So, the thinking was, better cut out the steak, treat yourself to one egg a week (if you must), switch from butter to margarine and hide the saltshaker. Oh, and don't waste time with exercise. Vigorous, pulse pounding exercise was the only way to keep your weight within limits and just as important, your heart properly toned. It was a spartan regimen and made folks who didn't follow it feel guiltier than ever, but it retained the virtue of being comprehensible. Recently, though, scientists seem to have gone mad. Hardly a week goes by without an expert issuing a report declaring that a particular food or vitamin or activity or condition will either restore cardiovascular health or ruin it and often the new advice seems to contradict the old. Among the new findings:
EGGS
Are not nearly as bad for the heart as doctors used to think. Sure, they're packed with cholesterol. But scientists now know that eating cholesterol doesn't necessarily result in high levels of harmful cholesterol in the blood, where the damage is done.
HOMOCYSTEINE
A substance in blood, may be as big a risk for heart disease as dietary cholesterol.
SATURATED FAT
Found in red meat, butter and other animal products, may be a bigger threat to the heart and blood vessels than cholesterol.
OTHER FATS
Olive oil, other vegetable oils and the oil found in salmon and tuna can drive down bad cholesterol and keep blood flowing freely
Heart attacks happen when coronary arteries become clogged with fatty deposits, depriving the heart muscle of the blood supply that nourishes it.
MARGARINE
Can be just as harmful as butter, if not worse; a process that stiffens vegetable oil into a butter like stick also transforms it into an artery blocker. In general, the softer the margarine, the better. New butter substitutes, such as Benecol, can lower blood cholesterol.
SALT
Has been considered taboo because it raises blood pressure. But it's not clear whether it's a problem for those whose pressure is normal.
EXERCISE
Need not be pulse pounding to be beneficial, say experts. A little gardening or strenuous housework isn't a bad prescription for cardiovascular health. The nutrition expert, Dr. Irwin Rosenberg, admits that nutrition science doesn't know what its doing. But despite appearances, the medical profession has not lost its collective mind. The bewildering flood of advice that assaults us week after week simply reflects the slow laborious gathering of knowledge that defines science in action. Like most works in progress, it moves ahead in fits and starts and occasionally goes down a blind alley. Yet despite the apparent confusion, scientists know more today about what keeps heart humming than they did a generation ago. The first glimmering of understanding gathered 30 ago were accurate as far as hey went-but rudimentary. Today scientists have a much deeper understanding of what foods and activities are healthful or harmful and why. The good news is that the path to a healthier heart is now pretty clear, once you master a few key concepts.
FAT AND CHOLESTEROL
Fat has been a staple of the human diet since our remote ancestors started eating meat more than 2 million years ago. In the 1960s, however, researchers began to notice that patients who had elevated blood levels of cholesterol-a fatty substance found in meat, poultry, eggs and dairy products also tended to suffer from heart disease. Cholesterol by-products would form thick, tough deposits, called plaques, on the inner walls of arteries, stiffening them and then starving the heart of blood and creating choke points where a clot could stop the flow entirely. At first blush, the solution, seemed obvious: consume low cholesterol foods; switch from butter to vegetable oil based margarine; eat fewer eggs; eat less meat. Indeed, it was the best advice at the time, based on the limited knowledge available.
As scientists learned more about how the body works, however, that prescription proved too simplistic. Some people's cholesterol levels stayed high, no matter what they ate. And a lot of heart-disease patients had normal cholesterol levels. Only recently have reasons emerged. For one thing, how much cholesterol you eat doesn't necessarily determine how much ends up in your blood. The body, it turns out, also manufactures its own cholesterol. And some people's bodies are just less efficient at vacuuming up excess cholesterol than others, for reasons that are largely genetic.
So, in the next phase of research, the object became keeping cholesterol levels in the blood under control and not necessarily keeping the cholesterol out of the diet. But how to do it? Again the key seemed to be eating less red meat, cream and butter, but it was based not so much on cholesterol as on saturated fat. Reason: saturated fat increases blood cholesterol. So eggs, high in cholesterol but not in saturated fat, were taken off the forbidden list, except for those people with the most serious cholesterol problems. To make things more complicated, researchers discovered that cholesterol travels around the body in two major forms: low-density lipoprotein (LDL), the kind that does most of the damage, and high-density lipoprotein (HDL), which actually seems to keep arteries clean. Beyond that, another class of fats, known as triglycerides, also circulates in the blood, doing more or less the same kind of damage as LDL.
Doctors then began recommending foods and activities that drive down LDL and triglycerides (eat less meat, cream and butter-one recommendation that has never changed add olive oil and fish to the diet) and at the same time push Up HDL (get more exercise and lose weight). Then came the news that taking benign foods like vegetable and peanut oils and hydrogenating them-a process that stiffens them to make stick margarine, peanut butter and solid shortening-transforms them into substances known as trans-fatty acids, which can drive LDL and triglyceride levels through the roof. Transfatty acids are not technically fats, which means, astonishingly, that a food labeled FAT FREE may be bursting with stuff that can give you heart disease. The fact that stick margarine is bad doesn't mean butter is good. Says Dr. Walter Willett, head of nutrition at the Harvard School of Public Health: I think the healthiest solution is none of the above. The recommendation to stay away from meats and animal fats, thus, hasn't been overthrown. It's been extended slightly to encompass a substance once thought to be relatively harmless.
How about staying away from fat entirely? Bad idea. The body needs fats, in part because vitamins like A and D must be dissolved in fat to enter the body or move about within the body. What about the super low fat diets, advocated by people like Dr. Dean Ornish, medicine researcher. They seem to work but perhaps not because they're low fat; the key may be the types of foods-beans, grains, vegetables, instead of meats and cheeses that he recommends. Indeed, Mediterranean men, who get more than 30% of their calories from fat (some three times what Ornish suggests) but who eat little saturated fat, have a very low rate of heart disease. HDL, LDL and triglycerides aren't quite the whole story either. Over the past few years, researchers have identified yet another form of fat that could rightly be labeled Bad Cholesterol. Called lipoprotein (a), or Lp(a), it behaves like LDL in the body. But because Lp(a) levels have more to do with your genes than your diet, they can't easily be controlled. At best, doctors think they can use Lp(a) screening to find people who should be working extra hard to reduce their other heart-attack risks. So fat, which started out as a good thing to eat and then became a bad thing, now turns out to be a collection of very different things, some good, some bad, some neutral. It's a pattern that has been repeated for a variety of cardiovascular risk factors. It's not pretty; the tortuous progress of scientific discovery rarely is.
SALT
Researchers realized decades ago that high blood pressure is a cardiovascular danger signal. Physicians think elevated pressure strains blood vessels, causing them to tear or develop weak areas where plaque can gain a foothold. Hypertension (to use the technical term) can also force small blood vessels to burst; if that happens in the brain, it's called a stroke-the other major cardiovascular killer besides heart attack. Medication can help with severe cases of hypertension, but the first line of defense, physicians agree, is to cut back on a substance that has been shown to keep blood pressure high: sodium, especially in the form of salt. If cutting back on salt is good for people with hypertension, it should logically be good for everyone else too. it may be, but dueling studies released three years ago demonstrate that the case is far from airtight. Scientists writing in the British Medical journal concluded that reducing salt intake reduces blood pressure in all people, even those who are not hypertensive. But a study published the very same week in the Journal of the American Medical Association argued that people with normal blood pressure got no significant benefit from salt reduction.
Which one was right? Probably neither, since both studies were flawed. The study included subjects who were on low-salt diets for a very short time perhaps too short for any effect to be noticed. And the another study could not effectively measure the influence of other factors that could have made a difference. Those who ate less salt may also have watched what they ate in general, for example, exercised more or been less overweight. The truth is that the question of what ordinary people should do about salt has simply not been settled yet. That doesn't mean we should throw up our hands in despair. Even without hard scientific proof, says Dr. Theodore Kotchen of the Medical College of Wisconsin, keeping sodium levels down is probably a good idea-particularly since there is no evidence that a low sodium diet is harmful. The one exception: people who are losing salt through heavy perspiration during exercise or hard physical work. Reducing salt intake in the middle of a heat wave can actually be dangerous to your health.
EXERCISE
Physical exertion is another area in which doctors have been sending mixed signals. As far back as 1953, studies showed that people who got more exercise had fewer heart attacks. The physiological explanation has come more slowly, but one reason is simply that the heart is a muscle; frequent workouts keep it strong. Another factor, doctors believe, is that exercise holds down blood pressure. When the heart pumps blood more quickly through the body, vessels dilate or widen to accommodate the extra flow. The overall effect is to lower pressure throughout the cardiovascular system. People who get regular exercise have about a 30% lower risk of developing heart-threatening hypertension than people who don't. Some studies have also shown that exercise raises HDL levels; that it increases the volume of plasma (blood's liquid portion), thinning the blood and thus keeping dangerous clots at a minimum; and that it may boost levels of an enzyme that vacuums cholesterol and fattv acids from the blood. None of these results is definitive, but it seem clear that however exercise works, its benefits increase if you do more of it. That s obviously true if your goal is to stay trim; exertion is fueled by calorie burning. But plenty of studies have shown it applies to staving off heart disease too, and for years the standard medical advice was to get a minimum of 20 to 30 min. of vigorous, continuous exercise at least three times each week.
Yet in the mid-1990s, the Centers for Disease Control and Prevention and the
VITAMIN E
The process that allow the body to turn food and air into nourishment for individual cells also create by-products that amount to toxic wastes-highly reactive oxygen molecules known as free radicals that can combine with otherwise innocent substances and transform them into killers. Free radicals may be responsible in part for the genetic damage that leads to some cancers. And they also appear to be what makes LDL and triglycerides so dangerous. When a free radical combines with one of these fatty molecules, the altered cholesterol turns into a biochemical cannonball that ricochets around the bloodstream, damaging the inner walls of vessels. Fortunately, nature has also created chemicals known as antioxidants, which can prevent dangerous oxidation from happening in the first place. Among the most powerful is vitamin E, found in vegetable oils and nuts. In 1996 a major study of postmenopausal women showed that those who eat a diet rich in vitamin E had a 62% lower than average risk of dying from heart disease. That doesn't mean, however, that popping vitamin E pills will stave off heart disease. Previous research had reached a split decision over whether supplementary E could guard against cardiovascular z problems. But the study on post menopausal women concluded that z the vitamin was protective only when eaten in foods; in pill form, it didn't seem to do much good at all. This result could mean that the vitamin works in tandem with some other, as yet unidentified, food-borne substance.
PHYTOCHEMICALS
Adding fruits and vegetables to the diet is good for the heart in many ways. It displaces meat and dairy products and thus reduces the intake of saturated fats. It puts more vitamins-not just E but also C and many of the B vitamins-into your body. Over the past several years, however, researchers have been investigating a whole new class of plant-based substances whose role in preventing heart disease may be even more important than vitamins. Known as phytochernicals, they fall into two classes: carotenoids, found mostly in orange-colored vegetables (beta carotene is the best known of the more than 600 carotenoids); and flavonoids-some 4,000 of them, found in, among other things, onions, broccoli, red wine and tea (green, black and oolong, but not herbal).
Like vitamin E, the flavonoids and the carotenoids appear to act as antioxidants, keeping LDL and triglycerides from being oxidized by free radicals. But they do so in different ways, explains Jeffrey Blumberg, a
As for figuring out which of the thousands of phytochemicals is most important, that is decades away. just as with vitamin E-and with studies that debunked betacarotene supplements as cancer fighters a few years ago-it may turn out that phytochemicals work only in tandem with one another or with other chemicals found in foods. Trying to find the active ingredient might be a fool's errand. Says Dr. Ronald Krauss, a nutrition and cholesterol researcher at the Lawrence Berkeley Lab in
INFECTION AND INFLAMMATION
Many years ago, one of the few things scientists were pretty sure did not trigger cardiac problems was infection. They are not quite so sure anymore. Evidence now suggests that the immune system plays a big role in heart disease. The initial damage is done by things like high blood pressure, smoking, oxidized LDL and triglycerides, which weaken and damage the inner walls of veins and arteries. Then the immune system responds, just as it's designed to do. Instead of fixing these problems, though, the immune response makes them worse. For one thing, the body tries to repair physical tears in blood vessels as it would any other wound: blood platelets rush to the site, clump together and form a clot, a biological bandage that binds up the injury. A clot on the outside of the body a scab, in other words eventually falls off with no problem. But inside a vein or artery, especially one that has been narrowed with plaque deposits, a clot can get snagged, causing a heart attack. Plaque buildup too may be an unintended by-product of immune-system action. When oxidized fatty molecules damage vessel walls, the tissues become inflamedengorged with immune cells whose job it is to fight the invaders. Instead of vacuuming up the oxidized molecules, however, the immune cells become entangled with them the whole mess welds itself onto the tough sticky plaques that narrow veins and arteries. That, researchers believe, is one reason aspirin is so good at preventing second heart attacks: not only does it thin the blood, it also damps down inflammation. This same sort of blood-vessel inflammation may be triggered by bacterial and viral infections. Chlamydia (which generally starts as a venereal disease) and gingivitis (a gum infection) have been implicated in heart disease, and more recently so has the herpesvirus that causes cold sores In the case of herpes, especially, it's far too early to tell whether this link is real or will evaporate under closer scrutiny.
ALCOHOL
It is known as the French paradox, people who live in
HOMOCYSTEINE
Victims of the rare genetic disorder known as homocystinuria usually die by age 20 from heart attack or stroke. They also have high blood levels of the amino acid homocysteine, a by-product of protein metabolism. That suggests a cause and effeet relationship, but after decades of study, the link between bomocysteine and heart disease is elusive. Says Dr. Andrew Bostom, co-director of the Cardiac Rehabilitative program at
But that would reflect a misunderstanding about how science works. It is not a steady march from ignorance to knowledge. It's more like a mountaineering expedition. On the way up an unsealed peak, climbers will gain some altitude on one route, then find it's a dead end. They'll spot a better one, backtrack a little and move on. The fact that they sometimes have to take a step backward for every two steps forward doesn't mean they're wasting their time. It means that inching up an uncharted mountain is tough work. When you step back, though, and take a look at the overall picture-a long view from the upper slopes of the mountain it turns out that the path was clear.
So it is with medical science. Worth of research points to a consistent theme: eat a balanced diet that includes lots of fruits and vegetables and fewer animal based foods; don't smoke; and get as much exercise as you can comfortably maintain. If it sounds as though nothing much has changed in the past three decades, that's because the fundamentals of cardiac health the base of the mountain have been there all along, What has changed is doctors' understanding of why it's all true. And they're continuing to refine their knowledge so that the confusing new re search emerging from the labs will one day stand on an equally firm footing. Until that happens, the best bet is to focus on those basics. Your heart will thank you for it.
CAN FOOD FEND OFF TUMORS
Eating right to prevent heart disease may seem complicated and confusing, but it's a breeze compared with trying to design an anticancer diet. Cardiovascular disease is relatively simple; it's the result of normal bodily processes taken to the extreme. Cancer, by contrast, involves changes in the programming of DNA within the nuclei of individual cells. Beyond that, heart disease is an illness that affects a single organ system, while cancer is dozens of different diseases that target body parts as radically different as the brain, breast and bone.
That being the case, it's no surprise that the relationship between diet and cancer is still largely a matter of educated guesswork-and in many cases, the guesses have turned out to be wrong. Take the much publicized link between high-fat diets and breast cancer, for example. Women who live in Western countries, where high fat diets are the norm, tend to have high breast-cancer rates. Even more telling: women of Japanese ancestry who live in the
A similar process of educated-guess-and-error led people to load up on the nutritional supplement beta carotene in the early 1990s. Scientists noted that those who eat lots of fruits and vegetables tend to get less cancer and speculated that carotenoidsthe same antioxidant substances that seem to protect against heart disease-were responsible. In particular, they focused on beta carotene, the most abundant and common carotenoid, as the most likely to prevent cancer.
Yet a series of targeted studies in
The same sort of logic may apply to tomatoes and prostate cancer. Studies have shown that men who eat cooked tomatoes in various forms have a lower incidence of malignancy. The reason may be lycopene, another of the carotenoids, which is released when tomatoes are heated but no one knows for sure, and even the tomato-prostate link isn't absolutely firm.
Another substance found in fruits and vegetables, though, does seem to have a protective effect against one form of malignancy: dietary fiber clearly reduces the risk of colon cancer. That link is sufficiently well established that the nutritionist recommends that people increase their average daily fiber intake.
Health experts are not ready to list the foods that will keep cancer at bay, but some broad outlines of an anticancer diet are taking shape. Beta carotene might not be the key but fruits and vegetables, which contain it, seem to help. Lycopene might not be the answer, but it too is found in fruits and vegetables. Fiber works and again, fruits and vegetables (especially beans), as well as whole grains, are an ideal source. So along with giving up tobacco (mouth, throat and lung cancer) and limiting alcohol consumption (too much booze leads to cirrhosis, which leads to liver cancer), the best way to prevent a broad range of cancers, given the current state of medical knowledge, is to eat more fruits and vegetables. That sort of diet will help you stay trim and prevent heart disease anyway-so if, against ail odds, it turns out to have no effect on cancer, it certainly can't hurt.
BELIEVE IT OR NOT
Hearth attacks have been linked not only to diet, smoking and obesity but also to less obvious risk factors -many of which we have no control over. Among the oddest:
BALDNESS
A shiny spot on top of the head has been linked to a risk of heart attack three times higher than average
FOUL WEATHER
Researchers have found that exposure to frigid temperatures can trigger heart attacks as well as angina and strokes
BAD GUMS
Studies suggest that if you have periodontal disease, your heart attack risk nearly doubles. Bacteria may enter the blood and cause deadly clots
BODY SHAPE
Being overweight is bad enough, but if your fat lies more in the abdomen than the hips, you are especially prone to heart disease
DAY OF THE WEEK/TIME OF DAY
Cardiac events tend to occur most often between 4 p.m. and 6 p.m. and on Mondays and Fridays
WHEN DIET IS NOT ENOUGH.
Changing your diet can only go so I far in cutting cholesterol levels. And because of their genetic makeup, that's not far enough for millions. Happily, there are all sorts of cholesterol-lowering nostrums available to help make up the difference, from well-tested prescription drugs to newer (and largely untested) alternative medicines. A brief guide:
STATINS
When combined with a low fat diet, these cholesterol-lowering drugs can cut the risk of death from heart disease 40%. Statins interfere with the liver's ability to make cholesterol, keeping LDL (bad) levels to a minimum while boosting levels Of HDL (the good stuff).
NICOTINIC ACID
In large doses, this B vitamin cuts LDL 30%, triglyceride levels as much as 55% and increases HDL 35%. The dosage that's needed, however, is up to 70 times the recommended daily allowance, and it comes at a price. Many patients experience flushing, itching and panic attacks. Adjusting the dose, taking an aspirin 30 min. beforehand, or taking the medication on a full stomach alleviates some of the symptoms.
ARGININE
This amino acid is gaining popularity as a nonprescription treatment for high cholesterol. Animal studies and preliminary studies in humans suggest that arginine may improve coronary blood flow and lower cholesterol levels by acting as an antioxidant and helping keep blood-vessel tissue elastic. Doctors have yet to show, however, that arginine can actually prevent heart disease.
COENZYME Q10
A powerful antioxidant, this natural compound has been studied as a treatment for heart failure-with mixed results. Many Japanese and European practitioners prescribe coenzyme QIO to keep arterial plaque at bay, but rigorous studies with a lot more patients are needed before
EATING SMART
The conventional wisdom about what’s good for you and what's bad has changed over the years. Here's what the experts now say:
BUTTER OR MARGARINE?
What we used to think.Butter packs a heart attack in every teaspoon. Switch to margarine
WHAT DOCTORS SAY NOW
Turning vegetable oil into sticks of margarine makes it just as bad
WHAT TO DO
Go for margarine in a tub or squeeze bottle. Or switch to a butter substitute, such as Benecol, that can boost good cholesterol Butter is bad because it's made from saturated-fat-laden cream. But other milk-based products can also threaten the heart. Unless they're labeled low fat or nonfat, stay away from desserts and other foods that come from milk
PASS THE SALT
What we used to think It will send your blood pressure sky-high. Always choose low sodium foods, and don't touch the shaker
WHAT DOCTORS SAY NOW
It is not necessarily so, unless you're already prone to high blood pressure
WHAT TO DO
A low sodium diet won't hurt and may help. But don't be paranoid about pretzels
OFF THE FORBIDDEN LIST
What we used to think.Eggs are so full of cholesterol they might as well be poison. Stay away
WHAT DOCTORS SAY NOW
Cholesterol in food doesn't necessarily raise blood-cholesterol levels
WHAT TO DO
If you've got cholesterol problems, avoid eggs. If not, they are fine in moderation
THE GREENER,THE BETTER
What we used to think. Iceberg lettuce and romaine are both green, leafy vegetables, so both are good for you
WHAT DOCTORS SAY NOW
Iceberg is barely green it isn't bad for you, but it's hardly more nutritious than water. Romaine and other dark-green leafy vegetables, however, contain flavonoids
WHAT TO DO
Try to get a little color into your salad bowl
CEREALS AND GRAINS
What we used to think Filling, but they don't help the heart
WHAT DOCTORS SAY NOW
They replace higher-fat foods, and when fortified by B vitamins, they help scour potentially harmful hornocysteine from the blood
WHAT TO DO
Eat plenty, especially the whole-grain kind; the extra fiber could help stave off colon cancer
RED WINE
What we used to think Alcohol is bad for you, no exceptions
WHAT DOCTORS SAY NOW
A substance called resveratrol, found in grape skins, may reduce levels of bad cholesterol
WHAT TO DO
Alcohol in excess is still bad for you, but a glass of wine with dinner is probably fine for nonalcoholics
MEAT VS. POULTRY
What we used to think. Red meat is higher in cholesterol than chicken, so stick with the birds
WHAT DOCTORS SAY NOW
Saturated fat is the real problem. Chicken is still better, especially if you avoid fatty skin and dark meat
WHAT TO DO
Order the chicken (but not fried)
PEANUT
In general, the leanerthe meat, the BURER better-and wild game tends to be the leanest
COFFEE OR TEA?
What we used to think Coffee raises blood pressure, may cause cardiovascular disease. Tea is harmless
WHAT DOCTORS SAY NOW
Coffee turns out to be pretty harmless too-yet doesn't provide any benefit either. But black, green and oolong (not herbal) teas are high in flavonoids, which may protect the heart
WHAT TO DO
Take a tea break
ONIONS AND GARLIC
What we used to think No nutritional value, give bad breath
WHAT DOCTORS SAY NOW
Onions contain flavonoids and garlic has, polyphenols, so both could protect your heart
WHAT TO DO
Get your date to eat some too
PEANUT BUTTER
What we used to think Has lots of protein,.so it's good for you
WHAT DOCTORS SAY NOW
The kind sold in most supermarkets is full of trans-fatty acids, which are bad for the heart
WHAT TO DO
Eat natural peanut butter, the kind in which the oil rises to the top
Nuts are a goodnews, bad-news food. The bad news is that they're full of oils that aren't great for the heart; the good news is that they contain vitamin E The general rule is that dark-green vegetables are good for your heart, pale vegetables are neutral.
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