Monday, 21 April 2008

Should you be watching your sodium intake?


According to the World Health Organization, hypertension is the leading risk factor for death in the world and according to Blood Pressure
Canada, it's the leading risk factor for death in Canada, causing most of the strokes and heart disease. High sodium intake has also been linked to increased severity and frequency of asthma, osteoporosis, stomach cancer, kidney stones and worsening of symptoms and signs of congestive heart failure.

Excess dietary sodium is said to be the cause of hypertension in at least one million Canadians. In Canada today, 46% of women and 38% of men over 60 years of age are taking anti-hypertensive medications.

The average Canadian consumed 3100-3500 mg sodium a day. On average, men consume more sodium than women: 4000 mg/day compared to 2700mg/day (19-30 year olds).

Health Canada and the US National Academy of Sciences (Institute of Medicine) have determined that an adequate intake (an intake you should aim for) is 1200-1500 mg/day of sodium. The research shows that lowering sodium intake to this level could reduce the incidence of stroke and heart disease by as much as 30%.

As the Director of the Canadian Stroke Network points out: “if we discovered that a food additive was causing 30% of all cancers, something would be done right away”.

An intake of 1500mg/day allows for sodium loss in sweat for those that are moderately physically active. Very active people may require a sodium intake that’s a bit higher.

Sodium recommendation by age are:


Sodium Intake per Day (mg)

0-6 months


7-12 months


1-3 years


4-8 years


9-50 years


50-70 years


>70 years


Tips to help you reduce your sodium intake:

  • Read labels. Nutrition Facts table lists the amount of sodium (in milligrams) per one serving of the food. You can also refer to the % Daily Value which compares the amount of sodium in one serving of your product to 2400 milligrams. Generally, foods low in sodium have a % Daily Value of 5% or less.
  • Pay attention to serving size. Sodium numbers on a nutrition label are for the serving indicated!
  • Use herbs and spices instead of salt when cooking - try garlic, lemon juice, onion, vinegar and herbs. Remove the salt shaker from the table to break the habit of salting food at the table.
  • Limit your intake of processed meats such as bologna, ham, sausage, hot dogs, bacon, deli meats, and smoked salmon.
  • Limit your use of salty condiments such as bouillon cubes, soy sauce, Worcestershire sauce, soy sauce or bbq sauce.
  • Rely less on convenience foods such as canned soups, frozen dinners and packaged rice and pasta mixes.
  • Choose lower sodium products.
  • Be assertive when dining out. Request that salt not be added and order sauces and dressings on the side so you can control the amount you use.
  • Rinse canned food when possible (like canned vegetable, beans, tuna). Research done at Duke University has shown that rinsing vegetables for 1 minute reduced sodium content by 41% and rinsing tuna 1 minute reduced sodium by 76%.


Press Releases - Reductions needed in the sodium added to foods Oct 25 2007

Sodium Policy – Blood Pressure Canada & Collaborating Organizations ttp:// Oct 25 2007

Brody, Jane. The Good Food Book: Living the High-Carbohydrate Way. Bantam: 1987.


Anonymous said...

hi sybil, good write up. Can you be too low on sodium? If one was to eat plenty of potassium but veryl ittle sodium is that ok?

thanks mike.

Sybil Hebert, RD said...

Hi Mike,
Thanks for the question (and for reading!).

Sodium helps maintain proper fluid balance between water in and around your cells, so you need some sodium- about 1000mg/day. Even if you’re active in hot weather and sweat, it’s possible to get that amount from sodium that naturally occurs in foods.

For the most part, your body adapts to the heat by conserving salt and sweating out more water. When you’re not used to the heat, like that first hot spring day you work out, you’ll sweat more salt than at the end of summer when you’re used to the heat.

Usually if you’re low in salt, your body will crave it.

Adequate sodium balance is necessary for transmitting nerve impulses and proper muscle function. Very active people who restrict sodium intake and lose a significant amount of sodium through sweat are at risk of developing a sodium imbalance and hyponatremia (low sodium in the blood) can develop, especially when the athlete replaces the lost fluid only with water.
People that exercise for more than 4 hours in hot, humid conditions are most at risk- ie. ultra-marathoners, tennis players, long-distance cyclists, triathletes.

The early warning signs are often subtle and may be similar to dehydration: nausea, muscle cramps, disorientation, slurred speech, confusion, and inappropriate behaviour. At this point, many athletes get into trouble by drinking water because they think they are dehydrated. At the most extreme an athlete may experience seizures, coma, or death.
At the first sign of nausea, muscle cramps, disorientation, an athlete should drink a sodium containing sports drink, such as Gatorade, or eat salty foods. If the symptoms are extreme, a medical professional should be seen.

Use a sodium containing sports drinks during long distance, high intensity events, eat salty foods before and during competition/hard and long workout if possible, weigh yourself before and after training and drink enough sodium based sports drink to offset any fluid loss during exercise, increase salt intake several days prior to competition/hard long workout.

Low potassium intake can lead to electrolyte imbalances that could result in muscle cramps. This combined with potassium losses in sweat could lead to a potassium deficiency. However, there’s usually no harm in consuming a potassium-rich diet.

Hope that your question was answered after all this!

Source: Nancy Clark's Sports Nutrition Guidebook. 3rd ed. 2003.

Anonymous said...

thanks for the info sybil! ~mike

Anonymous said...

salt anyone:


Sybil Hebert, RD said...

This is great Mike- thanks!
Saltiest dish: 7300 mg sodium!
Can you imagine how you must feel after eating that?!