Nutrition facts vs fiction: What are your patients asking?

British Columbians can now call or e-mail Health Link BC’s Dietitian Services with any nutrition or food-related concerns. As part of the pro­vince’s Healthy Families BC program, BC dietitians are available to answer physicians’ questions and those from the public on topics such as baby nutrition, allergies, managing chronic conditions, healthy eating, and how to access local dietitians. Registered dietitians provide phone advice through the 8-1-1 service from 8 a.m. to 8 p.m., Monday to Thursday.

Below are the top 10 nutrition questions from patients to HealthLink BC this past summer and the evidence-based answers. Some useful links can be found at the end.

1. Should rice cereal be the first solid food introduced to infants? 
Not any longer. Iron-containing foods are recommended as the first foods, but meat and alternatives (including meat, fish, poultry, cooked egg, well-cooked legumes, and tofu) as well as iron-fortified cereal may also be introduced at this time. Iron from meat sources is better absorbed than iron from non-meat sources.

2. Is there a danger of infection using powdered infant formula?
Yes, but steps can be taken to decrease the risk of Enterobacter sakazakii (Cronobacter spp.) infection and illness. Bacteria such as this can be found in unopened cans of powdered formula. Formula concentrate and ready to feed are sterile until opened but are much more costly, so methods have been researched to minimize the risk with use of powder. The safest method is to use hot water (greater than 70 °C) to prepare powdered infant formula be­cause this kills bacteria that may cause illness. The next best method is using previously boiled and cooled water. 

This method does not kill the E. sakazakii bacteria that may be in the powdered infant formula; therefore, the baby must drink the formula immediately so the potential bacteria are not given a chance to grow. Health Canada has determined that either method should be safe for healthy full-term infants. Of course, breast is best.

3. We have allergies in my fam­ily. Should I delay introduction of nuts, milk, shellfish, and eggs to my baby? 
No. In the past, delaying the introduction of potentially allergenic foods was recommended to help reduce the risk of allergies. But current research suggests that delaying these foods for longer than 4 to 6 months does not prevent food allergies and may even make them more likely to occur. For health reasons other than the prevention of allergic conditions, Health Canada recommends waiting until 6 months of age before offering solid foods.

4. Is organic food more nutri­tious than non-organic food?
No. The vitamin and mineral content of organic food is not significantly different from conventionally grown foods. A systematic review of the health effects of organic foods, published in 2010, found limited evidence of nutrition-related health effects re­sulting from eating organic food as compared with conventionally produced foods.

5. Are there risks of pesticides in food in Canada? 
No. Pesticide use is regulated by Health Canada. All foods available in Canada have minimal or low pesticide residue, with some data showing little difference between organic and conventionally produced foods. 

In 2006/07, 99% of Canada’s homegrown fruits and vegetables and imported foods tested were well below Canada’s pesticide residue limits. In 90% of Canadian fruits and vegetables and 89% of imported foods tested, no residue was found. Washing all fruits and vegetables is always recommended to reduce pesticide contamination as well as other contaminants such as bacteria. 

6. Are there foods recommend­ed to avoid in pregnancy? 
Yes. During pregnancy, the immune system is suppressed, resulting in an increased risk of foodborne illnesses such as listeriosis, E. coli, and salmonella. Foods to avoid include: 
• Unpasteurized milk and (mostly) soft cheeses such as feta, brie, and blue.
• Undercooked meat, fish, shellfish, and eggs.
• Deli meat and hot dogs that have not been cooked.
Other foods and beverages consumed during pregnancy do not cause food poisoning but may still affect an unborn child. These include:
• Caffeine-containing beverages.
• High-mercury fish such as mackerel, swordfish, and tuna.

7. Is sodium really an issue?
Yes. Eating a low-sodium diet has been shown to help prevent high blood pressure, help keep bones strong, and may lower the risk for getting kidney stones. Increased blood pressure has been linked to several chronic diseases such as stroke, heart disease, and kidney disease. Aim to consume 1500 mg of sodium daily and to stay below the upper tolerable intake of 2300 mg per day.

8. Do we need supplements? If so, which ones, and when?
Most people do not need supplements. The majority of individuals over 2 years of age, at most stages of life, can meet their nutritional needs using Eating Well with Canada’s Food Guide to plan their meals. However, there are some exceptions:

• Women of child-bearing age should take a supplement of 400 micrograms of folic acid per day to help prevent neural tube defects such as spina bifida. This should be continued while pregnant and breastfeeding.
• Pregnant women should take a supplement containing 16 to 20 mg of iron per day as their iron levels are likely to be low. 
• Many older adults are not able to absorb vitamin B12 found naturally in food. All adults over the age of 50 years should meet their vitamin B12 requirement from supplements, fortified foods, or both.
• As we age we need more vitamin D, and it becomes difficult to absorb enough vitamin D from food. Adults over 50 years should take a supplement of 400 IU vitamin D per day in addition to following Canada’s Food Guide. Vitamin D recommendations are under scrutiny and may be in­creased in the future.

9. What are the differences between a wheat-free diet and a gluten-free diet?
A wheat-free diet includes no wheat products or ingredients. It is recommended for anyone with a diagnosed or suspected sensitivity to wheat. A gluten-free diet includes no wheat, barley, rye, or related grains (triticale, kamut, and spelt). It is followed by someone suspected of or diagnosed with celiac disease or gluten sensitivity. Reading food labels and ingredient lists is an essential part of knowing what foods are safe to eat on each of these diets.

10. Is it true that goat milk is a good alternative for children with a cow-milk allergy?
No. Children with a cow-milk allergy are also likely to be allergic to goat milk. The allergenic proteins in goat milk are similar in structure to those in cow milk, so the immune system is unlikely to be able to distinguish between them. Therefore, in general children with a cow-milk allergy should also avoid goat milk and goat milk products.
—Kathleen Cadenhead MD, FCFP
Chair, Nutrition Committee
—Barb Leslie, RD
—Joanna Drake, RD

Useful nutrition links

BCMA (Salt: Check your food facts)
www.bcma.org/files/Salt.pdf

Canadian Food Inspection Agency
www.healthycanadians.gc.ca/init/cons/food-aliments/index-eng.php

Health Canada Food Safety
www.healthycanadians.gc.ca/init/cons/food-aliments/index-eng.php

HealthLink BC Dietitian Services
www.healthlinkbc.ca/dietitian/ead/disclaimer.stm.

HealthLink BC File Topics
www.healthlinkbc.ca/healthfiles/httoc.stm

 

This article is the opinion of the Council on Health Promotion and has not been peer reviewed by the BCMJ Editorial Board.

Kathleen Cadenhead, MD, Barbara Leslie, RD,, Joanna Drake, RD,. Nutrition facts vs fiction: What are your patients asking?. BCMJ, Vol. 53, No. 53, October, 2011, Page(s) 434 - COHP.



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