Friday, May 05, 2006

Eggs and your heart - dispelling the myth

Ingestion of several eggs a day tends to increase blood concentrations of cholesterol, particularly the amount circulating in low-density lipoproteins (LDLs)—the so-called bad cholesterol. However, a new study indicates eating eggs can increase the amount of cholesterol in high-density lipoproteins (HDLs)—the good cholesterol, too.

The study also showed that when people ate three or more eggs per day their bodies made bigger LDL- and HDL-lipoprotein particles than when they ate no eggs. That's important because other recent studies have suggested that larger LDLs are less likely than small ones to enter artery walls and contribute their cholesterol load to artery-clogging plaque. Similarly, larger HDLs are more robust than smaller ones at hauling cholesterol out of the bloodstream and, ultimately, out of the body.

The new findings contribute to a growing body of data suggesting that eggs shouldn't be construed "as a dietary evil."

Not all people respond similarly to cholesterol. Studies have shown that 30 to 40 percent of any given population is made up of "hyperresponders." In these people, blood-cholesterol concentrations spike disproportionately in response to dietary cholesterol. The study team decided to investigate whether such people put an egg's cholesterol into different-sized lipoproteins than most other people do.

So, the team recruited 29 postmenopausal women and 13 elderly men to take part in a dietary trial. None was taking cholesterol-lowering medicine at the time of the study, the author notes, which means that for a population of middle-aged-to-elderly people, the group was relatively heart healthy.

For 30 days, each volunteer received a liquid-egg product or a fat-and-cholesterol-free, protein-rich egg substitute in portions comparable to three large eggs per day. The real-egg ration delivered some 640 mg of cholesterol; the egg substitute contained no cholesterol. None of the participants knew which food he or she was getting until the end of the study.

After a month on the first diet, all volunteers took a 3-week breather and then resumed participation. For the second phase, each person received the alternative to the product he or she had initially received.

Throughout both phases of the trial, the amount of both HDL and LDL lipoproteins remained unchanged. However, the 15 hyperresponders among the volunteers had much higher amounts of cholesterol circulating with their lipoprotein particles while they were eating real eggs. "All of the increase went into large [lipoprotein] particles."

In contrast, among normal responders, only small increases in blood cholesterol occurred during the egg diet, and the size of LDL- and HDL-cholesterol particles covered the full range of lipoprotein sizes.

Not only did the two groups handle the eggs' cholesterol differently, but the hyperresponders handled the excess that showed up in their blood "in the most anti-atherogenic way"—by depositing it in the largest lipoproteins. The take-home message is that an LDL-cholesterol reading that ignores lipoprotein size may exaggerate the heart risks posed by eggs' cholesterol.

It's time to tell your healthcare provider to update his or her dietary recommendations.

Still nervous despite studies like this one? Then, try omega-3 eggs. You can now get them at most grocery chains.

Also, consider eggs to boost weight loss.

Wednesday, May 03, 2006

Insulin, NOT SODIUM, and hypertension

Insulin rather than salt is the major driver of hypertension, according to an analysis of data from a prospective study of 23 patients with confirmed atherosclerotic cardiovascular disease.

In the study, obese patients consuming a high saturated fat, low starch diet increased daily sodium intake from less than 2 grams a day to more than 20 grams a day. But they also lost an average of 5.5 kg-or about 5% of their total body weight-in six weeks.

"At the same time there were dramatic and significant reductions in fasting insulin and in mean arterial pressure, researchers said. The finding strongly suggests that "we need to stop paying so much attention to sodium and pay much more attention to fasting insulin." Insulin rises in response to a high carbohydrate, high calorie diet.

"It all comes back to obesity." Asked whether a similar weight loss achieved with a restricted calorie diet or a low fat diet could produce the same results, they agreed that it could.

"We are testing that hypothesis with a new study that will begin enrollment this summer," authors said. "We will be comparing the high fat, no-calorie-restriction diet, to a low fat diet plus Xenical (orlistat)."

And, insulin resistance has now been linked to Alzheimer's.

More on insulin resistance.

Monday, May 01, 2006

Treating periodontal disease cuts heart risk

Researchers aimed to estimate the effect of periodontal therapy on traditional and novel cardiovascular risk factors in systemically healthy individuals who have periodontitis.

A standard course of periodontal therapy (subgingival scaling and root planing) including the adjunctive use of a locally delivered antimicrobial, IPT, resulted in significant reductions in a cluster of inflammatory markers at 1 and 2 months together with an improvement in lipid markers at 2 and 6 months after therapy compared to subgingival scaling and root planing alone.

Intensive periodontal therapy produced greater reductions in IL-6 at 1 and 2 months, together with decreases in C-reactive protein and total cholesterol. Moreover, a 7 +/- 3-mm Hg decrease in systolic BP was observed at 2 months in the IPT group. Intensive periodontal therapy subjects exhibited a 1.53% +/- 1.20% and 2.00% +/- 1.42% decreases in cardiovascular risk scores (Framingham) at 2 and 6 months, respectively, when compared to those in the standard group.

The findings suggest that intensive periodontal treatment reduces systemic inflammatory markers and systolic BP, and improves lipid profiles with subsequent changes in cardiovascular risk when compared to standard therapy.

Twice a year dental visits.....a must.

Saturday, April 29, 2006

It's Mom's fault?

A patient's history of maternal coronary heart disease is a more significant risk factor than a paternal history, investigators reported here. But the risk escalates even more when both parents had the disease.

Compared with male patients with no family history of heart disease, men had a 55% greater risk of developing heart disease if they had a maternal history of coronary heart disease . Their risk was 41% greater if they had a paternal coronary heart disease history.

If both parents had heart disease, the risk for men more than doubled. For younger men, ages 30 to 39, the risk was up 500%.

Maternal transmission was also stronger in women, compared with reference women whose parents were not affected. Women had a 43% increased risk for maternal transmission, compared with a 17% increased risk for paternal transmission.

If both parents had coronary heart disease, the risks for women rose to 82%. Furthermore, like the men, the highest risk—up more than 450%—was found in the youngest age group, women 30 to 39.

The differences in percentages between men and women were not fully explained in the study. The transmission of coronary heart disease could be mediated through diabetes and hypertension but also through other genetic, biochemical, or behavioral factors.

However, study authors hypothesized that the increased maternal transmission may have been attributable to behavioral risk factors and to the fact that children spend more time with their mothers. As a result, children might be likely to pick up a mother's risky habits such as poor diet, smoking, and physical inactivity.

Now, that we're adults, and we have gotten over blaming our parents for all our thoughts and actions, isn't it time to get off the couch, get into the gym and the healthy kitchen, and take on Mom's genes?

Wednesday, April 26, 2006

Small changes 'add years to life'

Making small changes to your lifestyle can have a significant impact on how long you will live, research has shown.

The Cambridge University study looked at over 25,000 people.

It found that stopping smoking, exercising more and eating better could give you the life expectancy of a person 11 to 12 years younger.

  • Eating five portions of fruit and vegetables a day can give you the life expectancy of someone three years younger.
  • Not smoking turned the clock back by four to five years.
  • Increasing exercise by a moderate amount can take up to three years off. (An office worker would need to do one hour of exercise, such as swimming or jogging, every day, while a person with a moderately active job, such as a hairdresser, would need to take 30 minutes exercise a day. People with active jobs, including nurses and bricklayers, do not need to do any extra exercise - as their work is strenuous enough.)

Find out more about the small change, big difference campaign.

Need to add fruits and vegetables to your diet? Need to know what an added portion equals? You'll find that information here and here.

Friday, April 21, 2006

More benefits from the Mediterranean diet

A Mediterranean-style diet that appears to cut the risk of heart disease also may help protect against Alzheimer's disease, a new study suggests.

People who followed the diet were up to 40 percent less likely than those who largely avoided it to develop Alzheimer's during the course of the research, scientists reported.

The diet tested includes eating lots of vegetables, legumes, fruits, cereals and fish, while limiting intake of meat and dairy products, drinking moderate amounts of alcohol and emphasizing monounsaturated fats, such as in olive oil, over saturated fats. Previous research has suggested that such an approach can reduce the risk of heart disease.

The idea that a heart-healthy diet could also help fight Alzheimer's fits in with growing evidence that "the kinds of things we associate with being bad for our heart turn out to be bad for our brain."

Researchers followed 2,258 elderly residents of northern Manhattan for an average of four years. The participants were asked in detail about their dietary habits and evaluated every 18 months or so for signs of dementia. None showed any dementia at the start of the study, but by the end, 262 had developed Alzheimer's.

To look for an effect of diet, the researchers gave each participant a score of 0 to 9 to nine on a scale that measured how closely they followed the Mediterranean diet. Compared to those showing the lowest adherence, those who scored 4 or 5 showed 15 percent to 25 percent less risk of developing Alzheimer's during the study, while those with higher scores had about 40 percent less risk.

The Mediterranean diet.

See a video on the benefits of the Mediterranean-style diet. Scroll down to the November 28, 2005 entry.

Guess what else is good for the brain?

Wednesday, April 19, 2006

Microvascular disease in women - a real danger often overlooked

Puzzling differences have emerged between men and women with heart disease, making it plain that past studies, mostly on men, do not always apply to women. Researchers have come to realize that to improve diagnosis and treatment for women, they must sort out the differences.

"Every time we turn around, we find more gender differences, so it's important to study," said Dr. C. Noel Bairey Merz, a cardiologist at Cedars-Sinai Medical Center in Los Angeles.

Among the differences:
  • Women with chest pain and other heart symptoms are more likely than men to have clear coronary arteries when tests are performed, a surprising result that suggests there may be another cause for their problems.
  • When women do have blocked coronary arteries, they tend to be older than men with similar blockages and to have worse symptoms, including more chest pain and disability. And they are more likely than men to develop heart failure (most likely due to age of onset), a weakening of the heart muscle that can be debilitating and ultimately fatal.
  • When women have bypass surgery or balloon procedures for coronary blockages, they are less likely than men to have successful outcomes, and they are more likely to suffer from bad side effects.
  • Blood tests that pick up signs of heart damage in men do not always work in women.

For symptomatic women without clear atherosclerosis, the underlying problem may be a disorder called microvascular disease, a narrowing or stiffening of the smaller arteries that nourish the heart, vessels too tiny to show up on an angiogram. In microvascular disease, the small vessels lose their ability to dilate and increase blood flow to the heart. The cause does not seem to be fatty deposits such as the ones that can block the coronary arteries. Rather, the muscles in the arterioles thicken, and the walls may stiffen and begin to close in. The result is ischemia, lack of blood flow. Over time, it increases the risk of heart failure and heart attacks.

Three million women in the United States may have microvascular heart disease. Research, begun in 1996, included 936 women who had angiograms because of symptoms such as chest pain. The angiograms found that only a third had blockages in their coronary arteries. In men with similar symptoms, three-quarters or more would have had severe blockages.

Another third of the women had no blockages but did have low blood flow to the heart, most likely a result of microvascular disease. Among those with the disorder, the rate of deaths or heart attacks was 10 percent after four years, much higher than would be expected for women with normal angiograms.

The findings call for a major shift in the treatment of women with chest pain or other symptoms and normal angiograms, said Dr. George Sopko of the National Heart, Lung and Blood Institute. "Instead of tossing aside the angiogram and saying you're OK, let's make sure we are not missing anything."

High cholesterol and blood pressure are almost certainly among the causes of microvascular disease, and it is essential to treat them aggressively in women with chest pain and to urge women to exercise, avoid smoking and lose weight.

Read more on the WISE study and microvascular disease