Heart Disease Prevention
By Hope Ricciotti, MD
Treatment (not prevention) is responsible
for drop in heart attack
In the last twenty years, heart disease death rates have dropped very dramatically. Many of us believe that fewer people are dying from heart attacks because we have gotten better at preventing heart attacks. But we would be wrong. The truth is that fewer people are dying from heart disease because we have gotten much better at helping people survive their first heart attack, and even better at preventing a second one. The big success story of the last two decades has been in heart disease treatment. But, have our efforts to prevent a first heart attack measured up? Not as well as we would like.
Preventing heart disease
Part of the problem with preventing a first heart attack Called primary prevention is that it requires us to overcome a natural resistance to making changes in lifestyle choices. These are the behaviors that can be a lot more difficult than taking a pill, such as exercising regularly, eating a healthy diet, and quitting smoking. Many doctors are all too familiar with this resistance and will tell you that it is only a handful of patients in their practices that are able to make healthy changes and sustain them. "I've had a lot of success with helping my patients quit smoking, but the weight issue remains a hurdle that most continue to struggle with," says Dr. Jennifer Potter, an internist at the BIDMC and expert in women's health. Nonetheless, although it may be hard for people to change behavior and longstanding habits, it is not impossible.
Stop smoking
Smoking is the single biggest risk factor for heart attack. Women who smoke have up to six times the risk of heart attack compared to nonsmoking women. In fact, smoking poses greater risks for women than it does for men because it reduces levels of estrogen and HDL ("good") cholesterol, both of which naturally protect women against heart disease. Cigarette smoke puts added strain on the heart because it causes vessels to clamp down or constrict. If some of the blood vessels have already been narrowed or damaged by heart disease, smoking makes the problem worse. Smoking cessation among women would have a significant impact on heart disease. The American Lung Association estimates that 23% of all adult American women (22.5 million) are smokers. According to the Department of Health and Human Services, approximately 1,500 female teenagers start smoking every day.
Lower cholesterol
The risk of coronary heart disease rises as blood cholesterol levels increase. When other risk factors (such as high blood pressure and cigarette smoke) are present, this risk increases even further. A person's cholesterol level is also affected by age, sex, heredity and diet.
Lifestyle changes can lower your cholesterol and reduce your risk of heart disease and stroke. According to Dr. Walter Willet, author of Eat Drink and be Healthy-The Harvard Medical School Guide to Healthy Eating, the best approach to lowering cholesterol is to:
- Replace saturated and trans fats with mono and polyunsaturated fats
- Control weight
- Exercise for 30-40 minutes on most days of the week
- Consume fruits, vegetables and whole grains instead of refined carbohydrates. Refined carbohydrates, such as white bread, potatoes and white rice, generally cause us to feel hungry again soon after eating them. As a result, we may snack more.
When it comes to fat, the American Heart Association recommends:
- Use unhydrogenated oil such as canola, peanut, or olive oil.
- Look for processed foods made with unhydrogenated oil rather than hydrogenated, trans, or saturated fat.
- French fries, donuts, cookies and crackers are examples of foods that are high in trans fatty acids. Avoid these foods.
- Limit the fat in your diet. If you don't eat a lot of fat, you won't be consuming a lot of trans fatty acids.
- Avoid commercially fried foods and commercial baked goods. Not only are these foods very high in fat, but also that fat is also likely to be hydrogenated, meaning a lot of trans fatty acids.
What the cholesterol lab values mean
Total blood cholesterol levels:
- Less than 200 mg/dL
Desirable level that puts you at lower risk for heart disease
- 200-239 mg/dL
Borderline high
- 240 mg/dL and above
High blood cholesterol. A person with this level has more than twice the risk of heart disease as someone whose cholesterol is below 200 mg/dL.
HDL-cholesterol levels
HDL stands for high-density lipoprotein. HDL is considered "good" cholesterol because it seems to protect from heart disease. This means that, unlike other cholesterol levels, the higher the HDL, the better.
HDL can be raised by quitting smoking, losing excess weight and being more active. Drinking alcohol also helps raise HDL, but since alcohol can cause other problems, it isn't recommended that people start drinking or drink more to raise HDL.
- Less than 40 mg/dL
A major risk factor for heart disease.
- 40-59 mg/dL
Not yet protective but better.
- 60 mg/dL and above
An HDL of 60 mg/dL and above is considered protective against heart disease.
LDL-cholesterol levels
LDL stands for low-density lipoprotein. This is the main carrier of harmful cholesterol in your blood. A high level of LDL means there is a higher risk of heart disease.
- Less than 100 mg/dL
Optimal
- 100-129 mg/dL
Near or above optimal
- 130-159 mg/dL
Borderline high
- 160-189 mg/dL
High
- 190 mg/dL and above
- Very high
Drink alcohol in moderation
Alcohol in moderation is probably good for the hearts of most people. There is evidence that alcohol increases the amount of HDL cholesterol, or "good" cholesterol, and also reduces the formation of blood clots hat block arteries to the heart, which can cause heart attacks.
The question of what is meant by moderate alcohol consumption is tricky, especially for women. The Nurses Health Study and others have shown that two drinks a day increase the chances of developing breast cancer by 20 to 25 percent. This does not mean that 20 -25% of women who have two drinks a day will get breast cancer. Instead it means an increase in the total lifetime risk that women have for developing breast cancer. Rather than 12 of every 100 women it increases to 15 of every 100 women.
Interestingly, research shows that the increased risk of breast cancer linked to drinking alcohol is seen mostly in women with insufficient levels of folic acid in their diets. This has also been found among women who develop colon cancer. Therefore, it is likely wise for those who drink alcohol to take a multivitamin that contains folic acid (400 micrograms).
Lower high blood pressure
High blood pressure increases the heart's workload, causing the heart to enlarge and weaken over time. It also increases the risk of stroke, heart attack, kidney failure and congestive heart failure. When high blood pressure exists with obesity, smoking, high blood cholesterol levels or diabetes, the risk of heart attack or stroke increases several significantly. See your doctor regularly to make certain your blood pressure is well controlled.
Eating plenty fruits and vegetables may help lower high blood pressure, or even better, prevent high blood pressure from occurring. A clinical trial called DASH has shown that eating more fruits and vegetables can lower blood pressure, especially when they are part of a diet low in animal fat. This study also showed that aggressively cutting back on salt decreased blood pressure in some individuals.
Maintain healthy weight
According to Dr. Willet, there are three aspects of weight that influence your chance of dying of a heart attack, stroke or other type of cardiovascular disease:
- How much you weigh in relation to your height
- Your waist size
- How much weight you gain after your early twenties
A good measure of a healthy weight is the body mass index. This measure of weight is adjusted for height, and accounts for the fact that taller people weigh more than shorter people. A body mass index of less than 25 is associated with a lower risk of dying from heart disease. Body mass indices of 25-30 are considered over-weight, and those over 30 are classified as obese.
Two different body shapes have been called apples and pears. Those with an apple shape store their fat around the waist and chest, while pears store it around the hips and thighs. Scientific evidence has shown that individuals with a high waist-to-hip ratio have higher risks of heart disease. Simply measuring your waist is likely a pretty good measurement of this risk. Even if your weight remains stable, an expanding waist-line can be a warning sign for your health.
Get active
Lack of physical activity is a risk factor for coronary heart disease. Regular, moderate-to-vigorous exercise plays a significant role in preventing heart disease. Moderate cardiovascular exercise activity for 30-40 minutes a day is beneficial if done regularly (five days a week). Exercise can help control blood cholesterol, diabetes and obesity, as well as help to lower blood pressure.
According to Willett, physical activity also builds muscle an often-ignored ingredient in weight control. If you lose muscle, it turns into fat, which has a much lower metabolic activity- meaning it burns fewer calories. If you convert more and more muscle to fat, your resting metabolic rate decreases and your body requires fewer calories everyday to maintain its functions. If you do not decrease your calorie intake, the extra calories that your body no longer needs are converted into yet more fat a "tough- to -break cycle" according to Willett.
New discoveries
Everyday, new studies emerge about heart disease, and it is tempting for patients and for doctors to leap on the latest, greatest discovery. The following are a few examples that may turn out to help in the detection and prevention of heart disease:
C-reactive protein is a marker for inflammation. However, according to according to Dr. Kenneth Mukamal, an internist at the BIDMC and expert in heart disease prevention research, C-reactive protein also tracks with obesity. If C-reactive protein is merely a marker for obesity, then measuring it may be no different than using a scale to determine weight.
Homocysteine
Homocysteine, is a byproduct of eating protein. According to Mukamal, many experts do not believe that homocycteine is an accurate indication that your are at risk for heart disease. Since homocysteine is lowered by B-vitamins, its' presence may merely indicate a poor diet.
Vitamin E
Research on vitamin E has been very disappointing. Although early, population-based research indicated that vitamin E might help prevent heart disease, rigorous experiments in people have not shown this nutrient to add much benefit to heart disease prevention.
Omega-3 fatty acids
Omega-3 fatty acids and fish intake were first shown in population-based studies to lower risk of heart disease, and formal experiments have also emerged in support of this finding.
Many doctors do not recommend taking fish oil supplements since the actual content of these pills is not regulated. Omega-3 fatty acids can be found in fish, such as salmon, bluefish, tuna, swordfish, and wild striped bass, and also in walnuts. Many doctors caution people who are looking to the latest research for easy answers about heart disease prevention. According to Dr. Kenneth Mukamal, "We know how to prevent heart disease to a tremendous extent. Worrying about the latest research that comes down the pike, for the most part, may lead you to spin your wheels. Instead, we should focus on what we know works and works really well Which is having a good quality diet and exercising and taking prescribed medications regularly."
(Published March 2003)
