Authors: Marla Heller
Tags: #Health & Fitness / Diets
Not so surprisingly, since we now know that DASH has been rated as the best and the
healthiest diet plan, it did work to lower blood pressure, even in the people with the highest likelihood of having high blood pressure. In the initial study, there were three arms. The first group ate a typical American diet, the second group consumed the typical diet with additional fruits and vegetables, and the third group followed the DASH plan, which contained the extra fruits and vegetables and extra low-fat dairy foods.
Because the purpose of the study was to evaluate the effect of the food pattern on
blood pressure, the participants were not allowed to lose (or gain) weight during the study. Weight change would have muddied the waters when it came to evaluating the
effect of the diet plan on hypertension. Losing weight, on its own, can improve blood pressure.
Interestingly, the group with just added fruits and vegetables did not have an
improvement in blood pressure. It was only the group following the entire DASH diet
plan, including the additional dairy, which showed an improvement in blood pressure.
Many times the DASH diet is oversimplified and merely described as a plan rich in fruits and veggies. However, this misses the key balance of the overall plan. Without the
calcium and vitamin D from dairy, the plan did not work. On the other hand, many
people think that DASH is just another low-sodium plan. However, in this first study, sodium was significantly higher than the current DRI recommendations.
And yet significant reductions in blood pressure were seen in study participants who
had hypertension. SBP was reduced by 11.4 mm Hg and DBP by 5.5 mm Hg.
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Without lowering sodium. Without losing weight. The DASH diet, complete with dairy and extra
fruits and vegetables, was able to improve blood pressure, even without other important lifestyle changes.
A later study was designed to evaluate the benefit of sodium reduction in addition to the DASH food pattern. It was entitled the DASH-sodium study.
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This study showed that further reductions in sodium could be helpful for improving blood pressure for many
people with high blood pressure, especially African-American women and older people
in general.
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Since the DASH diet already lowers blood pressure without sodium restriction, the benefit of lowering salt intake was much stronger in people who were eating a typical American diet. The DASH diet with 3,500 milligrams of sodium
provided about the same degree of blood pressure reduction as the typical diet with
sodium reduced to 1,500 milligrams. The DASH diet thus provides some protection for
occasionally having higher-salt meals.
DASH has been shown to lower total cholesterol and LDL cholesterol
.6
There was a slight reduction in HDL cholesterol and no change in triglycerides. However, it should be remembered that the earliest DASH studies were relatively high in starchy foods, which are associated with depressing HDL levels and contributing to triglyceride levels.
A study of the DASH diet with patients who had metabolic syndrome (insulin
resistance, low HDL, elevated blood pressure, and/or high triglycerides) showed
improvements in LDL, HDL, triglycerides, fasting blood glucose, and blood pressure.
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Because the original DASH diet was developed at the time when high-starch, low-fat
diets were thought to be beneficial, starch is at the core of the original DASH research.
As more research in the 2000s was showing that there might be benefit to lowering the starch content of the diet, the DASH researchers decided to evaluate this modification.
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They evaluated replacing starch with either protein-rich foods or fats rich in
monounsaturated fats (MUFAs). This study was done under the name “OMNI-Heart
(Optimal Macro-Nutrient Intake Heart) Trial.
”9
The results showed that both substitutions (protein and MUFAs) were better than the original DASH food pattern for lowering
blood pressure (especially in people with hypertension) and in lowering triglycerides.
The people who were on the plan with the higher level of protein reported that their
hunger levels were lower than those on either the higher-fat plan or the starch-rich plan.
This could not be explained by differences in appetite hormone levels.
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Studies of Lower-Carb Diets and Weight Loss
I will briefly discuss a few of the studies that were run with the purpose of showing the negative effects of the high-protein, low-carb diets. One of the first studies was
sponsored in part by the American Heart Association, looking to discourage people from following the Atkins diet. This study, under the direction of Bonnie Brehm, PhD, RD,
provided guidance to about half of the participants on how to follow an Atkins-style diet while the other participants were provided advice on following a reduced-calorie,
relatively low-fat diet.
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The participants on the very low-carb diet plan lost more weight and more fat weight. Both groups had similar improvements in markers of heart health.
Another similar study also found improved weight loss with the low-carb plan, as
measured at 3 and 6 months, but with comparable results by one year, as compared with a conventional low-fat diet plan.
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Most markers of heart health and glucose control were improved similarly in both groups. However, in the low-carb group, HDL and
triglycerides were significantly improved.
Don Layman, PhD, professor emeritus from the University of Illinois, has focused
much of his research on helping to understand the effectiveness of higher-protein and lower-carbohydrate diets. His research has shown that they are beneficial in terms of promoting improved weight loss, while being heart healthy, and improving lean body
mass, which is associated with faster metabolism.
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Dr. Layman has shown that having a higher protein intake, around 125 grams per day, will help with improving body
composition (reduced fat loss versus muscle mass loss) while dieting, or help to preserve muscle mass for those dieting plus adding moderate exercise.
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For people who carry their excess weight around their middle and/or have some
degree of insulin resistance, carbohydrate restriction is recommended by many
endocrinologists
.15
It appears to be beneficial even independent of weight loss. This is a major contrast with the dietary advice in the 1990s, when the typical recommendations for people with type 2 diabetes included 55% of the calories coming from carbs.
Additional Health Benefits from the DASH Diet
Because the DASH diet has been found to be so healthful, many researchers have been
interested in knowing what the long-term benefits would be of following the diet. There are several ongoing studies that have been following people for long periods of time and have been tracking their food intake and health history. Many of the reports on the long-term benefits of DASH come from these studies, especially the Nurses’ Health Study
(NHS) and the Male Health Professionals Study (MHPS), which have been following
their participants for over 20 years.
From these studies, we have learned that people who follow the DASH diet for much
of their life have lower rates of strokes, heart attacks, and heart failure. An evaluation of the NHS showed that women who followed an eating pattern conforming to the DASH
diet, over 24 years of monitoring, had significantly lower rates of heart disease and stroke
.16
A study following 39,000 men aged 45–79 years old, for 7 years, found a 22%
lower risk of developing heart failure if they ate a diet that was consistent with the DASH
eating plan.
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A separate study, following the health history of 36,000 women over 7
years, showed that women who followed an eating pattern consistent with the DASH diet were 37% less likely to develop heart failure.
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Following over 40,000 men for over 20 years, in the Health Professionals Follow-Up
Study, it was seen that men who followed an eating pattern that conformed to the DASH
diet were less likely to develop type 2 diabetes
.19
Men who were heavier were more likely to see the benefits in risk reduction. A similar study of 37,000 women evaluated the effect of healthy diets rich in fruits and vegetables and saw reduced risk of type 2
diabetes in women.
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The DASH diet has also been shown to help preserve kidney function in women with
early signs of impaired function.
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Further, the risk of developing kidney stones was about 55% reduced in men and women following a DASH eating pattern.
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This study was especially powerful since it followed about 46,000 men for 18 years, and 196,000
women for 14 to 18 years. This reduction in risk came in spite of the fact that the people following the DASH eating pattern had much higher intake of calcium and oxalic acid,
which historically were discouraged for people with a history of kidney stones.
From the NHS we have learned that women who follow a DASH-style eating pattern
are less likely to develop estrogen receptor negative (ER-) breast cancer.
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Following a lower-carb diet also reduces the risk. Colorectal cancer rates have been shown to be about 20% lower in people following the DASH plan.
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Food patterns that are rich in plant-based foods are well known to be very good
sources of antioxidants. And a study performed by a group outside of the original DASH
consortium found that the DASH diet was very effective at lowering the oxidative stress of obesity, which may be a factor in improving blood pressure.
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A report by the DASH
group found that they were able to show reduced markers of oxidative stress and
increased antibodies for oxidized LDL cholesterol in one of their studies.
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The DASH
diet also appears to improve bone health, and has been shown to be associated with lower markers of bone turnover, which is associated with osteoporosis.
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Going to the Market, Going to Get Healthy
It can seem overwhelming to figure out which foods are healthy. There are
incomprehensible Nutrition Fact labels. American Heart Association Heart-Checks.
Claims of being a source of “whole grains” when there is very little actually in the
product. Low fat. Reduced fat. And now grocery chains are getting into the fray with
their own ideas of what makes healthy foods.
We are going to help you make sense of the food labels and health claims. Then, we
will help you with building a grocery list and stocking up your kitchen to make it very easy to follow the DASH Diet Weight Loss Solution. Add in some recommendations for
additional DASH-friendly recipes and favorite cookbooks, and you will be on track to be healthier for the rest of your life.
How to Make Sense of Food Labels, Check Marks, and Health Claims
Nutrition labels were developed to help people avoid less healthful foods, and choose foods with important nutrients. However, the net effect may have been to expect
everyone to become a dietitian. Who travels to the grocery store with a calculator to see how each food fits into their daily plan?
Whenever I am asked what people should look for on the food labels, I always
respond, “Choose mostly foods without labels.” What on earth does that mean? Fresh
fruits and vegetables don’t have food labels. Some fresh fish, poultry, and meat don’t have food labels. These are all unprocessed foods that happen to fit into a healthy diet.
Going one step beyond this to include relatively unprocessed foods such as milk, yogurt, frozen vegetables and fruits without additives makes a great foundation for a healthy diet.
It is more when you get into heavily processed foods (which we are not really
recommending in this plan) that food labels become important.
Many of the alternative food “health” labels, such as check marks, can be confusing
and may not correspond to the DASH recommendations. For example, some foods high
in added sugars may have a health claim because they have added some whole grain.
However, it probably is not something that you would choose to be part of your plan.
This chapter will help you make great choices for healthy foods for the DASH Diet
Weight Loss Solution.
In defense of the Nutrition Facts, many of the nutrients that are required on the labels can help people reduce their risk of developing or help manage some very common
diseases and conditions, such as heart disease, hypertension, diabetes, and obesity. The key nutrients include calories, total fat, saturated fat, trans fats, cholesterol, sodium, total carbohydrates, and protein. And the vitamins and minerals on the labels are those of