Soy Diet Worsens Heart Disease In Mice Carrying A Genetic Mutation

Researchers from the University of Colorado have shown that mice carrying a genetic mutation that is linked to altered heart growth and function in humans, have significantly worse heart problems if fed a soy diet, when compared to mice fed a soy-free (milk protein-based) diet. This is the first study to provide evidence that an environmental influence - in this case diet - can affect the heart. It will also force researchers to rethink the diets of their laboratory mice. The results appear in the January 4, 2006 issue of the Journal of Clinical Investigation.

Hypertrophic cardiomyopathy (HCM) is a genetic cardiovascular disease occurring in 1 in 500 individuals, and is characterized by shortness of breath, chest discomfort, and palpitations that may be a sign of life-threatening arrhythmias. While mutations in a number of genes have been linked to HCM, the variety of symptoms experienced by sufferers suggests that other genetic or environmental factors affect disease prognosis.

For years, soy-rich diets have been speculated to protect against heart disease. The biological consequences of a soy-diet have been attributed to the presence of phytoestrogens, which are plant-derived estrogen-like compounds that interact with the estrogen receptor. Leslie Leinwand and colleagues examined male and female mice that overexpressed a mutant form of the alpha myosin heavy chain gene, which is one known cause of HCM in humans. The researchers found significant growth (known as hypertrophy) of the heart of male mice fed a soy-based diet, in comparison to male and female mutant mice fed a soy-free diet.

The authors propose that the difference observed between the sexes is based on the fact that the female mice, who are constantly exposed to naturally circulating levels of estrogen compounds, are less sensitive than males to the change in estrogen level as a result of the soy diet. Interestingly, the authors observed a significant improvement in cardiac growth and function when the animals were switched to a soy-free diet. The new data provide a strong link between soy diet and the progression of cardiac disease, in mice.

In an accompanying commentary, Cathy Hatcher and Craig Basson from Weill Medical College of Cornell University discuss the influence of a soy diet on heart disease and highlight how in the future, researchers using animal models for the study of human disease will have to consider the diet fed to their animals and how it may influence the manifestation of a disease in animals of various genetic backgrounds.

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Diabetes and Erectile Dysfunction

For men with diabetes, erectile dysfunction (ED)—sometimes called impotence—is a common problem. And because it affects not only men, but also their partners, ED is really a "couples problem."

It is hard to tell whether ED is really more common among men with diabetes than it is among those without diabetes because so many men suffer ED in silence. However, we do know that:

• ED is age-related, often developing in men older than 50. Diabetes is also more common in this older age-group.
• Men with diabetes tend to develop ED 10–15 years earlier than men without diabetes.
• Fifty to sixty percent of all men with diabetes over age 50 have some problem with ED.

Exactly what is ED?

Having ED means that all, most, or some of the time, the penis fails to become or stay hard enough for sexual intercourse. If, on rare occasions, you cannot get an erection, you do not have ED. You also do not have ED if you have a decrease in sexual desire, have premature ejaculation, or if you fail to ejaculate or reach orgasm. ED means that you can’t get or keep an erection.

What causes ED?

ED can be caused by many things. The most common causes in men with diabetes are problems related to blood vessel– and nerve-related complications. Sometimes, though rarely, ED can be caused by a hormonal imbalance. Depression can also cause ED, as can stress and excessive worrying about sexual performance. Certain medications can cause temporary ED.

Can ED be avoided?

You can reduce your risk of developing ED by keeping your blood glucose levels as close to normal as possible. Quitting smoking, drinking less alcohol, and controlling your blood pressure will also help. Exercise can improve your diabetes, strengthen your muscles, promote weight loss, reduce stress, and help you feel better about yourself.

What if I do get ED?

Left untreated, erection problems can hurt self-confidence and relationships. The good news is that ED is a very treatable condition. The first step to restoring a satisfying sex life is to seek help from your health care provider.

Then what happens?

Because ED has several causes, sorting out exactly what is causing your problem may take some time. First, make sure your doctor knows about all the medicines you are using, including over-the-counter or herbal products. Drugs frequently used to treat high blood pressure, anxiety, depression, and peptic ulcers can all cause ED. But don’t stop taking any of your medications without first talking to your doctor.
Most healthy men have several erections each night when they sleep. Your doctor may order a sleep study to test whether you do, as well. If you do, your problem may be psychological, and you and your partner may be offered counseling.
To help identify physical causes, your doctor may order tests for blood vessel damage, nerve damage, and testosterone measurement. Depending on the underlying cause, there are many possible treatments available for ED, and treatment can be tailored to your specific medical problems and lifestyle.

What are the treatments?

Treatment options include pills such as Viagra, injections, vacuum pumps, implantable pumps, supplemental testosterone, and psychological counseling. All of these treatments have pros and cons, so discuss your options thoroughly with your health care provider.

Remember that ED is a "couples problem." Talk things over with your partner to be sure you both understand the problem you’re having and agree on the treatment and goals you hope to achieve.

And don’t forget that ED is one of the most treatable complications of diabetes. By working closely with your health care provider, you and your partner can find the solution that works best for you.

Footnotes

Permission is granted to reproduce this material for nonprofit educational purposes. Written permission is required for other uses. 2/01

http://clinical.diabetesjournals.org/cgi/content/full/19/1/48

Daycare Protects against Childhood Leukemia

Finding supports theory that early infections help prevent disease
Betterhumans Staff


Children who attend daycare in the first few months of life have a reduced risk of leukemia, supporting a theory that early infections protect against the disease.

In a study of more than 9,000 children, UK researchers have found that increasing levels of social activity outside the home are associated with consistent reductions in the risk of acute lymphoblastic leukaemia (ALL).

The greatest reduction was seen in children who attended formal daycare during the first three months of life.

"Our results provide further support that social activity with other infants and children during the first few months of life protects against subsequent risk of ALL," say the researchers.

The most likely interpretation, say the researchers, is that exposure to common infections protects against the disease, as has been reported for such diseases as type 1 diabetes and allergies in children.

"Whether early exposure to one or more specific infections, or to a spectrum of non-specific agents, protects against each of these disparate diseases remains to be clarified," say the researchers. "Nevertheless, we conclude that some degree of early exposure to infection seems to be important for child health."

The study involved 6,305 children aged two to 14 years without cancer and 3,140 children with cancer, of whom 1,286 had ALL.

The researchers interviewed the children's parents about daycare and social activity with children outside the family during the first year of life.

The research is reported in the British Medical Journal (read abstract) .

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Green Tea Compounds Prevent Prostate Cancer

Clinical trial finds them 90% effective in men with precancerous lesions
Betterhumans Staff

Credit: Andrzej Burak
Beneficial beverage: Men at high risk of prostate cancer are protected against the disease by compounds in green tea, according to a new study

A clinical trial has found green tea compounds 90% effective at preventing prostate cancer in men with precancerous lesions.

After one year of oral administration of green tea catechins (GTCs), just one man in a group of 32 at high-risk of prostate cancer developed the disease compared to nine out of 30 in a control group.

"Numerous earlier studies, including ours, have demonstrated that green tea catechins, or pure EGCG (a major component of GTCs), inhibited cancer cell growth in laboratory models," says researcher Saverio Bettuzzi of the School of Medicine at the University of Parma in Italy. "We wanted to conduct a clinical trial to find out whether catechins could prevent cancer in men. The answer clearly is yes."

Daily dose

Bettuzzi and colleagues recruited men with high-grade prostatic intraepithelial neoplasia, premalignant lesions that precede invasive prostate cancer by one year in nearly a third of cases.

Participants were between 45 and 75. To eliminate confounding variables, vegetarians and men already taking green tea, derived products or antioxidants were among those excluded.

Of 62 men in total, 32 received three tablets per day containing 200 mg of GTCs each. The rest of the participants received a placebo.

Follow-up biopsies at six months and one year revealed just one case of prostate cancer in men on 600 mg daily doses of GTCs while nine were found in the untreated group.

The 600 mg-per-day dosage is one to two times the amount of green tea consumed by people each day in China, where ten to 20 cups per day per person is normal.

Follow-up will continue for five years, and Bettuzzi says that a larger study is needed to confirm the results.

The research was reported in Anaheim, California at the annual meeting of the American Association for Cancer Research.


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B vitamins do not lower heart attack risk

STOCKHOLM, Sweden, -- Norwegian researchers have found treating heart attack patients with high doses of B vitamins does not lower the risk of another heart attack or stroke. The data were presented this week during the European Society of Cardiology Congress in Stockholm, Sweden. NORVIT, the Norwegian Vitamin Trial, is the first to examine whether high doses of B vitamins prevent recur- rent heart disease. The lead investigator, Dr. Kaare Harald Bønaa of the University of Tromsø, said the study indicates B vitamins should be prescribed only to patients who have B vitamin deficiency diseases. He said during the last 15 years interest in vitamin B research has rocketed worldwide after studies indicated folic acid and vitamin B-6 might prevent heart disease and stroke. Scientists said one patient in every three who suffers a heart attack has a recurrent heart attack or stroke within three years after the first attack. It was hoped B vitamins could lower the risk of recurrence. The NORVIT trial showed, however, B vitamins offered no protection against cardiovascular disease.

Medicine reduces angioplasty death risk

BOSTON, -- Scientists say they've found use of the antiplatelet drug clopidogrel reduces heart attack and cardiovascular death risks before and after angioplasty. The study, led by Dr. Marc Sabatine of the Harvard Medical School and Boston's Brigham and Women's Hospital, and colleagues concluded use of clopidogrel before a coronary angioplasty reduced the risk of cardiovascular death, heart attack or stroke within 30 days following the procedure. Dual anti-platelet therapy using a combination of drugs such as ticlopidine or clopidogrel, along with aspirin, following procedures such as angioplasty helps reduce platelet activation and thrombotic and ischemic complications, researchers said. However, the optimal timing of the initiation of clopidogrel remains incompletely defined, the study found. The study, funded by the U.S. National Institutes of Health, is detailed in the Sept. 4 issue of the Journal of the American Medical Association.