Colon cancer is the second leading cause of cancer death when you combine the statistics for men and women. Studies in the Journal of the National Cancer Institute suggest that 70-90% of colon cancer cases can be prevented through prudent dietary and lifestyle practices. One of the factors that appear to be linked to colon cancer prevention is the optimal intake of calcium from day to day. 

In fact, over the past 25 to 30 years, studies have suggested that calcium may confer protection against colorectal cancer. Animal studies have shown this effect, and many population studies (epidemiological studies) have shown a strong correlation between higher calcium intake and lower incidence of colorectal cancer.

What does meta-analysis reveal on calcium intake and colon cancer prevention ? 

A meta-analysis published in 2014 in the International Journal of Cancer has provided additional evidence that higher calcium intake, including calcium supplements, is associated with a significant reduction in risk of colorectal cancer. The meta-analysis combined the data from 15 various human studies. 

The data showed that for every 300 mg increase in calcium from supplements there was an associated 9% reduction in risk of colorectal cancer and that for every 300 mg increase in total calcium (combination of food and supplements) there was an associated reduction in risk of 8%. This means that a calcium intake of 1200 mg per day, which is what you should be shooting for to optimize bone density and prevent osteoporosis), is also associated with colon cancer prevention by 32-36%. That is a significant reduction in risk. Unfortunately, most people have a calcium intake that is much lower than that (500-800 mg per day).

How does calcium reduce colon cancer risk?

So, the take-home message appears to be to ensure that you are getting sufficient calcium-rich foods each day. And if necessary, use a supplement containing additional calcium and vitamin D. Vitamin D works with calcium for support but is also linked to colon cancer prevention.

I’ve included a list of healthy, calcium containing foods below, showing that number of milligrams of calcium available in a standard serving size. I think you’ll find it to be a good reference.

I also included the scientific reference below for the meta-analysis study.

Sources of Calcium From Common Healthy Foods

Food	Portion Size	Amount of Calcium (mg)
Low Fat Yogurt	1 cup	415
Low Fat Milk (nonfat,1%)	I cup	300
Low Fat Cottage Cheese	½ cup	75
Sardines with bones	3 oz	370
Salmon with bones (canned)	3 oz	165
Processed Tofu with calcium sulfate	4 oz	145
Canned Shrimp	3 oz	100
Cooked Lentils	1 cup	75
Chicken Breast	3 oz	10
Tuna	3 oz	5
Collard Greens	½ cup	180
Spinach	½ cup	85
Stalk of Broccoli	1 medium	70
Orange	I medium	55
Green Beans	½ cup	30
Lettuce	½ head	15
Orange Juice	½ cup	10
Apple	1 medium	10
Whole Wheat Bread	1 slice	20
Cooked Spaghetti	1 cup	15
Cooked Rice	½ cup	10
Apricots, raw, dried	4-6 halves	24
Dates	3-4	22
Figs Canned	3	35
Figs Dried	2	56
Grapefruit	I medium	40
Prunes, dried raw	5	27
Raisins	¼ cup	31
Raspberries	2/3 cup	40
Strawberries	1 cup	42
Roasted Almonds	1 oz	80
Kale	½ cup	47
Baked Beans	½ cup	78
White Beans	½ cup	96
Dry-roasted soybean nuts	½ cup	232

 Reference:

1. Keum N, Aune D, Greenwood D.C., Ju W, Giovannucci E.L. Calcium intake and colorectal cancer risk: Dose-response meta-analysis of prospective observational studies. International J Cancer (2014) 135 (8): 1940-1948)

Eat Smart, Live Well, Look Great!

Dr. James Meschino