In retrospect, I don't know why this wasn't obvious to me years ago, but my hindsight is really the only thing that didn't start failing me when I turned 17 and my opthamologist told me I was “just getting older.”
Ned Kock recently provided me with a philosophical breakthrough on fruit, buried in a post about boring food.
In 2007, I wrote the following in my Thyroid Toxins Special Report:
While anti-milk writers are quick to point out that cow’s milk is not meant to be a human food, one rarely encounters a writer who points out that leafy vegetables – that is, leaves – are not meant to be foods for any animal, but are meant instead to carry out photosynthesis for the survival of the plant from whom they have sprouted. Indeed, fruit and milk are the only foods that the producing organism “intends” to be food for animals; of the two, only milk is meant to nourish rather than attract the animal who consumes it. Since plants are immobile, they produce a variety of defenses that mobile animals do not need: some of them are structural, such as thorns; others are chemical and include a wide variety of toxins. Humans have developed ways to detoxify many such plants when used as staples, to selectively breed less toxic varieties, or to utilize some of these toxic components for specific medicinal purposes.
This reasoning always bothered me a little bit. Why, then, are fruits nutritious? Why do so many more people report problems with milk than report problems with fruit?
Granted, there is a lot of biological variability in humans, and a lot of new food intolerances thrown on top of that variation because of our industrial diets. Some people don't do well on fruit, perhaps because they consume it with fat (though I love berries in my yogurt), don't absorb fructose well, or have insulin resistance that needs to be corrected.
Nevertheless, fruit seems to be much more universal than milk. Heck, even the Inuit ate fruit:
The foods of these Eskimos in their native state includes caribou, ground nuts which are gathered by mice and stored in caches, kelp which is gathered in season and stored for winter use, berries including cranberries which are preserved by freezing, blossoms of flowers preserved in seal oil, sorrel grass preserved in seal oil, and quantities of frozen fish. Another important food factor consists of the organs of the large animals of the sea, including certain layers of the skin of one of the species of whale, which has been found to be very high in vitamin C. . . . Their fruits were gathered in the summer and stored in fat or frozen for winter use. (Weston Price, Nutrition and Physical Degeneration, pp. 71, 259).
Ned Kock has solved the puzzle:
Plants want animals to eat their fruits so that they can disperse the plants’ seeds. So they must be somewhat alluring to animals. Sugar plays a role here, but it certainly is not the only factor. The chemical composition of fruits is quite complex, and they usually contain a number of health-promoting substances, such as vitamins. For example, most fruits contain vitamin C, which happens to be a powerful antioxidant, and also has the ability to reversibly bind to proteins at the sites where sugar-induced glycation would occur. . . .
Two things must be kept in mind regarding fruits and their evolution. One is that dead animals do not eat fruit, and thus cannot disperse seeds. Sick animals would probably not be good candidates for fruit dispersion either. So the co-evolution of fruits and animals must have led fruits to incorporate many health-promoting attributes. The other is that seed dispersion success is correlated with the number of different animals that consume fruits from a plant. In other words, plants do not want all of their fruits to be eaten by one single animal, which must have led fruits to incorporate satiety-promoting attributes.
Plants need to make fruits relatively nutritious, satiating, and non-poisonous, in addition to deliciously sweet and visually alluring, because it is the only way to get a variety of animals to pick up their seeds and live long enough to poop them out somewhere else.
Of course, none of this philosophizing can tell us what the effects of fruit are on health or longevity, or how much if any fruit we should consume.
Plenty more on that in the future.
But next up, a series on the Masai, including sexuality and gender roles, their knowledge and use of hundreds of plants, whether they had any heart disease and how sure we can be, and why they had such massively low cholesterol, almost as low as Pygmies and Bushmen.Also coming up soon, can normalizing thyroid hormone abolish the risk of heart disease? What's with that temperature test that everyone either loves or hates? Plus a series on measuring and interpreting blood lipids, a couple of posts addressing whether insulin can block leptin signaling and whether blood triglycerides could be a starvation signal, why fat can cure carb cravings and when and if it may sometimes be better to just eat carbs, and lots more.
And none of that is meant to neglect the nowhere-near-done The New Genetics series (which will get much more interesting when I get into the controversial stuff) or the upcoming My Genetics series.
Stay tuned!