Salt and High Blood Pressure

Increased intake of salt is one of the main factors responsible for high blood pressure. There is dose dependant relationship between salt and high blood pressure. People emphasizing more on low salt diet are less prone to high blood pressure. We often get confuse with words like salt and sodium but this two terms are used interchangeably. In any food package you will find words like “low salt” but you if you are referring to nutritional food panels, term “sodium” would be displayed. Salt has indeed very important role in maintaining our body functions. It regulates blood pressure, helps in transmission of nerve impulses, and maintaining cell integrity and fluid balance.  However above mentioned function can be accomplished only in presence of potassium. Thus we require adequate balance between sodium and potassium. This balanced ratio of potassium to sodium is known as k-factor. Intracellular fluid is predominant in potassium and extracellular fluid has more sodium.        

An exchange between this ions results in generation of nerve impulse which triggers certain important function like pumping of heart or release of acids or enzymes by gastric cells into stomach etc. Generally for every 3 molecules of potassium, one molecules of sodium gets exchanged. Thus ratio of 3:1 of potassium and sodium respectively or we can say that k factor of 3 is required to maintain normal body functions.Distortion in such ratios may lead to life threatening condition.

The ratio is same for all animals but in case of plants, as they lack in nervous system and don’t require any nerve impulse, they require less sodium and ratio is around10 or 20. That’s why plants are rich in sodium as compared to potassium.

Salt and high blood pressure

Human body has natural ways to regulate excess amount of sodium, like by facilitating sodium excretion via kidney. But in certain situation, kidney might not be able to excrete sodium efficiently. In such cases, kidney pumps more sodium into circulating blood that causes constriction of blood vessels and increase in resistance to blood flow and ultimately increase in blood pressure. Increased sodium level also attracts water, and thus causes increase in fluid volume.  It dilutes the excess sodium in extracellular fluid and such increased volume of water and sodium is excreted by kidney. During this process blood pressure gets elevated and if such elevation occurs more often, the blood volume increases significantly, vascular system adopts to increase volume and blood pressure stays elevated.

Various organisations like national health and medical research council (NHMRC). National heart foundation of Australia etc. recommends daily intake of 2300mg of sodium for a healthy individual.  Daily intake of 1500mg of sodium is recommended for people like

  • Above age of 51 yrs.
  • An African American
  • Suffering from diabetes or chronic kidney disease.

For Americas of age 2yrs or older, daily recommended value is 3400mg of sodium.  Diuretics help in lowering blood pressure by excretion of excess fluid and sodium by kidneys, but it also eliminates potassium. Therefore it is necessary to include potassium supplement along with diuretics. The people with low salt diet or restricted salt diet should reduce dose or avoid use of antihypertensive drugs like beta-adrenoceptor blocker, angiotensin converting enzyme etc. because it may lead to condition of hypotension.

Tips to reduce salt intake

Salt and high blood pressure goes hand by hand, which means that increases in salt intake increases blood pressure and if salt level decreases blood pressure also decreases. So, the easy way via which hypertensive patients can lower blood pressure by reducing their sodium level in body. But which foods need to be restricted? Well first look at the level of salt supplied by various foods. Drinking water supply 1% of our salt intake. Fruits, vegetables and dairy products supplies with 12 % of daily salt need and cooking add 5%.  But naturally we can’t stop drinking water or eat fruits and vegetables. Processed, manufactured or packaged foods are loaded with salt i.e. 70-75% of salt, so you basically need to cut down intake of processed foods.

Always buy fresh fruits and vegetables. Canned foods are loaded with salt as salt acts as preservative. Whenever you go for buying foods, check for the label like No added salt, reduced salt, unsalted, sodium free or low sodium.  If the salt level is above 100mg, don’t buy that product. Even while cooking add  less salt, the low salt level can be compensated by using garlics, onions, shallots, spices and other herbs. However we can also reduce salt by bringing small changes in to our diet.  An amount of K- factor in various food preparation is mentioned in Table 1 below:

K Factor in Foods

salt and high blood pressure

List of food items with low salt level

Here is a list of that you need to include into our daily diet is given below-

Fruit and fruit juices

Fruits are highly recommended and at least 4-5 servings of fruit should be consumed in a day. Fruit are rich source of sodium, potassium and calcium, vitamins etc. but it’s not possible to eat all fruits in a day. But you can try for variety of fruits every day. Consumption of fruit in form of juice or as topping in cereals or salads provide with equal benefits. Fruits can eaten along with meal

Precaution
Canned Fruit or fruit juice are not loaded with salt, so there’s no harm in opting for such preparation. But many preparations are loaded with high sugar and preservatives and little of real fruit. So, I would suggest going for fresh fruits or fruit juices, as it will provide with maximum benefit. 

Vegetables                                                                                                                   

Always fresh or frozen vegetables should be selected in your diet. Avoid canned vegetables. However, mixed frozen vegetables can be considered but be careful with the sodium added with such preparation. Vegetables are either boiled or cooked, don’t add salt while boiling and be careful while selecting the type of oil for cooking. Beans are good for health but avoid canned beans.

Oil                                                                                                                                       blood pressure

Oils can be used for cooking or for dressing purpose. Thus, the choice of oil varies according to its use. The oil rich in poly unsaturated fatty acid like sunflower oil or safflower oil can be utilised for dressing purpose but shouldn’t be utilised for cooking purpose. This is because, while heating at high temperature these oils changes their natural structure and converts into harmful substance that may increase risk of heart disease or cancer. Oil mainly recommended for cooking are olive oil, peanut oil or sea same oil.

Cereals

Cooked cereals or ready to eat cereals, both provide equal benefit. Use only those cereals that consist less sodium.  But don’t add salt while cooking cereal. Instead of salt you can add Tabasco, as 6 drops of Tabasco provides with only 15mg of salt and secondly it enhances flavour. Use of milk should be avoided with cereals because 1 glass of milk provides with 120mg sodium and 375mg potassium.

Breads

Breads or baked foods provides with high amount of salt. Use low salt breads like oroweat breads where 2 slices of oroweat adds only 10 mg of salt. If oroweat bread is not available, check label and select breads with low sodium content.

Fish

Fish consist of less amount of polyunsaturated fat but high amount of salt, over 75mg per serving, but this salt is not present in the form of sodium chloride. Fish serving for 2-3 times a week provides with good health benefit. Be careful while eating shell fish as they provide with 25% of daily salt allowance of 800mg. fish must be consumed in the form of Broiled, baked, poached. If you want to fry, use olive oil and don’t add salt. Instead of salt use Tabasco and ginger, onion or garlic can meet flavour requirement. 

Beverages

Most of the water intake is in the beverages like tea, coffee, sodas etc. Hypertensive patient requires drinking at least 8 ounce glass of water daily. Before drinking make sure that water is less in sodium. Charged seltzer water can be the best choice as drinking water as they contain minimum amount of sodium. Next option would be to boil water first and then drink.

Soup

People doesn’t prefer to drink soup with low sodium as it taste bad, however, taste can be improved if you 4-6 drops of Tabasco or table spoon full of horseradish. Choice of onion, mustard or garlic soups will be healthier. Please don’t buy canned or dry soup preparation as they are consisting of rich deposits of salt.

Spices, herbs and flavouring agents

Since long time, we are using herbs as flavouring agent and preservative. Herbs help us too limit our sodium intake. One spoon of herbs provides with less than 1 mg of sodium and about 20-30mg of potassium. Garlic has been used long for as spice condiment and plays important role in reducing high blood pressure. Others herbs that can be helpful in treatment of hypertension are gingko biloba and hawthorn, gingko biloba help in narrowing down the blood vessels and thus increase blood flow.