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Table of Interventions - Nutrition
What is the connection between diet and cardiovascular disease?
Diet directly affects the development of atherosclerosis (lesions which can block arteries), the underlying cause for CVD. Diet also affects blood cholesterol levels, body weight, blood pressure, and blood glucose levels. Changing lifestyle habits, including the way people eat, has long been known to be effective in managing these risk factors.
What are the dietary recommendations for preventing cardiovascular disease?
For the population, a healthy diet that can be recommended for all healthy people over two years of age is low in total fat, saturated fat, and cholesterol and that is moderate in sodium. Fat intake should be lowered to no more than 30% of calories, while limiting saturated fat intake to less than 10% of calories. Cholesterol intake is limited to no more than 300 mg per day. For persons who have already been diagnosed with some form of CVD, further modifications are usually advised. Increase fiber intake to 25 grams per day, especially increase soluble fiber for persons with high blood cholesterol and diabetes.
Does a high fat diet during childhood and adolescence increase the risk of heart disease?
Yes. Prevention of heart and blood vessel disease needs to begin at an early age. Atherosclerosis, or fatty deposits in the walls of the blood vessels, was shown in otherwise healthy young soldiers killed in battle in the Korean War. More recently, an autopsy study of 1,079 men and women who died between the ages of 15 and 34 showed fatty deposits and lesions in those with high levels of blood cholesterol. Eating habits that develop early can be difficult to change. Therefore, a preventive diet is recommended for all healthy children over the age of two years.
Is poor diet a public health problem?
Yes. The National Health and Nutrition Examination Survey (NHANES), one of the major national surveys in the National Nutrition Monitoring and Related Research Program, is a major source of periodic information of the dietary, nutritional and health status of the U.S. population. The dietary assessment component included a 24-hour recall interview. Highlights of this survey include: Mean daily intake of energy was 2,095 kilocalories (kcal) for persons two months of age and older. The overall dietary pattern for the U.S. population ages two months and older was 50% of energy from carbohydrate, 15% of energy from protein, 34% of energy from fat, and 2% of energy from alcohol.
When comparing mean intakes of energy and protein with the Recommended Dietary Allowances (RDAs) it has been found that although the percent of energy from fat has declined since the 1970s and 1980s, mean values for the population are still above the Year 2000 goal of 30% of energy or less from total fat and less than 10% of energy in the population. Mean cholesterol intakes decreased in adults. The mean cholesterol intakes for adult males was still above the recommended level of 300 milligrams or less per day. (Reference: McDowell MA, Briefel RR, Alaimo K, et al. Energy and Macronutrient Intakes of Persons Ages Two Months and Over in the United States: Third National Health and Nutrition Examination Survey, Phase 1, 1988-91. Advance date No. 255. October 24, 1994.)
The most obvious result of eating improperly is weight gain. Obesity is a serious and growing public health problem. In 1990, 29% of adult West Virginians were obese (defined as being at least 20% over one's ideal weight as calculated from the Metropolitan Life Insurance Company's weight tables). By 1994, according to the Behavioral Risk Factor Survey, 35% of West Virginia adults were identified as obese, ranking the state the 3rd highest in the nation. That same year, the state's rate of hypertension, also directly associated to heart disease and stroke, was 26%. Experts predict that increasing rates of obesity will result in increased diagnoses of diabetes, hypertension, and cardiovascular diseases. The treatment of these conditions and their complications could result in enormous expenditures of public and private funds at a time when resources are shrinking.
Is there a relationship between diet and hypertension, or high blood pressure
. Obesity and overweight increase high blood pressure in all ethnic groups at all ages. The risk of developing high blood pressure is two to six times greater in people that are overweight. Modest weight loss may be the key to the control of hypertension in some people. Some persons seem to be "salt sensitive." In these persons a high sodium diet aggravates high blood pressure. The American Heart Association presents evidence that eating a diet low in total fat, saturated fat, and cholesterol and rich in fruits and vegetables effectively lowers blood pressure.
Why is diet so important in preventing or controlling diabetes?
In those persons with a family history of diabetes, control of weight gain through diet and exercise may delay or even prevent a diagnosis of diabetes. In those persons who have diabetes, careful balancing of foods and modest restriction of calories, fats, and all types of carbohydrates is the most important key to controlling the blood sugar, even if insulin or pills are also used.
What changes in eating habits could be promoted safely to the general public?
Simple programs that promote increased use of nutritious foods high in fiber, low in fat, and high in nutrients are safe for most persons at any age. The Five-a-Day Program promotes consumption of at least five servings daily of fruits and/or vegetables. Encouraging the public to drink milk, but to choose lower fat varieties, is the target of the "One Percent or Less" campaign that has been successfully used in Bridgeport and Parkersburg. The use of the USDA Food Guide Pyramid encourages balanced eating and suggests target goals for consumption of different foods. The new food labeling requirements make much more information available to consumers who
are interested in monitoring fat intake. Cooking schools and demonstrations of lower fat cooking techniques can show consumers how to improve on long-standing habits. The public could be encouraged to grow vegetables in containers or in small home gardens.
Are there persons who should not follow these recommendations?
. Most people in the population should follow a heart healthy diet. There are few exceptions. Infants and children under the age of two years should have whole milk. All other persons will gain full nutritional benefit using skim or 1% milk. Persons on certain restricted diets, such as those experiencing renal failure or inflammatory bowel diseases, should consult their physicians or nutritionists before changing diets.
Why do so many people continue to eat in unhealthy ways if there is so much information available telling us this is dangerous?
Diet, or the food we choose to eat day in and day out, is the result of many factors. Among these are ethnic and religious preferences; learned ways of cooking, seasoning, and eating; availability of money and time for food preparation; availability of refrigeration, storage, and cooking facilities, and even transportation for the purchasing of healthy foods. Changing the diets of families is a complex undertaking. Statistics for weight loss programs reveal that most people who lose weight eventually regain the lost weight. Obviously changing the usual diets of a large number of people is not a simple undertaking.
Published July 1997
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