Eat what your grandmother eats!

by Wei Perng, PhD

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In Michael Pollan’s book, In Defense of Food: An Eater’s Manifesto, he laid out 12 Commandments for Serious Eaters. The first commandment is “Don’t eat anything your grandmother wouldn’t recognize as food.” This makes sense, given evidence that processed, hard-to-digest, chemical-ridden foods are a large contributor to our expanding waistlines and declining health. I’ve always thought that this was a good rule to follow. After all, it’s hard to argue with the fact that my grandmother, who eats lots of steamed veggies, fruits, and wild poultry, would likely not identify Cheetos, Hot Pockets, Power Bars, or Lunchables as food. As it turns out, there is yet another reason why we should eat what our grandparents eat: evolution!

Evolution says that I shouldn’t eat too much ice cream. An article in Maclean’s, a Canadian weekly current affairs magazine, made the argument that eating similar foods to what your grandparents ate – or better yet, what your great-great-great grandparents ate – is the key to a long and healthy life. The idea behind this notion is that foods that are healthiest for you may be tied to your specific cultural and genetic history. This concept really hit home a few nights ago when I watched my husband, who is of German descent and comes from a family of dairy farmers, chase a bowl of ice cream with a glass of milk without a trace of indigestion. Me? On a good day, I can only eat a small amount of baked or fermented dairy unless I plan to spend the next few hours on the porcelain throne. This is likely a remnant of the fact that my ancestors in Taiwan did not practice dairy husbandry and as a consequence, dairy has not historically been a part of the Taiwanese diet, rendering many Asians like myself lactose-intolerant. Therefore, while a dairy-rich diet may be perfectly fine for my husband, I am better off consuming smaller amounts of this food group.

Pass on the juice cleanse and the coconut oil! The author of the Maclean’s article also discussed how many popular diets considered to be “healthy” may actually be detrimental. For example, while fruits and vegetables are undoubtably beneficial to our health, the ever-popular juice cleanses expose us to much higher levels of fructose and uric acid than our ancestors were ever exposed to and can result in insulin resistance, high blood pressure, and gout. Likewise, the recent emphasis on eating raw foods (think: Paleo diet) may lead to increased consumption of toxins in uncooked vegetables (e.g., cyanide in lima beans and phytates in peas and tomatoes). Excreting and neutralizing these toxins may not only deplete our bodies of important minerals, but can also lead to indigestion. In the long-term, following mainstream diet fads – even those that have received positive support from the research community, like the Mediterranean diet (discussed in Gary Paul Nabhan’s book Food, Genes, and Culture: Eating Right for Your Origins) – can result in suboptimal health outcomes.

So, what is the take-home message? With all the different recommendations on how to eat optimally for good health, it’s a tough world to navigate for the average consumer. As someone with a background in nutrition, epidemiology, and obesity, I would say that it’s a good idea to eat whole foods (particularly those that your grandmother would approve of), while limiting your consumption of processed foods with a long list of impossible-to-pronounce ingredients. And of course, moderation is key; if something is tasty, eat some (but not too much) of it!