PEN eNews 13(1) January 2023 - Welcome to 2023!

What is the Latest on Prebiotics, Probiotics, Synbiotics and Osteoporosis?

What is the role of pre-, pro- or synbiotics in the maintenance of bone health and prevention or treatment of osteoporosis?

Recommendation

Although probiotic, prebiotic and/or synbiotic supplementation has been shown to improve some biochemical markers of bone health (e.g. serum calcium), they have largely been shown to have no effect on bone mineral density at various sites. More evidence is necessary to elucidate the relationship between probiotic, prebiotic and/or synbiotic supplements and bone health. 

Evidence Summary

A 2021 systematic review and meta-analysis of 44 experimental trials concluded that probiotic supplementation may affect biochemical markers of bone health such as serum calcium, urinary calcium and parathyroid hormone (PTH) but not bone mineral density (BMD) at the spine or hip. 

A 2019 systematic review of eight RCTs concluded that prebiotic, probiotic or synbiotic supplementation did not appear to affect overall bone health, although it did significantly increase serum calcium. 

A 2021 systematic review and meta-analysis of 10 RCTs concluded that probiotic supplementation may improve lumbar BMD in adults with osteopenia or osteoporosis, but more evidence is necessary to confirm this effect. 

Grade of Evidence C

To see the full practice question, including the Evidence Statements, Comments, Rationale and References, click here.

Check Out the other new and updated practice question in the Bone Health and Osteoporosis Knowledge Pathway:

• Should individuals with osteoporosis be screened for chronic gastrointestinal diseases (e.g. Crohn’s disease, ulcerative colitis, irritable bowel syndrome, celiac disease)?
• What are the effects of lower carbohydrate/higher protein diets (LCDs) on bone health among adults?
• Does the consumption of coffee or tea affect bone health or risk of osteoporosis?
• Is the consumption of alcohol detrimental to bone health and osteoporosis?
• Does the consumption of soft drinks impact bone health?
• What are the recommendations for calcium and vitamin D intake for the prevention and treatment of osteoporosis?
• What type of vitamin D supplement is the most effective and in what dose for osteoporosis prevention?
• Besides calcium and vitamin D, are dietary supplements or nutraceuticals recommended for the prevention and/or treatment of osteoporosis?

Blood Pressure and Dietary Patterns – Are You in the Know?

What dietary patterns may affect blood pressure in individuals with or at risk for hypertension?

Recommendation

Adults with and without Hypertension
Evidence, with at least moderate certainty, suggests the following dietary patterns result in a potential clinically meaningful (≥5 mmHg) lowering effect on blood pressure reductions in adults, with and without hypertension:

• DASH diet
• Nordic diet
• Low sodium/salt diets.

Evidence, with at least moderate certainty, suggests the following dietary patterns have a lowering effect on blood pressure in adults, with and without hypertension, yet these reductions may not be clinically meaningful as the change observed was <5 mmHg:

• Mediterranean diet 
• Portfolio dietary pattern 
• Plant-based dietary patterns
• Pulse dietary pattern (systolic only)
• Low glycemic index (GI) diet (high confidence) (diastolic only).

Low certainty and/or inconsistent evidence suggests the following dietary patterns result in a potential clinically meaningful (≥5 mmHg) lowering effect on blood pressure reductions in adults, with and without hypertension:

• Lacto-ovo vegetarian diet.

Evidence, with low certainty and/or was inconsistent, suggests the following dietary patterns have a lowering effect on blood pressure in adults, with and without hypertension, yet these reductions may not be clinically meaningful as the change observed was <5 mmHg:

• Paleolithic diet

• Vegetarian diets (including lacto vegetarian and pescatarian)
• Low glycemic index (GI) diet (systolic only)
• Low carbohydrate diets
• Low fat diets
• Weight loss dietary patterns.

No effect on blood pressure was observed in adults with and without hypertension for the following dietary patterns:

• High protein diets
• Vegan diet
• High fibre diets.

Adults with Hypertension 
In adults with hypertension, there is limited moderate and low certainty evidence for a potential clinically meaningful (≥5 mmHg) blood pressure reduction for the following dietary pattern:

• DASH diet.

In adults with hypertension, there is limited moderate and low certainty evidence for blood pressure reduction that may not be clinically meaningful (<5 mmHg) for the following dietary pattern:

• Weight loss dietary patterns.

Among the assessed dietary patterns, the DASH diet was associated with the greatest overall consistent reduction in blood pressure. Adherence to the Nordic, Mediterranean and Portfolio dietary patterns also significantly decreased systolic and diastolic blood pressure levels. This may be due to shared common dietary attributes with all being rich in fruit and vegetables, whole grains, legumes, seeds, nuts, fish and dairy products with low levels of processed meats, saturated fats, refined carbohydrates and sweet foods. Low salt/sodium diets have a blood pressure-lowering effect in most meta-analyses, with the greatest effect found for Afro-Caribbean and Asian populations with hypertension.    

Evidence was inconsistent or limited for the efficacy of blood pressure-lowering using the vegetarian, Paleolithic, low glycemic index, low carbohydrate, low fat diets and weight loss dietary patterns, and available evidence showed no blood pressure-lowering effect using a high protein or vegan dietary pattern.  

International and Country-specific Guidelines
Hypertension guidelines, including those from the International Society of Hypertension, Australia, Canada, the United Kingdom, Europe and the United States, recommend following a healthy dietary pattern for the prevention and management of hypertension, which generally emphasizes vegetables, fruit and whole grain foods, with the DASH diet being the most noted dietary pattern.

To see the full practice question, including the Evidence Summary, Grades of Evidence, Evidence Statements, Remarks, Comments and References, click here. 

Looking for more cardiovascular disease (CVD) content? The PEN System has:

• 5 CVD Knowledge Pathways
• 136 CVD Practice Questions
• 68 CVD Handouts.

Enter “Cardiovascular” in the PEN Search and check out the results!

Knowledge Pathway Alert: Allergic Disease - Low Risk Infant

The Allergic Disease – Low Risk Infant Knowledge Pathway has been updated. Check out these updated practice questions:

Among healthy term infants without parental history of allergy, does exclusive breastfeeding for either three or six months reduce the incidence of allergy?

Among healthy term infants under the age of six months of age without parental history of allergy, does feeding cow's milk-based infant formula increase the risk of developing food allergies?

Among preterm infants under the age of six months (adjusted) without parental history of allergy, does feeding cow's milk-based infant formula increase the risk of developing food allergy compared to human milk (with or without fortification)?

Among low birth weight infants without parental history of allergy, does feeding cow's milk-based infant formula when compared to exclusive breastfeeding increase the risk of developing allergic disease?

Among infants under the age of six months of age without parental history of allergy, does feeding a hydrolyzed formula decrease the risk of developing allergic disease as compared to feeding a cow's milk-based infant formula?

Among infants under the age of six months, without parental history of allergy, does feeding soy protein-based infant formula decrease the risk of developing allergic disease compared to feeding breastmilk or cow's milk-based infant formula?

Among healthy term infants at low risk of developing food allergy, does delaying the introduction of common allergenic foods (cow's milk, egg, peanut, tree nuts, wheat, soy, seafood) until after six months of age or later decrease the risk of developing food allergies? 

Sign up for PEN Content Alerts to find out when new and updated content is added.

We want to share a fantastic opportunity to help shape PEN content to ensure it is relevant to dietitians in everyday food and nutrition practice.

Are you a researcher or practitioner who specializes in Media Skills or Cannabis? The following PEN knowledge pathways are being updated:

• Media Skills*
• Cannabis and Nutritional Health.

*We are specifically looking for input from dietitians practicing in Australia and the United Kingdom.

Contact the PEN Content Manager (coordinator@pennutrition.com) to learn how you can contribute.

When developing new or updating existing PEN content, we look for input on practice questions that make up a knowledge pathway. Specifically, this will look like:

• Providing input on the existing practice questions that reflect the everyday practice situations faced by dietitians in the specific topic area.  
• Providing direction on any practice guidelines, national policy documents or reports that would be important for authors to include in their work.
• Recommending reviewers for content review once it's been written.

This is a 1:1 request. Meaning it's a one-time request that requires about one hour of your time (you are not committing to writing or reviewing content). 

With your permission, you will be acknowledged for your role as a Topic Advisor. You can also download a letter of contribution signed by PEN's Director of Knowledge Translation acknowledging your contributions to the PEN System once the content is published.

Are you interested? That’s great! Reach out to our PEN Content Manager (elizabeth.manafo@dietitians.ca) by January 31st, 2023. Your input will be required by late February.

2022 Year in Review

Happy New Year! Have a look at all this small but mighty team has accomplished in 2022.  

The PEN Team has been busy this year. You can review the previous year's infographics on the PEN Website.