- Nutrition -

The pH Factor

Some foods make you acid. Some foods make you alkaline. But why should you care? Here’s what everyone should know about the body’s delicate acid-alkaline balance.

Back in high school chemistry, we learned about pH: A pH of 7.0 is neutral, acids have lower numbers, alkalines have higher numbers — and it all meant absolutely nothing in terms of day-to-day life.

It turns out, though, that we have a better shot at long-term health if our body’s pH is neutral or slightly alkaline. When we tilt toward greater acidity and throw off our acid-alkaline balance, we have a greater risk of developing osteoporosis, weak muscles, heart disease, diabetes, kidney disease and a host of other health problems.

An important key to maintaining a healthy acid- alkaline balance, according to doctors and nutritionists, is eating a diet with a relative balance of alkaline-forming and acid-forming foods. Unfortunately, the typical American diet — which is high in acid-producing foods like meat, dairy, sugar, and highly refined and processed foods, and low in alkaline-forming foods such as fresh vegetables — causes many Americans to suffer from “chronic low-grade metabolic acidosis,” a condition characterized by a subtle, yet definite, acid buildup within our system.

The solution, predictably, is eating an alkaline-forming diet — one that’s high in fruits and vegetables. The bonus, of course, is that this dietary recommendation not only helps balance pH, but also offers a host of other healthy benefits.

Acidity’s Toll

If the idea of balancing acid and alkaline foods seems a bit off the wall to you, you’re not alone. Most people, including physicians, aren’t yet familiar with the dangers of acidosis, except in the most extreme situations. We tend to confine our nutritional concerns to essential vitamins and minerals.

But the problem with acid-producing eating habits is very real, contends Loren Cordain, PhD, a professor and researcher in the department of health and exercise science at Colorado State University in Fort Collins. “After digestion, all foods report to the kidneys as being either acidic or alkaline,” he says. “The kidneys are responsible for fluid balance and maintaining a relatively neutral pH in the body.”

That’s where things get interesting. While the body can and does draw on its alkaline reserves in an effort to correct the incipient excess acidity in our bodily fluids and tissues, some experts argue that the arduous process of stabilizing our body chemistry depletes our bodies of important nutrients and undermines our cellular vitality, bone and organ health, and immunity in ways that can leave our bodies susceptible to a host of chronic diseases.

When acid-yielding foods lower the body’s pH, for example, the kidneys coordinate efforts to buffer that acidity. The kidneys signal the bones to release calcium and magnesium to reestablish alkalinity, and muscles are broken down to produce ammonia, which is strongly alkaline. The result? By the time the response is done, important bone minerals and broken-down muscle get excreted in urine.

This acidity-balancing response can lead to thinner bones and lower muscle mass, points out Anthony Sebastian, MD, professor of medicine at the University of California, San Francisco. Long-term calcium and magnesium losses can also result in health problems — both minerals play essential roles in bone formation and normal heart rhythm, and low magnesium levels in particular can cause muscle cramps, arrhythmia and anxiety.

It’s possible that years of eating an acid-yielding diet could have other far-reaching ramifications. Some health experts, such as Christopher Vasey, ND, author of The Acid-Alkaline Diet for Optimum Health (Inner Traditions, 2003), assert that chronic acidosis can leave the body vulnerable to everything from chronic fatigue syndrome to eczema.

To date, few such problems have been formally studied in terms of how they relate to pH. Still, Sebastian acknowledges that we may have only scratched the surface when it comes to the health concerns related to mild lifelong acidosis. For example, it’s possible that low-grade acidosis increases insulin resistance (the hallmark of both prediabetes and full-blown type 2 diabetes), as well as the risk of kidney stones and kidney failure. A 2005 study published in the Journal of Cellular Biochemistry suggests that it might even alter gene activity and raise the risk of breast cancer. Sebastian admits that no one yet knows all the outcomes of a fundamental shift in the body’s acid-alkaline balance, but he suspects it’s broad. Like most nutritional problems, pH imbalances may take years to manifest symptoms that reach clinical significance and are thus unlikely to be the subject of large-scale, definitive clinical research anytime soon.

Causes of Dietary Acidosis

Sebastian, widely regarded as the top researcher in the field of diet-related acidosis, admits that understanding which foods are acid yielding or alkaline yielding can, at first glance, appear counterintuitive — because acidic foods don’t always have an acid-yielding effect. Citrus fruits and tomatoes are acidic, for example, but they have a net alkaline yield once their constituents get to the kidneys.

So if acid foods don’t necessarily make for an acid pH, what’s wreaking havoc with our pH? Sebastian points to four big issues:

  • According to Cordain’s research, humans evolved eating a 10:1 ratio of potassium — a natural buffer against acid pH — to sodium. Today, however, because of our low intake of fruits and vegetables, which are rich in potassium, and the rise in heavily salted, processed and fast foods, the ratio is 3:1 in favor of sodium. That reversal, Cordain says, throws pH out of whack.
  • Second, there has been a similar reversal in the consumption of bicarbonate (such as potassium bicarbonate) in foods and in added chloride (mostly in the form of sodium chloride, or table salt). Bicarbonate is alkaline, whereas chloride is acid yielding. Chloride also constricts blood vessels, and narrow blood vessels reduce circulation, Sebastian says, which can contribute to heart disease, stroke, dementia and other degenerative diseases.
  • Third, Americans eat a large amount of animal protein (including meat, fowl, seafood and dairy products), which has a highly acidic effect in the body. This acidic shift can be offset by eating more fruits and vegetables.
  • Fourth, grains, such as wheat, rye and corn, have a net acid-yielding effect, regardless of whether they’re in the form of white bread, breakfast cereal, pasta or whole grains. “Grains are the most frequently consumed plant food in the United States,” says Sebastian, “and they account for 65 percent of the plant foods eaten by Americans.”

The real problem, says Sebastian, “is one of alkaline deficiency,” particularly in relation to our acid surplus. People eat plenty of acid-yielding animal protein, dairy products and grains, he notes, and not nearly enough alkaline-yielding fruits and vegetables. In fact, most Americans don’t eat even the minimum five daily servings of fruits and vegetables recommended by the FDA — much less the nine servings most health experts would prefer.

Acidosis and Osteoporosis

Some of the strongest evidence in support of maintaining an acid-alkaline balance relates to osteoporosis. “Consider that Americans consume more calcium-rich dairy foods than almost every other nation, and that we have one of the highest rates of osteoporosis,” says Cordain. “There’s a disconnect here. Dairy may be rich in calcium, but most dairy foods also produce an acid yield.”

Susan Brown, PhD ( www.susanbrownphd.com), director of the Osteoporosis Education Project in East Syracuse, N.Y., and coauthor of The Acid-Alkaline Food Guide: A Quick Reference to Foods & Their Effect on pH Levels (Square One Publishers, 2006), frames the acid-alkaline issue as one of mineral adequacy and depletion. “It’s a little like over-farming and depleting mineral levels in soil,” she says. “If we eat foods that create an acidic pH in the body, we will deplete our bones of minerals and our muscles of protein.”

Brown describes a client named Janet whose doctor diagnosed her at age 52 with osteopenia, a demineralizing of bone that often foreshadows osteoporosis. At 55, Janet began following Brown’s recommendations for eating more fruits and vegetables, using appropriate vitamin D supplementation, taking other bone-building nutrients, and increasing her exercise program. Three years later, Janet was clearly building bone mass in her spine and hip, even while going through menopause.

Can Supplements Help?

Millions of women dutifully take calcium supplements to help maintain their bone mass and reduce their chances of developing severe osteoporosis with age. But do supplements have any real benefit in alkalizing the body?

Brown does see a benefit from a wide range of supplements, but she says they won’t cancel out bad eating habits. “Acid-alkaline balance is primarily a food issue, and it’s important to stem calcium, potassium and magnesium losses by eating more alkaline-yielding foods,” she emphasizes. “Your pH is also a sign of how your body is managing your overall reserves, and supplements combined with better eating habits can help people get back on track.”

Studies show that supplements such as potassium citrate and potassium bicarbonate slow bone loss, mainly by promoting alkalinity. Still, it’s hard for supplements to deliver the same potassium riches that foods can.

A handful of raisins, two dates or a small banana each provide more than 300 mg of potassium. (By law, potassium supplements must be under 99 mg because of a risk of arrhythmia at high doses; potassium from food, however, is perfectly safe.) Some supplements, such as coral calcium, have been promoted as a way to restore alkaline pH. But coral calcium is largely calcium carbonate, which is not as well absorbed as potassium citrate, for example. Again, a bowl of fresh produce does far more in terms of pH than supplements, so emphasize fruits and vegetables over capsules and pills.

What Should You Eat?

Nutritional recommendations are as varied as political and religious beliefs, and sometimes held to just as stridently. The good news? You don’t have to be a vegetarian to gain the alkalizing benefits of fruits and vegetables. “It takes about 35 percent of total calories as fruits and veggies to produce a net alkaline load,” Cordain explains.

In essence, we could all do better simply by adding more fruits, vegetables, nuts, seeds and spices to our diets, agrees Brown: “It’s all another scientific justification for what your mother always told you — eat your fruits and veggies.”

What’s Your pH?

The pH level of your blood remains relatively constant at 7.4, but many natural-health experts assert that you can get a sense your body’s variable pH status by using pH test strips (available at many health-food stores and natural pharmacies) to test your urine or saliva.

Here’s how: Tear off two 3-inch strips. As soon as you wake up, before you drink or eat, put some saliva on the test strip. Compare the color with those on a pH color chart included with the test strips. Note the corresponding number. Next, measure the pH of your second urination of the morning by collecting the urine in a plastic or glass cup and dipping the test strip. Again, compare the color with the pH color chart.

Decker Weiss, NMD, FASA, a naturopathic physician based in Scottsdale, Ariz., recommends doing these two tests for 10 mornings in a row: “Ignore the top three and bottom three tests because they’re extremes. Average the remaining four to determine your pH.” Weiss aims for a pH of 6.8 to 7 in his heart patients, and 7.2 to 7.4 in his osteoporosis patients. You can retest a few weeks after changing your eating habits.

You can order test strips from www.alkalineforlife.com or by calling 888-206-7119. One roll, which is good for a few dozen tests, is $14.

Nutrition expert Jack Challem lives in Tucson, Ariz., and is the author of several books, including Feed Your Genes Right (John Wiley & Sons, 2005) and The Food-Mood Solution (John Wiley & Sons, 2007).

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