Wednesday, January 19, 2011

Calcium Supplements: Do they really increase the risk of heart attacks?

According to a recent study, calcium supplements increase the risk of heart disease. The report appeared in the British Journal of Medicine.

This has put the medical community into a tizzy. Some practitioners have already taken patients off calcium supplements, while other practitioners have criticized the research and are cautious about believing it. I don’t feel like there is enough data to say for sure if it is correct or not. However, I do feel it is best to get our nutrients from food and herbs and turn to supplements only when this is not working for us. If we are getting enough calcium in our diets, we not only don't need to take calcium supplements but it may be harmful to do so according to this meta-analysis. It does make sense that calcium supplementation above what our body needs may be harmful.

Lets take a look at this research.

This study was a meta-analysis of other studies. It has been criticized on a variety of levels. The criticisms have been as follows.

• Ingesting calcium carbonate can simulate “heart attack” (This is explained below.)

• In an editorial accompanying the article, Dr John Cleland (Castle Hill Hospital, Kingston upon Hull, UK) and colleagues wonder why calcium supplements should increase cardiovascular risk, as found in this meta-analysis. "Accumulation of calcium in the arterial wall leading to reduced compliance would be expected to take years, but the increased risk of myocardial infarction reported by Bolland and colleagues occurred early after calcium supplementation (median follow-up of 3.6 years)."

• The researchers only examined cases where people were given calcium by itself and not with other vitamins and minerals that are usually given at the same time.

• Dr John Schindler (University of Pittsburgh Medical Center, PA)  pointed out that the real risk of heart attack appeared to be in people who took calcium supplements on top of high levels of dietary calcium. "I think the safest thing to tell your patients right now is if you can get your dietary calcium from good dietary sources, such as yogurt, sardines, and skim milk, that potentially might be all you need to ward off the risk of osteoporosis. Then we don't have to deal with this increased cardiovascular risk."

• Schindler noted the absence in the meta-analysis of the Women's Health Initiative, a large study that looked at the role of calcium supplementation with vitamin D in reducing osteoporotic fracture. "There are a lot of data that show that vitamin D is protective from a cardiovascular standpoint. They excluded studies with vitamin D probably because they are trying to isolate one variable. They didn't want to cloud the picture."

It is not conclusive that calcium taken by itself as a supplement may increase a persons risk of heart attacks. More research needs to be done. However, it does make us question the use of calcium supplements by themselves. There is research showing that calcium in the form of food does not do this. If we assume this meta-analysis is correct, we would then want to know more.
For instance:

• Is supplemental calcium only conducive to heart attacks when the diet already provides adequate or even excessive calcium and we are ingesting more calcium than we need in the form of a supplement?

• Is supplemental calcium taken in conjunction with other supplements conducive to heart attacks or do other minerals and vitamins taken in conjunction with calcium as usually suggested by alternative practitioners act protectively?

• Is one particular type of calcium supplement more problematic than others?

• It appears there may be a difference in how women and men react to supplemental calcium. Is this true?

More research needs to be done. This is definitely not conclusive research but it does make you question the safety of calcium supplements when given alone. It especially questions their safety when our diet is already providing adequate calcium.

It is always best to get our nutrients from food and herbs, which supply a full spectrum of nutrients in just the amount that spirit intended. It is important to note another Swedish investigation with men looking at their dietary calcium consumption showed the top dietary calcium consumers had a 25 percent lower risk of dying from any cause and a 23 percent lower risk of dying from heart disease.

There is a new Swedish research study starting soon that will examine various types of calcium supplements to see how they compare to each other. Perhaps it will shed new light on the subject.  It will be a few years before the research is available.

The most common form of calcium people take is calcium carbonate because it is inexpensive. However, it is not a form that most alternative practitioners that I know usually give to their patients for the following reasons.

• Calcium carbonate ingestion can cause indigestion. Calcium carbonate decreases stomach acid. When people don’t have enough acid in their stomach it leads to poor digestion. (Protein has to have an acidic environment for digestion to start.) With the stomach contents not moving forward appropriately, it can lead to reflux of the stomach contents into the esophagus. (The tube going from mouth to stomach.) Stomach contents are not meant to be in the sensitive esophagus.  Even this lowered amount of acid will burn their esophagus and cause pain. This leads the person to believe they have too much acid when in fact they really don’t have enough in their stomach. Sometimes they will take Tums (calcium carbonate) to lower the acid even more in their stomach, as they don’t understand what is going on. This creates a continual cycle of ill digestion and gastric reflux.
There was a note accompanying the meta-analysis in question that relates to this gastric reflux that can happen. Dr John Cleland and colleagues wrote an editorial accompanying the research suggesting that the increased risk of heart attacks may not be a true effect, because the increased risk of heart attacks was not accompanied by an increase in mortality. "Calcium supplements could simply be causing gastrointestinal symptoms that could be misdiagnosed as cardiac chest pain.” Indeed gastric reflux and some other types of digestive symptoms can mimic heart attacks.

•  Calcium carbonate may be poorly absorbed. Here is why. If the stomach produces too little stomach acid (hydrochloric acid), calcium remains insoluble and cannot be ionized, which is necessary for it to be assimilated in the intestines. Remember, calcium carbonate decreases stomach acidity itself, therefore it decreases calcium ionization and absorption. So even though the person is eating calcium, they are decreasing the absorption of it when they take it in the form of calcium carbonate. This is especially true as we get older and have decreased acid production in our stomachs. These people should  consider taking a calcium which is absorbed better such as calcium citrate.
It is also important to note that calcium taken for bone growth and to prevent osteoporosis should be taken with other nutrients such as vitamin D3, vitamin K2, magnesium, zinc, selenium, copper, manganese, boron, silica and vitamins B2, B6 and folate.
I do believe diet is the best way to get our calcium. Lets look at how we can get calcium in diet and from herbs.
You should be able to get enough calcium from your diet if eating lots of dairy or dark green leafy veggies If you are not getting enough and don’t want to take a supplement what can you do? Eat herbs. We know that kale has a lot of calcium in it, but did you know that nettle and red raspberry leaf both have more? These are both herbs that are healthy to eat in our diet. I will put out a blog about stinging nettle soon so you know how to collect and prepare it. It is a very nutritious plant.

Herbs can be mixed in with our meals or taken as teas.

Consider using a variety of herbal teas that are all high in calcium. Simply make sure you infuse them overnight or decoct them 25 minutes. (Infusing overnight gives a more pleasant drink.) In the past I have sent samples of nettle tea decocted with boiling water for 25 minutes compared to nettle tea that has infused overnight to a lab. The results showed they have almost the exact same amount of calcium extracted. Teas to consider are oat straw, nettle, raspberry, and dandelion root. Horsetail also has very high calcium as well as silica but chronic ingestion of it can decrease the level of thiamin due to thiaminase content. Therefore this is an herb you should not take on a continual basis or you should supplement with thiamin or eat thiamin rich foods/herbs if you are. You can find a comparison of some of these herbs with spinach and kale to see how much calcium each contains by clicking on Nutrient Comparison in herbs & food pdf:

Something to know about calcium absorption: A number of factors affect calcium absorption in the gut. Absorption is greatest when the intake of calcium is low and the need is high. Vitamin D levels, an acidic environment in the stomach, age, estrogen levels, and dietary fiber intake all play a role in calcium absorption. Calcium absorption decreases with age, low vitamin D levels, low stomach acid levels, low estrogen levels, and a high-fiber diet.

The actual meta-analysis is here:

New research shows calcium in food might do more to protect bones than supplemental calcium in pill form.

Getting a bit more calcium in your diet could help you live longer, new research suggests.