5. “Healthy” Greens with a Deceptive Dark Side: Oxalates
This one might surprise you. The same food can be an ally or an enemy to your bones depending on how you prepare it. Take spinach, for example. Raw in your salad, it might actually be stealing calcium. Cooked, it becomes a great source of it. Why the transformation? It all has to do with compounds called oxalates. Oxalates, found in high amounts in foods like spinach, chard, and rhubarb, are like magnets for calcium. When you eat these foods raw, the oxalates bind with calcium in your intestine, forming crystals that your body cannot break down or absorb.
A cup of raw spinach has an impressive 245 mg of calcium, but it also has 750 mg of oxalates. The result? You barely absorb 5% of that calcium. Not only do you miss out on the calcium, but these calcium-oxalate crystals can accumulate in your kidneys and form painful kidney stones. But here’s the magic of cooking: when you boil spinach for just three minutes and discard the water, you eliminate up to 50% of the oxalates. If you steam it, you remove about 30%. Suddenly, that spinach becomes a true friend to your bones.
4. The Anti-Nutrient Trap in Legumes and Grains: Phytates
Similar to oxalates, another group of compounds called phytates can prevent you from getting the minerals you need. Found in legumes (beans, lentils), nuts, seeds, and whole grains, phytates are anti-nutrients that plants use to protect their seeds. When you eat these foods, the phytates latch onto minerals like calcium, iron, and zinc, wrapping them so tightly that your intestine can’t absorb them. It’s like having a treasure chest of minerals that you can’t open. Phytates can block up to 80% of the available calcium in a food.
This doesn’t mean you should avoid these foods! They are incredibly valuable sources of plant protein, fiber, and other benefits. The trick is in the preparation. If you soak legumes for 8 to 12 hours before cooking them, you activate enzymes that disarm these anti-nutrients, reducing phytates by more than half. Adding a splash of lemon juice or vinegar to the soaking water helps break them down even faster. Germinating or sprouting legumes is even better, as it eliminates almost all the phytates and even increases their vitamin content.
3. The Sweet Poison: How Sugar Crumbles Your Skeleton
Now we’re getting to the bigger enemies. Sugar, that white powder that sweetens your life, can be embittering the future of your skeleton. When you consume sugar, your body releases inflammatory molecules called cytokines. These molecules act like an alarm system, but in this case, they trigger the osteoclasts—the cells that destroy bone. At the same time, they inhibit the osteoblasts, the cells that build new bone. If you eat sugar every day, you’re keeping your body in a constant state of bone-destroying inflammation.
But that’s just the beginning. Sugar also makes your blood more acidic. Your body needs to maintain a slightly alkaline pH. To neutralize the acid from sugar, your body pulls alkaline minerals from wherever it can find them. And where is your body’s largest mineral reservoir? Your skeleton. Your body literally extracts calcium, magnesium, and potassium from your bones to buffer the acid. Sugar also spikes cortisol, the stress hormone, which is a known enemy of bone health, and it directly interferes with vitamin D’s ability to help you absorb calcium. The first step is to become a detective and find where the sugar is hiding. Read labels for corn syrup, dextrose, maltose—any word ending in “-ose” is sugar.
2. Refined Flours: Sugar in Disguise
If sugar is a direct enemy of your bones, then refined white flours are its sneaky cousin. White bread, white pasta, cookies, and pastries are all essentially sugar in disguise. Your body processes these foods so quickly that their effect on your bones is almost identical to eating pure sugar. When grains are refined, all the fiber and nutrients that slow down their absorption are stripped away. A piece of white bread turns into glucose in your blood in a matter of minutes. This causes your pancreas to panic and release a flood of insulin. This mountain of glucose and insulin generates the same inflammatory cascade we saw with sugar, accelerating bone demineralization.
Worse yet, whole grains come packaged with minerals like magnesium and zinc that your body needs to use calcium properly. Refined grains not only lack these minerals, but your body has to use up its own mineral reserves just to process them. It’s like paying to be robbed. The solution isn’t to eliminate carbs, but to choose complex ones that come with their fiber intact: whole-grain rice, quinoa, and 100% whole-wheat bread release their energy slowly, protecting your bones from the acid and inflammatory attack.
1. The #1 Enemy of Your Bones: Trans Fats
And with this, we arrive at the great enemy, the food that orchestrates the most devastating attacks on your bones: trans fats. These are the partially hydrogenated oils found everywhere in margarine, industrial baked goods, microwave popcorn, and fast food. They are artificial fats that the food industry created to make products last longer on shelves. When the industry takes a liquid vegetable oil and pumps it with hydrogen to make it solid, it creates a deformed fat that your body doesn’t recognize. When these deformed fats get incorporated into your cell membranes, everything starts to go wrong. But their most cruel attack is against your bone-remodeling balance. Trans fats tip the scales so that bone is destroyed much faster than it is built. It’s like trying to repair a house while a demolition crew is working at double speed.
But here is the most treacherous part: trans fats sabotage vitamin K2 in your body. Vitamin K2 is the crucial nutrient that acts like a traffic cop, directing calcium into your bones and away from your arteries. Without it, calcium just floats around your blood, unable to get where it needs to go. Trans fats block the enzymes that activate vitamin K2. They cut off the communication. This sabotage is what makes trans fats the ultimate enemy. They don’t just attack directly; they cut off your supply lines and disable your repair systems. The bone you do have becomes worse quality—like poorly tempered glass, ready to break from an impact that it should have been able to withstand. The good news is that trans fats are completely avoidable. Read labels and if you see “partially hydrogenated oil,” leave that product on the shelf. Replace them with natural, healthy fats that nourish your bones, like extra virgin olive oil, avocados, nuts, and seeds.
Conclusion
So there you have it: the top enemies of your bones. From the sodium that silently leaches calcium to the trans fats that sabotage your entire repair system, each one attacks in a different way. But they all work toward the same goal of weakening your skeleton. The best news is that you now have the knowledge to defend yourself. Prepare your legumes properly. Cook your leafy greens. Choose whole grains. And avoid ultra-processed foods packed with sugar, salt, and trans fats. These are simple changes that make a huge difference. Your bones are not static structures; they are living, dynamic tissue, and it is absolutely worth the effort to protect them.
Source: Dr. Iñigo Martín