
A study by Proceedings of the National Academy of Sciences of the United States of America (PNAS) shows that global diets have become more similar in composition over the last 50 years. According to the study, “the narrowing of diversity in crop species contributing to the world’s food supplies has been considered a potential threat to food security.” (Khoury et al, 2014). Important staple crops and cereals such as sorghum, millets, rye, cassava, sweet potato, and yam have lost their dietary contribution while oil crops like soybean, sunflower, and palm oil have increased in contribution to diet and production (Khoury et al, 2014).

The study notes that over the past 50 years, production of energy dense foods (i.e., animal products, plant oils, and sugars) increased around the world. The liberalization of international trade and globalization has helped accelerate the homogenization of global food supply (Khoury et al, 2014).
To download and read the study published by PNAS, click here.
The following is an an important excerpt from NBC News on homogenization of food variety produced and susceptibility to crop disease and natural calamities by Colin Khoury, one of the study authors:
“Examples like the Irish potato famine [and] the southern corn leaf blight in the ’70s in the United States,” he noted, “have shown that if you have one variety, pests will find it and make trouble.” (NBC NEWS, 2014).
To read more about the authors and the publication, click here.