Tuesday, August 14, 2012

Can Curcumin Really Improve Heart Health?

Recently week blogs were abuzz with reports about how to prevent heart problems with curcumin.

Chances are that you have heard about curcumin. Curcumin is the bright orange pigment that gives curry powder its distinctive color. Curcumin is often recommended for preventing heart problems because it is a natural anti-inflammatory.

Excessively enthusiastic natural health authorities often tout curcumin and the turmeric from which is obtained (you'll usually  get both curcumin extract and the raw herb turmeric in the same capsule) as some kind of miracle cure for many of chronic diseases of aging, including arthritis, cancer, diabetes, and heart problems, and especially curcumin for skin cancer and curcumin for colon cancer.

 The truth is that curcumin is almost certainly helpful for many disease indications. Curcumin is a complement to good medical care, not an alternative to it. But let's take a closer look at the reports about turmeric that are going around this week.

Curcumin and Inflammatory Heart Disease

The latest spurt of interest in curcumin and turmeric was inspired by an article published in a scientific journal called the Journal of Nutritional Biochemistry. It's a legitimate scientific publication. It's listed in PubMed.

In the March 2012 edition of this journal, a group of researchers at the Heart Research Center and Chonnam National University in Korea report a study conducted with Sprague-Dewey rats. The scientists fed the rodents 30 milligrams of curcumin per every kilogram of body weight per day. That's roughly equivalent to a 200-pound human being eating an ounce of curry powder per day, although not all the curcumin in the curry powder would be absorbed in that amount.

After the scientists gave the rats curcumin for two weeks, they gave them artificially induced heart attacks. They killed the rats and observed how the heart cells responded to oxygen, after being deprived of it in the "heart attack," with and without curcumin pre-treatment.

The researchers observed that heart cells were less likely to "burn out" when oxygen was reintroduced if they came from rats that had been given high-dose curcumin. To me, these results don't scream that curcumin is a miracle cure for heart attacks and everybody should run out and buy a bottle right now.

Actually, if you have the kind of heart trouble that the scientists gave the rats, running is not a good idea. Curcumin probably is nonetheless a legitimate heart health supplement. Here's why.

 urcumin and How Heart Attacks Are Caused

The phenomenon the Korean scientists were studying is something called reperfusion injury. This refers to the fact that after a blood clot causes a heart attack, it sooner or later breaks up. Heart cells that were deprived of oxygen during the heart attack go into a kind of resting mode. Breaking up a clot restores the flow of blood (assuming the heart attack was not fatal), and wakes up the resting cells.

Lots of changes take place in heart cells during a heart attack. I'm only going to address a few of them here. One of the changes that happens in individual cells in the heart muscle after a heart attack, at least in the cells that survive a heart attack, is a tremendous change in its sensitivity to oxygen. While the cell has been resting, it has been using its stored energy in a way that creates a chemical called hypoxanthine. This makes the cell very sensitive to oxygen, which is a good thing when the cell is oxygen-deprived.

But when oxygen supply is restored, some of the extra oxygen become free radicals. They damage DNA and set off a process called apoptosis. This "takes out" the cell because the DNA is read as dysfunctional. This is the reason the "attack" of  heart attack may not occur right after a blood clot is formed in a coronary artery. It may only occurs hours or days later.

That's not all. Restoring blood flow brings both red blood cells and white blood cells. One of the tasks of white blood cells is to remove damaged cells with inflammation. A white blood cell comes in with contact with a reawakening heart cell and destroys it by releasing inflammatory chemicals. These chemicals injure more than just the target cell. They can also take out healthy cells and cause swelling--which blocks off circulation again.

Curcumin seems to stop the inflammation that damages cells that survive the heart attack. This is undoubtedly a good thing. But you'd have to have the curcumin in your system before you have the heart attack and you'd have to have a sufficiently mild heart attack that most of your heart muscle was still functioning. But that isn't all curcumin can do.

Curcumin for the Diabetic Heart

Another area of curcumin research has been the relationship between blood sugar levels, insulin levels, blood pressure, heart rate, and heart health. It gets a little complicated, but the key relationships go something like this: Diabetics, as you probably know, often have high blood sugar levels.

In the early stages of type 2 diabetes, the pancreas tries to produce more insulin to lower blood sugar levels. The problem is that the insulin does not work because muscles, including the heart muscle, can't respond to insulin without risking cellular damage (that "burning out" thing again) so they become insulin resistant. The pancreas makes more and more insulin that is less and less effective.

This induces another set of changes that activate an enzyme called hormone-sensitive lipase. This enzyme locks fat inside fat cells to "force" the heart and other muscles to burn glucose (sugar) instead of fat.  Fatty acids build up in the bloodstream.

Blood vessels tighten. This makes them easier to block when a clot forms. And since the heart can't find a second source of fuel (it is resistant to insulin bringing in glucose and it is also blocked from burning fat) it slows down to a steady beat. It can't pump blood faster when needed to supply the brain. The tight blood vessels lead to greater risk of heart attack.

The loss of heart rate variability makes a heart attack much more damaging to the rest of the body. This is the reason diabetics are at greater risk of heart attacks and they are more likely to die of a heart attack if they have one. Some studies with laboratory animals indicate that curcumin and turmeric turn off the enzyme that keeps the heart from using fatty acids as a back-up fuel. Science really has not proved that curcumin or turmeric can do this in humans, but it is known that populations of people who eat lots of curry have fewer heart attacks and the heart dysfunction known as congestive heart failure.

How Much Curcumin Is Enough?

The short answer to how much curcumin is enough to produce a measurable difference in heart disease is "a lot." You don't need a whole field of turmeric, but about 20,000 mg a day and even as much as 30,000 mg a day would seem be to be most likely to be effective for most adults, or at least that is the implication of the laboratory studies.

But it's important to remember three things about translating the results of experiments with lab rats to people.

1. Humans and lab rats won't necessarily react to a supplement or a medication in exactly the same way.

2. Experiments are designed to get unquestionable results. They use a maximum dose rather than an optimal dose because otherwise the statistics won't come out right.

3. The supplement has to be absorbed into the bloodstream to make a difference.

Most makers of curcumin supplements add a compound called piperine to help make their products more absorbable. Piperine is extracted from black pepper.

The ancient sages of Ayurvedic medicine recognized centuries ago that black pepper made turmeric more effective. That same principle seems to apply to piperine (from black pepper) and curcumin (from turmeric).

Dr. Peter Liu of the Canadian Institutes of Health isn't recommending that people take curcumin prophylactically on the basis of his laboratory's research, but he found heart-protective benefits for lab rats (preventing scar tissue in the heart) from a dosage equivalent to 2,000 to 4,000 of mg per day for humans. There are no reports of side effects from that dosage, or even 10 times as much, but 2 to 4 curcumin capsules a day is probably heart-protective.

Is curcumin the same thing as turmeric? Actually, tumeric, the herb, is up to about 3% curcumin, the pigment and antioxidant. A tablespoon of curry powder a day probably gives you about 1,000 mg of curcumin.

But it's easier to buy a good quality product so you can know your dosage and eventually know what to expect in the way you feel after you take it.

Will curcumin prevent a heart attack? Nobody can say that yet. But there are many indications it just might help you survive one. It's just better to eat right, keep your blood pressure under control, and do what your doctor tells you is best. If you are destined to have a heart attack anyway, then it might be a good thing also to have taken your curcumin.

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