Should I cut back on salt since I have high blood pressure?

[teo123]

A few weeks ago, my doctor measured my blood pressure and heart rate. My blood pressure was 170/110 and my heart rate was 158 beats per minute. So, my doctor prescribed me a beta-blocker called Bisoprololfumarate and told me to cut back on salt.
Now, the evidence that beta-blockers are safe, if not beneficial, is overwhelming: I have read somewhere (I think it was on ScienceBasedMedicine) about a study that was preventatively giving beta-blockers to people without measuring their blood pressure (so, we can assume most of them had normal or even low blood pressure), and there turned out to be no difference in all-cause mortality between people who were receiving beta-blockers and people who were receiving placebo. So I started taking them.
However, I don't know how much science the recommendation to eat less salt is based on. I know WHO recommends people not to take more than 6 grams of salt per day, and that the standard American diet includes around twice that amount. However, there doesn't appear to be a correlation between salt intake and heart disease. For example, a typical Japanese diet includes around 40 grams of salt per day, yet Japanese have significantly lower mortality from heart disease than Americans do. And I really like salty food. So, what do you think, should I try to eat less salt?

[brimstoneSalad]

At your age, high blood pressure is rather concerning (and unusual, I think). Are you obese?
You should probably start exercising more. I think that will make more difference than a dietary sodium reduction.

You can also drink more water and eat more potassium (bananas, vegetables, etc.), which will flush out extra sodium/replace the lost potassium. Obviously don't go overboard on water, but try to meet recommendations. Most people do not.

[teo123]

At your age, high blood pressure is rather concerning

Really? I thought blood pressure is not as much of a concern for young people such as me and that I am being a bit of a hypochondriac by bothering my doctor with it.

Are you obese?

Well, I am slightly overweight. I am 75kg heavy and 164cm tall. I used to be significantly underweight before I started taking Risperidone.

[brimstoneSalad]

It's not concerning in the same way, but rather it's concerning regarding an unknown underlying cause, not that it's an immediate risk of death. If your weight and likely activity level explain it then it's no longer concerning (as I understand it, it's not rare among obese children).
You should consider getting a blood pressure tracker and work on changing habits, like increasing activity, to see if you can get it under control. It's probably just that. But if not, it could be another underlying condition.

[teo123]

Anyway, I was carrying an EKG holter a few days ago, and my cardiologist increased my Bisoprolol dosage from 1.25mg/day to 2.5mg/day. My blood pressure was 140/85. I was walking 10 km per day for a few weeks, but, apparently, that didn't decrease my blood pressure and pulse enough.

[brimstoneSalad]

Anyway, I was carrying an EKG holter a few days ago, and my cardiologist increased my Bisoprolol dosage from 1.25mg/day to 2.5mg/day. My blood pressure was 140/85. I was walking 10 km per day for a few weeks, but, apparently, that didn't decrease my blood pressure and pulse enough.

It will probably take longer than that. Get something like a fitbit if you can and keep an eye on it. Keep up the good walking habit and talk to your cadiologist at your followup. That's all you can do.

If he really thinks you're at immediate risk, then cutting back on salt isn't necessarily a terrible idea. Mechanistically, it does reduce risk. Salt = water retention = short term increase in blood pressure. Just keep in mind that only lowers your overall risk much on the day (or even hours) you eat less salt and doesn't compound greatly over time to reduce your risk more -- unlike exercise which will improve your fitness and lower other risk factors like high BMI more and more over time.
If you're over weight, a calorie deficit is more important than salt restriction.
If salt is what helps you eat healthy things like vegetables, then there's a good reason to *not* focus on it if the alternative is eating more sugar and other low sodium but unhealthy processed foods. (This is, FYI, probably why it doesn't correlate on a population level, high salt diets are also sometimes high vegetable ones and vegetables are far more important than salt restriction on mortality at that scale)

That said, talk to your doctor about why you want to continue using salt and about weight and activity goals.
Also, talk to your doctor about lowering salt intake if you're going to. A sudden significant drop could leave you over-medicated and cause light headedness or something.
Basically just talk to your doctor before you make any decisions.