heart disease

Loco for cocoa – chocolate and your heart

Posted by Liz on Jan 9, 2012 in heart disease | 2 comments

Last June and August, I wrote about the link between eating chocolate and improving heart health. Briefly, researchers have long been interested in flavonoids and in particular (at least in so far as menopause goes) in isoflavones. (See soy posts for more on isoflavones). The specific compound or molecule of interest in cocoa (the non-fat component cocoa bean extract or liquor) are flavanols, which are also found in lower concentration in apricots, peaches, apples, green and black tea, red wine and cider). Note that the quantity of flavanols in chocolate depends on manufacturing, including fermentation and roasting, and how much treatment is given to reducing bitterness and improving consistency. What this means is that dark chocolate has the highest concentration of flavanols and milk, the lowest.

What have researchers learned so far?

• Flavanols found in cocoa and cocoa powder may be powerful antioxidants and as such, help to mitigate certain factors that contribute to atherosclerosis, such as the formation of plaques in the arteries that lead to stroke and other coronary events. Thus, as antioxidants, they may actually neutralize toxic oxygen species circulating in the bloodstream.
• Experimental data suggest that ingestion of flavanols may help to regulate proteins and other compounds that encourage an inflammatory response to leads to heart disease.
• Flavanols may also help to stabilize the lining and muscular tone of the arteries and prevent them from narrowing.
• Additionally, flavanols may moderately protect against high blood pressures, although studies have been mixed.
• Finally, flavanols may help to maintain blood sugar levels and improve the ratio of good to bad fats in the blood.

However, while numerous studies suggest that chocolate may benefit the heart, less clear is whether or not a causal relationship exists. Still, the idea is attractive enough that researchers continue to delve into the potential benefits of functional foods containing flavonoids and in flavonols found in dark chocolate. This time, writing in the journal Appetite, they report on a newly published study that examined the effect of eating flavonoid-rich dark chocolate on a process called oxidative stress, in which the ratio of circulating oxygen free radicals  to circulating antioxidants is imbalanced (free radicals are those nasty, unstable molecules or atoms that can wreak havoc and lead to disease, including heart disease, diabetes and high cholesterol).

Over a period of three weeks, 25 healthy men and women were asked to eat 50 g of dark chocolate daily. The women in this particular study were premenopausal, primarily because use of hormone replacement has been shown to modify oxidative stress that has been attributed specifically to LDL (low density lipoprotein, also known as the bad cholesterol). They also omitted any other cocoa products from their diet and tea, red wine and other drinks that were rich in antioxidants.

Not only did eating dark chocolate daily have no impact on body mass index or the subjects’ weight, but it significantly increased the percentage of HDL (high density lipoprotein or good cholesterol) and led to a significant declines in blood fats levels as well. Dark chocolate consumption also appeared to lower markers of oxidative stress and damage to good fats in cells by almost 27% in women in the study, indicating a favorable effect on LDL, a change that was not similarly observed in men. This suggests that eating dark chocolate could possibly benefit women more than men, at least in terms of the heart. And, while menopausal women were not studied, the researchers say that the protective role of dark chocolate could possibly be especially favorable during menopause, when waning levels of estrogen make women particularly sensitive to oxidative damage and heart disease.

As with similar studies, we still don’t have a definitive cause and effect. However, a little dark chocolate has the potential to go a very long way.

Be still my beating heart?

Posted by Liz on Sep 12, 2011 in heart disease | 4 comments

Menopause causes a woman’s risk for dying from heart to disease to spike, correct? If you take a look at the studies I’ve been writing about since starting this blog, the answer would be an unequivocal “yes.”

What we do know to be true is that risk for heart disease increases with age and that heart disease is a leading cause of death among women. Yet, symptoms can be different in women and may even show up at a later age compared to men. Still, the long-held theory that menopause acts as an accelerator and an equalizer has just been turned on it’s toes by a newly published study in the British Medical Journal.

The study authors say that clinical and epidemiological data that demonstrate that menopause is key culprit are simply not there. Rather, they believe that women’s increase in deaths from heart disease can be attributed to a gradual decline of cells that act to repair and replenish our circulation. To prove their point, they reviewed death from heart disease over time in three different cohorts based on the time period when they were born (i.e. 1916-1925, 1926-1935 and 1936-1945).

Indeed, what they found was that none of the groups of women had any sort of significant upswing in heart disease deaths around the time of menopause. Instead, deaths from heart disease increased exponentially over time — by 7.9% per age year. In contrast, death from heart disease in men increased by about 30% per year up to age 45 and then slowed to about 5.2% per year thereafter.

When it comes to heart disease, the great equalizer between women and men appears to be age and not hormones. Even then, more men can be expected to die from heart disease than women, at least until an advanced age.

The reason this is so important is that the focus in women has long been on menopause and efforts to improve heart health based on that time period. The findings imply that we need a wake up call and that efforts to improve our hearts should be based on lifetime risk rather than the time from menopause and beyond.

The time is now ladies. Be kind to your heart; focus on diet, exercise and weight. And truly, still the risk for heart disease before it stills your beating heart for good.

Wednesday bubble: more cocoa loco – chocolate consumption and your heart

Posted by Liz on Aug 31, 2011 in heart disease | 2 comments

Back in June, I provided a thorough lowdown on the mysterious wonder known as chocolate and how it may or may not benefit your heart. Because I imagine that many of you have seen the latest headlines extolling the health power of chocolate, I thought it was important to clarify some of these latest findings, especially because women have a significant increase in heart disease as they enter and go through menopause.

So is it? Or isn’t it? That is, good for the heart?

A group of researchers have published an extensive review of studies examining chocolate consumption and risk of certain heart-related metabolic disorders (i.e. diabetes, coronary heart disease, congestive heart failure, heart attack and stroke). Of the seven included in the final writeup, five showed that the highest intake of chocolate was associated with roughly a third decrease in risk for any type of heart related metabolic disorder listed above, about 37% reduction for any type of heart disease, slightly over a third reduction in the risk for diabetes and about 29% reduced risk for stroke. These results remained even after the researchers looked at factors that might skew the results one way or another, such as age, level of physical activity, BMI, smoking, diet and drug use. However, all of the studies reported chocolate consumption differently, e.g. how often people ate chocolate, the type of chocolate (versus cocoa) consumed (chocolate bars, drinks or snacks) and the actually amount eaten daily or weekly. Most also relied on patient recall on how much chocolate they ate versus scientific records of chocolate eating patterns.

What you really need to know is that despite the sensationalist headlines about chocolate and its heart healthy benefits, these studies only showed an association and not a true cause (eating chocolate) and effect (less heart disease), which is critical.

The researchers say that excessive consumption of chocolate may actually have another effect: wight gain and increased risk for high blood pressure, diabetes, blood fat disorders and the like. And, as one of the researchers points out to my friend and colleague Nancy Shute, a reporter and blogger for NPR, all the study really showed was that people who reported that they ate a lot of chocolate were about a third less likely to develop diabetes, stroke or have a heart attack.

So, what’s next on the chocolate horizon? Researchers need cause and effect studies that corroborate the association that they are seeing. That means a randomized, scientific trial that compares amounts, types and conditions among healthy or unhealthy individuals. In the interim, it’s probably not the best idea to start eating mega amounts of chocolate to save your heart.

However, as grandma always told me “everything in moderation.” A little bit of chocolate can go a long, long way! And certainly can’t hurt.

Meditation in motion: Tai Chi and the ‘pause

Posted by Liz on Jul 11, 2011 in aging, heart disease, mind-body therapy | 0 comments

I’ve written about yoga and meditation/mindfulness training and how both may help with menopausal symptoms in terms of alleviating stress and improving overall wellbeing. However, what about Tai Chi?

Tai Chi is an ancient Chinese martial arts practice that uses a self-paced system of soft flowing movements to improve respiration and deep relaxation. It has also been shown to boost muscle strength, coordination and physical condition, improve balance and like yoga and mindfulness training, benefit overall wellbeing. On the health side, it’s been linked with better sleep quality and duration, enhanced circulation and in fact, is considered a weight-bearing exercise akin to aerobic exercise of moderate intensity. As such, it may even help prevent osteoporosis. Yet, unlike regular strength training Tai Chi appears to offer an important means by which risk of metabolic heart disease during menopause may be reduced.

For women specifically, hormonal changes – namely a steeply progressive increase in testosterone — can contribute to a risk of developing metabolic syndrome (i.e. the cluster of risk factors — abdominal fat, high blood pressure and cholesterol levels and insulin resistance –that increases the likelihood of developing heart disease and diabetes). Moreover, as women age, the ability to effectively metabolize blood fats and maintain ample antioxidant defenses in their bodies requires higher maximal aerobic capacities (which inherently decline with age). Conversely, being sedentary deteriorates the efficiency by which fats are burned or utilized by the body and also negatively affects antioxidant defense lines and their ability to adapt to sudden or chronic exposure to oxidative imbalances in our bodies that can wreak havoc on cells and lead to build up of plaques and heart disease.

Where does Tai Chi fit in?

Yogic pranayma breathing has been linked to improvements in antioxidant capacity and in lower oxidative stress markers. Moreover, it may also improve cardiorespiratory function. Tai Chi combines postures with slow, deep breathing (i.e. 6 breaths per minute) and may also convey the same benefits. In a recent study published in the Journal of Aging Research, 8 premenopausal and 7 post menopausal sedentary women were asked to participate in an 8-week Tai Chi program that involved the following:

• 75 minute training sessions twice weekly consisting of  a 5 minute check in, 10 minutes of stretching/warm-up, and 60 minutes of a modified 18-posture Tai Chi and Tai Chi fan style. The Tai Chi routines coupled breathing to music, took a minute to a minute and a half per motion. The women learned five to 10 postures per week and the complete set was practiced for two weeks. Instructors were also sure to monitor and correct postures during each class.
• Twice-weekly, 60 minute at-home practice that also included completion of a log that detailed the practice (to insure compliance).
• Measures of body weight, diet, physical fitness, balance, flexibility, muscle strength, maximal aerobic capacity and blood samples.

Not only did 8 weeks of Tai Chi practice significantly improve balance, muscle strength and flexibility in both groups, but also produced as much as an 18% decline in a major marker for heart disease risk (i.e. plasma total homocysteine). Additionally, Tai Chi combined with measured, slow deep breathing improved the activities of antioxidant markers in the bloodstream that play a role in defending cells against damage from oxidative stress.

Although this study is quite small and bears repeating with significantly higher numbers of women, the findings do imply that Tai Chi and slow deep breathing have the potential to play an important role in improving functional/physical declines that occur during menopause and equally if not more importantly, improve antioxidant defenses against metabolic diseases, especially heart disease. Tai Chi is not only low impact, low-velocity and safe, but within the framework of menopause, it may prove to be a golden ring amongst alternatives to prevent disease. Meditation in motion, indeed.

Cocoa loco? The lowdown on chocolate and heart disease

Posted by Liz on Jun 17, 2011 in heart disease | 0 comments

[youtube=http://www.youtube.com/watch?v=RZ-uV72pQKI]

If you are a chocoholic, I bet you’ve noticed the headlines linking chocolate to a reduced risk of heart disease. In fact, data from the Kuna Indians (a tribe indigenous to Panama) have shown that cocoa and in particular dark chocolate are associated with declines in blood pressure. More recently, a large government study showed an even greater benefit in terms of a significant reduction in coronary heart disease prevalence. And in women, who have an increased risk for heart disease as they age (not only due to the increase in abdominal fat or changes in their blood fat levels but also to loss of ovarian function), chocolate has ben shown to slightly lower the risk of dying from heart disease.

Sounds promising and quite frankly, awesome, right?

Well…before you run out to the grocery or chocolate shop, you may want to read further…

Researchers have long been interested in flavonoids and in particular (at least in so far as menopause goes) in isoflavones. (See soy posts for more on isoflavones). The specific compound or molecule of interest in cocoa (the non-fat component cocoa bean extract or liquor) are flavanols, which are also found in lower concentration in apricots, peaches, apples, green and black tea, red wine and cider). Note that the quantity of flavanols in chocolate depends on manufacturing, including fermentation and roasting, and how much treatment is given to reducing bitterness and improving consistency. What this means is that dark chocolate has the highest concentration of flavanols and milk, the lowest.

What have researchers learned so far?

• Flavanols found in cocoa and cocoa powder may be powerful antioxidants and as such, help to mitigate certain factors that contribute to atherosclerosis, such as the formation of plaques in the arteries that lead to stroke and other coronary events. Thus, as antioxidants, they may actually neutralize toxic oxygen species circulating in the bloodstream.
• Experimental data suggest that ingestion of flavanols may help to regulate proteins and other compounds that encourage an inflammatory response to leads to heart disease.
• Flavanols may also help to stabilize the lining and muscular tone of the arteries and prevent them from narrowing.
• Additionally, flavanols may moderately protect against high blood pressures, although studies have been mixed.
• Finally, flavanols may help to maintain blood sugar levels and improve the ratio of good to bad fats in the blood.

Wow, this sounds fantastic! And all it takes is a daily diet of dark chocolate?

Here’s the great news. Researchers are devoting increasing amounts of time toward learning how certain foods affect (and benefit) health. However, in so far as chocolate goes? In a thorough review published online in Maturitas, they write that of the studies that have been conducted, it’s truly difficult to determine whether or not there is a causal relationship, i.e. eating A causes B, or eating chocolate prevents heart disease. In the case of chocolate in particular, factors like manufacturing can influence study findings. Moreover, researchers still aren’t sure if they should be focusing on flavanols or some other component of cocoa. It is also possible that only people who already have some sort of problem or condition will benefit  from eating more chocolate.

The bottom line? Dark chocolate in moderation, won’t hurt you and may actually help you. However, you may want to temper expectations. At least a wee bit. Dare to dream though…perhaps cocoa will ultimately defy explanation!

Calcium, vitamin D and heart disease. What’s the 4-11?

Posted by Liz on May 2, 2011 in bone health, heart disease | 5 comments

“Calcium supplements cause heart attacks in postmenopausal women.”

Whoa! What?!

If you saw the headlines last week, you may be wondering what’s up with calcium supplementation. Afterall, don’t medical professionals advise the use of supplements to stave off bone loss associated with osteoporosis? And as a result, the Centers for Disease Control reports that over 50% of adults currently use calcium supplements and more than 60% of women over age 60.

It’s important to get away from the sensational headline and take a closer look at what the research shows and what you need to know.

Previous studies have suggested that there may be a link between use of calcium supplements (without vitamin D) and heart attack; in fact, as Reuters‘ reported last year, calcium supplements were shown to increase the risk of heart attack by as much as 31%, possibly as a result of plaque formation in blood vessels. However, is the risk the same if calcium is used alone versus if it is used in conjunction with vitamin D?  In the Women’s Health Initiative study, the use of calcium and vitamin D did not appear to influence heart disease risk at all.

However, researchers decided to take another look at the data because they say that in this trial, more than half of participants were taking ‘personal calcium’ (i.e. not regulated or standardized to all trial participants) and almost half were also adding Vitamin D.

In this reanalysis, published just last week in the British Medical Journal, the researchers discounted the women who were characterized as personal users of calcium supplements and instead, limited their evaluation to a group of women who were not using personal calcium supplements at the study’s start and previously unpublished data from the trial. The findings? The use of calcium with or without vitamin D appeared to cause a 25% to 30% increase in the risk for heart attack and a 15% to 20% increased risk for stroke. However, the researchers say that even small increases in the incidence in heart disease may manifest substantially, especially in the elderly. They add that if you take a look at the risk-benefit ratio, it is unfavourable, meaning that taking calcium with or without vitamin D for five years would cause twice as many heart attacks or strokes than then numbers of fractures that would be prevented.  Additionally, the data analysis suggests that dosing is not a factor, and that the total amount of calcium taken daily is less important than the abrupt changes in blood calcium levels immediately following supplementation.

Although this research answers a few questions about potential risks about calcium supplementation, it also leaves a key question unanswered:  how does the addition of magnesium and vitamin K, which are often included in commercially-available calcium supplements, affect these findings? Data suggest that these minerals and vitamins are added to keep calcium in the bones where it belongs and out the arteries where it does not.

The best guideline, as always, is to visit a physician to assess your bone health and come up with a plan that works specifically for you. Although calcium supplementation appears to be risky, more data are needed before leading organizations start to change their tune about calcium and bone health. Meanwhile, stay ahead of the headlines and try to focus on increasing the amount of calcium-rich foods in your diet:

* DV = Daily Value. DVs were developed by the U.S. Food and Drug Administration to help consumers compare the nutrient contents among products within the context of a total daily diet. The DV for calcium is 1,000 mg for adults and children aged 4 years and older. Foods providing 20% of more of the DV are considered to be high sources of a nutrient, but foods providing lower percentages of the DV also contribute to a healthful diet. The U.S. Department of Agriculture’s Nutrient Database Web site lists the nutrient content of many foods. It also provides a comprehensive list of foods containing calcium.
** Calcium content varies slightly by fat content; the more fat, the less calcium the food contains.
*** Calcium content is for tofu processed with a calcium salt. Tofu processed with other salts does not provide significant amounts of calcium.