Did you know that drinking kombucha could help protect against heart attack?
Well, now you do. 🙂
Today’s research article demonstrates that, in rats at least, a daily dose of kombucha leads to higher HDL cholesterol (the good kind), lower triglycerides, and a better outcome if a heart attack does happen.
Everyone in the modern world is aware of what a big deal heart attacks are. According to the New Zealand Ministry of Health data, Cardiovascular disease is the number one cause of death in New Zealand, causing 30% of all deaths each year, and you can be sure that those numbers are very similar in other countries. And even though heart disease is thought to mostly be a man’s problem, it is also, according to the WHO, the number one killer of women around the world.
The kombucha research article we’re looking at today is by Lobo and Shenoy, two researchers based in Mangalore, India.
Myocardial potency of Bio-tea against Isoproterenol induced myocardial damage in rats, found in J Food Sci Technol (July 2015)52(7):4491-4498
This research paper looks into how a daily dose of kombucha protected lab rats from heart attacks.
But before we get into the nitty gritty of the paper, we’ll back up a bit and look at heart disease in general, so that we have a handle on what the researchers were measuring, why they were looking at these factors, and what that says about the effect that kombucha had.
Note: In this article I’ll use the term ‘heart attack’, because it is commonly used and understood by the majority of us. When I use it, I am generally talking about what doctors call an ‘acute myocardial infarction’.
So, what’s the story then? How can we lower our risk of heart disease? And if, heaven forbid, we actually have a heart attack, how can we maximize our chances of surviving it well? And what does kombucha have to do with it all?
Risk factors for heart disease
Biochemically speaking, there are two main measurements that a doctor will make to assess your risk for heart disease – your cholesterol levels and your triglyceride levels. These two measurements will tell her a few things about what is going on in your body. It can be a fairly complicated picture, but we’ll keep it very simple here.
Basically, if you have a high level of HDL compared to LDL that is good, and if you have a low amount of triglycerides that is also good. On the other hand, if you have low HDL and high triglycerides, that is bad. There are a few other things that your doc would look at, too – your total cholesterol count, your blood pressure and resting heart rate would go into the mix, and she might run a test on how well your body is processing sugar, as there is a relationship between pre-diabetes and heart health.
But I said we’d keep it simple, so for this blog post, just keep in mind that if you have high HDL and low triglycerides, then you probably have good heart health, and vice versa.
What if I actually have a heart attack?
In short, the more damaged your heart is by the attack, the worse your prospects.
Once a person actually has a heart attack, there are a whole different set of blood tests and examinations that the doctors will do to evaluate how bad the heart attack was, what the likely cause of it was – was it a blocked artery? was it electrical/neural issues? etc – and what they should do from there.
Factors that they look for include:
- Is the heart physically swollen and enlarged? (cardiac hypertrophy) Just like other muscles, when your heart is damaged it can have swelling.
- How high is your blood glucose level? (high glucose at admission to hospital is common with heart attacks)
- Presence of a range of enzymes, known as cardiac markers, in your blood. These enzymes usually live in the muscle cells of your heart. When they are present in high numbers in your blood, that means the tissue of your heart has been damaged.
So basically, your heart is a muscle, and if it gets too badly damaged it stops working. The fitter and healthier your heart is, the more likely it is to stay okay after an injury, and the faster it will recover from it.
The tests that the hospital runs when you arrive there with heart attack symptoms are to a) check that it is actually a heart attack, and b) to find out how badly damaged your heart is.
The TLDR so far:
In order to reduce heart attack risk, you want to do things which reduce your triglycerides and increase your HDL.
If you have a heart attack, you’re most likely to heal quickly and well if your heart isn’t too swollen, you don’t have high blood glucose, and you have low levels of those cardiac marker enzymes in your blood, because that means your heart isn’t too badly damaged.
Back to the kombucha research paper.
This Indian research group wanted to find out what effect kombucha would have on heart risk factors, like cholesterol and triglyceride levels. And they also wanted to see if there was any impact on how well a heart coped with a heart attack.
Warning: this research, like a lot of biomedical research, involves the use of animals. The research was conducted according to accepted guidelines, and approved by the International Animal Ethics Committee of Mangalore University. It was also designed to use a minimal number of animals while still being statistically useful. There are no pictures, and I don’t go into details, but if you’d still rather skip over reading about the research itself, scroll down to the What They Found section, below.
Still with me?
Okay. Because you can’t conduct experimental research on human hearts, the researchers chose an animal model for studying heart attacks. They used a well established rat model. Basically, you take healthy rats, inject them with a chemical called Isoproterenol (ISO), and they have a heart attack that is very similar to a human Myocardial Infarction. Like all animal models of human disease it has its limitations (it only mimics certain types of heart injury seen in humans), but it is widely used in heart research in combination with other models.
The researchers took 24 rats and divided them into 4 groups:
- normal control rats
- heart attack control rats
- tea pre-treat then heart attack rats
- kombucha pre-treat then heart attack rats.
They included a group that just drank tea to account for any effects that might be due to plain tea on top of the ordinary rat diet, and not due to any of the fermented products in kombucha.
They kept the rats in identical conditions for 30 days. The tea and kombucha groups were given a dose of the relevant beverage each day equivalent to a human drinking about half a cup.
On day 29, the first dose of ISO was given, and 24 hours later a second dose was given and the animals were euthanized and examined.
The researchers performed blood tests to check the following:
- Serum glucose
- Total protein
- Serum albumin
- Total cholesterol
- HDL cholesterol
- Cardiac marker enzymes
They also physically examined the rats’ hearts, testing their weights to see if they were swollen and if so by how much.
What they found:
What they found was that kombucha provided a significant protective effect against heart attack. Drinking tea did provide some protection, but kombucha was significantly better than tea.
The rats that had been fed kombucha had the highest HDL levels and lowest triglycerides, so they had the healthiest looking hearts according to the standard ‘heart health’ measures, like we discussed near the start.
The kombucha-drinking rats also had hearts that survived the heart attack challenge much better than the other rats. Their hearts were significantly less swollen and heavy than the heart-attack hearts, and they had fewer cardiac markers in their blood stream, indicating that the heart muscle itself was not as badly damaged as in the rats that had been drinking tea, or those on an ordinary rat diet.
The kombucha rats also had the lowest blood glucose level of the 4 groups.
These are all results that would make your doctor pretty happy.
The researchers speculated that the reason for this result is due to a family of flavenoid antioxidants found in kombucha called Gallocatechins. Gallocatechins have been shown to lower cholesterol in other studies.
Now, it is important to remember that a rat is not a human, and it’s unlikely that we’d see exactly the same results to the same degree in humans. There’s no way to know if the kombucha effect would be stronger or weaker, and more research needs to be done, especially to see if similar results are seen when a different model of heart attack is used.
But all the same, this paper is very very good news.
What can we take away from this research?
The concluding paragraph of the research paper says it all, really:
“Kombucha can be recommended for consumption by people suffering from cardiovascular diseases as well as by healthy individuals, on a daily basis.”
Can’t get much better than that.
Remember: I am not a doctor and this blog does not constitute medical advice in any way. Please see your health professional for medical advice.