Heart News and Notes

Researchers at the Medical University of South Carolina tell us our lifestyle is deteriorating. Only 8 percent of patients today, compared with 15 percent in 1988, follow all five healthy habits: controlling weight, eating fruits and vegetables, moderate use of alcohol, exercising, and not smoking. Weight is up, activity and fruit and vegetable consumption are down, smoking is unchanged, while moderate drinking is up.

Is our weight going up because we’re exercising less? A study of American weight gain by Australians, presented last month in Amsterdam, calculated from food supply data how much weight we should gain. If the weight gain matched the prediction it would be entirely due to caloric intake, not inactivity.

They found that for children the facts matched the prediction, meaning that childhood obesity is entirely due to eating more. But exercise can still counteract the effect of overeating. Adults weighed less than predicted, meaning we must have increased our physical activity. The researchers suggest that the increased intake is due to successful marketing by the food industry.

Losing weight doesn’t require strenuous exercise, according to another study comparing two groups of overweight heart patients. The control group followed a typical cardiac rehab program of walking, biking or rowing three times a week. The other group, walking at lower intensity 45 to 60 minutes five or six days a week, lost twice as much weight and had a greater reduction in insulin resistance and other risk factors.

But another study, reviewing previous trials, found that fitness counts. Participants with low cardiorespiratory fitness, as measured by exercise tolerance, had 70 percent higher risk of death from all causes, and 56 percent higher risk of cardiovascular events, than those with high fitness.

Five classes of drugs lower blood pressure: beta blockers, ACE inhibitors, ARBs, calcium channel blockers, and diuretics. A review of past trials, led by Dr. James Elliott of Rush Medical College in Chicago, found that all but ARBs prevented heart events and all were effective in preventing stroke.

A broader review done in the UK concluded that all five drug classes lowered the incidence of stroke and heart events, even if the patients had normal blood pressure. Don’t measure blood pressure, the authors say, just give blood pressure drugs to everyone at risk for stroke and heart disease.

Dr. Elliott and others disagree. Too many different trials were lumped together. Some patients’ blood pressure is already too low. Lifestyle change is safer than drugs. Measure blood pressure, they say, before you treat it.

Scientists are still trying to come to grips with what they call the “obesity paradox.” People who weigh too much are more likely to have heart attacks, heart failure, sudden cardiac death, and atrial fibrillation. But once they get these conditions, they’re more likely to survive than thinner people. A recent review article by Dr. Carl J. Lavie in the Journal of the American College of Cardiology summarized the current state of knowledge of this paradox.

In some conditions their extra weight apparently provides an energy reserve. But for conditions like hypertension and peripheral vascular disease this is an unlikely explanation. Lavie conjectures that the heart disease people get from being obese may be different from the disease thin people get.

All things considered, your chances are better if you maintain normal weight and stay healthy in the first place.

Free radicals are not anarchists at large. Strenuous exercise makes muscle cells create certain “free radicals” - highly reactive oxygen compounds - that can damage tissues and have been linked to the aging process, and it seems logical to take antioxidants, like Vitamins C and E, to deactivate them.

But in an experiment in Jena, Germany, in which forty men exercised regularly for a month, the half who took daily doses of Vitamins C and E did not experience the improvement in insulin sensitivity (which protects against type II diabetes), and the activation of the body’s natural defenses against oxidants, that the control group did. The researchers stress that their results apply only to supplements, not to fruits and vegetables containing these vitamins.

They also warn against taking action based on only one study, but in fact other studies support their conclusions. One published last year, at the University of Valencia, Spain, found that a different antioxidant interfered with useful adaptations to exercise.

Last month the FDA (the federal Food and Drug Administration) sent a letter to General Mills, makers of the breakfast cereal Cheerios, warning that the labeling on the box was in violation of the law.

Statements on the box and on a website claim that Cheerios (ostensibly without any other treatment or lifestyle change) can lower bad cholesterol by a specific amount in a specific time, and that Cheerios is “clinically proven” to lower cholesterol. These statements go beyond the claims allowed by law for the health benefits of whole grains, and would be permitted only after approval as a new drug.

Cheerios is still safe, nutritious and heart-healthy. The only issue is the labeling.