What’s Really Behind Preeclampsia? The Two Theories That Changed How I Eat

I used to think there was one answer. I wanted one. I wanted a doctor to look at my chart and say, “Here’s the single reason this is happening to you, and here’s exactly what to do.” Instead, I got fragments. A nurse handing me a pamphlet about low-dose aspirin. A midwife whispering about protein. A forum post insisting that salt was either my enemy or my savior, depending on who was typing. When I finally sat down and dug into the research, both the old Brewer archives and the newer studies, I realized something that nobody had laid out clearly for me. There are actually two completely different answers to the question “What is the number one cause of preeclampsia?” And they both matter, depending on which woman you are and which pregnancy you’re in.

Let’s walk through both of them, not as competing theories you have to pick between, but as two lenses that, when you put them together, finally give you a full picture of what’s happening inside your body.

The Brewer Lens: Maternal Malnutrition and the Albumin Crisis

Dr. Tom Brewer would have answered the question without hesitation: preeclampsia is a nutritional deficiency disease. He called it metabolic toxemia of late pregnancy, and he believed the primary culprit was a mother’s failure to eat enough protein, calories, and salt to support the massive blood volume expansion pregnancy demands. If that sounds similar to how I described the root cause of preeclampsia in another post, it’s because Brewer’s entire framework rests on that single cascade. But here I want to zoom in on what he saw as the very first domino to fall: the liver’s inability to produce enough albumin.

Albumin is a plasma protein that acts like a sponge inside your blood vessels, holding fluid where it belongs. Your liver makes it from the amino acids you eat. If you’re short on protein, or if you’re not eating enough calories to spare that protein from being burned as fuel, your liver simply runs out of raw material. Albumin levels drop. Fluid leaks out of your bloodstream into your tissues, that sudden, rapid swelling in your face and hands that often shows up right around the week preeclampsia most common, 34 to 37. Your blood volume shrinks, your blood thickens, your kidneys panic, and your blood pressure spikes. In Brewer’s view, that spike isn’t the disease. It’s your body’s desperate, intelligent attempt to keep your baby alive when your circulatory system is running on empty.

Brewer worked with thousands of low-income, malnourished women in California, and when he put them on his protocol, 80 to 120 grams of whole-food protein, 2,600 calories, salt to taste, their preeclampsia rates plummeted. He was convinced he’d found the root cause and the solution. And for many women, especially those whose diets were genuinely inadequate, he was right.

The Modern Medical Lens: Defective Placentation and the Narrowed Artery

Here’s where mainstream obstetrics parts ways with Brewer. Today, the number one cause of preeclampsia is understood not as a problem with the mother’s diet, but as a problem with how the placenta implanted in the very first weeks of pregnancy. It’s not that nutrition doesn’t matter, it absolutely does, but the initiating event, in this view, happened long before you ever picked up a fork.

Around weeks 8 to 12, specialized fetal cells called trophoblasts are supposed to invade the mother’s uterine wall and completely remodel the tiny spiral arteries that feed the placenta. They tear down the muscular, high-resistance walls and rebuild them as wide, floppy, low-resistance channels that can carry a massive volume of blood. When this remodeling fails, due to genetics, immune factors, or some other unknown trigger, the arteries stay narrow and stiff. The placenta gets less blood than it needs from the very beginning.

Fast forward to the third trimester, when your baby’s growth demands spike. The narrow pipes can’t deliver enough oxygen. The placenta becomes hypoxic, damaged, and inflamed. It sheds toxic proteins into your bloodstream, triggering widespread endothelial dysfunction, the inner lining of your blood vessels gets angry, leaky, and constricted. Your kidneys start spilling protein, which is why doctors track the protein in urine threshold so closely. Your blood pressure climbs. The condition progresses through the 4 stages of eclampsia, from gestational hypertension to preeclampsia to severe preeclampsia to eclampsia with seizures. And none of it, in this model, started with what you ate. It started with an implantation event you had no control over.

Why Both Explanations Matter and How They Interact

Here’s where things get interesting, and where I stopped feeling like I had to pick a side. These two causes aren’t mutually exclusive. They’re layers of the same problem. Think of it like plumbing. The modern medical cause is about the size of the pipes: if your spiral arteries are narrow and stiff, you have a structural bottleneck. The Brewer cause is about the volume and pressure of the water flowing through those pipes: if your blood volume is low and your blood is thick and dehydrated, even wide pipes can’t deliver enough flow.

A woman with a mild structural placental defect might sail through pregnancy without ever developing preeclampsia, if her blood volume is robust, her albumin levels are high, and her circulation is fully expanded. The rich, fluid blood supply compensates for the narrower pipes. Conversely, a woman with perfect arterial remodeling might still crash if her blood volume collapses from months of calorie restriction, salt avoidance, and protein insufficiency. And a woman with both, a structurally compromised placenta and a nutritionally depleted body, is in the most dangerous position of all. That’s why trying to avoid high risk pre-eclampsia means paying attention to both sides of the equation.

What This Means for Your Plate (And Your Peace of Mind)

If the number one cause of preeclampsia has two faces, then a smart prevention strategy addresses both. The structural piece the spiral artery remodeling, is largely outside your control. It happens before most women even know they’re pregnant. Modern medicine’s answer to that is low-dose aspirin, started early in high-risk pregnancies, which helps reduce inflammation and improve placental blood flow. That’s a conversation for you and your provider.

The nutritional piece, though? That’s where the Brewer diet steps in, and it’s entirely within your power. By eating enough protein to keep your liver making albumin, enough calories to spare that protein, and enough salt to hold fluid in your vessels, you build the biggest, richest, most resilient blood supply your body can produce. You maximize the flow through whatever pipes you have. You also avoid the foods making preeclampsia worse, the diuretic teas that shrink your blood volume, the low-sodium products that strip away osmotic pressure, the sugary snacks that spike inflammation and damage your blood vessel linings. And you steer clear of the 5 worst foods for blood pressure: processed junk, refined sugar, industrial seed oils, and anything that leaves your endothelium more inflamed than it was before.

I know this can feel heavy. You want a single cause, a single fix. But there’s something freeing in knowing that even if you can’t control the structural side, you can absolutely control the nutritional side. Every hard-boiled egg, every glass of whole milk, every pinch of salt on your vegetables is a vote for your blood volume. It’s a buffer against whatever hand you were dealt at implantation. It’s not a guarantee, nothing in pregnancy is, but it’s meaningful, and it’s yours to do.

The Bottom Line from My Kitchen Table

The number one cause of preeclampsia depends on who you ask, and when you ask, and which layer of the problem you’re looking at. For Dr. Brewer, it was malnutrition. For modern obstetrics, it’s defective placentation. The truth, as far as I can tell, is that they’re two halves of the same story, one about the pipes, one about the water. You can’t rebuild your spiral arteries with a meal plan, but you can give your body the fullest, richest blood supply possible to navigate whatever arteries you have. And that matters. It matters a lot. Come find me on the blog if you’re working through this yourself. Whatever you’re eating today, you’re already doing a good job.