Tuesday, November 16, 2010

Controversial food

The chaos of nutritional change, contradiction, and confusion.

Nutrition science advances through a fog of change, contradiction and confusion.  Eggs are good for you, eggs are bad for you, more than one a day will boost your life-threatening cholesterol. An Australian doctor tries a diet of four eggs a day and his cholesterol level is said to drop so low it can’t be measured. A young bodybuilder thrives on a diet of 18 eggs a day. Saturated fats can clog your arteries and kill you but at least one study says there is no link between saturated fats and heart disease. But replacing saturated with unsaturated fat is found to reduce the risk of heart disease.  Coconut oil, at 77 percent, has the highest level of saturated fat. Pacific islanders get 30 to 60 percent of their calories from coconut oil and have virtually no heart disease. Yet despite the chaos, there is no doubt that advances in nutritional knowledge and advice help extend healthy and vigorous lives.

My previous blog reported the study of three academics who assert in the Canadian Journal of Cardiology that eggs are dangerous to your health. Does a contrary report from Australia put egg on our faces?
     Rick Carpenter of Lindsay, one of my astute blog readers, emailed me the Australian report.
     Dr. Andrew Rochford is a 30-year-old family man, handsome enough on the Web that he would have no trouble as the star in a soap opera, Young Doctor Rochford.  The father of a toddler son and twin baby girls, his daytime job is emergency registrar at Sydney’s Royal North Shore Hospital.
     In 2005, Rochord and his then girlfriend Jamie Nicholson were winners of a TV reality show called The Block, copping prize money of AUD$178,000. The reality contest endowed Rochford with some celebrity status and a role in a television show, What’s Good For You. “In his role on the series he has eaten 15 kilos of carrots to see whether his eyesight improves, stung himself with bluebottles to test five different remedies, and waxed one side of his body to see if the hair will grow back coarser and darker,” the show’s report states.

     One of Dr. Rochord’s TV assignments in 2006 was to eat four eggs a day (yoke included) for two weeks “to find out if eggs are bad for our heart and if there is a limit to how many we should be eating.” The experiment also included testing the cholesterol level of Oscar McGill, then an 18-year-old body builder who was training for the world championships and whose regular daily diet included 18 eggs.
     After two weeks and 56 eggs, “Andrew’s cholesterol levels have actually fallen… so low the machine doesn’t have a number for it.” As for Oscar, “Another great result from a bloke whose diet is totally dominated by eggs.”
     Brisbane cardiologist Dr. Karam Koster offers an explanation why—counterintuitively—eating lots of cholesterol might actually lower the cholesterol in your blood. “People who eat a lot of eggs actually shut down their body’s production of cholesterol,” he said. “So the more eggs somebody eats, the less cholesterol our body produces. So that’s why a lot of people who eat a lot of eggs don’t get heart disease necessarily.” Note the qualifier.
     I’m skeptical. A couple of my blog readers are much better role models. At 65, Rick Carpenter confesses to overweight and poor diet at an earlier age, but now watches his diet closely (with special research about pure cocoa, cayenne pepper, fresh garlic, and turmeric and black pepper), and vigorously exercises 30 minutes every day (“an absolute must”). He eats lots of fresh fruits and vegetables, and “maybe an egg or two a couple of times a week,” well within the American Heart Association’s recommended daily average of no more than 300 mg of dietary cholesterol.  He now has everything under control.
     Lois Brennan has limited herself to just one egg a wek (her special Sunday treat) ever since she suffered a heart attack 25 years ago. For exercise, she walks every day, outdoors if the weather is fine, on her treadmill if it’s not. I know of no one who is brighter or who keeps up to date on the Internet at age 90.

     The reason that the findings and advice of nutrition experts—about eggs and a hundred other foods—is so constantly changing and often contradictory is because nutrition science is empirical, unlike physical sciences with their ironclad laws of nature. Every since an apple supposedly fell on the head of Newton, scientists have known precisely how the law of gravity will affect the fall of a feather or a bar of pig iron. In the apparent absence of such clear nutritional laws, nutritionists must rely on thousands of observations of the different health effects of different foods, involving an incredible number of variables.
     Consider the potato. It’s loaded with nutrition, but might give your blood a big, unhealthy sugar rush. Just how it will affect you is difficult to say. It depends in part on the potato: where it was grown, the type of fertilizer used, how old it is, how it was stored, how it was cooked, and perhaps a dozen other factors. Worse, the same cooked potato will affect different people differently. And it can affect a person differently at different times of the day. Since there are a score of factors about the potato that govern its effects, nearly seven billion different people, and 24 hours in the day, does mean that potatoes have a trillion possible different health effects?
     Thus anomalies abound.  Jazz pianist Eubie Blake, who smoked, drank, didn’t exercise, and lived to age 96, famously said, “If I’d known I was going to live so long, I would have taken better care of myself.” At the other end of the spectrum was Max Bell, whom I knew six decades ago when I worked as a neophyte reporter in Calgary on his newspaper, The Albertan. Max made his pile in oil and became the de facto controlling shareholder of what for a time was Canada’s largest newspaper chain, including the Globe and Mail. Max was a total alcohol and tobacco abstainer, an exercise fanatic who liked to amuse party guests with the endurance of his pushups, urged his son to “Keep up the physical jerks,” and died at age 60. The Max Bell Foundation continues to fund research on “public policies and practices with an emphasis on health and wellness, education, and the environment.”
     Another factor adding to the confusion will hardly be a big surprise. It is the apparent conformity of the findings of at least some studies to the interests of they who paid for the studies. Thus we read a few years back of a study from Scotland about the health benefits of Scotch whisky. Not that such findings are necessarily wrong. My former cardiologist (he has since retired) claimed that whisky (no more than two ounces a day) is “good stuff.” Indeed, even nutritionists at Berkeley University say that there is now “hardly any argument” about the findings of dozens of studies that moderate or light drinkers have a 30 to 50 percent lower risk of heart disease than nondrinkers. But because too many people drink too much, booze winds up killing more people in accidents and illness than it saves by preventing heart attacks.

Let’s consider a few fat facts. Fats are worth considering for at least two reasons. Possibly more than anything else, fats illustrate how much dietary advice has changed in just the past couple of decades. Fats are said to have greater impact—both good and bad—on your cardiovascular health than egg yokes or other dietary cholesterol. And cardiovascular illness is the biggest single cause of death among North Americans, most Europeans, and many others.
     Twenty years ago Dr. Dean Ornish’s Program for Reversing Heart Disease was the best selling layman’s book for preventing or recovering from or preventing hart disease. Ornish advocated a strict, ultra low-fat vegetarian diet to reverse heart disease, and a somewhat less strict preventive diet.  Based on 14 years of controlled experiments, the book offered evidence, including scanned images, that exercise, stress management and the vegetarian diet can clean out the pipes and reverse heart disease. My cardiologist said it is an excellent diet, but few people can manage to stick to it. Fish were ruled out because fish are loaded with fat. Today, we are urged to eat fish two or three times a week, precisely because of their fat.
     “It used to be so simple,” says the Harvard Medical School in its 2008 booklet, Healthy Eating. “Fats were the villains, and carbohydrates were the heroes,” so “experts encouraged people to eat less fat.” Now we are bombarded with messages to eat unsaturated fats (especially the type found in fish); limit our consumption of saturated fats; and completely avoid trans fats, if we can.
     Saturated fats are saturated with the maximum hydrogen found in nature; trans fats are man-made and “partially hydrogenated” to increase the hydrogen load to unnatural levels. Trans fats are the worst, not least because they increase that bad LDL and reduce the good HDL in our blood.
     Unsaturated fatty acids (UFAS) are, as you would guess, less saturated with hydrogen. They consist of monounsatured fatty acids (MUFAS) and polyunsatured fatty acids (PUFFAS)

Not too confuse things too much, the MUFAS and the PUFAS include, among others, Omega 3, Omega 6, ALA , EPA and DHA fats. Let’s sort them out.
     MUFAS seem to get the most of the credit among the UFAS for lowering the LDL s and boosting HDLs, which help clean up LDL’s artery-clogging mess. MUFAS are commonly found in a number of cooking oils and nuts. Two of the most widely advocated  are Canola and Olive oils. Olive oil is 75 percent MUFAS, which is better than Canola’s 61 percent; but Canola has only 7 percent saturated fat, which is better than the 15 percent in Olive oil. Don’t ask me which of these two champs is the winner: undoubtedly you could find contradictory studies. We use both.
     PUFAS are said to have an enormous range of health benefits, especially in reducing the risk of heart trouble.  But at least one major study claims they have no such effect at all.
     PUFAS are called “essential fatty acids” because our bodies do not produce them, so we must eat the foods that contain them. The two PUFAS of most interest are Omega 3 and Omega 6, with the three types of Omega 3 fats that have long scientific names, more easily known as ALA, EPA and DHA.
     Omega 6 are ALA fats, said to help healthy skin, hair, nails and hormonal and emotional balance. We usually get all the Omega 6 we need from most vegetables, meats, eggs, grains, nuts and baked goods. But a proper balance between Omega 6 and 3 is said to be important, and most western diets do not include enough Omega 3 for a good balance.
     EPA and DHA are the forms of Omega 3 fats said in most studies to reduce the risk of heart trouble. They are most commonly found in cold water fish, especially salmon, herring, mackerel, anchovies and sardines. The U.S. Food and Drug Administration states that “Supportive but not conclusive research shows that consumption of EPA and DHA fatty acids may reduce the risk of coronary heart disease.” The Canadian Food Inspection Agency has approved a food label claim that doesn’t mention the heart but says that DHA “supports the normal development of the brain, eyes and nerves.” The DHA and EPA fats come from seawater algae eaten by the fish. A Wikipedia article helpfully notes that if you’re opposed to killing fish you can get your quota of DHA and EPA by eating algae.
     The biggest source of the ALA Omega 3 fats—by a country mile—is flax seeds (which must be ground to get the full benefit). Your body converts ALA into the heart-healthy DHA and EPA fats, but it’s a slow and inefficient process and nutritionists says it’s better to get these two fats by eating fish. Flax seeds, however, are also very high in fibre and phytochemicals known as lignans. The synergistic effects of the ALA, the fibre and the lignans are widely touted as a cure for whatever ails you, or for avoiding it—including constipation;  heart trouble; diabetes; breast, colon and prostate cancer; arthritis; Alzheimer’s disease, and feelings of depression. Although perhaps not supporting every claim, a daily dose of flax seed is recommended by thousands of doctors, the Mayo Clinic and the registered dietitians at HealthCastle.com, while the U.S. National Cancer Institute says it’s worth more study.

In the lottery of life there are no rules and no guarantees. But no one disputes that good diet, exercise and healthy lifestyle can at least improve the odds of a long and vigorous life for most of us. Life expectancies continue to expand—age 100 is no longer remarkable. Despite all the change, confusion and contradiction, who can doubt that today’s nutritional advice is a part of that improvement?
     My father died at age 54 and Joan’s mother at age 51, both from heart trouble. There’s no doubt in my mind that if 50 to 70 years ago doctors and nutritionists had the knowledge to offer the nutritional advice now universally dispensed to cardiac patients, both would have lived considerably longer. There was no one to advise my father that hamburgers were not the healthy choice he thought, and that suet pudding and bread fried in bacon fat are dietary disasters.
     Perhaps those who say it is safe for even diabetics, pre-diabetics (like me) and those in danger of or with heart trouble (like me) to eat two or more eggs a day are right. Or perhaps the report in the Canadian Journal of Cardiology is right. But the safest advice seems to come from the American Heart Association, which recommends no more than 300 mg of dietary cholesterol per day for health people and 200 mg for those of us in the risky category—essentially on egg a day for the healthy people and virtually none for the rest of us.
     As for Joan and I, we’re switching back to simulated eggs that provide the great health benefits of the white without the risk of the yoke, and make fabulous scrambled eggs. And we’ll more sharply limit saturated fats.
     I had said I would talk in this blog about how I plan to reduce my LDL cholesterol without the aid of medication. In my next blog I will tackle how we plan to meet the special diet needs of both Joan and I. It turns out to be little different than the most widely accepted diet advice for everyone, except for some fine-tuning.

TAGS: Coronary heart disease. Eggs. Dietary cholesterol. Dietary fats. Canadian Journal of Cardiology. Potatoes. Whisky. Flax seeds. Harvard Medical School. National Cancer Institute. Mayo Clinic. Andrew Rochford. Eubie Blake. Max Bell. Dean Ornish.

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