Lowering Cholesterol Early in Life Protects Against Heart Disease Later

New research from UT Southwestern Medical Center indicates that lowering “bad” blood cholesterol earlier in life, even by a modest amount, confers substantial protection from coronary heart disease.

The new findings, appearing in the March 23 issue of The New England Journal of Medicine, found that people with genetic variations affording them lower low-density lipoprotein (LDL) cholesterol in their blood from birth were significantly less likely to develop coronary heart disease later in life than those without the variations. These variations exist in a recently discovered gene called PCSK9.

Based on 15 years of data tracking more than 12,000 multiethnic subjects ranging in age from 45 to 64, the researchers found that people who had cholesterol-lowering genetic variations that lowered their LDL level by about 40 milligrams per deciliter were eight times less likely to develop coronary heart disease than those without the mutations. Those with genetic profiles lowering their LDL by about 20 mg/dl from average had a twofold reduction in heart disease.

“These data indicate that a moderate, life-long reduction in LDL cholesterol is associated with substantial reduction in the incidence of coronary events, even in populations with a high prevalence of other cardiovascular risk factors,” said Dr. Helen Hobbs, the study’s senior author, director of the Eugene McDermott Center for Human Growth and Development and an investigator in the Howard Hughes Medical Institute at UT Southwestern. She also directs the Donald W. Reynolds Cardiovascular Clinical Research Center at UT Southwestern. Dr. Hobbs coauthored the study with Dr. Jonathan Cohen, professor of internal medicine and researchers from the UT Health Science Center in Houston and the University of Mississippi Medical Center in Jackson.

Dr. Scott Grundy, director of the Center for Human Nutrition at UT Southwestern, served as chairman of the National Cholesterol Education Program’s Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults, which in 2001 set guidelines for the clinical use of cholesterol-lowering medications to reduce the risk of cardiovascular disease. “This study demonstrates the great importance of high blood cholesterol in causing coronary heart disease,” said Dr. Grundy.

“It also shows the benefit of maintaining a low cholesterol level throughout life. The foundation for keeping low blood cholesterol is a reduced intake of saturated fats and cholesterol and maintaining a desirable body weight. But in some people it may be necessary to add drugs to reduce cholesterol levels. Fortunately, newer cholesterol-lowering drugs have been developed that are both effective and safe for most people.

Previous research has established that people with a high level of LDL cholesterol in their blood are at greater risk of developing coronary heart disease. The present study further documents that life-long reductions in LDL cholesterol can actually help prevent heart disease.

Previous findings by Dr. Hobbs and colleagues at UT Southwestern had identified specific mutations in the gene called PCSK9 that are associated with lower LDL cholesterol levels in people who have the mutations. Those genetic studies were based on data gathered from the UT Southwestern-directed Dallas Heart Study, a groundbreaking multiyear investigation of cardiovascular disease involving 6,000 Dallas County residents.

The new findings are based on data obtained from subjects drawn from the Atherosclerosis Risk in Communities Study (ARIC), which tracked the health of participants from four communities in Mississippi, Minnesota, North Carolina and Maryland for 15 years, beginning in 1987. UT Southwestern’s collaborators at the UT Health Science Center in Houston analyzed blood samples from those participants to determine who carried the cholesterol-lowering genetic variations. The researchers then tracked the subjects’15-year health history and found the association between lower long-term LDL levels and lower risk of heart disease.

The PCSK9 gene produces an enzyme that normally controls the number of LDL receptors lining the surface of liver cells. These LDL receptors latch on to LDL and remove it from the blood. Dr. Hobbs and co-workers previously found that genetic mutations that inactivate PCSK9 result in lower levels of the PCSK9 enzyme, leading to higher levels of LDL receptors. By increasing the amount of “bad” cholesterol the liver cells can remove from the blood, LDL levels are lower in the blood of people with the mutations.

High levels of PCSK9 tend to raise the blood concentrations of LDL. Currently statins are the standard class of drugs prescribed to lower LDL in patients. However, statin treatment may increase the production of the PCSK9 enzyme, Dr. Hobbs said, which in turn may limit the effectiveness of these drugs. Developing new therapies that inhibit PCSK9 activity not only should lower LDL levels, but in addition, might enhance the effectiveness of statins, she said.

Research Links Soy Protein with Heart Health

Cardiovascular diseases kill more than 16 million people worldwide and account for some 30 percent of all deaths each year. In the United States, heart disease and stroke, the main components of cardiovascular disease, account for nearly 40 percent of all adult deaths. Physicians have known for many years that lifestyle change helps prevent heart attack and stroke. Only recently, however, have scientists studied how a diet low in fat and rich in soy protein helps lower cholesterol and may help reduce one’s risk of heart disease.

Soy Protein’s Role in Lowering Cholesterol

Two daily servings of soy protein can lower blood cholesterol levels by as much as 9 percent, according to a new study by a scientist at the University of Kentucky – Lexington. (1) More than 40 other studies have also found that adding soy protein to the diet, or replacing animal protein with soy, lowers blood cholesterol. (2,3) In a 1995 meta-analysis of 38 clinical studies, researchers found that soy protein resulted in a 12.9 percent average reduction in LDL (“bad”) cholesterol levels. (4)

1 Anderson, JW. University of Kentucky. 2005. 2 Carroll KK. J Am Dier Assoc, 91:820, 1991. 3 Sitori CR, Even R, Lovatt, MR. Ann NY Acad Sci, 676:188, 1993. 4 Anderson JW, Johonstone BM, Cook-Newell ME. N Engl J Med 333:276, 1995.

American Heart Association, FDA Endorse Soy Protein

A strong body of research into soy protein and heart disease prevention has prompted many health experts to endorse the value of soy protein within a low fat, low cholesterol diet. In 1999, The Food and Drug Administration (FDA) approved an unqualified health claim in support of soy’s heart health benefits, which came in response to a body of scientific evidence compiled, reviewed and presented by The Solae Company. The claim is based on scientific evidence from more than 50 independent studies, many of which included soy protein from The Solae Company.

This month, the American Heart Association publicly acknowledged that soy protein was a high quality, heart healthy protein source. Many foods containing soy protein are considered beneficial because of their high content of polyunsaturated fats, fiber, vitamins, minerals and low content of saturated fat.

Additional Health Benefits of Soy

Researchers have found other ways in which soy protein may help reduce a person’s risk for cardiovascular diseases. Blood clots, for example, can completely block an artery that has already been narrowed by atherosclerosis. Research findings suggest that certain bioactive properties found in soyfoods may help prevent these blockages from occurring, thereby reducing the chances of heart attack or stroke. (5,6) Still more research has indicated that soy protein may be linked to lower blood pressure. (7) Uncontrolled high blood pressure can lead to stroke, heart attack, heart failure and/or kidney failure. More research is still needed, and scientists continue to examine soy protein’s affect on a variety of heart health issues.

Potassium-enriched salt may cut heart risks

Replacing regular salt with a potassium-fortified alternative may help lower older adults' risk of dying from cardiovascular disease, new research suggests.

In a study of nearly 2,000 elderly Taiwanese men, researchers found that those given a potassium-enriched salt substitute were 40 percent less likely to die of heart disease or stroke over the next two to three years.

The salt alternative, which was half sodium chloride, half potassium chloride, helped the men make a moderate cut in their sodium intake and a substantial increase in their potassium consumption.

This potassium boost may have been largely responsible for the lower risk of cardiovascular death, the researchers conclude in the American Journal of Clinical Nutrition.

Like sodium, potassium is an electrolyte needed for maintaining the body's fluid balance. It's also involved in proper nerve and muscle control, as well as blood pressure regulation. A number of studies have suggested that diets high in potassium -- from foods like raisins, bananas, melon, beans and potatoes -- may help maintain a healthy blood pressure.

The new findings suggest the mineral may also help lower the risk of dying from heart disease or stroke -- possibly by protecting blood vessel function, according to study co-author Dr. Wen-Harn Pan, a researcher at the Institute of Biomedical Sciences, Academia Sinica in Taipei.

While the study looked at a potassium-enriched salt, Pan told Reuters Health she suspects that a diet high in potassium-rich fruits and vegetables could be even more beneficial.

The study included 1,981 elderly men who were residents of a veterans' retirement home. Half of the men were randomly assigned to eat meals prepared with the potassium-enriched salt, while the rest had meals made with regular salt.

Over the next 30 months, the researchers found, men given the salt alternative were 40 percent less likely to die of cardiovascular disease.

The findings are in line with general nutrition advice for controlling blood pressure and lowering heart risks: eat more fresh fruits and vegetables, beans and low-fat dairy, while limiting salty processed foods.

An advantage of whole-food sources of potassium is that they contain other nutrients important to overall health, Pan noted. Still, potassium-enriched salt offers a "convenient and fast way" to alter the diet's sodium-potassium ratio, she added.

It is possible, however, for the body's potassium levels to get too high, particularly in older people who have kidney dysfunction or are taking certain medications -- including blood pressure drugs called ACE inhibitors.

Older adults should check with their doctors before using potassium-enriched salt substitutes or potassium supplements.

Work Stress Leads to Heart Disease and Diabetes

Chronic stress at work and the metabolic syndrome: prospective study BMJ Online First

Stress at work is an important risk factor for the development of heart disease and diabetes, finds a study published online by the BMJ today.

Stress at work has been linked with heart disease, but the biological processes were unclear. This study provides new evidence for the biological plausibility of the link between work stress and heart disease.

Researchers examined the association between work stress and the metabolic syndrome (a cluster of factors that increases the risk of heart disease and type 2 diabetes) in 10,308 British civil servants aged between 35 and 55, over a 14 year period.

Work stress was measured on four occasions between 1985 and 1999. Components of the metabolic syndrome, such as obesity, high blood pressure, and high cholesterol levels, were measured between 1997 and 1999. Social position and health damaging behaviours, such as smoking, heavy alcohol consumption, and lack of exercise, were also recorded.

A dose-response relation was found between exposure to job stress and the metabolic syndrome, even after adjusting for other risk factors. For example, men with chronic work stress were nearly twice as likely to develop the syndrome than those with no exposure to work stress. Women with chronic work stress were also more likely to have the syndrome, but they formed a small group.

Both men and women from lower employment grades were more likely to have the syndrome, confirming previous reports that the syndrome has a social gradient.

The association between the metabolic syndrome and exposure to health damaging behaviours was stronger among men than women. Poor diet (no fruit and vegetable consumption), smoking, heavy alcohol consumption, and physical inactivity were all associated with higher odds of the syndrome.

Despite some study limitations, a dose-response relation exists between exposure to work stress and the metabolic syndrome, even after other risk factors are taken into account, say the authors.

One possible explanation is that prolonged exposure to work stress may affect the nervous system. Alternatively, chronic stress may reduce biological resilience and thus disturb the body’s physiological balance (homoeostasis).

This study provides evidence for the biological plausibility of psychosocial stress mechanisms linking stressors from everyday life with heart disease, they conclude.

Larger Waistline Linked to Increased Risk for Heart Disease in Women

Women with waistlines of 35 inches or more are at greater risk of heart disease than thinner women, according to a new study by researchers at NewYork-Presbyterian Hospital/Columbia and Sister to Sister: Everyone Has a Heart Foundation. The study is published in today's Journal of Women's Health.

Of more than 6,000 women without known heart disease whose waistlines were measured on Women's Heart Day, February 18, 2005, the study found that 90 percent had at least one major risk factor for heart disease, and one-third had three or more. These risk factors included high cholesterol and high blood pressure, among others. Increased waist circumference was also correlated with a woman's 10-year chance of having a heart attack or dying of heart disease.

"Measuring waist circumference may be a simple method that women can identify themselves as being at increased heart-attack risk and empower them to seek further evaluation and possible treatment from their doctors," says lead author Dr. Lori Mosca, director of preventive cardiology at NewYork-Presbyterian Hospital and professor of medicine at Columbia University College of Physicians and Surgeons.

A substantial proportion of women screened were found to have major risk factors for heart disease they were unaware of. Nearly half of all women with elevated cholesterol or low HDL cholesterol ("good" cholesterol) did not report a history of being told they had abnormal cholesterol from a health-care provider. Alarmingly, 43 percent of women who participated in the screening had blood glucose above what is considered normal (< 100 mg/dL). And, 16 percent of women with no documented history of hypertension had elevated blood pressure (> 140/90 mmHg) that should receive intervention based on national standards.

According to Dr. Mosca, who also serves as the chief medical advisor for the Sister to Sister: Everyone Has a Heart Foundation, "These findings underscore the need to educate women about their personal risk of cardiovascular disease and educate them that where there is one risk factor present, there are likely more. Lifestyle is critical in treating the risk factors for heart-disease-related conditions like hypertension, high cholesterol, and diabetes that are associated with abdominal obesity and each other. Weight management, good nutrition, regular exercise, and avoidance of smoking can go a long way to lowering overall cardiovascular risk. Because so many participants in our screening program were unaware of their risk, our study makes clear that women need to ask their physician if they have any of these risk factors."

Sister to Sister: Everyone Has a Heart Foundation, Inc. is a not-for-profit grassroots organization founded in 2000 by Mrs. Irene Pollin with a mission to bring free heart-disease screenings and "heart-healthy" prevention information and support to women nationwide. Since its inception, Sister to Sister has touched the lives of thousands of women through the National Woman's Heart Day® Campaign. So far, nearly 20,000 women of all ages, races, and socioeconomic backgrounds have been screened for cardiovascular disease risk factors.

"We now know that these screenings provide an additional and unforeseen benefit," says Mrs. Pollin. "Not only have they allowed us to identify and educate women at risk, but they have provided a rich opportunity for research that will be useful in educating the millions of women who may not be able to attend the screenings in person but are at risk of heart disease."

Heavy Stress Plays Hefty Role in Heart Disease

Stress can contribute to the development of heart disease and lead to a fatal heart attack like the one reportedly suffered by Ken Lay, former chief executive officer of Enron, on Wednesday, according to a psychiatrist at Duke University Medical Center.

"Mr. Lay is an unfortunate example of the fact that stress can play a role in precipitating an acute heart attack," said Redford Williams, M.D., director of the Behavioral Medicine Research Center at Duke University Medical Center. "Stress from major life events that we can't control, such as legal difficulties, can be highly detrimental."

Williams has published more than 150 scientific articles on stress and heart disease. He is also co-author of the book Anger Kills.

"People with high-demand jobs but little control over those jobs could be at high risk for stress-related heart disease," Williams said. "Stress can play nearly as important a role in having a heart attack as high cholesterol or high blood pressure," he added.

Anyone with an underlying heart condition is much more susceptible to the effects of stress, Williams said.

Individuals who feel constantly depressed, worried, anxious or angry should visit their doctor. Fatigue, a racing heart or difficulty breathing should also prompt a call to a physician to determine if the physical factors leading to heart disease are under control, Williams said. If necessary, doctors can recommend aspirin, antihypertensive medication or drugs known as beta blockers to control or prevent potential problems.

Williams recommends talking about problems with loved ones and brainstorming about ways to alleviate stressful situations. Regular meditation or relaxation, he said, can also help reduce the amount of stress hormones and protect the mind and body from the harmful effects of extreme stress.

Green tea found to significantly reduce risk of death, heart disease

A Japanese study found that drinking green tea can lower the risk of death from a variety of illnesses, including cardiovascular disease. The Tohoku University study -- started in 1994 -- looked at 40,530 healthy adults aged 40 to 79 who lived in Northeastern Japan, where roughly 80 percent of people drink green tea and more than half drink three or more cups daily.

Over the course of the 11-year study, people who drank five or more cups of green tea per day had a 16 percent lowered risk of dying from any cause and, during the seven-year follow-up, had a 26 percent lower risk of dying from cardiovascular disease when compared to people who drank fewer than one cup a day. The study found no association between green tea consumption and death from cancer.

The study noted that women seemed to get a greater benefit from the tea than men, as the risk of death from cardiovascular disease was reduced by 31 percent in women who drank more than five cups of green tea a day.

"The most important finding is that green tea may prolong people's lives through reducing the risk of cardiovascular disease," said lead researcher Dr. Shinichi Kuriyama.

Ellen mason, a cardiac nurse at the British Heart Foundation, said the results may not apply to people who consume Western diets because the Japanese diet as a whole is recognized for its healthy properties.

"The rate of heart disease in Japan is already one of the lowest in the world, and the Japanese diet is believed to play a substantial role in keeping this low," she said. "The average British diet contains more saturated fat than the average Japanese diet, and our levels of heart disease are relatively high compared with many other countries in the world.

"It is questionable whether drinking the same amount of green tea a day in the UK would have a significant impact on levels of heart disease," Mason said, adding that subsequent clinical trials would be needed to prove whether green tea can prevent deaths from heart disease.

"I reach the exact opposition conclusion," said Mike Adams, a consumer health advocate and creator of the HerbReference.com website. "If green tea can significantly reduce the risk of heart disease in Japanese people who already have excellent cardiovascular health, the herb may be even more beneficial in Westerners who don't follow heart-healthy diets," he said. "Americans have more room for improvement."

More than 3 million tons of tea is produced annually worldwide, and it is hailed as the most consumed beverage on Earth after water. Adams cautions consumers to buy green tea only from reputable sources, as much of the green tea sold around the world is contaminated with fluoride.