Does Avoiding Milk & Other Dairy Products Reduce Cancer Risk?

I was raised to believe that drinking skim milk is good for my health. Growing up, everyone in my family had a glass of skim milk with dinner. When I heard that some people have cut milk and dairy from their diets to try to reduce their chance of getting cancer or to try to help stay in remission, I had to investigate!

When I started researching the topic, I found there were conflicting messages. For example, here is a quick summary of what clinical research suggests:

• Choosing lower fat foods, including dairy, may help to keep breast cancer from returning¹
• Eating and drinking dairy products with milk fat (M.F.) above 2% like cream, whole milk, condensed or evaporated milk, may be linked to higher risk of mortality after breast cancer diagnosis²
• Some cancer treatments increase the need for bone-building nutrients found in dairy products, including calcium and vitamin D³
• Vitamin D from food and supplements may have a protective effect against colorectal cancer^{4, 5}
• Calcium from food sources, including milk, appear to lower the risk of colorectal and bladder cancer⁶
• Limited evidence suggests that getting more than 1500 mg of calcium daily may increase the risk of developing prostate cancer⁷

No wonder people are confused!

Although the link between cancer and calcium, calcium supplements, and dairy has been highly researched, we need more research to understand how these factors are linked before we can make concrete recommendations. But after all my research, I feel confident drinking skim milk (or a fortified milk alternative!) with dinner each night. Here's why.

Are dairy products essential in our diet?

Eating foods from the ‘Milk & Alternatives’ food group gives us many beneficial nutrients for growth, including the bone-building powerhouses calcium and vitamin D. It is possible to meet your daily requirements for calcium and vitamin D solely through non-dairy foods. It is your choice if you wish to consume dairy, non-dairy, or a combination of these foods.

How much calcium and vitamin D do I need?

Adults between 19-50 years old need 1000 mg of calcium each day. This daily requirement increases to 1200 mg for women over 50, and for men over 70.

Daily vitamin D recommendations are 600 IU for Canadians between 9-70 years old, and increases to 800 IU for adults over 70, although levels up to 4000 IU are considered safe. See Health Canada’s website for further details, including their recommendations for children.

But note that your requirements may be different if you have certain health conditions, so it’s important to speak to a Registered Dietitian for more details.

How can I get the calcium and vitamin D I need?

The best way to ensure that you get enough of both calcium and vitamin D is to have 500 mL (two servings) each day of milk or fortified milk alternatives such as soy, cashew, almond, oat, or rice milks⁸. If you are over 50, aim for three servings a day. See Canada’s Food Guide for other serving recommendations.

Taking a calcium supplement is only recommended if you can’t meet your needs through diet alone⁸. A doctor or Registered Dietitian can help you determine if you need a supplement.

The following foods can help you meet your calcium requirements:

• +300 mg calcium: 50 g brick cheese, 3/4 cup plain yogurt, 1/3 cup tofu with calcium sulfate
• 200-300 mg calcium: 1/2 can salmon with bones or 6 pieces of sardines
• 100-200 mg calcium: 1/4 cup almonds, 1 cup baked or navy beans, 1 tbsp blackstrap molasses, 1/2 cup fortified orange juice
• 50-100 mg calcium: 1/2 cup cooked bok choy, 1 medium orange, 1 cup broccoli or kale, 4 oz cottage cheese

Egg yolks and fatty fish (like salmon, mackerel, trout, herring, and snapper) are natural sources of vitamin D. Other sources include supplements or fortified foods, like fortified margarine, fortified orange juice, or yogurts and cheeses made with fortified milk⁸. Exposing our skin to the sun provides us with some vitamin D, but adding a daily vitamin D supplement of 400 IU is beneficial and recommended for adults over age 50.

Tips for Choosing Dairy Products

If you eat and drink dairy products, choose products with lower percentages of milk fat (% M.F.). For example, buy 0% (skim) or 1% milk, cottage cheese or yogurt, or cheese with 20% or less M.F. A lower % M.F. means less calories and unhealthy saturated fat, but the amount of calcium and vitamin D stays the same⁸.

For more information, check out:

1. What you need to know about Vitamin D, EatRight Ontario. (2015)
2. Calcium Sources, EatRight Ontario. (2015)
3. Canada’s Food Guide, Health Canada (2008)

Reviewed by Christy Brissette MSc, RD