New Guidelines on the Risk Reduction of Cognitive Decline and Dementia
The World Health Organization (WHO) has released new evidence-based guidelines, Risk Reduction of Cognitive Decline and Dementia, developed using the GRADE process. The nutrition section includes conditional recommendations for the Mediterranean diet and a healthy, balanced diet to reduce the risk of cognitive decline and/or dementia; and a strong recommendation not to use supplemental polyunsaturated fatty acids, vitamins B and E and/or a multi-complex supplement for reducing the risk of cognitive decline and/or dementia.
The release of these guidelines is timely as the PEN Team is in the early stages of updating the Mental Health - Dementia Knowledge Pathway. Watch for updates in the near future.
Medically-Tailored Home Meal Program Associated with Reduced Inpatient Admissions and Health Care Costs
“Is participating in a medically tailored meal delivery program for medically and socially complex adults associated with fewer inpatient admissions?” (1). The cohort study published in JAMA examining this question looked at weekly home delivery of 10 free ready-to-eat medically-tailored meals (MTMs) (median duration of MTMs was nine months) to 499 individuals who were independently living and had a medical condition (such as heart disease or diabetes). A registered dietitian determined the appropriate diet and meals based on the individual’s health condition(s) as identified by the referring health provider. The authors compared health care use/inpatient admissions (primary data), admission to a skilled nursing facility and health care costs (secondary outcomes) with 521 non-meal recipients who were matched to the recipients (mean [SD] age, 52.7 [14.5] years; 568 [55.7%] female) based on demographics, disease states and neighborhood characteristics. The authors found that those who received MTMs were less likely to have hospital and skilled nursing facility admissions resulting in less overall health care costs.
See this commentary, Food Is Medicine—The Promise and Challenges of Integrating Food and Nutrition Into Health Care, for more information on the study and its results.
- Berkowitz SA, Terranova J, Randall L, Cranston K, Hsu J. Association between receipt of a medically tailored meal program and health care use. JAMA. 2019 Apr. doi: 10.1001/jamainternmed.2019.0198. [Epub ahead of print]. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/31009050
Warning Against Eating Human Placenta
A Canadian Television Network (CTV) news posting writes, “A group of Canadian gynecologists is urging people not to eat the human placenta. A recommendation from the Society of Obstetricians and Gynaecologists of Canada, recently published in the Journal of Obstetrics and Gynaecology Canada, indicates there is no evidence of a health benefit from the practice known as placentophagy and there [is] a potential for serious harm”.
See Additional Information:
Report Card on Access to Obesity Treatment for Adults in Canada
Obesity Canada has just released an updated 2019 report card on access to obesity treatments for adults in Canada. The report focuses on four key obesity management tools:
- specialists and interdisciplinary teams for behavioural intervention
- medically supervised weight-management programs with meal replacements
- anti-obesity medications
- bariatric surgery (1).
Major findings indicate that since the 2017 report there have been:
- no improvements in treatment
- obesity is still regarded as self-inflicted
- there are a lack of interdisciplinary teams to treat patients
- patients cover their own costs for weight management programs and foods
- obesity drugs are not covered in public programs
- there are no policies or guidelines to treat or manage obesity in Canada
- there are long wait times for bariatric surgery (1).
Five key recommendations are provided as follows:
- “Governments, employers and the health insurance industry should officially adopt the position of the Canadian Medical Association that obesity is a chronic disease and orient their approach/resources accordingly.
- Governments should recognize that weight bias and stigma are barriers to helping people with obesity and enshrine rights in provincial/territorial human rights codes, workplace regulations, healthcare systems and education.
- Governments should include anti-obesity medications, weight-management programs with meal replacement and other evidence-based products and programs in their provincial drug benefit plans.
- Employers should recognize and respond to obesity as a chronic disease and provide coverage for evidence-based obesity programs and Health Canada approved treatments for their employees through health benefit plans.
- Governments and health authorities should increase the availability of interdisciplinary teams and increase their capacity to provide evidence-based obesity management.”(1).
The PEN® Team will be reviewing the included evidence as it relates to existing content.
- Obesity Canada-Obésité Canada. Report Card on Access to Obesity Treatment for Adults in Canada 2019. April 2019. Available from: http://obesitycanada.ca/wp-content/uploads/2019/04/OC-Report-Card-2019-Eng-F-web.pdf
Red Meat, Comparison Diets and CVD
A new meta-analysis of random control studies looked at the effects of red meat consumption and risk factors for cardiovascular disease (blood lipids, apolipoproteins, blood pressure) (1). The meta-analysis involved 1,803 participants from 36 RCTs that compared red meat diets with diets that replaced red meat with a variety of foods. The study found that the results depended on the composition of the comparison diet: there were improvements in blood lipids when red meat was substituted with high quality plant protein sources but not when replaced with low quality carbohydrates. The senior author of the study, Meir Stampfer, stated: “Asking 'Is red meat good or bad?' is useless,"…. "It has to be 'Compared to what?' If you replace burgers with cookies or fries, you don't get healthier. But if you replace red meat with healthy plant protein sources, like nuts and beans, you get a health benefit" (1).
PEN Team Comment:
This study combined the results from 36 randomized controlled trials. Randomized controlled trials can give more certainty of the findings. If the trials were well-designed and conducted, the intervention and control groups should be similar, providing confidence that any differences in outcome were due to the intervention compared to the comparison group. The confidence intervals from the individual studies (seen as the horizontal lines for each study in the Figures) were wide, indicating variability in the results and/or small sample sizes.
In addition, this study identified one of the difficulties of nutrition trials: “Inconsistencies regarding the effects of red meat on cardiovascular disease risk factors are attributable, in part, to the composition of the comparison diet” (2).
- ScienceDaily. Substituting healthy plant proteins for red meat lowers risk for heart disease. 2019 Apr 9. Available from: https://www.sciencedaily.com/releases/2019/04/190409141808.htm
- Guasch-Ferre M, Satija A, Blondin SA, Janiszewski M, Emlen E, O’Connor LE, et al. Meta-analysis of randomized controlled trials of red meat consumption in comparison with various comparison diets or cardiovascular risk factors. Circulation. 2019 Apr 9;139(15):1828-45. doi:10.1161/CIRCULATIONAHA.118.035225. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/30958719
Is Diet Associated with Death Rates Across the Globe?
A study published in the Lancet of the global burden of disease tracked consumption trends of 15 dietary factors between 1990 and 2017 in 195 countries. The study looked at major food groups, some nutrients and examined the associations between diet and death and disability-adjusted life-years from non-communicable diseases (e.g. diabetes, cardiovascular disease, cancer). Dietary elements examined included estimated intakes of fruit, vegetables, legumes, whole grains, nuts and seeds, milk, fibre, calcium, seafood omega-3 fatty acids, polyunsaturated fats, red meat, processed meat, sugar-sweetened beverages, trans fatty acids and sodium.
The authors observed that diets low in whole grains and fruit, and high in sodium were associated with more than half of all diet-related global deaths. In North America, the data suggested that the largest dietary contributor to death was from the low intake of whole grains. For more reading about the study and a discussion of some the limitations, see the Science News article Globally, One in Five Deaths are Associated with Poor Diets.
This study is an ecologic study, since the researchers analyzed country-specific data rather than individuals’ data (1,2). They did not know whether the people who died were the people with inferior diets, rather they assumed that the diet information represented everyone in the country (1). The study primarily used dietary intake data prepared by others, usually 24-hour recall data for dietary estimates. There were likely differences in how diets were measured in the various countries. Twenty-four-hour recall data is likely to vary in quality and may not provide strong representations of participants diets (3).
The researchers adjusted the country mortality rates for differences in age and sex distributions in the countries (1). There were no considerations for smoking, physical activity, weight status, other lifestyle variables or inequality in the countries. The analysis assumed that everyone in the countries consumed the average diet of those studied in each country. The results stratified by socioeconomic status (SES), showed weaker relationships between diet and mortality for people with the highest and lowest SES. These findings suggest that other factors, such as social determinants of health, which influence economic conditions, lifestyle, smoking etc., are likely more influential (positively for high SES and negatively for low SES) making diet relatively less influential on mortality at the extremes of SES.
This study has a positive focus on foods that may improve health outcomes. Caution is needed in interpreting this ecologic studies’ results since interpretations could be considered an “ecological fallacy”, especially if these findings are used to assume that the noted association exists for individuals and that if individuals make these dietary changes it would decrease their risk of death (2).
- GBD 2017 Diet Collaborators. Health effects of dietary risks in 195 countries, 1990-2017: a systematic analysis for the Global Burden of Disease study 2017. The Lancet. Published online 2019 Apr 3. Available from DOI: http://dx.doi.org/10.1016/S0140-6736(19)30041-8
- Barratt B, Kirwan M 2009, Shantikumar S 2018. The design, applications, strengths and weaknesses of descriptive studies and ecological studies. HealthKnowledge. Education, CPD and Revalidation from PHAST. 1a-Epidemiology. 2018. [cited 2019 Apr 7]. Available from: https://www.healthknowledge.org.uk/public-health-textbook/research-methods/1a-epidemiology/descriptive-studies-ecological-studies
- Amoutzopoulos B, Steer T, Roberts C, Cade JE, Boushey CJ, Collins CE, et al. Traditional methods v. new technologies – dilemmas for dietary assessment in large-scale nutrition surveys and studies: a report following an international panel discussion at the 9th
International Conference on Diet and Activity Methods (ICDAM9), Brisbane, 3
September 2015. J Nutr Sci. 2018 Apr 2;7e:11.
DOI: 10.1017/jns.2018.4. eCollection 2018. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/?term=29686860
Gut Microbiota in Nutrition and Health
This article, on the role of the gut microbiota in nutrition and health, is another in the BMJ series of open access, peer-reviewed articles examining controversial nutrition topics where there are uncertainties in the evidence and debate among experts. References
Most of the human studies of the gut microbiota and its associations with disease conditions are case control observational studies, conducted at one point in time (1). It is not possible from these studies to know whether the patterns of microbiota caused the disease or whether the disease, its treatment or some related factor caused the microbiota pattern. Animal studies of some topics are suggestive of a causal relationship, but the mechanisms might be different in animals versus humans (1). Future longitudinal and randomized trials will help to understand these relationships.
This BMJ article describes the gut microbiota and its associations with health, the influence of diet and medication on the microbiota, and how the gut microbiota can be manipulated by diet, probiotics and dietary fibre. It summarizes the current state of understanding of this complex topic, describing what is known from human randomized trials and animal studies and current areas yet to be clarified.
Looking for more information? See the Additional PEN Content:
- Valdes AM, Walter J, Segal E, Spector TD. Role of the gut microbiota in nutrition and health. BMJ. 2018 Jun 13;361:k2179. doi: 10.1136/bmj.k2179. Abstract available from: https://www.ncbi.nlm.nih.gov/pubmed/29899036
Another Study on Cholesterol, Eggs and CVD Risk
A recent study by Zhong, et al. published in JAMA has been cited in the press including MedicalNewsToday on March 15, 2019. The study analyzed pool data from six prospective studies covering a period up to 31 years (median 17 years follow up) and involving 29,615 men and women in the U.S. It reviewed self-reported intake of cholesterol-containing foods, including eggs, and identified a positive association with an increased risk of cardiovascular disease (CVD) and deaths from other causes.
Here are two analyses of the study:
Note that this was not a systematic review and the findings are not consistent with systematic reviews and meta-analyses of other cohort studies. For more information and practice recommendations, see PEN Practice Question: Are interventions to decrease dietary cholesterol intake (e.g. restricting eggs) recommended for the primary prevention of cardiovascular disease (CVD)?