How Fat Lowers Your Blood Pressure
Hypertension (elevated blood pressure) is one of the triad symptoms of metabolic syndrome. Most of the hypertension that I see clinically is driven by insulin resistance as the underlying cause. I see this problem in a very large majority of the people in my office and I am seeing people younger and younger show up with continually increasing blood pressure.
In medical school, we were taught to treat “borderline” or “slightly elevated blood pressure,” through “lifestyle changes” which was another way of saying exercise, caloric restriction & hold the salt. But most physicians today will tell you that exercise, salt & caloric restriction doesn’t work. When asked why the 34 year old male in my office suddenly has elevated blood pressure, the only explanation we had was it is a “genetic problem,” or “blood pressure naturally goes up as we get older,” or “you’ve been eating too much salt,” and they are started on blood pressure medication and sent on their way. But, as time went on, I found that I had to keep adding more and more blood pressure medication to control the continually rising blood pressure of the patients in my practice.
Most of these people will have a progressive elevation in blood pressure over time, and these blood pressure (anti-hypertensive) medications are/were continually raised until the person is on four or five different blood pressure pills at maximal doses. Again, when questioned why, their genetics are blamed and that is the end of it. Or is it?!
What shocked me was that when I took patients off of salt & caloric restriction, and placed them on low carbohydrate high fat diets (and yes, I gave them back their salt), their blood pressure normalized. I noticed that as their fasting insulin levels began to fall, their blood pressure began to return to normal.
What?! Blood pressure rise is caused by insulin?!
Ummm . . . Yes!
I am a prime example. During the first few years of my medical practice and reserve military service, we had routine vitals checkups. I was working out 3-5 days a week with weights and running 3-5 miles 2-3 times a week and restricting my calories to 1500 per day. So, I thought I was in pretty good shape. However, it was not uncommon for for the nurse to raise her eyebrows at my blood pressure readings in the 140-160 systolic and 85-98 range diastolic. “Oh, it’s the lack of sleep last night,” or “it’s the caffeine I had this morning,” would be my excuse. But I was making a lot of excuses, and in light of those excuses, my caloric restriction, exercise and salt restriction, I was also still gaining weight.
By the 5th year of my medical practice, I weighed 60 lbs heavier than I do today and I struggled to keep my blood pressure under 150/95. I was violating my own counsel . . . don’t trust a fat doctor for nutritional advise. (Or, was that advise from Dr.House?)
After cutting out the carbohydrates (I’ve kept my carbohydrate intake < 20 grams per day), moderating my protein intake and eating all the fat I am hungry for each day, my recent physical examination at the beginning of June 2016 revealed my blood pressure at 112/64. I don’t remember ever having blood pressure that low. And to be honest, I didn’t sleep well the night before my exam due to a number of middle of the night patient calls.
When I first started treating the insulin resistance problem in the human, rather than the blood pressure problem, I began to see immediate reductions in blood pressure within one to two weeks. So much of a reduction that if I didn’t warn the patient that they should begin to back down their blood pressure medications, they would experience symptoms of dizziness, light-headedness, headache and a few patient’s nearly passing out. On a low-carbohydrate, high-fat (ketogenic) diet you need salt (sodium, potassium, & magnesium).
The process of burning fat as fuel causes you to lose increased amounts of sodium & potassium, and you have to replace these electrolytes. A number of my patients begin a low-carbohydrate, high-fat diet and are afraid of increasing their salt intake. Not replacing these electrolytes while on a ketogenic diet can also lead to low blood pressure, dehydrate and dizziness.
I often wondered why applying a ketogenic diet had such a profound effect on blood pressure so quickly. Dr. Robert Lustig helped answer that question for me.
In order to understand how the Standard American Diet (we call it the SAD diet in my office) raises your blood pressure, it is important to understand how the body processes the basic sugar molecule. Sugar is one glucose molecule bound to a fructose molecule. This is broken down in the body and 20% of the glucose is metabolized in the liver, the other 80% is sent on to be used as fuel throughout the body. Fructose, however, is where the problems arise. 100% of the fructose is metabolized in the liver, and the by product of fructose metabolism is increasing the liver’s production of MORE glucose and the byproduct of uric acid. Uric acid is produced and this inhibits the production of nitric oxide. The diminished nitric oxide in the presence of an increased level of glucose (stimulating increased insulin production due to eating starches) constricts the blood vessels and raises blood pressure. Yes, that donut you just ate raised your blood pressure for the next 12 hours.
The mechanism that fructose containing carbohydrates, sugars and starches raise blood pressure, cholesterol and cause weight gain can be seen in the really complex diagram found in Dr. Lustig’s 2010 article:
So, how do you lower your blood pressure through diet?
First, cut out all the simple sugars. These include anything with table sugar, high fructose corn syrup and corn syrup. (This is why people with any change in diet see some improvement in weight and blood pressure as they remove the simple sugars like candy, sugared drinks and pastries from their diet.)
Second, limit your overall intake of other sources of carbohydrates including any type of bread, rice, pasta, tortilla, potato, corn and carrots. Realize that carbohydrate in fruit is fructose, and when taken with other forms of glucose can have the same effect as table sugar – it can and will raise your blood pressure, as well as halt or cause weight gain.
Third, if you are taking blood pressure medications, see your doctor about close monitoring of your blood pressure as it can and will drop within 2-4 weeks of making these dietary changes.
Maintaining ketosis is really important for weight loss and blood pressure control. I am very much an advocate of using real food for this process, but I have also found that the use of exogenous ketone salts aid significantly in maintaining ketosis. I have found that exogenous ketones are the next step in bridging the difficulty of day to day maintenance of ketosis.
It isn’t making the mistakes that’s critical; it’s correcting them and getting on with the task that’s important. If you’ve been calorie restricting and exercising to lower you blood pressure, don’t fret. A simple change in your diet focused on restricting starches and carbohydrates has been demonstrated in my office to be more powerful than many of the blood pressure medications we’ve used for years.