High Potassium Foods

High potassium foods, low potassium foods and associated potassium symptoms info

 

Aldosterone Secretion, Genes And Diet

A high potassium diet is the single most important factor to prevent hypertension. There is more extensive evidence for the role of the dietary potassium sodium ratio than for any of the other factors that may be involved in hypertension. There is evidence from epidemiological studies, population studies, basic physiological studies, and animal and tissue studies. Presently many studies are being done at the cellular and molecular levels to determine how processes at these levels cause hypertension.

We previously discussed, in this post, how a fully developed hypertensive heart failure model has shown the importance of a high potassium diet. The model is complete from the level of the heart organ to the level of molecules in the heart cells.

Aldosterone SynthaseAldosterone Secretion, Potassium And Hypertension

The model for aldosterone secretion by the adrenal gland is not as complete as the heart failure model. This is an important model because of the central role of aldosterone and the RAAS (renin-angiotensin-aldosterone system) in the development of hypertension. Potassium and the potassium sodium ratio play a central role here, just as they do in hypertensive heart failure.

By studying at the cellular level abnormal secretion of aldosterone by adrenal gland cells, such as occurs in primary aldosteronism, researchers can more fully understand how hypertension occurs. And they can possibly devise methods for how it can be prevented.

Primary aldosteronism is the main cause of secondary hypertension. Sometimes it runs in families. Sometimes it is caused by a tumor in the adrenal gland. It signifies that too much aldosterone is being produced by the adrenal gland(s) without outside stimulation. This is one of the same mechanisms that cause primary hypertension. And the end result is the same – high blood pressure.

Hypertension Genetics

By studying the cellular abnormalities in primary aldosteronism researchers can also learn a great deal about how primary hypertension occurs. In 2013 a European Journal of Endocrinology published its prize lecture (1) about the genetics of primary aldosteronism. The publication gave a nice summary of what was then known about primary aldosteronism at the cellular and genetic level. The publication reveals a great deal about how potassium can affect adrenal cells. The article also reveals at the cellular level how an increase or decrease in the blood level of potassium causes changes in aldosterone secretion, and thus in blood pressure.

The report discusses the multiple studies done on adrenal cells, many of which the author’s group did, especially in primary aldosteronism. The author discusses genetic studies on animals and human genomes. These studies have identified genes that are associated with increased aldosterone. Many of the abnormal genes were found to control the proteins in potassium channels, and the proteins involved in transporting potassium for the sodium potassium ATPase pump.

These abnormal proteins cause these channels and pumps to handle potassium so poorly that there is not enough potassium inside the cell to maintain the electrical charges needed for normal cell function. This is the same problem that occurs when not enough potassium (or too much sodium) is in the diet. The result is excessive secretion of aldosterone and a rise in blood pressure.

The Basics

Before discussing the article, let’s review the previously known basics. Many years ago researchers showed that an increase in extracellular potassium leads to an increase in aldosterone secretion into the blood stream. This initiates a series of reactions that lead to an increase in blood pressure. However the increase in blood pressure is just one of many effects previously discovered. An excessive aldosterone blood level, even without an increase in blood pressure, damages the cardiovascular system and the kidney.

Today’s Research

Much research today focuses on what happens inside cells. To study aldosterone secretion, molecular pathways inside the cell and the genes that affect the pathways are being studied. Much of the work is being done on mice with experimentally produced changes in their genes. They have what are called knockout genes, which are specific genes that no longer function.

Many of the genes leading to excessive aldosterone secretion are genes that affect the electrical charge of the cell membranes in the cells that secrete aldosterone. The electrical charge is determined by the function of potassium channels, sodium potassium pumps, and intracellular calcium. Calcium controls much of the signaling inside the cell, and is affected by channels and pumps itself.

One of the genes that was studied was the gene that makes the enzyme (pictured above) that makes aldosterone in the adrenal cells. Potassium outside the cell (and angiotensin II) regulates the gene that makes this enzyme. Very minor changes in the extracellular potassium concentration control a signaling cascade. The potassium causes a change in the calcium concentration inside the cell. The calcium change starts a cascade of signaling molecules. The final signaling molecule reaches the DNA in the nucleus to upregulate (or downregulate) the gene so more (or less) enzyme is made.

This cascade happens within minutes of the change in potassium concentration. And it continues to occur for days (even years) when there is chronic stimulation. There are a great many specific types of potassium channels in the cells that make aldosterone. Changes in any of these specific channels affect the electrical charge of membranes in the cell. This in turn affects molecular reactions in the cell. These reactions affect the production and secretion of aldosterone. An increase in aldosterone secretion occurs with these abnormal genes, even when renin (another molecule affecting blood pressure) stays low.

Circadian Rhythm And Hypertension

Interestingly, the researchers also discovered how our circadian rhythm was involved in aldosterone secretion. One of the genes that was knocked out in these mice was a gene that is a core gene for the circadian clock. This circadian clock gene was found to affect aldosterone secretion from the adrenal gland cells. The researchers found that high salt intake increased the secretion of aldosterone in these animals. Furthermore they found that a constant daily salt intake resulted in aldosterone-dependent weekly rhythms of sodium storage (along with water weight) in the body.

Genome Wide Association Studies (GWAS)

This method has been used to identify genes involved in many different diseases. For diseases related to aldosterone, DNA arrays from patients with adrenal tumors and familial adrenal syndromes are used to study a large quantity of genes. Variations in how frequently a gene occurs show an association that can be further investigated as possibly causing a change in aldosterone secretion.

These studies are the type of studies we discussed here. That post discussed a study that identified 130 hypertensive genes. The majority of the genes were associated with potassium, sodium and calcium activity.

Other Genetic Methods

The author’s group has used other genetic methods to identify genes that lead to excessive aldosterone secretion. These genes involve some specific potassium channels that allow calcium in the interior of the cell to start the cell signaling process for aldosterone secretion.

Another pair of genes they identified affects proteins carrying potassium to the sodium-potassium-ATPase pump. They found that the pump was slowed, resulting in a change in the electrical charge of cell membranes that led to more aldosterone secretion.

There have been more and more studies on how cells that secrete aldosterone increase their aldosterone secretion, and thus increase blood pressure. The electrical charge of the membranes in the cell is the key factor. This charge is determined by the potassium sodium ratio inside and outside the cell. When the charge cannot be maintained at an appropriate level, aldosterone secretion is affected.

Studies of the genes that cause increased aldosterone secretion are consistently showing how critical the potassium channels are. These channels are critical to maintaining the proper level of potassium inside cellular compartments. The proper level of potassium is critical to maintaining correct electrical charges throughout the cell. When potassium is genetically prevented from maintaining a proper level inside aldosterone secreting cells, hypertension results.

More common than this genetic prevention of potassium balance is dietary prevention of potassium balance. Too little potassium (or too much sodium) in the diet will mean that there will be too little potassium inside the cell. This will lead to improper electrical charges throughout the cell. No matter what causes these improper electrical charges, the result will be the same as occurs with the genetic changes. Aldosterone will be affected. Hypertension and organ damage will result.

Food Tables

To find links to tables of the amounts of potassium and sodium in various foods, click on the List Of Posts tab at the top of the page.
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1. Regulation of aldosterone secretion: from physiology to disease. Beuschlein F. Eur J Endocrinol. 2013 Apr 24;168(6):R85-93. doi: 10.1530/EJE-13-0263. Print 2013 Jun.

Bran to Prevent CHD And Hypertension

Many publications have shown that eating whole grain reduces the likelihood of diabetes, coronary heart disease, and hypertension. A recent article (1) analyzed 11 prospective studies about how whole-grain food prevents these diseases. It points to bran, and specifically a particular component of bran, as the most important preventive component of whole grain.

BranThe Results

In analyzing the studies, the authors determine that 40 gm of whole grain a day reduces these diseases. 40 gm per day (one bowl of cereal) of whole-grain reduces the incidence of hypertension about 20% and of diabetes about 50%. They then analyze the components of whole grain to find what aspect of whole grain is responsible for whole grain’s beneficial effects.

The FDA has defined a whole grain product as a product with at least 50% whole grain, and whole grain as having all three elements (bran, germ and endosperm) in the same proportions as an intact grain. It differs from an unbroken grain. Polished rice can be considered unbroken, but it does not have bran and germ.

The bran and germ are responsible for the beneficial effects of whole grain. Studies of refined grain (without bran and germ) have not shown the same reduction in diabetes, coronary heart disease and hypertension that whole grain has.

The authors feel that because whole grain has much more bran than germ, bran would contribute more to the beneficial effects of whole grain than the germ component would. They also cite several studies that determined that the beneficial effects of whole grain came from bran.

They then try to determine what it is about bran that confers the benefits. Fiber is the most often mentioned component in the medical literature. Other components the authors examined were vitamins, minerals, polyphenols, and the antioxidant ferulic acid (one of the polyphenols).

Fiber

The authors question today’s emphasis on indigestible fiber as the beneficial component of whole grain. Because Burkitt emphasized fiber in his classic study, indigestible fiber has been the subject of many of the studies about improved health from whole grain.

There are three separate benefits that can be attributed to fiber. The first is the stool bulking effect that speeds transit of the stool through the gut. The second is the formation of gels, which slows carbohydrate absorption. The third possible benefit is the formation of absorbable healthy fatty acids from fermentation of the fiber.

Bran And Aleurone

The authors place a greater emphasis on the nutritive aspects of bran. They find that the greatest concentration of these nutrients is in the aleurone. Aleurone is a major component of bran and is generally overlooked. It remains attached to bran during processing of whole grain. During processing, the production of bran results in approximately 50% live aleurone cells.

The remainder of bran is pericarp – the indigestible fiber. It is resistant to digestion and provides bulk to speed passage of stool. It resists our digestive enzymes and the enzymes secreted by bacteria in our gut. The main advantage it may provide is preventing prolonged exposure to possibly adverse toxic products that could affect us.

The bran aleurone, on the other hand, is nutrient rich with vitamins, minerals, and polyphenols (especially ferulic acid). Comparing whole wheat flour to wheat flour, for example, shows an 80 to 90% drop in thiamine, niacin and vitamin B6, and a 50 to 80% drop in minerals.

And bran has over 90% of the polyphenols in whole grains, while germ has only 1%. It also has 4 to 11 times as much vitamins and minerals as germ.

These minerals are found in the aleurone cells. The publication has some excellent photomicrographs showing the fluorescence from the minerals in the aleurone cells.

Phytates And Minerals

The minerals are chemically bound to phytates in the cells. Some other publications have raised concerns about the phytates in whole grain, as well as in legumes. Animal studies showed that consuming them led to a smaller proportion of minerals being absorbed. However, because food containing phytates has so much more mineral content, the actual amount of minerals absorbed is greater, even though the proportion is less.

Thus bran is a great source of minerals. The study emphasizes the role of magnesium in preventing hypertension and cardiovascular disease. It does not discuss the role of potassium, even though it admits that potassium is more abundant inside cell. The importance of magnesium in cardiovascular health is highly supported in the medical literature. But potassium and the potassium sodium ratio have even more extensive literature supporting their importance in preventing hypertension and cardiovascular disease.

Antioxidants

The authors also discuss the role of antioxidants. Antioxidants, especially ferulic acid, are abundant in bran. They are well aware of the findings that ORAC (the test tube antioxidant test) has no correlation with what happens in our bodies. They correctly points out that the use of antioxidant supplements as therapy reflects “a far too superficial view on how physiology manages and controls reactive oxygen and other reactive species.”

They point out how a host of enzymes are involved inside the cell to combat ROS (reactive oxygen species). Ferulic acid has been shown to activate some key antioxidant proteins. Thus they feel that the main antioxidant value in food is provided by stimulating the cells natural antioxidant mechanisms. And ferulic acid has been shown to do this.
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1. Whole grains, type 2 diabetes, coronary heart disease, and hypertension: links to the aleurone preferred over indigestible fiber. Lillioja S, Neal AL, Tapsell L, Jacobs DR Jr. Biofactors. 2013 May-Jun;39(3):242-58. doi: 10.1002/biof.1077. Epub 2013 Jan 28.

C Reactive Protein Reduced By Diet

Lately a great deal of medical research has been looking at inflammation as a possible cause of cardiovascular disease. Doctors and researchers use CRP (C reactive protein) to determine the amount of inflammation a person is experiencing. C reactive protein is a compound made in the liver and released into the blood stream in response to an inflammatory stimulus. The CRP test has been shown to correlate with inflammation and it is been found to correlate with the severity of coronary artery disease. A recent study (1) sought to determine if a diet could lower C reactive protein.

C reactive proteinEarly Research

This is still relatively early research since no studies have shown that reducing C reactive protein will reduce coronary artery disease. Also there were no studies prior to this one showing that cholesterol lowering diets, such as the NCEP (National Cholesterol Education Program), could reduce inflammation.

The NCEP diet is a low fat diet many doctors use to lower blood cholesterol. The researchers in this recent study wanted to find out if the NCEP diet could lower C reactive protein as much as a medication. A medication that has been shown to reduce C reactive protein is lovastatin.

In this particular study a variation of the NCEP diet was compared to lovastatin for its ability to reduce C reactive protein. The participants in the study were all on a low saturated fat diet for a month prior to the study.

They were then randomly chosen to be on the control diet only, or the control diet and lovastatin, or on the experimental diet. The control diet was the usual NCEP diet. The experimental diet was designed to provide more plant sterol, fiber, soy protein, and almonds.

The remainder of the experimental diet was fairly similar to the control diet. The experimental diet had the same amount of protein, slightly less carbohydrates, and slightly more fat and cholesterol than the control diet.

Differences In Diets

But the experimental diet probably differed in unintended ways as well as the intended ways. The intended ways the experimental diet differed was that it had 4 times the amount of vegetable protein and 40% more fiber.

Since it was not measured, the difference in the type of fiber in each diet was probably unintended. The experimental diet included oats and barley, whereas the control diet included whole wheat. Thus the experimental diet had more beta-glucan, a soluble fiber, and the control diet had more insoluble fiber. These types of fiber have different known effects in the body.

Another important difference not measured was the potassium and sodium in each diet. The potassium sodium ratio has been shown to affect the amount of inflammation in the heart in heart failure. A previous post discussed how inflammation can be reduced with a diet that has a high potassium to sodium ratio. This was shown directly in animals in the study cited in that post. Among other findings, the researchers directly saw the inflammation by looking at heart samples under the microscope.

These differences in the experimental diet rather than the designed differences may have been responsible for the results. Because of the increased amount of vegetables and nuts in the diet, it is highly likely that the people put on the experimental diet had a better potassium to sodium ratio. The blood pressure in the experimental group was also reduced more than in either the lovastatin or the control group. This is another indication of a better potassium to sodium ratio in the experimental group.

C Reactive Protein Lowered By Diet

So the researchers did find that the experimental diet reduced C reactive protein just as much as lovastatin did. And the increased intake of vegetables and nuts were likely the difference. But whether it was the vegetable protein, vegetable sterols and vegetable fiber (no matter what type) that made the difference is not clear.

The researchers did not measure the types of fiber and did not study potassium or sodium. The different types of fiber and the difference in potassium and sodium in the diets may have been the critical difference. Further studies that include these variables may help determine how much of the improvement in C reactive protein was due to potassium and sodium.

Food Tables

Links to tables of the potassium and sodium content of various foods can be found by clicking the List Of Posts tab at the top of the page.
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1. Direct comparison of dietary portfolio vs statin on C-reactive protein. Jenkins DJ, Kendall CW, Marchie A, Faulkner DA, Josse AR, Wong JM, de Souza R, Emam A, Parker TL, Li TJ, Josse RG, Leiter LA, Singer W, Connelly PW. Eur J Clin Nutr. 2005 Jul;59(7):851-60.

Whole Grain And Cardiovascular Disease

A follow-up study to the study in the last post was published just this past month. That previous study was one of the early reports on whole grain and cardiovascular disease. It showed that whole grain consumption lowers cardiovascular deaths. Along with some other early studies, it resulted in the FDA defining “whole grain” and allowing health claims for “whole grain” products.

The study in the last post has a link to the entire publication. The link to the recent study (1) is only to the abstract. However the basic findings were the same.

Whole WheatWhole Grain And Cardiovascular Disease

The original report was known as the Nurses’ Health Study and included over 75,000 participants. The present study included over 74,000 from the Nurses’ Health Study and over 43,000 from the Health Professionals Follow-up Study. This resulted in over 118,000 persons being studied for 2,727,006 person-years of follow-up.

Similar to the earlier study, the researchers divided the participants into 5 groups according to how much whole grain they ate. They then determined total mortality from all causes, cardiovascular mortality and cancer mortality for each group. As in the prior study a higher whole grain intake was associated with lower total and lower cardiovascular mortality.

They corrected the results for the same non-dietary factors that they had in the original study. Age, smoking, body mass index, physical activity, and a modified Alternate Healthy Eating Index were examined for the possibility of influencing the results. There was an improvement in mortality for those eating whole grain products compared to those who did not eat whole grain, even among those who had healthy habits in each of those categories.

They also looked for an association of eating whole grain with cancer mortality. Although their statistics showed a mild effect, it was not statistically significant. The researchers concluded that whole grain did not affect cancer deaths.

Importance Of Bran

Just like it did in the early study, bran appeared to have a very strong correlation with improved total mortality and improved cardiovascular mortality. It was the component of whole grain that had the strongest effect on mortality.

They also considered whether the germ in the grain had an effect. Germ had an improvement in mortality. But after the bran effect was corrected for, the improvement was not significant.

This study, like the prior study, used a food frequency questionnaire to determine the eating habits of the participants. So, as discussed in last week’s post, this study has the same strengths and weaknesses as the prior study concerning the data used.

The difference in fruit and vegetable consumption is another factor that may be influence cardiovascular mortality. Fruit and vegetable consumption is known to reduce the prevalence of cardiovascular disease. A large number of studies have shown this improvement.

Also a large number of studies have shown the improvement in heart and vascular health from a high potassium sodium ratio in the diet. Fruits, vegetables, and intact grains (and especially bran) all have high ratios. This high ratio seems to be the common thread in studies concerning diet and cardiovascular disease.
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1. Association Between Dietary Whole Grain Intake and Risk of Mortality: Two Large Prospective Studies in US Men and Women. Wu H, Flint AJ, Qi Q, van Dam RM, Sampson LA, Rimm EB, Holmes MD, Willett WC, Hu FB, Sun Q. JAMA Intern Med. 2015 Jan 5. doi: 10.1001/jamainternmed.2014.6283. [Epub ahead of print]

Early Whole Grains Study

Most people know that refined grain removes a great deal of the nutritional value of a grain. Whole grain is felt to be healthier because it has more nutritional value. A number of medical studies have been done that show a lower risk of heart disease for those people who eat more whole grain foods. One early whole grains study that is often discussed is from the Nurses’ Health Study (1).

Grain FieldThe Nurses’ Health Study

An early report was done on this prospective study of over 75,000 nurses during a 10 year period. In this particular whole grains study report (1) the nurses were divided into 5 groups. They were ranked according to how much whole grain they ate. The researchers compared the number of nonfatal and fatal heart attacks in the five groups. The percentage of people experiencing heart attacks decreased as the amount of whole grain eaten increased.

The study was started at a time when dietary fat was considered the main culprit in heart disease. Other components of food were only beginning to be considered. There was little emphasis on whole grain. This was one of the early studies of grain products.

The definition of whole grain by the FDA did not come until after this study had been started. The main sources of whole grain were dark bread and breakfast cereal. In this whole grains study, if only 25% of a cereal was whole grain or bran, it qualified as a whole grain cereal. Despite this difference, most subsequent studies using other whole grain definitions have confirmed their conclusions.

Most Americans eat very little whole-grain. The average American eats only 1/2 serving a day. In this particular study the group eating the least amount of whole grain ate 1/7 serving a day and those eating the most ate 2 1/2 servings a day.

Other food groups and food macronutrients were also considered as possible influences. In addition to studying grain, the researchers also followed the vegetable fruit and red meat intake. They also kept track of the fat and protein.

Most other food groups and macronutrients were consumed in approximately the same amount by the participants. There was no difference in the amount of red meat eaten by each group. And each group ate almost the same amount of fat and protein.

Other Possible Explanations For The Reduced Risk

One big difference was the amount of bran eaten by those eating more whole grain. Since whole grain contains bran, it would be expected that they ate more bran. What was unexpected was bran’s strong correlation with less cardiac risk. Among the whole grain factors examined, bran showed the strongest likelihood of being correctly correlated with less coronary heart disease.

Because bran has a very high potassium to sodium ratio this makes it likely that bran is a major, although not only, component in whole-grain that reduces cardiac risk. This study was before the contribution of low potassium intake to cardiac risk was well understood, so the potassium and sodium levels were not studied. Thus we do not know how much the potassium sodium ratio of bran contributed to the reduced risk.

The biggest difference in food group consumption among those eating more whole grain was that they also ate significantly more vegetables and fruit. Both vegetables and fruit are high potassium foods (as is bran and intact grain). So, like bran, they also provide a higher potassium sodium ratio. This may have been an additional contribution to the reduced cardiac risk in the higher whole grain groups. Other more recent studies that have measured potassium and sodium intake have shown the reduction of cardiac risk from a higher ratio.

Possible Non-food Explanations

One concern of the researchers was that the high grain eaters may have had the improved risk from leading a healthier lifestyle rather than from eating more whole grain. At the time of this whole grains study, other known confounders included smoking, alcohol drinking, and lack of physical exercise.

The researchers corrected for these factors, and then compared the lowest to the highest quintile of whole-grain intake.  They found that although these factors had an effect on cardiac risk, the effect did not erase the effect from whole-grain.

One example is that smoking may have explained the risk. If smokers and non-smokers were included, the risk was reduced by 33%. However if only non-smokers were looked at, the risk for nonfatal and fatal coronary heart disease was reduced by 50%. This indicated that smoking did not fully account for the risk reduction.

Some other problems studies face today are the same as they were at the time of the study. “Whole-grain” has a different meaning to different people. See this post to find out what can be labeled whole grain. This particular study was done with a food frequency questionnaire. Food frequency questionnaires are the most common way of estimating food intake. They ask the participants to estimate the amount of different types of food they have eaten. Memory is not always accurate.

Even with an accurate memory, there are labeling problems. There are so many food labeling problems for “whole-grain” that it is difficult to determine the true amount of whole-grain products that are eaten. This is true even if you record everything you eat while you are eating.

Up to 50% of the product can be other substances, such as the marshmallows found in cereal labeled “whole grain,” as discussed here. Some people may consider these types of cereal a whole-grain food when filling out the questionnaire. However such a cereal will be unlikely to reduce their cardiac risk.
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1. Whole-grain consumption and risk of coronary heart disease: results from the Nurses’ Health Study. Liu S, Stampfer MJ, Hu FB, Giovannucci E, Rimm E, Manson JE, Hennekens CH, Willett WC. Am J Clin Nutr. 1999 Sep;70(3):412-9.

LDL-Cholesterol And Dietary Fat

In the last century there was a lot of research into the connection of diet with coronary artery disease. Focus has changed over the years from one dietary factor to another. During the last half of the twentieth century the emphasis was on the effect of saturated fat in the diet on coronary artery disease. Because of the association of a high blood LDL-cholesterol with coronary artery disease, short term dietary studies have been done to find diets that can lower blood LDL-cholesterol.

Possible contributors to LDL-cholesterolThe Study

One of the diets showing modest effect was the NCEP diet. This diet has evolved over the years. It was based on the concept that less fat in the diet would lower cholesterol, known to be associated with atherosclerotic plaques and coronary artery disease. However a study done in 2003 (1) compared the LDL lowering ability of one version of the NCEP diet to a statin drug, lovastatin.

Statin drugs have been shown to reduce blood cholesterol and subsequent heart events in large randomized controlled studies. Early diets involving eating less fat showed modest improvements in blood cholesterol and cardiac events. This study tried to determine if a diet could do as well as a drug.

By delivering plant sterols, fiber, soy protein and nuts, this diet was able to reduce LDL-cholesterol as much as 20 mg of lovastatin. It also lowered the overall coronary heart disease risk score based on a well accepted risk equation.

No Change In Dietary Fat

The diet was able to do this without lowering the fat content of the diet. In fact, the total fat, saturated fat and cholesterol intakes were slightly more in the experimental diet than the control diet. This study showed that without lowering fat intake, a diet can be designed to lower the risk of coronary artery disease.

The researchers felt this diet reduced cholesterol absorption, and cholesterol formation in the liver. And it may have increased the loss of cholesterol from the body. Some prior basic science studies indicated these mechanisms as possible ways the components of the diet worked.

Sadly, the study did not determine the sodium and potassium content of the diet. Because of this we cannot know if a change in potassium and sodium intake contributed. But it does show that a low fat diet is not the only consideration for reducing the risk of heart disease.
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1. Effects of a dietary portfolio of cholesterol-lowering foods vs lovastatin on serum lipids and C-reactive protein. Jenkins DJ, Kendall CW, Marchie A, Faulkner DA, Wong JM, de Souza R, Emam A, Parker TL, Vidgen E, Lapsley KG, Trautwein EA, Josse RG, Leiter LA, Connelly PW. JAMA. 2003 Jul 23;290(4):502-10.

Intact Grain Types

In previous posts we’ve discussed how grains and grain products can be mislabeled. The FDA has provided a definition that allows food manufacturers to claim a product as whole-grain when it has unhealthy characteristics such as we discussed two posts ago. Eating intact grain avoids these problems.

Intact GrainProcessing Grains

Last post we discussed how processing changes the health value of grains. The amount of processing makes a difference. Some processing is minimal and does not change the nutrients or other characteristics of a grain. These grains are as healthy as completely unprocessed grains because they remain intact. They have the full complement of nutrients, including potassium, and absorb as slowly as completely unprocessed grains.

Of course, whenever they are ground into flour, they will absorb more quickly. This occurs even if the flour is whole grain and includes all three components of grain. Eating products made from whole grain flour results in hunger returning quickly, usually within about 2 hours.

There are various different terms that are used with grains. And it can be confusing. Different grains use different terms even though the grains have the same components. Intact barley, oats, brown rice, wheat, millet, buckwheat, and rye use different terms to indicate an intact or minimally processed grain.

Types Of Intact Grain

Barley

Hulled barley is an intact grain. The outer hull is removed. However the grain itself is still composed of bran, germ and endosperm. Pearled barley, on the other hand, is not intact. The bran has been removed.

There are some differences for hulled barley from pearled barley in cooking and soaking. Hulled barley requires a longer soaking time and cooking time than pearled barley.

It is often used to replace rice in dishes. It is high in beta glucan and in this way is similar to oats. Beta glucan is felt to lower cholesterol and to bind bile salts. One caution however, is that it does have gluten. So like wheat it should be avoided if you have gluten intolerance.

Oats

Oats are initially hulled and roasted. This minimal processing still results in an intact grain. The oat grain retains the bran and germ, as well as the endosperm. There is no loss of nutrients.

There are multiple labels associated with intact oats. These include oat groats, steel cut oats, and rolled or old-fashioned oats. Quick cooking or instant oats are intact grain. However they have been crushed into a finer powder that is absorbed more quickly. And sometimes quick oats and instant oats have sodium added.

Brown rice

Brown rice can be considered intact grain. Only the hull has been removed. But the bran and germ are intact. However, when it is made into white rice the fiber, fatty acids, and many vitamins and minerals have been removed. White rice is not an intact grain.

Quinoa

Quinoa is considered a pseudo grain. Quinoa is not the seed of a grass, so it technically is not a grain. It has some unique characteristics that are very helpful to vegans. Quinoa contains lysine and isoleucine. Vegans may otherwise get very little of these two amino acids. Many vegetables and fruits, as well as many true grains, lack these two amino acids. Quinoa also has some fatty acids that are not common in grains, such as oleic acid and ALA.

Quinoa can be substituted for rice many dishes. It should be rinsed in cold water to remove saponins because of their bitter taste. To cook quinoa use one cup quinoa to 2 cups of water.

Millet

Millet has no gluten. It can be used in place of rice. It is very useful for giving different types of texture. If it is not stirred at all during cooking, it will become fluffy. If it is stirred, it will become like mashed potatoes. Use 1 cup of millet to 2 1/2 cups of water to cook.

Buckwheat

Buckwheat is another pseudo grain. Like quinoa it is not the seed of a grass, and it has no gluten. And like quinoa it has all 8 essential amino acids. Intact buckwheat is called groats. Toasting it improves its taste. When it has been pretoasted, buckwheat groats are known as kasha. Use 1 cup of groats or kasha with 2 cups of water to cook.

Wheat

Wheat is a true grain. It is the main grain found in most grain products. Usually only the endosperm is used. It is the main source of gluten in many products. The usual processing of wheat is milling, which breaks the wheat grain into parts. Wheat is grain in which the hull is bran, so that dehulling wheat removes the bran. However when the bran is added back in along with the germ it can be labeled “whole wheat,” as discussed in the last two posts.

Rye

Rye grains can be eaten intact. Rye is most usually mixed with other flours. It is made into breads and into crisps with mixed flour. However, pumpernickel is made from unmixed rye flour. Because the bran and germ are difficult to separate from endosperm in rye, its flour usually includes all three grain components and has more nutrients.

There you have it – the most common grains and two popular pseudo grains. These all can be eaten as intact grains. And when eaten as intact grains they will provide more nutrition, absorb more slowly and be healthier than processed grain products.

Whole Grain Processing

“Whole grain” does not mean what you may think it means. You may think that it means the grain is whole and intact. But it doesn’t. The FDA has defined what whole grain is. Highly processed grain can be labeled “whole grain.”

Grain KernelSome Definitions

The FDA defines whole grain as any grain product that has the same relative proportions of endosperm, germ, and bran as intact grain. And the product does not have to be 100% whole grain. Just 51% is adequate for it to receive a “whole grain” label. Our last post discussed how this allows a cereal with loads of marshmallows to be labelled “whole grain.”

But what is a grain? A grain is the fruit or seed of a cereal crop. Cereal is a grass the produces a fruit or seed that is used as food. How that grain is turned into food can make a big difference in its labeling and its effects on your body.

Grains are usually small hard dry seeds. They are composed of 3 layers. The outer layer is generally bran. The next layer is germ. And the inner layer is endosperm. All of these layers have nutrients in different proportions. A great many of the healthy components are found in the bran and germ layer. The most usual component of the endosperm layer is starch.

To be labeled “whole grain” all you need to do is put together the bran, germ and endosperm in the same proportions as found in the original grain and make that combination 51% of a product. Most producers are not so foolish as to add a bunch of marshmallows and call their product “whole grain.” But even without the marshmallows, the product still does not have many of the healthy characteristics of intact grain.

Whole Grain Processing

Processing the grain always affects the characteristics of the grain. But some processing only minimally affects the nutrient value of the grain. These minimal types of processing consist of stone grinding, steel cutting for oats, cracking for wheat, steaming and rolling for oats.

The most common processing is milling. Milling is used to produce the many grain products that are produced from flour. Refined flour removes the bran and germ leaving only the endosperm. Whole grain flour adds back the bran and germ after having removed them.

Some Health Effects Of Processing Grain

Because refined flour is composed mostly of starch it absorbs very quickly. Adding bran and germ slows absorption slightly. But because milling results in a fine powder (flour), absorption is quick even with whole grain. This is the reason for the high glycemic index of most baked goods whether refined or whole grain.

An example of how this type of processing results in a whole grain product being almost the same as refined grain can be found by comparing whole-wheat bread to white bread. The glycemic index for whole-wheat bread is 71 and that for white bread is between 71 and 73. In contrast, coarse barley bread composed of 75 to 80% intact kernels has a glycemic index of 34 (1).

High glycemic foods lead to a spike in blood sugar. It is not certain how much this spike contributes to the development of diabetes, but it does make diabetes more difficult to control once someone has developed diabetes. And it very likely contributes to an increase in obesity.

In addition to the effect on the glycemic index, milling also has an effect on other nutrients. Fats are removed from the grain during milling. But they are not replaced when the bran and germ are added back to the endosperm to produce whole grain flour. This results in the healthy fats found in intact grain being absent from whole grain.

In addition, potassium is often removed. Often potassium is found in a higher concentration in the bran and germ of a grain. But even when the bran and germ are replaced, the potassium may go lower. Raw oats have a potassium sodium ratio of 215. Oats with some bran removed have a lower ratio of 20. Raw wheat has a ratio of 170 – 218. Whole-grain wheat flour has a ratio of 182. Wheat flour for bread or cake has a ratio of 50 – 54. And self-rising flour has a ratio of 0.1 – 0.15.

But it is not just the change in the flour that makes a difference. The way the flour is subsequently used may damage the ratio even more. Flour is often combined with baking soda or baking powder, which will increase the sodium and reduce the potassium sodium ratio considerably. It will usually reverse the ratio from being above 1 below 1. The above mentioned self-rising wheat flour is a prime example of this.

Minimal Processing

Minimally processed grain, however, will still retain a very good ratio, even if it is lowered somewhat. Steaming simply drives water into a grain to soften it with minimal loss of potassium. Steel cutting will not affect starch absorption or the potassium sodium ratio.

Roasting and toasting are also often done to a grain. This will have minimal effect on the potassium and the sodium although the heat may affect phytochemicals and antioxidants.

Knowing that processing changes the characteristics of grains means it is best to avoid processing as much as possible. Intact grains can be used for many products that are normally made from refined grain or whole grain. As can be seen from the coarse barley bread example, a very tasty product can retain healthy characteristics.

But “whole grain” is not good enough. The grain should be intact.

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1. http://www.health.harvard.edu/newsweek/Glycemic_index_and_glycemic_load_for_100_foods.htm

Is Whole Grain Healthy?

Does it really make any difference whether you eat whole grain? An American Society of Nutrition report (1) reviewed multiple publications to determine whether whole grain lowers the risk of cardiovascular disease and diabetes. It found only weak evidence for any reduction of risk. This is understandable because of the FDA definition of whole grain. Some products labelled whole grain may actually increase risk.

Whole Grain CerealWhat Is Whole Grain?

The FDA defines whole grain as any grain product that has the same relative proportions of endosperm, germ, and bran as intact grain. And the product does not have to be 100% whole grain. Just 51% is adequate. The rest can be sugar or marshmallows. See the accompanying photograph of Lucky Charms with “Whole Grain” plastered across its front.

Whole grain is perceived as healthy. So there is a big desire to be able to label a product “whole grain.” The product will have a halo of “healthy.” Lucky Charms is only one example of the problem with the present definition of whole grain.

There are plenty of other products labelled whole grain that are not as obviously ludicrous as Lucky Charms in trying to be perceived as healthy. Even those without marshmallows and added sugar may have undesirable effects.

What Is Bad About Processed Whole Grain?

Just the usual milling and processing of grains can reduce the health value of whole grains. Processing changes the food characteristics of the grain. Processing often removes fats, adds sodium, degrades antioxidants, reduces fiber, and changes the phytochemicals in the grain.

Whole grain can be a product that has separated the 3 main parts of a grain, and then put the parts back together. But in separating them big changes occur. The fat is lost and is not added back in. This gives the “whole grain” product a longer shelf life. But nutritional value is reduced.

Grinding the grain or puffing the grain will add more surface area. Digestive enzymes have more places to work on right away. They don’t have to break down part of the grain to get to other parts of it. This means that the natural sugar and starch within the grain is absorbed more quickly. You don’t need added sugar to get a blood sugar spike.

Sodium is a major problem with processed grains. It is added to most, including “whole grain.” There are only a few ready to eat breakfast cereals with a favorable content of sodium and potassium. See this post for a table of ready to eat breakfast cereals with a favorable ratio.

How Intact Grains Make A Difference

How can you get the nutrition from grains without the problems found in processed grain products? It is simple – use intact grain.

Intact grain has not had the three main parts of a grain separated. The kernel remains intact. This means it retains its nutrients. The healthy fats are still present.

And when the grain is intact, it is degraded by digestion more slowly. This results in slower absorption and less hunger for a longer time after a meal. You no longer get the blood sugar spike and drop. It is this drop that results in hunger two hours after eating.

Instead of hunger returning in two hours, intact grain results in hunger taking several hours to return. The next time you eat will be later and you will eat less. A study comparing those who ate processed whole grain versus those who ate intact grain showed that those who ate intact grain for breakfast ate approximately 1/3 fewer calories at lunch (2).

Refined grain is even worse than “whole grain.” It removes the germ and the bran from the grain. This results in even fewer nutrients than in “whole grain.” And of course, refined grain gives you the same spike and drop in blood sugar.

Sodium Is Usually Added To Flour

Processed refined grain and processed whole grain are ground and milled into a fine powder. In addition to breakfast cereal, the resulting flour is often used for other products. Whole grain breads, muffins and other baked goods have become popular because they are perceived as healthy.

But in producing these other products sodium is often added in the form of salt. Or it may be added as baking soda or baking powder. This addition will ruin the favorable potassium sodium ratio found in intact grains. It almost always results in a reversal of the potassium sodium ratio. Whereas intact grain has a favorable potassium sodium ratio much greater than 1, products from processed whole grain usually have a very unfavorable ratio less than 1.

The few nutrients still left in the processed whole grain product will not be able to overcome the unfavorable effects of the poor potassium sodium ratio. So it is as important to avoid processed whole grain products as it is to avoid refined grain products. If salt, baking soda, or baking powder are used to make the product, it will lower your potassium sodium ratio for the day. This is true for all baked goods except those that are low in sodium.

Using intact grains for hot cereal, porridge or other dishes can provide a great amount of potassium and little sodium. It can improve your potassium sodium ratio for the day. Using processed whole grain products will have the opposite effect, and will increase your odds of developing hypertension, cardiovascular disease, and diabetes.
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1. Consumption of cereal fiber, mixtures of whole grains and bran, and whole grains and risk reduction in type 2 diabetes, obesity, and cardiovascular disease. Cho SS, Qi L, Fahey GC Jr, Klurfeld DM. Am J Clin Nutr. 2013 Aug;98(2):594-619. doi: 10.3945/ajcn.113.067629. Epub 2013 Jun 26.

2. High glycemic index foods, overeating, and obesity. Ludwig DS, Majzoub JA, Al-Zahrani A, Dallal GE, Blanco I, Roberts SB. Pediatrics. 1999 Mar;103(3):E26.

Stroke Reduction – Nutritional Factors

A recent article (1) considered multiple nutritional factors associated with a reduction in strokes. It reviewed much of the medical literature concerning diet and stroke reduction. The authors found an association of stroke reduction with antioxidants, fiber, the DASH and Mediterranean diets, whole-grain foods, fruits and vegetables, and increased potassium and decreased sodium in the diet. It did not find an association with saturated fat, polyunsaturated fat, monounsaturated fat, but did find an association with DHA and EPA.

Nutritional Factors Associated With Stroke Reduction

There is a great deal of overlap in these factors. The DASH and Mediterranean diets include more fruits and vegetables than the typical Western diet. Increased fiber is found in fruits, vegetables and intact grains. Antioxidants are also found in these foods. As found in fruits, vegetables and grains, antioxidants are associated with stroke reduction. But as found in supplements, most studies have not shown any consistent association with health benefits.

Stroke Reduction VeggiesMain Nutritional Factor For Stroke Reduction

While these factors most likely provide some benefits, the main beneficial factor in fruits, vegetables and grains is their potassium sodium ratio. Previous posts discussed how fruits and vegetables are not associated with improved cardiovascular mortality if salt is added to them.

In India, Iran, and Korea people eat more fruits and vegetables than found in a Western diet. But they have an increased sodium intake because they salt their vegetables. As a result, they have the same stroke incidence as Western countries. So the fruits and vegetables are only associated with an improved cardiovascular and stroke mortality if they retain their high potassium sodium ratio.

Even without an increase in fruit and vegetable consumption, reducing the sodium and increasing the potassium in the salt added to food can reduce stroke and cardiovascular mortality. The post about stroke rates falling in Finland discussed how Finland did this.

This means that there really is only one conclusion about what the most important factor is. It is not something magical about fruits and vegetables, or something magical about the DASH or Mediterranean diet that results in improved cardiovascular health. It is the improved potassium to sodium ratio found in these foods and diets. Of course, the fiber, antioxidants, types of fats, and phytochemicals found in fruits and vegetables provide healthful benefits. But to get improved cardiovascular and stroke mortality, food must retain its high potassium sodium ratio.

This is backed by a great deal of basic science research. There are multiple posts on this blog about basic science research on the potassium sodium ratio. These studies confirm the potassium sodium ratio’s importance.

Tables Of High Potassium Foods

To find links to tables of the sodium and potassium content of food, click on the tab at the top of the table entitled List of Posts.
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1. Stroke and nutrition: a review of studies. Foroughi M, Akhavanzanjani M, Maghsoudi Z, Ghiasvand R, Khorvash F, Askari G. Int J Prev Med. 2013 May;4(Suppl 2):S165-79.

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Recommended

Two excellent books about high potassium foods and blood pressure reduction are available on Amazon. The first is a practical guide to changing your diet to a high potassium foods diet. It is helpful even if you do not have hypertension. The second is a scientific explanation of the diet. It discusses the changes to your body that occur with high potassium foods.

Practical Guide

Scientific Explanation

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