甜菜根中的硝酸盐可以降低血压

Nitrates in beetroot can lower blood pressure

 

甜菜根中的硝酸盐和一氧化氮可以降低血压。硝酸盐在我们的新陈代谢系统中起着重要作用。

　

　

 

人体可以将它们转化为一种叫做一氧化氮的信号分子，一氧化氮是血液流动的主要机制。它向你动脉中的细胞发出软化和放松(血管舒张)的信号，这个作用可以大大降低血压。

　

 

这是一氧化氮作用的基本说明。

一氧化氮机制降低血压的原理

 

人类饮食中硝酸盐(因此也是一氧化氮)的最大来源是蔬菜。甜菜根是最好的，大多数研究集中在甜菜根汁的补充。

 

2013年一项对254名参与者的回顾研究发现，摄入甜菜根汁能在短短几个小时内把血压降低4-10毫米汞柱。从这个角度来看，至少降低点据说可以减少14%的致命中风和9%的心血管疾病。

　

　

图示：一氧化氮作用的基本说明。

　

 

虽然甜菜根汁的长期效果还没有被检测出来，但它似乎不太可能是危险的。

 

摘要:甜菜根是硝酸盐的丰富来源，对我们的新陈代谢健康起着重要的作用。大量证据表明甜菜根汁可以在几小时内降低4-10毫米汞柱的高血压。

　

哪种蔬菜的亚硝酸盐含量最高

1.暴腌菜，刚腌不久的蔬菜含有大量亚硝酸盐。 
2。新鲜蔬菜煮熟后若存置过久，或不新鲜蔬菜中，亚硝酸盐的含量会明显增高，吃了过多的新鲜的叶菜类，如菠菜、芹菜、大白菜、小白菜、圆白菜、生菜、韭菜、甜菜、菜花、萝卜叶、灰菜、芥菜等，或者煮熟又放了很久的叶菜类。 
3.苦井水含较多的硝酸盐，当用该水煮粥或食物，再在不洁的锅内放置过夜后，则硝酸盐在细菌作用下可还原成亚硝酸盐。 
4.腌肉制

　

 

Nitrates in beetroot can lower blood pressure

 

Nitrates and nitric oxide in beetroot lower blood pressure. Nitrates are compounds that play a big role in our metabolic system.

 

The body can convert them into a signalling molecule called Nitric Oxide, which is a major mechanism related to blood flow. It signals to the cells in your arteries to soften and relax (vasodilation), an action that can greatly reduce blood pressure (5, 6).

 

Here is a basic illustration of the action nitric oxide has.

 

nitric oxide mechanism to lower blood pressure Photo source.

 

 

The largest source of nitrates (and therefore nitric oxide) in the human diet is vegetables. Beetroot is the best of the bunch, with most research focusing on beetroot juice supplementation (5).

 

A 2013 review study of 254 participants found that beetroot juice intake reduces blood pressure by 4-10 points (mm Hg) in just a few hours. To put that into perspective, a reduction of at least 5 points is said to reduce your risk of a life-ending stroke by 14% and cardiovascular diseases by 9% (7, 8).

 

While long-term effects have not yet been examined, it seems highly unlikely beetroot juice would be dangerous.

 

Summary: Beetroot is a rich source of nitrates that play an important role in our metabolic health. The weight of evidence suggest beetroot juice can reduce high blood pressure by 4-10 mm Hg in a matter of hours.

 

http://themindunleashed.com/2017/01/18-foods-scientifically-shown-lower-blood-pressure.html

　

　

Are Nitrates and Nitrites in Foods Harmful?

　

Dietary Nitrates/Nitrites Lower Blood Pressure and Have Major Benefits for Heart Health

If nitrite loses an oxygen atom, it turns into Nitric Oxide, an important molecule.

Nitric Oxide (NO) is a short-lived gas, which has various functions in the body (14).

Most importantly, it is a signalling molecule. It travels through the artery wall and sends signals to the tiny muscle cells around the arteries, telling them to relax (15).

When these cells relax, our blood vessels dilate and blood pressure goes down.

This is actually how the well known drug nitroglycerin works. It is a source of nitrate, which quickly turns into nitric oxide and dilates the blood vessels (16).

This can prevent or reverse angina, chest pain that occurs when the heart muscle doesn't get enough oxygen due to reduced blood flow.

Dietary nitrates and nitrites can also turn into Nitric Oxide, dilate the blood vessels and lower blood pressure (17).

Studies have shown that nitrate supplements, such as beet roots or beet root juice, can reduce blood pressure by up to 4-10 mm/Hg over a period of a few hours. The effect may be weaker in women (18, 19, 20).

Elevated blood pressure is one of the strongest risk factors for heart disease and stroke (the world's biggest killers), so the importance of this can not be overstated.

　

They Are Only a Problem When They Form Nitrosamines... Which Can Happen During High Heat Cooking
Unfortunately, there is a dark side to all of this.

When nitrites are exposed to high heat, in the presence of amino acids, they can turn into compounds called nitrosamines (25).

There are many different types of nitrosamines... and most of them are potent carcinogens (26).

They are among the main carcinogens in tobacco smoke, for example.

Because most bacon, hot dogs and processed meat tend to be high in sodium nitrite and they're high protein foods (a source of amino acids), exposing them to high heat creates the perfect conditions for nitrosamine formation (27).

It's important to keep in mind that nitrosamines mostly form during very high heat. Even though vegetables also contain nitrates/nitrites, they are rarely exposed to such high heat.

Nitrosamines can also form during the acidic conditions in the stomach.

BOTTOM LINE:
When nitrites and amino acids are present, carcinogenic compounds called nitrosamines can form during high heat cooking.

　

Are Nitrates and Nitrites in Foods Harmful?
https://www.healthline.com/nutrition/are-nitrates-and-nitrites-harmful