9.3: Keeping the Pipes Open

Although we can’t change our gender or genetic predisposition, we can alter other risk factors. Because atherosclerosis develops over many years, even a modest reduction in its rate of progression can delay significantly the onset of symptoms. For example, dietary changes beginning in young adulthood to lower LDL-cholesterol levels could possibly slow the progression of atherosclerosis so that a heart attack or stroke that might have occurred at age 65 might be delayed to age 80 or older.

Do Not Smoke

It seems that much of the smoking-caused damage to the arteries can be reversed by quitting smoking. Some of smoking’s immediate effects, such as constriction of blood vessels (from tobacco’s nicotine), and reduced oxygen in the blood (smoke’s carbon monoxide displaces oxygen), are reduced quite fast. Studies indicate that smoking’s added risk of heart attack and stroke falls markedly within a year after quitting. But it doesn’t seem to disappear entirely for a number of years, depending on how long and how much a person had smoked.

Prevention or Early Treatment of High Blood Pressure

Maintaining normal blood pressure (less than 130/80) can help prevent heart attacks and strokes. Everyone should check their blood pressure periodically. The exact cause of high blood pressure in most cases isn’t known, but genetic factors are involved. Regardless of cause, there are effective treatments.

Medications to lower blood pressure have to be taken continually. A barrier to this is that high blood pressure itself doesn’t make you feel bad (so you don’t feel any better taking the pills), yet there can be side effects, such as impotence and blood pressure falling to where one feels faint. Changes in dose or medication are made to avoid or lessen such side-effects.

High blood pressure also increases the risk of other diseases such as kidney and heart problems. So early treatment of high blood pressure helps prevent these diseases as well.

Body Weight: If a person with high blood pressure is overweight, weight reduction to a healthy weight may, in itself, normalize blood pressure. If one can’t reach a healthy weight, any weight loss—or at least not gaining more—can help.

Weight loss can also lower risk in other ways. Among those genetically susceptible, obesity can cause a type of diabetes that can be reversible upon return to a normal weight. The progression of atherosclerosis is accelerated in diabetics— diabetes increases by more than three-fold the risk of dying from diseases related to atherosclerosis.

Psychological Stress can result in high blood pressure in those who are genetically susceptible.

Salt Intake: Some people can lower their blood pressure by limiting salt in food, but a high-salt diet doesn’t always cause high blood pressure. Many people don’t develop high blood pressure despite a salty diet, presumably because they don’t have the genetic predisposition. However, since most of us don’t know if we’re genetically susceptible, and there’s no known advantage to consuming excess salt, the general advice is to avoid eating a lot of salty foods.

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Salt (sodium chloride) = 40% sodium

1 tsp salt (5000 mg) = about 2,000 mg sodium.

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Sodium is thought to be the culprit in high-salt diets, but there’s some evidence that the chloride in salt may be a contributing factor. Low dietary calcium might also play a role.

The sodium intake in the typical American diet is estimated to exceed 3400 mg per day. The 2020-2025 Dietary Guidelines for Americans advises that adults lower their sodium intake if it exceeds 2300 mg sodium.⁶

Alcohol intake in excess can increase both blood pressure and the risk of a hemorrhagic stroke independently of high blood pressure.

“Moderate drinking” is up to 1 drink a day for women, and up to 2 drinks a day for men. “One drink” has about a half-ounce of pure alcohol, e.g., a 12-oz. can of beer or wine cooler; a 5-oz. glass of wine; 1 1/2 oz. (jigger) of gin, rum, whisky, or vodka.

Reducing High Levels of LDL-Cholesterol

To lower LDL-cholesterol levels, the Dietary Guidelines Advisory Committee established by U.S. Dept. of Agriculture and the U.S. Dept. of Health and Human Services has dietary recommendations for the general U.S. population, except for children under 2 years old. A program of such magnitude is said to be warranted because:

• Even if blood-cholesterol is at the recommended level, lowering LDL-cholesterol seems to reduce further the risk of heart disease.
• Since LDL-cholesterol generally goes up as we age, a life-long “prudent diet” may help maintain blood cholesterol at recommended levels.
• For those who have atherosclerosis, it appears that lowering LDL-cholesterol can partially reverse the atherosclerotic process by reducing the size of fatty deposits already formed in arteries.

Some people’s LDL-cholesterol levels can be modified by diet within a few weeks. But there’s a wide variation in how people’s bodies respond to diet, since the body’s own cholesterol-producing processes are involved.

As discussed in the last chapter, triglycerides make up most of the fat in our diet, and are called saturated, monounsaturated, or polyunsaturated fat, depending on which fatty acids predominate.

Diets high in saturated fat and/or trans fat tend to increase LDL-cholesterol levels in the blood. The “typical American diet” contains a lot of saturated fat in such favorite foods as meat, high-fat dairy products, and pastries. The advice to eat less saturated fat to lower LDL-cholesterol means cutting down on such foods.

Trans fat is found predominantly in foods that contain partially hydrogenated fat. Avoid foods that, according to the food label, contain trans fat. Besides raising LDL-cholesterol, trans fat can lower HDL-cholesterol.

The American diet contains more saturated fat than either monounsaturated or polyunsaturated fat, so fat consumption in general tends to increase LDL-cholesterol. However, since the total amount of fat in the American diet is high, the aim should be to substitute foods high in saturated fat with those rich in unsaturated fats, rather than simply adding more unsaturated fat to one’s diet.

The 2020-2025 Dietary Guidelines for Americans advises that less than 10% of your calories comes from saturated fat, and to keep trans fat intake as low as possible.⁶ One might, for example, replace fatty cuts of meat with poultry, fish, or lean cuts of meat; drink fat-free or low-fat milk instead of whole milk; and eat sherbet, ice milk, or frozen low-fat yogurt instead of ice cream.

Dietary Cholesterol: Cholesterol in the diet is unnecessary (our body can make what it needs). The 2010-2015 Dietary Guidelines for Americans) recommended that the amount of cholesterol in the diet be restricted. However, more recent evidence shows that dietary cholesterol doesn’t necessarily raise LDL-cholesterol or risk of heart disease.⁷

The main source of cholesterol in our diet is egg yolk, since other rich sources of cholesterol (e.g., liver, brain) aren’t widely consumed. Eliminating dietary restriction of cholesterol meant that eating eggs didn’t have to be restricted.

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One egg yolk has about 215 mg cholesterol. Egg white is virtually fat-free and has no cholesterol.

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Limiting eggs in the diet can be a hardship for some people. Eggs are inexpensive, keep a long time in the home refrigerator, and are tasty and easy and quick to cook. Also, the softness of eggs makes them desirable for people with missing teeth or ill-fitting dentures. These are significant considerations for many people, especially the poor and elderly. For many of these people, eggs are a major source of several nutrients.

Fiber: Soluble fibers (see Chap. 4) can help lower LDL-cholesterol. As discussed earlier, soluble fiber can promote the excretion of bile acids (which are made from cholesterol), and can interfere with the intestinal absorption of dietary cholesterol. Also, some breakdown products of certain fibers (broken down by bacteria in the colon) are absorbed into the blood from the colon and may inhibit cholesterol production by the body.

Foods that are particularly rich in soluble fibers include oats, beans, and fruits. Dietary fiber—soluble or insoluble—is not found in animal foods.

Niacin: One particular form of the B-vitamin niacin—nicotinic acid—is used in huge doses 1,000-9,000 mg/day) to lower LDL-cholesterol. It functions as a drug, rather than a vitamin (adult RDA = 14-16 mg/day), when taken in such huge doses. Nicotinic acid is called niacin to avoid confusion with nicotine, the addictive drug in tobacco. Another form of niacin, known as nicotinamide or niacinamide, doesn’t have the same effect as nicotinic acid in lowering LDL-cholesterol.

Because nicotinic acid is a vitamin, it can be purchased without prescription. However, huge doses should be taken only under the supervision of a physician. Milder side-effects include itching and hot flushes in the skin, and digestive upsets. More serious side-effects include irregular heartbeats and liver damage. Physicians generally prescribe liver-function tests when treating patients with large doses of nicotinic acid.

Maintaining Normal Levels of HDL-Cholesterol

A blood HDL-cholesterol of less than 40 is associated with increased risk of atherosclerosis. Smoking, lack of exercise, and obesity all tend to lower HDL-cholesterol. Thus, quitting smoking, exercising, and losing excess weight lowers risk by increasing HDL-cholesterol.

A moderate intake of alcohol is associated with higher HDL-cholesterol. But it’s unwise to start drinking simply to raise HDL-cholesterol. Even moderate amounts of alcohol can cause problems for some people and, as noted earlier, excessive alcohol tends to increase both blood pressure and the risk of hemorrhagic stroke. Also, alcohol raises the risk of some cancers, including breast cancer.

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Some people are genetically endowed with unusually high HDL-cholesterol. This protects them against atherosclerosis, and they tend to have a family history of longevity.

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Some people who hear repeatedly through the mass media that exercise increases “good cholesterol” are misled into thinking that more and more exercise will lead to such high HDL-cholesterol that other risk factors don’t matter as much. It’s better to focus on the other side of the coin—that low HDL-cholesterol is associated with increased risk of atherosclerosis. Where it’s stated that a sedentary lifestyle lowers HDL-cholesterol, people are more likely to conclude simply that moderate exercise is a good idea.

Added exercise (beyond moderate exercise) doesn’t proportionately raise HDL-cholesterol. While regular exercise can be important in lowering risk of atherosclerosis, its importance shouldn’t be either underestimated or overestimated.

Fish in the Diet

Eating fish is associated with a reduced risk of atherosclerosis. It’s thought that the omega-3 fatty acids (see Chap. 8) found mainly in fish are what reduce risk.

The native Eskimo diet, which includes large quantities of fish, seal, and whale, is very rich in omega-3 fatty acids. Eskimos have a low incidence of heart disease even though their diet is high in cholesterol.

Omega-3 fatty acids are used in the body to make substances that reduce the dangers of heart attack and stroke by dilating arteries, reducing the ability of the blood to clot, lowering blood pressure, and increasing the amount of a substance in blood that helps dissolve clots.

Extensive studies have shown that men who eat fish regularly have a lower rate of death from cardiovascular disease than those who don’t. But the studies do not conclusively show that omega-3 fatty acids alone reduce risk. Other protective factor for the fish eaters (and the Eskimos) might be other substances in fish, or something different about fish-eaters, other than eating fish.

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Nosebleed is a side effect of a high intake of omega-3 fatty acids. Eskimos eating a native diet are more prone to hemorrhage and hemorrhagic stroke; one suspects an excessive intake of omega-3.

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Eating fish about twice a week is also linked to a lower chance of dying suddenly from a heart attack. The sudden lack of oxygen to heart muscle in a heart attack can cause the heart to quiver (fibrillate) instead of beat. Omega-3 fatty acids in fish are incorporated into heart tissue, and this may help stabilize it in a heart attack, lessening the chance of sudden death.⁸

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Defibrillators are available in many public places to shock the heart into resuming its beat. Best place to have a heart attack? Casinos have their eye on you and can get a defibrillator to you very fast.⁹

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The American Heart Association does not recommend taking fish-oil supplements or capsules of omega-3 fatty acids, except for patients with diagnosed heart disease under the supervision of a physician.