D.A.S.H. Diet (Dietary Approaches to Stop Hypertension)

Hypertension (high blood pressure) affects about 1 out of every 3 American adults (an estimated 67 million Americans).  Blood pressure is the force of blood against artery walls.  It is measured in millimeters of mercury (mmHg) and recorded as two numbers--systolic pressure (when the heart beats) over diastolic pressure (when the heart relaxes between beats).  Both numbers are important.  Normal blood pressure is lower than 120/80 mmHg.  High blood pressure (hypertension) is when your blood pressure is 140/90 mmHg or above.  Blood pressure between 120/80 and 140/90 is called prehypertension.  If you have prehypertension, you are more likely to develop high blood pressure.  Almost 30 percent of American adults ages 18 and older, or about 59 million people, have prehypertension.  

High blood pressure is dangerous because it makes the heart work too hard, and the high force of the blood flow can harm arteries and organs such as the heart, kidneys, brain, and eyes.  If uncontrolled, it can lead to heart and kidney disease, stroke, blindness and early death.  If you have heart or kidney problems, or if you had a stroke, your doctor may want your blood pressure to be even lower than that of people who do not have these conditions.  You are more likely to be told your blood pressure is too high as you get older because your blood vessels become stiffer as you age.

There are many things you can do to help control your blood pressure:

• Eat a heart-healthy diet, including potassium and fiber, and drink plenty of water.

• Limit the amount of sodium (and salt) you eat--aim for less than 1,500 mg per day.

• Reduce stress--try to avoid things that cause you to stress.

• Stay at a healthy body weight.

• Limit how much alcohol you drink--one drink a day for women, two a day for men.

• If you smoke, quit!

• Exercise regularly--at least 30 minutes of aerobic exercise a day (all at once or "piecemeal" in 10-minute bouts).  If your blood pressure is moderately elevated, 30 minutes of brisk walking on most days of the week may be enough to keep you off medication.  If you don’t have high blood pressure, being physically active can help prevent it.  If you have normal blood pressure but are not active, your chances of developing high blood pressure increase, especially as you get older.  If you have been sedentary, gradually build up the amount of exercise and do something you enjoy.  If you have a chronic health problem or a family history of heart disease, talk with your doctor before beginning a new physical activity program.

The DASH Diet (Dietary Approaches to Stop Hypertension) issued by the U.S. Dept. of Health and Human Services, National Institutes of Health, National Heart, Lung, and Blood Institute (NHLBI) is proven to lower blood pressure.  The DASH Diet emphasizes fruits (4-6/day, depending on body weight), vegetables (3-6 servings/day), nuts (approximately a handful of nuts most days of the week) and fat-reduced milk products, and includes whole grain products, fish and poultry.  The diet is low in saturated fat (6%), cholesterol (150 mg), and total fat (27%) and is lower in lean meat, sweets, added sugars, and sugar-containing beverages than the typical American diet.  The eating plan is rich in potassium, magnesium, calcium, protein and fiber.  Studies conducted by scientists supported by the National Heart, Lung, and Blood Institute (NHLBI) and performed at 4 major medical centers found that the DASH Diet significantly reduces blood pressure.  The results were dramatic and fast, achieving reduced blood pressure within 2 weeks.  Even a modified plan that just added more fruits and vegetables to a typical American diet reduced blood pressure.  Another benefit of eating the DASH eating plan is that it reduces (bad) LDL cholesterol, further reducing your risk for cardiovascular disease.  You should be aware that since the DASH eating plan has more daily servings of fruits, vegetables, and whole grain foods than you may be used to eating and is high in fiber, it can cause bloating and diarrhea in some persons.  To avoid these problems, gradually increase your intake of fruit, vegetables, and whole grain foods.

While the studies show that eating the DASH Diet lowers blood pressure, the combination of the eating plan and a reduced sodium intake gives the biggest benefit and may help prevent the development of high blood pressure.  The highest level of sodium intake considered acceptable by the National High Blood Pressure Education Program and U.S. Dietary Guidelines for Americans is 2300 milligrams (the equivalent of 1 tsp. of table salt, or sodium chloride).  The 2010 Dietary Guidelines for Americans recommends that sodium intake be reduced to 1,500 mg (2/3 tsp. of table salt) among persons who are 51 and older and those of any age who are African American or have hypertension, diabetes, or chronic kidney disease.  The 1,500 recommendation applies to about half of the U.S. population overall and the majority of adults and is the amount recommended by the Institute of Medicine as an adequate intake level and one that most people should try to achieve.  Adult men in the U.S. currently eat about 3,100 - 4,200 mg/day (that's 2-3x the recommendation!).  Adult women in the U.S. eat about 2,500- 3,000 mg/day.  Furthermore, the average daily sodium intake for Americans age 2 years and older is 3,436 mg.  Only a small amount of salt that we consume comes from the salt added at the table, and only small amounts of sodium occur naturally in food.  Processed foods account for most of the sodium Americans consume so read food labels--you may be surprised to find which foods have sodium.  For example, which McDonald’s product has more sodium—the french fries, vanilla shake or apple pie?  The 16-oz. vanilla McCafe shake (200 mg) and the apple pie (170 mg) both have more sodium than the small french fries (160 mg)!  It tastes like there is more sodium in the french fries because the salt is on the surface.

The DASH eating plan also emphasizes potassium from fruits and vegetables.  A potassium-rich diet helps reduce elevated blood pressure, but be sure to get your potassium from food sources not from supplements. Many fruits and vegetables, some milk products, and fish are rich sources of potassium.  While salt substitutes containing potassium are sometimes needed by persons on drug therapy for high blood pressure, these supplements can be harmful to people with certain medical conditions.  People who have kidney problems or who take certain medicines must be careful about how much potassium they consume.  If this is you, before you increase the potassium in your diet or use salt substitutes which contain potassium, check with your doctor.

Mediterranean Diet

It turns out that the healthiest diet is one of the most enjoyable diets.  Lucky for us, one of the most enjoyable ways to eat a more plant-based, animal-reduced diet is to eat as the traditional Greeks--the dietary pattern affectionately known as the "Mediterranean diet".

In the 1960’s Professor Ancel Keys first reported on the health benefits of people who ate the traditional diet in the Greek island of Crete and Southern Italy in the 7 Countries Study.  Professor Keys documented the diets of 13,000 middle-aged men (ages 40-59) living in Southern Italy, Crete, Yugoslavia, Finland, Netherlands, Japan and the US.  Interestingly, the Cretan diet was one of the highest fat diets in the study (40% fat), but it was low in saturated fat and high in monounsaturated fat, and the Cretan Greeks eating it came out with some of the lowest rates of coronary heart disease and all-cause mortality and had the longest life expectancy in the world at that time. The population of Finland ate the most saturated fat (mostly from cow’s milk products) and had the highest levels of blood cholesterol and the most heart disease.  Even though the population from Finland had a similar intake of fat to that of the Cretans, the population of Finland had 30 times higher the rate of heart disease!  

The Cretan diet was also relatively low in carbohydrates (45% energy) with most of the carbohydrates consumed being of low glycemic index.  However, this is not a “low carbohydrate diet” as has been popularized to Americans in the recent high-protein diet craze (those diets are usually based on a dangerously low carbohydrate intake of about 30-40%).  Unlike the popular “low-carbohydrate diets” of America, the Cretan diet was based on a large volume of plant foods and consisted of a high intake of vegetables (2-3 cups/day, especially green leafy types including purslane), high intakes of legumes (30g/day), nuts (30g/day, especially walnuts), fruit (2-3 fruits/day) and wholegrain cereals (equivalent to 8 slices of bread/day).  They also had moderate intakes of fish (40g/day), alcohol (20g/day with meals, i.e. 2 standard drinks/day) and low intakes of red/white meat (35g/day) and fermented sheep/goats milk products (cheese/yogurt consumed weekly). This is the equivalent of a 5 oz. serving of fish 2x/week, a 4-5 ounce serving of chicken/pork once a week, a 4-5 ounce serving of lamb once a week or less, and bean/lentil soups or casseroles about 2-3 times a week.

The Cretan diet was also low in animal and saturated fat (8% energy), but high in total fat (40% energy) and monounsaturated fat (25% energy).  The major source of fat was olive oil (about 4 tablespoons/day), which was nearly always consumed as 'extra virgin' or the first pressing of the olive and nearly always consumed with plant food.  The combination of vegetables with olive oil in the Mediterranean cuisine may be an important component responsible for its protective effect.  For example, the antioxidant lycopene in tomatoes is better absorbed in the intestine if the tomatoes are cooked, and absorption is even better if cooked with oil, which makes sense since these pigments are fat soluble.  

Countless studies have consistently verified the health benefits of the Mediterranean diet. The Mediterranean Diet pyramid was developed by Professor Walter Willet and colleagues at Harvard University. 

An Optimal Diet

There are numerous ways to discuss (and eat) an optimal diet—the overall health-supporting Mediterranean Diet, the metabolic syndrome-preventing Syndrome X Diet, the hypertension-reducing D.A.S.H. (Dietary Approaches to Stop Hypertension) Diet.  These are just a few of the more well-known (the topic of previous and upcoming blogs), but they are all based on the same idea--more plant, less animal food.  While they approach the healthy diet from different perspectives (a healthy culture, resolving metabolic syndrome, reducing hypertension), they really are all quite similar in composition.  The good news is there is not one diet for heart disease, one diet for cancer, one diet for diabetes, etc.  A healthy diet has significant impact on our overall health, and all of the public health organizations reflect that truth in their dietary recommendations.  The American Heart Association, National Cancer Institute, American Diabetes Association, Dietary Guidelines for Americans and others have always had variable but similar recommendations, but in recent years they have all become the same: eat a plant-based monounsaturated fat-rich diet based on whole grains, beans, nuts and seeds, fruits and vegetables with small portions of lean meat, poultry and dairy, generous amounts of fish (3-4x/week) and olive oil to prevent cardiovascular disease, cancer, diabetes, intestinal disease and more.  Also, what always has been, still is, and always will be an optimal diet.  It is not going to change—it is only our rather limited understanding that has been changing over the years. 

The amount of plant food in an optimal diet is significantly higher than the standard American diet (S.A.D.).  Healthy cultures around the world eat a strikingly similar 90% plant:10% animal food diet (in a variety of ways) whereas the typical American diet is based on 70% animal food and only 30% plant.  An optimal plant-based diet is low in animal protein and animal fat, low in processed foods, and high in health-supporting, disease-preventing plant foods with their 900+ discovered (so far) phytochemicals and fiber. 

This may sound extreme to our American meat-loving ears, but around the world people do not think it is normal to die of such long-term degenerative diseases which are the norm in America.  

Trans Fats

In the last several blogs I have mentioned the danger of processed “trans fats” in our diet.  Let's explore them a little more.

“Trans fatty acids”, otherwise labeled as “partially hydrogenated fatty acids” (or hydrogenated vegetable oils) are now widely used in many products to lengthen shelf life and improve the texture of foods.  Fatty acids are based on carbon chains that have hydrogens attached.  Saturated fatty acids have hydrogens attached at every available bond (they are saturated with hydrogens), whereas unsaturated fatty acids have one (monounsaturated fat) or more (polyunsaturated fat) places on the carbon chain that do not have a hydrogen attached (an "empty bond").  Normally, when oxygen attaches to the site on the carbon chain of the fatty acid where there is an empty (available) bond the product goes rancid faster.  Partially hydrogenated oils undergo a chemical process which adds hydrogens to unsaturated fat to make it more saturated, making less available bonds for oxygen to attach so the product stays fresher longer.  The purpose of “partially hydrogenating” a fat is to increase the product’s shelf life, not your life. 

In addition to making a perfectly healthy unsaturated fat more “saturated” (with hydrogens), hydrogenation causes the structure of the fatty acid to be altered.  During the process the structure of a natural unsaturated fat (where the "cis" configuration of the fatty acid hydrogens are attached on the same side of the carbon chain) may be changed to a "trans" configuration (where the hydrogen atoms occur on both sides).  Thus the name “trans” fatty acids.

Trans fatty acids are harmful!

Trans fatty acids have been implicated in a host of degenerative diseases including cardiovascular disease (which does not just happen because there is too much cholesterol—there is an initial insult to the inside of the arteries), cancer, arthritis, and even premature aging!  Trans fatty acids are at least as bad as, if not worse than, saturated fats as they have an equally negative effect on increasing the LDL (“bad”) cholesterol.  An increasing number of researchers and nutrition experts agree that trans fats are actually worse (and some say much worse) than saturated fats because they not only increase LDL cholesterol like saturated fats do but also significantly reduce HDL (“good”) cholesterol, delivering a “double whammy”.  Additionally, trans fatty acids increase Lp(a) lipoprotein levels (a particularly harmful type of LDL cholesterol associated with an increased risk of coronary heart disease) and triglycerides.  Many studies have confirmed the adverse effects of trans fatty acids, prompting the FDA to require labeling of trans fatty acid content of foods on product labels starting January 2006.

In June 2006 the American Heart Association issued updated dietary recommendations which set a goal for trans fatty acids of less than 1% of total calories.  The typical American diet contributes 10 grams of trans fatty acids for every 3,000 calories (equivalent to 3%).  The largest single source of trans fatty acids is margarine.  Watch out for peanut butter too!  Steer clear of the big brand name peanut butters which advertise “low cholesterol”, “low sugar” and/or “low fat” on the front of the label and check the label for “partially hydrogenated” oil.  Choose the brand that lists only “peanuts and salt” on the ingredients label.  While there are a lot of “natural” brands of peanut butter without partially hydrogenated fat, there is usually an inexpensive store brand with just “peanuts and salt” too.   

Dieting is Harmful to Your Health

In the last blog I presented overwhelming evidence that our obsessive focus on weight is misguided when it comes to actual mortality data.  In a previous blog I discussed the futility (failure) of dieting.  Whether your goal is prevention of lifestyle disease or weight-loss, I encourage you to take the obsessive focus off of weight and focus on the real problems instead--lack of activity and plant foods, and a high animal (saturated) and processed (trans) fat diet.  Today I hope to strengthen that focus by sharing about the downright danger of dieting.  Again, from the book Big Fat Lies by Glenn Gaesser, a large amount of research (and thus a longer-than-usual blog to make you aware of the danger) shows just how harmful dieting can be:

·   Fifteen studies published between 1983-1993 show that weight loss increases risk of premature death by up to 260%.

·    Dieters, especially yo-yo dieters (who make up about 90% of the dieters in this country), have a risk for Type II diabetes and cardiovascular disease that is up to twice that of “overweight” people who remain fat.

·    Weight loss was associated with 40-260% higher death rate when researchers devised 36 different ways of comparing causes of death and amount of body weight lost in a follow-up of the NHANES I study (1971-74) in 2,453 men and 2,739 women.

Focus on Fitness, Not Fatness

The following information is from the book Big Fat Lies by Glenn Gaesser, Ph.D. which I highly recommend.  I present this information in an effort to help you take the focus  off of body weight, and focus instead on physical activity and a healthy diet.  The evidence is overwhelming (and the blog is longer than usual to make you aware of the amount of evidence, though this is only a small overview) that body weight does not deserve the blame we have assigned to it.  And the evidence keeps coming in--you may have heard the "new" evidence consistently reported in the news over the past 2-3 years that "surprises" the experts (and reporters), concluding that body weight is not to blame.  The bottom line--fitness matters more than fatness.  The caveat is that abdominal fat is strongly associated with cardiovascular disease and diabetes.  Note how large and long these studies are, and how well-respected the sources are.

·      Dr. Steven Blair and associates at the Cooper Institute of Aerobics Research in Dallas, Texas studied 10,244 men and 3,124 women between 1970-1981 and found that being heavy did NOT increase the risk of dying prematurely.  Furthermore, when considered in combination with fitness, being overweight seemed to be better than being underweight!