The Western diet underwent a significant shift during the 20th century. This change was even more drastic than the shift attributed to agriculture discussed above. Most of this has been due to the widespread use of vegetable oils in packaged foods and their addition to many of the condiments we use to flavor food.
To put things into perspective here are a few facts regarding this shift:
- the estimated per capita consumption of soybean oil alone increased more than 1000-fold from 1909 to 1999
- the consumption of margarine increased by 1038% from 1909 to 1999
- in the 13 years after its introduction in 1986, canola oil consumption increase 167-fold
- soybean oil only accounted for 0.006% of our dietary caloric energy in 1909, while this level reached a staggering 7.38% by 1999
- the amount of linoleic acid (LA) our bodies have available for energy increased from 2.79% to 7.21% (2.6x), while alpha-linolenic acid (ALA) only increase from 0.39% to 0.72% (1.8x)
- the ratio of LA to ALA increased from 6.4:1 in 1909 to 10:1 in 1999
Considering all the positive research regarding the importance of a health ratio of omega-3 to omega-6s, this data raises several concerns. The first question that comes to mind, is, can we really sustain health on such diets? Second, who is responsible for these unhealthy changes, the consumers driving demand or the sellers who used quality marketing to drive the shift?
Fortunately, healthy dietary choices are on an upward trend, and consumers are finally realizing which products are worth buying. These trends are making it less profitable to produce unhealthy products, and thus, in an ideal world, the problem will correct itself. However, we shouldn't forget the power of marketing and the potential for sellers to simply replace a known unhealthy ingredient will a lesser known alternative.