Undetected Heart Attacks

The good news is you have no chest pain. The bad news is you’ve just had a heart attack. People who have had painless and unrecognized heart attacks are more likely to die than people without a history of heart trouble.

A study of 5,888 men and women aged 65 and older found that 20 percent of elderly people who suffered a heart attack never even knew it happened. Left untreated, their risk for future complications rises.

The findings have prompted researchers to call for cost-effective screening methods to promote early detection and better management to improve outcomes.

Sheifer SE, Gersh BJ, Yanez ND, Ades PA, Burke GL, Manolio TA. Prevalence, predisposing factors, and prognosis of clinically unrecognized myocardial in-farction in the elderly. J Am Coll Cardiol 2000 Jan;35(1):119-26.

If You Have High Blood Pressure, Have It in Tokyo

Men in the U.S. with high blood pressure are more likely to die from a heart attack than their middle-aged peers in Tokyo, a new study has found. Although genetics may play a role, researchers believe that differences in diet have the greatest impact.

Researchers followed 12,031 men in six geographic areas and found that for each ten-point increase in systolic blood pressure, risk of death rose 28 percent. However, men with equal blood pressure rates were more likely to die if they lived in Northern Europe or the U.S. as opposed to Japan or the Mediterranean. Researchers note that diets in the latter group contained less meat and dairy products.

Ideally, eating a low-fat, vegan diet, avoiding tobacco, exercising, and keeping blood pressure well below the often prescribed 140/90 are all vital keys to keeping the heart in tip-top shape.

van den Hoogen PC, Feskens EJ, Nagelkerke NJ, Menotti A, Nissinen A, Kromhout D. The relationship between blood pressure and mortality due to coronary heart disease among men in different parts of the world. Seven countries study research group. N Engl J Med 2000;342:1-8.

Calcium Supplements Ineffective for Lowering Blood Pressure

While the dairy industry has claimed that calcium lowers blood pressure, its effect, if any, is trivial, as was again confirmed by a new study.

For six months, University of South Carolina researchers followed 193 men and women, one group taking a placebo and the other taking calcium carbonate tablets twice daily. Blood pressure was measured several times throughout the trial and ultimately showed calcium to have no significant effect on blood pressure.

Potassium has been shown to lower blood pressure, providing support for nutritional guidelines to increase dietary potassium to prevent hypertension. Bananas, oranges, and green leafy vegetables are excellent sources of potassium and their effect may be even greater in hypertensive individuals. Vitamin C, which abounds in plant-based diets, is also effective. In fact, vegetarians have only about one-third the prevalence of high blood pressure compared to meat-eaters.

Bostick RM, Fosdick L, Grandits GA, et al. Effect of calcium supplementation on serum cholesterol and blood pressure. Arch Fam Med 2000;9:31-40.

Fruits and Veggies Boost Density, Cut Loss

Fruits and vegetables can help keep a woman’s bones strong, according to researchers at the University of Surrey. Their study evaluated 62 healthy women aged 45 to 55 who underwent bone mineral density screenings and completed detailed diet questionnaires about the foods they consumed in the past 12 months as well as in childhood. The women who ate the highest amounts of fruits and vegetables had higher bone density scores and less evidence of bone loss.

Lead investigator Dr. Susan A. New notes that although most studies on osteoporosis have focused on calcium, "intakes of nutrients found in an abundance of fruits and vegetables—namely potassium, beta-carotene, vitamin C, and magnesium—were positively associated with bone health." Researchers believe that potassium slows the excretion of calcium while it and vitamin C increase rates of bone formation.

New SA, Robins PA, Campbell MK, et al. Dietary influence on bone mass and bone metabolism: further evidence of a positive link between fruit and vegetable consumption and bone health. Am J Clin Nutr 2000;71:142-51.

Just Say NO to Useless Animal Testing

PCRM has joined the Doris Day Animal League, People for the Ethical Treatment of Animals, Earth Island Institute, and the National Anti-Vivisection Society in a petition urging the Environmental Protection Agency (EPA) to force U.S. chemical companies to bring forth all of their existing data regarding the safety of chemicals they manufacture or import.

Currently, the EPA only requires companies to name chemicals which have been deemed harmful. This petition is meant to disclose those that have been found safe, so that the repetition of cruel and unnecessary tests may be halted.

It is hoped that chemical companies will share these data amongst themselves, further reducing animal tests, that nonhazardous chemicals will be permanently removed from the High Production Volume (HPV) chemical testing list, and that ultimately more relevant human trials will replace all such procedures.

Red Flags for Animal Experiments

In a look at animal-based research methods in Canada, Anne Innis Dagg of the University of Waterloo analyzed 14 mainstream animal research journals and "flagged" their articles according to three criteria: 1) number of animals used in the experiment, 2) number of citations each received, and 3) the nature of the experiment (deprivation of food or water, invasive procedure, or killing of the animal).

Four journals received three flags. These publications covered experiments that were assumed to have caused the most pain and involved the most animals, and yet they were infrequently cited in other journals, suggesting they had little influence on subsequent research. The three-flag journals were Behavioral Neuroscience, Brain Research Bulletin, Neuroendocrinology, and Behavioral Brain Research.

Dagg recommends that animal care committees be allowed to reject their colleagues’ research proposals through secret ballot, that highly-stressful studies receive more vigorous screenings before funding is provided, and that quality of research, among other standards, be more carefully scrutinized.

Dagg A. Responsible animal-based research: three flags to consider. J App Animal Wel Sci 1999;2(4):337-46.

Cutting out Dissection for a Better Alternative

High school students who are ethically opposed to dissecting frogs for biology class now have a state-of-the-art alternative thanks to Digital Frog International, Inc., a software developer in Canada that sells the interactive program.

Developed in 1995 by veterinary student Simon Clark, the CD-ROM allows students to probe the intricate internal workings of the computer-generated frog. Students make incisions with their mouse, as a narrator explains the functions of various organs. High-resolution and 3-D animation allow students to add cartilage and muscle to the frog’s skeleton and discover how amphibians move.

Demand is on the rise for the $170 program. "More and more people are environmentally conscious and don’t want to use something that has been killed just to be cut up," says the company’s marketing manager.

Dieting Does More Harm Than Good

A new study reveals that weight-loss attempts can actually increase the risk for major weight gain. Researchers at the University of Helsinki followed 3,536 men and 4,193 women aged 18 to 54 for a period of 6 to 15 years and found that almost all normal-weight subjects who dieted end up gaining weight.

At greatest risk for gaining more than 22 pounds over a 15-year period were men between 18 and 29 years and women between 30 and 54 years, regardless of other factors such as smoking, social class, alcohol use, or marital status.

Being overweight increases the risk for developing diabetes, high blood pressure, and heart disease. Unfortunately, approximately 30 percent of the American population is dieting at any given time. A better approach is not to focus on how much you eat, but on what you eat. A PCRM study revealed how a total change in eating habits—through adopting a low-fat, vegan diet—helped participants lose an average of 16 pounds over a 12-week period, increased their energy levels, and cut their need for high blood pressure and diabetes medications.

Korkeila M, Rissanen A, Kaprio J, Sorensen T, Koskenvuo M. Weight-loss attempts and risk of major weight gain: a prospective study in Finnish adults. Am J Clin Nutr 1999;70:965-75.