Salt is Good for You in Moderation

(May, 2013) Salt is necessary for life, and has been used since ancient times as a seasoning, preservative, disinfectant, ceremonial offering, and unit of exchange. The Bible repeatedly references salt to signify permanence, loyalty, durability, fidelity, usefulness, value, and purification. Throughout history, salt has been valued highly, until recently.

We hear so many conflicting stories about the impact of salt on health. No wonder we’re all confused. That’s why I’m pleased to see a new publication explaining why the data are so inconsistent (O’Donnell et al., 2013). The good news is that, with certain exceptions, salt is good for you, unless your sodium intake is excessive (over 5 grams per day). And, even then, the hazard ratio is not dangerously elevated until intake exceeds 8 grams per day. That’s a lot of salt. You would have to be chugging the shaker to get that much, or eating an inordinate amount of junk food or restaurant food. At the other end of the curve, sodium intakes of less than 2 grams per day are also linked to cardiovascular disease (CVD). The bottom line is that moderate salt intake is good for you. Enjoy it, but exercise a little discipline.

Dietary factors

Many factors besides sodium affect the risk of CVD. Some high-sodium diets contain nutrients that protect the heart, like vitamins, minerals, essential oils, antioxidants and anti-inflammatory agents. For example, Japan’s traditional high-sodium diet was associated with the lowest risk of CVD, since it is rich in fish and vegetables (Shimazu et al., 2007). Other high-sodium diets (fast, processed junk foods) are low in protective factors and are linked to high CVD risk. These variables contribute greatly to the inconsistency in studies on salt intake.

The most important dietary factor that may modify the link is potassium intake (Morris et al., 2006). The lowest rate of CVD is found among those with moderate sodium and high potassium intake (O’Donnell et al., 2011). Potassium intake is also a barometer for a healthy diet, since many foods linked to reduced CVD risk are potassium rich, especially fruits and vegetables.  Antioxidants like vitamins C, E, carotenoids (beta-carotene, lycopene, lutein, zeaxanthin, astaxanthin), and numerous substances from plants also protect heart health, as do an assortment of essential minerals, fibers, and oils.

My favorite high-potassium foods are coconut water and sweet potatoes. In contrast, white potatoes and bananas are carbohydrate dense, and are not the best potassium source for those with obesity and other metabolic conditions. One exception is purple fingerlings, skin and all, but not deep-fried. These provide many more antioxidants, fiber and minerals than do regular potatoes. Smother with organic butter, which is full of fat-soluble nutrients. Eat them once or twice weekly, smothered in organic butter. Regular butter may contain factory-farm toxins, and not nearly as many nutrients as the organic variety. Quality organic milk fat is part of the solution, not part of the problem.

One way to quickly increase potassium intake is with potassium bicarbonate. This healthier form of baking soda substitutes potassium for sodium. It can be used in baking, or to neutralize acidic foods (e.g., lemonade, coffee, sodas). It quickly turns the body more alkaline, which confers numerous health benefits. Just don’t go overboard and over-alkalinize the body. With 1/4 teaspoon potassium bicarb (1/8th teaspoon per pot of coffee or tea), I brought my urine pH from roughly 5.5 to 7, which is about where you want it to be.

The Salt Police

The Center for Science in the Public Interest (CSPI) believes that salt is the single most harmful substance in the food supply. Processed foods and restaurant meals provide nearly 80% of the sodium intake in the modern diet. That’s about 4 grams of sodium daily on average, or twice the recommended limit. These scientists claim that cutting sodium consumption by half could save roughly 150,000 lives per year and reduce health care costs by roughly $1.5 trillion over 20 years. They recommend that consumers eat less-salty foods; that food manufacturers/restaurants should reduce salt in their products; and that government should set limits on salt content, encourage the food industry to use less salt, require warning notices on menus, and improve labeling of packaged foods.

While acknowledging the good intentions of these scientists, I firmly believe they are on the wrong track. While it is true that the modern diet contains entirely too much processed salt, and that people would benefit greatly by improving their diet, salt is not even close to the most harmful substance in our food. That distinction goes to sugar and refined carbohydrates, consumption of which parallels the epidemic of obesity, heart disease and diabetes. Bad fats also trump salt when it comes to their negative impact on heart health and inflammation. Placing so much emphasis on salt detracts from far more dangerous substances in food. To their credit, CSPI also urges safe limits on sugar intake. They should focus more on this effort.

Population variance

The science on salt intake and CVD is highly inconsistent, and varies greatly from one region to another. A meta-analysis of 13 clinical studies worldwide reported a significant association between sodium and CVD (Strazzullo et al., 2009). The association was strong in regions with high intake, but not in regions with moderate intake (Alderman & Cohen, 2012). Countries like Japan and Finland have some of the highest sodium intakes, but also have some of the highest life expectancies. There is an association between salt and stroke in Asia, but not in Europe or North America.  Marked reductions in stroke have occurred in the US over the last few decades, without a reduction in sodium intake (Bernstein & Willett, 2010). There seems to be no method to the salt phobia madness.

Preconditions

Certain populations or individuals may be at increased CVD risk with sodium intake. Salt-sensitive people respond favorably (e.g., reduced blood pressure) to sodium reduction. Ethnicity, blood pressure level, and obesity may modify the association between sodium intake and CVD. Genetic underpinnings for salt sensitivity are likely, but have yet to be determined.

Elevated blood pressure may have many determinants besides high sodium intake, including low potassium, fruit and vegetable, and antioxidant intake, obesity, and lack of physical activity. Specific gut microbes may also protect against salt-induced high blood pressure. Addressing all these factors may prove more impactful on blood pressure than sodium alone.

People with CVD may be more susceptible to extreme sodium intake, and may benefit most from salt reduction. However, in congestive heart failure patients, low sodium intake was also linked to increased mortality. In fact, low sodium may be as detrimental to this population as high sodium intake. Moderation is key, not strict salt reduction.

Sea salt

Salt gets a bad rap from the so-called experts. Yet, salt provides sodium, which is necessary for life. Sodium enables muscle contraction and expansion, nerve stimulation, adrenal function, energy production and many other biological processes. Salt also provides chloride, which helps produce acids for digestion, and is necessary for brain function and growth.

What experts don’t usually acknowledge is the big difference between table salt and sea salt. Sea salt contains magnesium, which is a cofactor in numerous enzymes, enables nerve transmission and muscle contraction, induces relaxation, relieves constipation, promotes bone formation and tooth enamel, and reduces blood pressure and heart disease.  Sea salt contains many trace minerals. Babies and children are in special need of salt for their developing brains, and benefit greatly from obtaining essential minerals. In contrast, table salt has virtually none of these minerals. But it does contain various additives – aluminum, dextrose and a bleaching agent – none of which adds to its health benefits. Iodine is also added, because natural iodine is destroyed during the refining process.

Sea salt also alkalizes the body, whereas table salt is acid forming. This was shown conclusively in tests conducted by Dr. Susan Brown, a bone health specialist from Syracuse, NY, and co-author of The Acid-Alkaline Food Guide. The modern diet is already overly acidic, and sea salt helps to restore balance due to its mineral content. Sea salt also tastes saltier than table salt, so less is needed.

Many health benefits have been attributed to sea salt, but it really depends on the quality. Most products branded as sea salt are actually refined and inferior. It’s easy to tell, because inferior sea salt is white, like table salt. Unrefined sea salt is typically grayish, but can also have a red or black hue. Celtic sea salt is the real deal; so is Himalayan sea salt. Red sea salt from Hawaii is another option. Use the white stuff to melt ice.

Shaking out the truth

The current recommendation for sodium intake is 2.3 g/day (a bit over 5 g salt/day) or lower. Some experts are now advocating a re-evaluation of these guidelines. To put this in perspective, one teaspoon contains roughly 6 g of salt. The debate comes down to limiting salt intake to either one or two teaspoons daily. While reducing high sodium intake makes some sense, further reduction from moderate to low levels (<3 g/day) is not warranted for most people, and may have adverse consequences. At present, no high-quality clinical trial has linked low sodium intake to reduced CVD incidence. Rather than worry about sodium,  it is wise to consume less fast and processed foods, which not only contain high sodium, but are detrimental to health in myriad ways. Furthermore, potassium intake mitigates the effects of a high-sodium diet. Optimally, applying unrefined sea salt in a disciplined manner will make foods tastier and contributes to overall health.

References

Alderman MH, Cohen HW. Dietary sodium intake and cardiovascular mortality: controversy resolved? Curr Hypertens Rep 2012;14:193–201.

Bernstein AM, Willett WC. Trends in 24-h urinary sodium excretion in the United States, 1957–2003: a systematic review. Am J Clin Nutr 2010;92:1172–1180.

Morris RC Jr., Schmidlin O, Frassetto LA, Sebastian A. Relationship and interaction between sodium and potassium. J Am Coll Nutr 2006;25(Suppl.):262S-270S.

O’Donnell MJ, Yusuf S, Mente A, et al. Urinary sodium and potassium excretion and risk of cardiovascular events. JAMA 2011;306:2229–2238.

O’Donnell MJ, Mente A, Smyth A, Yusuf S. Salt intake and cardiovascular disease: Why are the data inconsistent? Eur Heart J. 2013;34(14):1034-1040. http://www.medscape.com/viewarticle/782465.

Shimazu T, Kuriyama S, Hozawa A, Ohmori K, Sato Y, Nakaya N, Nishino Y, Tsubono Y, Tsuji I. Dietary patterns and cardiovascular disease mortality in Japan: a prospective cohort study. Int J Epidemiol 2007;36:600–609.

Strazzullo P, D’Elia L, Kandala NB, Cappuccio FP. Salt intake, stroke, and cardiovascular disease: meta-analysis of prospective studies. BMJ 2009;339:b4567.

http://en.wikipedia.org/wiki/Salt

https://www.cspinet.org/salt/

http://www.cspinet.org/new/201302131.html

http://www.wellnessresources.com/health/articles/potassium_offsets_salt-induced_cardiovascular_distress/