species is not incidental. Rather, these foods are central to a Jewish spiritual path that endeavors to elevate the physical through intentional living. Eating the seven species in a conscious way can promote our well-being, help us connect to the land of Israel, and deepen our relationship with Hashem. Each of the seven species contains deep lessons about G-d and our spiritual lives. Every time we eat them we have the opportunity to tune into their spiritual messages, eat consciously, and bring the world a step closer to its perfected state.