Health Benefits Of Nuts & Seeds
Next Time You Reach For A Bag Of Peanuts, Here's Something You Should Know First
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By now, we should all know that nutrition and body weight is not all about calories. It took a while, but we’ve managed to convince many calorie-counters that it’s the quality of our food (and its effects on our hormones), and not the quantity of food we eat that contributes to significant changes in body composition. Research shows that dieting by cutting your portion sizes simply doesn’t work. In one study, 66% of individuals who cut calories to lose weight ended up fatter two years later than they were when they started their diet. And when dieters cut down on calories, they cut down on foods that are high in fat.
In theory it makes sense. Among the macronutrients, fat has the highest amount of calories per gram: 9 calories per gram, while both carbohydrates and protein have only 4 calories (and alcohol has 7 cruel calories per gram). This is the basis for the low-fat craze of the '80s and '90s and, unintentionally, perhaps, the obesity epidemic. It turns out that fat doesn’t make you fat. Part of the problem is that low-fat diets are often high in carbs, especially from rapidly digested sources like bread (including whole wheat bread), rice, and sugar. More important is the type of fat that is eaten. The biggest villain in our diet was partially hydrogenated oil, the primary source of trans fats, that were no longer deemed “generally regarded as safe” by the FDA in November 2013. Saturated fats, the type of fat predominantly found in animals, has also been blamed for causing health problems, but this has been difficult to prove scientifically. The association between saturated fats and cardiovascular disease is very questionable or at the very least much more complex than we once thought.
Among the good fats are the heart-healthy mono- and polyunsaturated fats found in plant foods and marine animals. And at the top of the high-fat plant list are nuts and seeds, basically small packages of high calorie fat bombs. Avocado should be mentioned here — it is, after all, renowned to be a very fatty fruit. The strange thing is, though, that the avocado doesn’t really belong in our time. It shouldn’t even exist anymore. Their natural hosts for dispersing its huge seeds were mammoths, giant ground sloths, and other megafauna that have been extinct for 13,000 years. How avocado survived in the wild until humans came along to propagate it is still a puzzle. Nuts and seeds, on the other hand, have evolved to rely on rodents and birds for their dispersal for the last 60 million years. That also means that nuts were already around when humans showed up on the stage. And it was love at first crunch.
We Skipped Fruit And Went For The Nuts
Nuts are a very attractive food source because of their caloric content. But nuts and seeds are the botanical equivalent of an embryo, and while the tree is interested in spreading its seed far and wide, it’s not interested in having them eaten by predators. That’s why they’ve evolved hard outer shells, to make it physically difficult to break through, and chemical defenses (like tannins) to discourage consumption. Nevertheless, nut and seed mortality in the wild is still very high. But at least the trees made it difficult for us to gorge ourselves on them. Many nut trees have mast years, meaning that they, as a group, periodically and synchronously produce a huge crop of nuts. This strategy ensures a higher nut and seed survival rate than producing a smaller yearly crop. But when the trees did mast, the nut lovers had a feast. Humans evolved to seasonal and spatial changes in food resources and, out of necessity, became omnivorous.During the fall and during mast years, early humans ate as many nuts as they could gather and crack open. They even evolved the teeth and jaws to favor nut consumption over fleshy fruit. Recent analyses of teeth belonging to our human ancestors suggest that we ate mostly root vegetables and nuts, along with insects and meat. The thickness of our enamel and the strength of our bite indicate that, unlike our fruit-loving chimpanzee cousins, early humans were able to chew hard crunchy stuff. But it wasn’t easy and it certainly wasn’t convenient.
Today, nuts and seeds are probably the least inconvenient food. Not only can we get bags of shelled almonds, we can buy them sliced, shaved, ground, halved, slivered, roasted, salted, Tamari-flavored, chocolate-coated, and candied. Imagine how long it took our caveman ancestor to break through just one walnut with his teeth and/or a pair of rocks. The number of calories spent on trying to get to the nut might not justify the number of calories provided by the nut itself. But in today’s world of convenience, there are few whole foods that fit the category of “snack.” Shelled nuts make an excellent snack, and like any other snack, they’re easy to overeat. Like potato chips and cats, you can’t have just one.
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