Calcium Associated with Reduced Risk of Digestive Cancers

A new study suggests that calcium may help reduce the risk of digestive cancers in older adults.

Calcium is needed for muscle contraction, blood vessel constriction and relaxation, the secretion of hormones and enzymes and nervous system signaling. The recommended dietary allowance (RDA) in adults is 1,000 milligrams.

The authors analyzed data from nearly 500,000 adults aged 50-71 who participated in the National Institutes of Health (NIH)-AARP Diet and Health Study. The participants filled out questionnaires about their food and supplement intake. During the seven-year follow-up period, cancer rates were linked through state cancer registries.

By the end of the study, 36,965 men and 16,605 women developed cancer. The authors found that calcium intake was associated with a reduced risk of digestive cancers in both men and women. On average, men who consumed up to 1,300 milligrams of calcium daily had a 16 percent reduced risk and women had a 23 percent reduced risk of developing digestive cancers compared to those who consumed the least amount.

Calcium also reduced the risk of developing all types of cancer in women. However, this effect was not observed in men.

Additional research is needed to conclusively determine if calcium helps prevent cancer.

For more information about calcium, please visit Natural Standard’s Foods, Herbs & Supplements database.

Comments

[liz]

There are risks associated with taking too much calcium, such as kidney stones in those prone to them, arrythmias, etc. So "mega" dosing is not recommended. All types of calcium provide the same results in your body -- whether from oyster shells or other sources. Calcium is calcium. I get asked these questions often in the pharmacy, so thought this would help.

[Kelly Anne]

I think it is interesting that calcium was found to lower the risk of developing all types of cancer in women. Women are urged to increase their calcium intake to avoid osteoporosis, and it is great that in doing so, the risk of developing cancer is also reduced.

[Gary Sana]

It would be interesting to see what else other than dairy was included in the diets of these individuals. Although increasing your calcium intake is beneficial, seven years is a long time, and I'm pretty sure that other factors pertaining to diet and exercise played a role in the reduced risk of developing cancer.

[Shaily M.]

I hear that dairy can be fattening. What are some low-fat alternatives to dairy that still provide the necessary calcium for our bodies? Is soy milk a good source of calcium?

[stacy roberts]

The whopping sample size of this study is impressive and bodes well for reliability, I would think, except that I heard on NPR that the participants were all AARP members. Their journalist commented that this might skew results due to the fact that these folks tend to be healthier and financially more stable than the aging population at large.

I’d like to know how these participants got their calcium. supplements. From food sources, such as milk and other dairy products that are high in calcium? And does it make a difference to the body how the nutrient is delivered?

Seems like good advice for adults to heed, especially since it’s well confirmed that calcium is very important for bone health as well.

I heard about another study recently that indicated that the frequency of bone fractures in children is way up because children today don’t get enough calcium. So it may be important for parents to know this news, too!

[Marty]

This is an interesting study, as it does not assess the role of vitamin D in calcium's efficacy. It is my understanding that calcium cannot ensue its numerous roles in the body without vitamin D. For this reason, many researchers have begun to emphasize the importance of both nutrients for maximizing protection against cancer. It is great to know that calcium plays a protective role against digestive cancers, but it has also been established that the vitamin plays an enormous protective role against colorectal and pancreatic cancers. It would be an interesting study to compare both nutrients together.

[ET]

Does anyone know the correlation between bone density and rates of cancer for women? While this study looked at calcium supplementation, this information does not actually tell us how much calcium is actually in the body, whether it be in bones or bloodstream.

n addition, one limitation that I question is the method of collecting data. Filling out questionnaires over a seven-year period may be difficult to pinpoint a true cause/effect relationship. However, I still firmly believe that calcium supplementation is very important (if needed), even if its only use is for healthy bones.

[Leighton]

Shaily,

Soy milk does contain calcium and there are also soy milk brands that are fortified with calcium. Your concern with dairy products being fattening may be true if you are looking at the regular or heavy products. There is much benefit from drinking skim milk and eating low-fat yogurt and cheese. Getting important vitamins and minerals from the diet is often easier and less expensive than taking supplements, so don't give up!

[Reyna]

What interesting results! There are a few parts of the study design that may have influenced the results, but overall, I was impressed by the number of participants and length of follow-up period. As mentioned by Gary, seven years is a significant amount of time for these participants to have developed other healthy habits or changed lifestyle decisions. Depending on the specifics of the questionnaires, the participants would have been documenting all these changes throughout the course of the study. The statistical analyses should have taken some of these things into account during the evaluation, so it is probably safe to say that these results were truly significant. Just another great reason to be well-balanced and healthy!

[Trinity]

The authors mention that "calcium also reduced the risk of developing all types of cancer in women. However, this effect was not observed in men." It might be more helpful if the study states what types of cancers these are. There might be a correlation, genetically speaking.

Anyway, the study is encouraging overall -- one more reason to increase calcium intake in people's daily diets. And in response to someone's comment regarding high-fat content in dairy -- we can use low-fat and zero-fat dairy foods daily. It provides the required calcium and reduced unwanted fat content/calories.

[JO]

Are there any added health benefits between "regular" milk and organic milk? From what I understand, many people dislike the taste of skim milk, yet at the same time, I've heard that organic milk that contains less fat and tastes pretty similar to "regular" milk. Any comments?

[Cherry]

Jo,

Organic milk is just milk that comes from cows that are fed less or no hormones. In terms of the fat content and taste, it all depends on your liking. I myself prefer 2% milk; I find 1% milk a little too watery.

[AJ]

I agree with Liz above. If this information was given to the public without any parameters of how much calcium they can consume, it may cause people to think "more is better" since it helps with bones and now maybe with cancer prevention. More is not better! Always advise your patients on how much they should consume.

[YB]

What are the risks of over-consumption of dietary calcium supplementation? I am unaware of the fact that drinking three glasses of milk every day may have adverse effects on my health!

[jill payne]

There are other sources of calcium besides dairy. Peas, baked beans, even oranges, collard greens, kale, canned salmon and sardines all can provide calcium as well the added benefit of increased dietary fiber or fish oil.

[Ian M.]

I read an interesting theory that states that cancer is caused by a lack of free oxygen, and because calcium can eliminate acid that robs the body of oxygen, this may diminish cancer risk. What do you guys think about this theory?

[Suzie]

I actually read a story about a doctor (Dr. Carl Reich) who cured thousands of people, but eventually lost his license because he explained that consumption of mineral nutrients (like calcium) could prevent cancer. This was in the 1980s, and I think we’ve come a long way since then.

[Charles Leighton]

The benefits of calcium supplementation have been known for some time, just not in the realm of cancer prophylaxis. Calcium is responsible for muscle contractions, which one can only assume aids in the peristaltic actions of the digestive system. A more active and efficient digestive system would leave less toxic metabolites and digestive “gunk” building up within the digestive tract. Older adults should be taking calcium anyways, especially women for the prevention of osteoporosis. Unfortunately, the average person does not get enough calcium in their diets and supplementation is often recommended. Now there is even more reasoning to do so.

[Mike]

Calcium is the most abundant mineral in our body, and it is needed to help the body perform various daily tasks. Bones and teeth are two major sites that store more than 99% of total body’s calcium, while the remaining calcium is in muscles, blood and intracellular fluids.

Calcium is important for muscle contraction, blood vessels constriction and relaxation, nervous system signaling and the secretion of enzyme and hormones.

According to the Natural Standard monograph calcium has a grade of C for the stomach cancer, and that means that their is unclear scientific evidence for the use of calcium to reduce the risk of digestive cancers.

[Nathan]

Being a dairy fan, the correlation between calcium and reduced digestive cancer risk is an added bonus for me when I consume dairy foods. However, I would think the exact opposite would occur. Dairy products contain a lot of calcium and I thought they were also fat-containing foods. Wouldn't increased consumption of fat-containing foods like this lead to a higher risk of diseases and cancer?