The Longevity Solution
Page 14
WHY IS SALT RESTRICTION DANGEROUS?
Salt is crucial for maintaining an adequate blood volume and blood pressure to ensure that our tissues are perfused with oxygen-carrying blood and nutrients. Salt is composed of equal parts sodium and chloride. When we measure the electrolytes in the blood, sodium and chloride (salt) are by far and away the most common ions. For example, normal blood contains sodium at a concentration of approximately 140 mmol/L and chloride at 100 mmol/L. Potassium concentration in the blood is only at 4 mmol/L, and calcium is at 2.2 mmol/L. There is more than 50 times more sodium than calcium in the blood. No wonder we need salt so badly.
There is speculation about the evolutionary reasons why our blood evolved to be mostly salt. Some believe that we evolved from single-celled organisms in Earth’s ancient seas. As we developed multicellularity and moved onto land, we needed to carry some of the ocean with us as “salt water” inside our veins; hence, salt comprises the vast majority of the electrolytes of the blood. Salt is vital, not a villain.
The unintended consequences of the low-salt advice have been conveniently swept under the rug. For example, eating less than ½ teaspoon of salt per day can lower blood volume by 10 to 15 percent.18 This may lead to low blood pressure upon standing (orthostatic hypotension), cause dizziness, and, potentially, result in a bone-breaking fall. Low-salt intake increases erectile dysfunction, sleep disturbances, and fatigue.19
During exercise,20 the average person sweats more than two-thirds of a teaspoon of salt per hour.21 That’s the amount the AHA suggests you take for the entire day! With limited reserves of salt in the body, you can quickly develop low blood volume and dehydration.
Salt also makes food taste sweeter, so less salt on your food may mean that you end up eating more sugar as a way to compensate. In fact, salt has been blamed for many of the ills that are caused by sugar, including hypertension, chronic kidney disease, and cardiovascular disease.22 We blamed the wrong white crystal.
Experts recommended salt restriction because they believed that less salt in the diet could decrease blood pressure without any harmful side effects. However, this assumption has long been known to be incorrect. As early as 1973, an editorial in the prestigious New England Journal of Medicine worried that when salt is restricted, the hormones aldosterone, angiotensin II, and sympathetic tone increase. High levels of all these hormones are known to be bad for heart disease, which is the very reason we block them with lifesaving medications such as spironolactone, ACE inhibitors, and beta-blockers. Thus, doing something that might raise these hormones, such as restricting salt, is potentially dangerous or, even lethal. This increased risk was borne out in a 2011 study.23 Those patients who ate the least salt had more than three times the rate of cardiovascular death compared to those who ate the most. Eating a low-salt diet was bad, very bad (see Figure 10.4).
What’s more, a low salt intake has been consistently found to worsen insulin resistance24 and increase fasting insulin levels,25 which potentially increases fat gain because insulin is a fat-storing hormone. Thus, the low-salt advice might increase your risk of developing diabetes and obesity. Along with raising artery-stiffening hormones,26 the low-salt advice causes the very diseases it supposedly prevents: hypertension, kidney disease, heart failure, and cardiovascular disease. What delicious irony.
Fig. 10.4: Lower salt intake, higher risk of dying from cardiovascular disease
These findings explain why countries that eat a salt-heavy diet—like Japan, South Korea, and France—also have some of the lowest rates of coronary heart disease mortality in the world and live the longest.27 The most recent, largest, and most rigorous population study ever done—Prospective Urban Rural Epidemiology (PURE)—confirmed what we should already have known. The study examined more than 100,000 people in seventeen countries, and the data conclusively found that the lowest risk of death for cardiovascular events was in those people who consume between 3,000 and 6,000 milligrams of sodium per day.28 Conveniently, Americans average 3,400 milligrams of sodium intake daily, which is right in the sweet spot. Another meta-analysis in almost 275,000 patients came to virtually the same conclusion. Consuming between 2,645 to 4,945 milligrams of sodium per day was associated with the lowest risk of death and cardiovascular events.29 So the best current evidence suggests that the optimal intake of sodium is between 3,000 and 6,000 milligrams per day which is in direct contrast to sodium restriction recommendations of 2,300 milligrams of sodium or less.
THE PREMATURE CONVICTION OF SALT AS A DIETARY VILLAIN
We need salt to live, so our bodies tightly regulate the salt level in our blood. If we couldn’t do this, we would all be dead.
When we become salt depleted, we crave it.30 For you, this may manifest as absentmindedly reaching for popcorn or potato chips, but your hunger for salt has evolved over 100 million years,31 and it has helped all land animals, including humans, to survive. During salt depletion, our kidneys hold onto the precious salt like Ebenezer Scrooge holds onto his precious pennies. When we eat too much salt, the kidneys simply pass it out through the urine.
Our brain automatically and unconsciously controls our salt craving,32 just as it controls our thirst for water. You don’t manage your salt levels by adjusting your diet; your body maintains a steady salt level regardless of how much or how little salt you eat. The amount of salt in your body, which is so critical to your overall well-being, is not left up to the vagaries of what you put in your mouth, which changes from hour to hour, day to day, and season to season.
An overturn of the premature conviction on salt should have occurred with the publication of a 2014 Cochrane meta-analysis,33 which found that a salt-restricted diet minimally reduced blood pressure, but there were no significant reductions in death or cardiovascular disease. A 2016 systemic analysis concluded once again that low-salt diets did not lower blood pressure in patients without hypertension.34 Millions of people with normal blood pressure who try to eat less salt get no benefit from their efforts. So, why recommend salt restriction for the entire population of the world? How much more evidence do we need to overturn the low-salt advice?
If you still fear the salt shaker, know that your fear is not based on fact. Don’t feel guilty about salting your food and recognize that salt is an essential micronutrient. To this day, there is still no definitive proof that restricting our salt intake will improve health, but there is strong evidence that consuming a normal salt intake will prolong life and reduce strokes and heart attacks. For years we have gotten it wrong about salt, and our health has been suffering for it ever since. We need to bring salt back to its cherished place at the dinner table.
OBTAIN A QUALITY SALT
Because of pollution, sea salts can be contaminated with plastics and heavy metals, so choose a salt that comes from an underground ancient ocean, such as Redmond Real Salt (www.realsalt.com), which has the additional advantage of a high iodine concentration. Most sea salt contains little to no iodine, but it often includes artificial potassium iodide that the manufacturer adds. Redmond Real Salt naturally contains iodine and therefore does not require iodide. Getting sufficient iodine is important because you can lose anywhere from 50 to 100 micrograms of iodine in sweat per hour of exercise in the heat. If you are constantly exercising and sweating out iodine but not replacing, the result could be hypothyroidism, weight gain, and metabolic issues. Give yourself a Salt Fix, throw out that processed table salt and pick up a healthy unrefined salt like Redmond Real Salt.
We need to bring salt back to its cherished place at the dinner table.
Magnesium: The Other Salt
Magnesium is one of the most common ions in the human body. The human body contains around 25 grams of it, with 99 percent of it inside the cell and just 1 percent of it in the blood. Magnesium is necessary for the proper functioning of at least 600 enzymes35—including the important Na-K-ATPase, DNA, and RNA—and protein synthesis.36 The elimination of magnesium from your body is mainly controlled by the kidneys.
There are more than sixty factors that cause magnesium deficiency.43 Some of the most common include consuming and using alcohol, sugar, antacids (and other stomach-acid-suppressing therapies), calcium supplements, and diuretics; gastrointestinal disorders (celiac disease, Crohn’s, and ulcerative colitis); vitamin D excess or deficiency; and sodium deficiency. Magnesium deficiency is very hard to diagnose because symptoms are nonspecific, and blood magnesium levels may be normal even when there’s an overall deficiency. Less severe signs of magnesium deficiency include anxiety, muscle cramps, disorientation, involuntary muscle contractions, muscular weakness, photosensitivity, spasticity, tinnitus, and tremors. The more severe signs of magnesium deficiency include arrhythmias, calcifications of soft tissue, cataracts, convulsions, coronary artery disease, depression, hearing loss, heart failure, hypertension, migraines, headaches, mitral valve prolapse, osteoporosis, seizures, and sudden cardiac death.
Magnesium deficiency causes an accumulation of calcium within the cell, leading to calcification of the arteries, which is sometimes called hardening of the arteries. Think of magnesium as a natural calcium blocker because it prevents calcium from accumulating where it shouldn’t. Magnesium deficiency also increases oxidative stress and lipid peroxidation in the body and leads to coronary artery spasms that can be fatal.44 Ensuring adequate dietary magnesium intake has been associated with lower risks for hypertension, arrhythmias, calcifications, heart failure, myocardial infarction, stroke, and sudden death.45
Many people following a low-carb, high-fat diet might not be getting enough magnesium. Dietary fat can reduce the absorption of magnesium,46 and many good dietary sources of magnesium, such as dark chocolate, beans, nuts, seeds, bananas, and unrefined whole grains, are relatively scarce in a low-carb, high-fat diet. Following a higher protein diet also increases the need for magnesium. Thus, eating more protein or more fat increases the need for magnesium, but foods higher in protein or fat tend to also be relatively low in magnesium. If you follow one of these diets, you need to be aware of meeting your body’s need for magnesium.
SALT AND MAGNESIUM: A CONNECTION LONG FORGOTTEN
Salt deficiency actually increases the risk for magnesium and calcium deficiency47 and all the harmful consequences that come with it, such as hypertension, cardiovascular disease, heart failure, and kidney disease. Not so coincidentally, these are the very diseases we pin on consuming too much salt.
With a low-salt diet, the body pulls sodium out of the bones to maintain normal blood levels.48 Unfortunately, the calcium and magnesium contained in bones are also stripped out, leading to deficiency. Low-salt diets may mean more magnesium lost in your sweat. When you restrict your salt intake, your body also increases the excretion of magnesium in sweat as a way to conserve sodium.49 Additionally, the salt-retaining hormone, called aldosterone, skyrockets in the blood, which increases the excretion of magnesium through the urine.50 The chance of magnesium being stripped from bones, excreted through sweat, and eliminated through urine poses a triple magnesium-depleting threat!
IS MAGNESIUM DEFICIENCY COMMON?
Magnesium deficiency affects at least 20 to 30 percent of the general population51 and can cause heart arrhythmias, muscle spasms, and muscle cramps.52 Magnesium deficiency is common and a serious public health problem, and it can lead to potassium and calcium deficiency. You can lose calcium because magnesium is required to activate vitamin D; when you’re magnesium-deficient, that activation doesn’t occur, and calcium deficiency results. On the flip side, magnesium deficiency increases the calcifications of arteries and blood vessels throughout the body. Salt depletion depletes the body of other healthy minerals such as magnesium, calcium, and potassium. In other words, you should consider sodium to be the “master controller” when it comes to the minerals in your body because it controls your magnesium status, which controls potassium and calcium.
Magnesium deficiency also can lead to increases in sodium and calcium within our cells, which may cause high blood pressure.53 That’s right, low-salt diets might cause high blood pressure by inducing magnesium (but also calcium and potassium) deficiency.
SUPPLEMENTAL MAGNESIUM
Most people need an additional 300 milligrams of magnesium per day (on top of what they’re already getting in their diet) to lower their risk of developing numerous chronic diseases. So even if your average intake of magnesium is somewhere between 250 and 300 milligrams per day, an optimal intake might be around 500 to 600 milligrams of magnesium per day for most people, and it’s perhaps even higher (up to 1,800 milligrams) for people with certain health conditions, such as hypertension or diabetes.54
Most magnesium supplements are the less expensive magnesium oxide form, which is not the best type. For the general population, magnesium glycinate (or diglycinate) has better absorption.55 Adding vitamin B6 to magnesium supplements can increase its absorption and penetration into the cell.56 Magnesium L-aspartate and magnesium chloride are also great choices with the greatest bioavailability of twenty different magnesium salts that have been tested.57
For those people suffering from kidney stones, magnesium citrate may be the best form to use because citrate can help reduce the formation of calcium-containing kidney stones.58 For those people with heart failure, magnesium orotate at 6,000 milligrams once daily for one month and then 3,000 milligrams once daily for maintenance significantly reduces mortality.59 However, the best way to get magnesium is from whole foods. Great options to get your daily dose of magnesium include cacao paste, nibs, beans, or powder from a company like Organic Traditions (http://organictraditions.com).
Don’t Follow Dogma; Follow Evidence
You’ve been told for decades to eat less salt. This recommendation is dangerously outdated advice. These long-standing nutritional dogmas fall flat under the withering light of evidence-based medicine. The salt–blood pressure connection was oversimplified, and you’ve been suffering the consequences.
For the sake of your magnesium levels, think twice before restricting your salt intake. Eating more salt might help prevent magnesium deficiency to potentially reduce the risk of high blood pressure and cardiovascular disease. It’s time you stopped fearing the salt shaker and started embracing your salt hunger; your magnesium levels might depend on it.
As we look back over the last forty years, it’s hard to understand how we could have been as gullible as we’ve been. We believed that fat—more specifically saturated fat, which is the fat found primarily in animal foods—increased cholesterol and caused heart disease. To make matters worse, we were led to believe that we needed to switch to “heart-healthy” vegetable oils, like cottonseed, corn, safflower, and soy oils. Recent evidence suggests we were making a deal with the devil when we made this switch. The industrially processed seed oils were much worse than fat from animal sources. It was all a terrible mistake that began with Crisco.1
The Rise of Seed Oils
Cotton plantations were established in the United States as early as 1736 to cultivate cotton for fabric. Before this, cotton was largely a
n ornamental plant. At first, most cotton was home-spun into garments, but the success of the crop meant that some could be exported to England. A modest 600 pounds of cotton was produced in 1784; by 1790, that amount grew to more than 200,000 pounds. When Eli Whitney invented the cotton gin in 1793, the amount of cotton produced increased to a staggering 40,000,000 pounds.
But cotton is two crops: the fiber and the seed. The by-product of every 100 pounds of fiber produced from cotton was 162 pounds of cotton seeds, which were largely useless. Farmers needed only 5 percent of this seed for planting. Farmers could use some seed for livestock feed, but the remainder was still a mountain of garbage. What could farmers do with this garbage? In most cases, they left it to rot or illegally dumped it into rivers. It was toxic waste.
Meanwhile, in the 1820s and 1830s, a growing population in the United States resulted in an increased demand for oil for cooking and lighting. A decreased supply of whale oil for lamps meant that prices rose steeply. Enterprising entrepreneurs tried to crush the worthless cotton seeds to extract the oil, but it was not until the 1850s that the technology matured to the point that commercial production could commence. Then in 1859 something happened that would transform the modern world. Edwin Drake, who was known as Colonel Drake, struck oil in Pennsylvania and introduced a massive supply of fossil fuels to the market. Before long, the demand for cottonseed oil for lighting had completely evaporated, and cottonseeds were, once again, toxic waste.