Many people mistakenly believe that fats will cause high blood pressure. This is an outdated belief caused by reports in the 70s that dietary cholesterol increased blood cholesterol, and fat in our diets made us fat. This was a concern where blood pressure is concerned, as high blood cholesterol and obesity are driving causes of high blood pressure. However, following recommendations to not eat as much fat, and especially animal fats, we found the problem only got worse. Why?
The mistake we had made in the 70s was to try and place the blame on a whole macronutient, focusing too much on the broader picture and not accepting nuances. The fats that were making Western nations ill were all highly processed, refined fats. Trans fats, the brown oil from deep frying, and burnt animal fats from slow roasting and grilling. These fats are terrible for our bodies, as they cause oxidation of the cells, which leads to internal damage, obesity, a weakened immune system, lethargy, stress, damaged arteries, clogged arteries, and eventually death.
On the other hand, as we found out later, the fats that were being blamed are actually very good for us. Dietary cholesterol does not raise blood cholesterol in the long term, nor do unprocessed saturated fats. In fact, eating these types of fats increases our amount of high density cholesterol, the good kind, whilst decreasing low density cholesterol and triglycerides. This means lower inflammation, but also fewer high density fat cells which could attach themselves to injured artery walls and cause blockages.
Animal fats, especially from fish, eggs, and naturally-reared red meats, are essential sources of omega 3 oils, as well as of fat-soluble vitamins. Omega oils are one of the best antioxidants we could have, but when we focus too much on plant fats we eat an excess of omega 6 and too little omega 3. When the ratio of omega oils is out of balance, then we do not gain these antioxidant benefits. Therefore, we must balance plant fats with animal ones. And all natural fats help us carry vitamins around our bodies, which further reduces inflammation and damage to the artery walls. When the artery walls are less damaged, our low density cholesterol does not stick to the walls or form plaques, protecting us against heart disease.
But another aspect of why we suffered increased blood pressure is what we replaced the fats in our diets with. When fats were no longer an option, we replaced their flavors with simple carbs and salt. Both of these have been found to increase blood pressure. Nowadays we all follow guidelines to eat the right amount of salt, not too much, nor too little, so anyone who is even trying will not be suffering blood pressure problems due to salt. Carbs are another story, though.
Because carbs are lower in calories per gram than fats, when we replace fat in our diet with carbs, we eat a lot more carbohydrate. This amount of carbohydrate is too much for our bodies. It spikes our blood sugars, which spikes our insulin, which results in glucose being stored in our muscles and liver. For every gram of this glucose we store, we need to store three grams of fluid. The end result of this is more fluid in our bodies, which increases pressure, but also less fluid for our essential processes, such as urine production. This means some parts of us dehydrate and others suffer high pressure. What is more, there is only so much glucose our bodies can store. Over a certain amount, our insulin moves the glucose to our fat cells. This means that if we spike our blood sugar too fast, the glucose becomes fat too quickly, which then results in increased hunger. This cycle eventually causes obesity, which is a leading cause of high blood pressure.
If we swap most of our carbs for fats, and ensure that the remaining carbs are whole grains, chilled cooked starches, and combined with fiber and fats to ensure they are slow-release, then we limit the negative effects of carbohydrate. This results in less fluid retention, clearer arteries, less body fat, and over all lower blood pressure.