The AICR infographic that was provided in class indicates that processed meat should be limited.  In 2015 the WHO classified all processed meat as carcinogenic.  Sodium nitrate has long been used in processed meats as an anti-microbial agent, to extend shelf-life and enhance color in processed meats. Processed meats include items such as bacon, sausages and ham.  As I was researching dietary nitrates with regards to colorectal cancer I ran across the research article by Crowe et. al. The article suggests that processed meats should be further researched and categorized as to whether or not the processed meat contains nitrites or not because the researchers found in their meta-analysis that not all studies exploring the link between processed meats and colorectal cancer indicated a connection.  However, 2/3rds of the studies in the meta-analysis that specifically looked at processed meat containing nitrites found a link between nitrites and colorectal cancer.  

What does this mean?  There are other preservatives, besides nitrates and nitrites, that are used in meat preservation and the authors of the study recommend that future research involve a distinction between those processed meats using nitrites and those that do not.  As not all preservatives used may have such a strong link to cancer.  

I also found two articles that mentioned plant polyphenols and alpha-tocopherols as possible alternatives to synthetic nitrates and nitrites used in processed meats.  1) Cantwell M, Elliott C (2017) Nitrates, Nitrites and Nitrosamines from Processed Meat Intake and Colorectal Cancer Risk. J Clin Nutr Diet 3:27. doi: 10.4172/2472-1921.100062.  2) Ferysiuk, K., & Wójciak, K. M. (2020). Reduction of Nitrite in Meat Products through the Application of Various Plant-Based Ingredients. Antioxidants (Basel, Switzerland), 9(8), 711. https://doi.org/10.3390/antiox9080711.

What’s the application? It would be logical to conclude that processed meats (especially those containing synthetic nitrites such as sodium nitrite/nitrate) should be limited.  But it is also worth considing how the meat is cooked (grilled, smoked), what other foods the meat is consumed with, temperature of cooking, fat content of the meat and form of meat (beef, pork, turkey, chicken), sodium content of the meat, etc. Bottom line= I think it’s more complicated than just nitrate/nitrite content as there are other factors that have to be considered.  But would agree that based on the research by Crowe et.al that additional research is needed and that is would be a safe recommendation to limit intake of processed meats because in addition to any concerns regarding nitrates/nitrites these types of food also tend to be high in sodium and saturated fat.  

Study importance: 

To assess the effectiveness of ketogenic diets (KD) on the therapy of neurodegenerative diseases. Ketogenic diets bring the body into a state of ketosis through a fasting-like effect, which for a long time has been used in drug-resistant epilepsy. Studies have shown a possible neuroprotective effect. However, one of the key concern has been maintaining adequate nutritional intake while on ketogenic diet given its propensity to reduce appetite and therefore, increase the risk of malnutrition in a population already at risk for it. 

Key study finding:

The KD was found to reduce the volumes of solved amyloid-beta in homogenates of murine brains. It was also observed that a long-term administration of ketone body esters to mice improved their cognitive functions and reduced beta-amyloid and highly phosphorylated tau proteins in the brain. Animal and in vitro studies have demonstrated a beneficial effect of ketone bodies on the course of Parkinson disease. 

Clinical implications:

The animal studies on the benefits of ketogenic diet have been positive, however we lack adequate studies in humans to validate these. The elderly are a special population where the application of KD may be restricted by the presence of pre existing malnutrition or other co-morbidities. 

Why is this study important:  I selected this review because RA is a disease state that is interesting to me, but still one of the muddy points discussed during this semester. I went back to our Week 3 Wall as well to review the previous studies and I don’t believe that I saw this one so decided to post this review because I really feel like that it summarized my interest and confusion with this topic, but also positioned the discussion on nutrition and the development of RA, versus established RA.

It’s an important review because of the potential impact that individual foods as well as the health of our gut microbiota might have on the cause and / or prevention of this debilitating disease. 

This review focusses on two potential RA influencers but then pulls these factors together, hypothesizing that the trigger for RA is a cascading event of one factor, causing another, which then causes RA.  The first focus is on dietary patterns and individual foods, and the second is on the role that the gut microbiota might play in RA.  

A number of dietary patterns and associated studies were reviewed.  Of note, alcohol (low intake) has been shown to have some protective effects.  Other dietary patterns such as high salt consumption and sweetened beverages have been found to be ‘hazardous factors’.  Those still considered conflictive include the Mediterranean diet, meat and dairy consumption, vegan, fasting and elemental diets, PUFAs, coffee/ teas and vitamin D.  

There is also considerable research on the influence of gut microbiota in RA development.  This review looks at a number of studies that focus on the intestinal barrier and factors influencing this barrier including a specific bacterial species, Prevotella, as well as other factors such as NSAIDs, hyperglycemia, acute stress, high fructose or fat diet and vitamin D deficiency. 

Finally, the authors link these factors together with the hypotheses that it is many nutritional and dietary factors that disrupt the gut microbiota, causing a breach in the intestinal barrier which ultimately, through various immune regulating dysfunctions, causes RA in high risk individuals.

 

Clinical implications:  As with most of the disease states that we have studied this semester, the personal and economic impact can be devastating.  As this review noted, much of our research is on patients that already have RA, but if we can better isolate any nutritional factors that are causing or could prevent RA, we can have a greater impact on prevention of this disease. Continuing research, as well as education on the latest research, will help us to develop the most sound guidance regarding dietary patterns and behavior that can truly make a difference in disease prevention.

BNDF = regulates synaptic change and use-dependent brain plasticity.

For this last Weekly Wall, I wanted to revisit the topic of multiple sclerosis. 

This study is important because it looks at exercise to shift an individual’s cytokine and growth-promoting protein levels to a ‘repair’ phenotype in diseases such as multiple sclerosis. Being sedentary is linked to elevated inflammatory markers such as Il-6 that increase brain inflammation and growth factors that decrease neuroplasticity. However, this can be inhibited by exercise.

In this study, individuals with MS that used walking aids and healthy controls matched for sex and age performed a graded exercise test (GXT). Blood levels of IL-6 and BDNF (brain-derived neurotrophic factor) were measured before and after the GXT. BDNF can be released in the blood, but it is dependent on intensity of exercise. Therefore, researchers found that, in the MS patients in this study, BDNF levels did not increase since they were in poor physical condition and could not complete the GXT at a high enough intensity. However, the MS patients had an increase of IL-6 levels post-GXT. Exercise-induced IL-6 levels have the potential to weaken the M1 phenotype in adipose tissue macrophages (mouse studies cited in this paper).

This research is clinically relevant because, MS patients that CAN achieve intense enough exercise to increase BDNF levels in their blood can benefit from the positive effects. Also, even patients who have a greater disability and cannot achieve the intensity can still possibly benefit from the increase of exercise-induced IL-6 levels. 

This study concludes people with hypertension do not adhere healthy diets or lifestyle change. In this course, some classmates mentioned that patients with more than one chronic disease tend to ignore professional instruction. This is the exact same situation. This study is important because it suggests that physicians might be missing to emphasize the importance of dietary changes to their patients. 

Hypertension is known as the silent killer and prevalent. Because it is caused by high sodium, saturated fat, total fat and protein, the DASH diet is recommended. Also, overweight, sedately lifestyle, smoking and alcohol are associated. This study used survey from the National Health and Nutrition Examination Survey (NHANES). Without doubt, highest rates are in age between 50 and 64, with obesity, diabetes and heart diseases. Surprising facts are that people with highest income level and with some college-level tend to ignore diet recommendation.

It reports that people who are diagnosed as hypertension are less likely to follow healthy diet than people with hypertension without diagnosis. 

There are many points I couldn’t agree, but this study’s warning to professionals about treating patients with hypertension is very important. There is a lack of awareness in benefits of nutrition to lower BP, and physicians should recommend it more often with more information.

This study is important because it looks at how a physical activity intervention designed for metabolic syndrome impacts the fitness, bone health, and quality of life in overweight and obese breast cancer survivors who were less than six months post-treatment for cancer. One hundred breast cancer survivors were included in this randomized controlled trial. The women included in the study were randomly assigned to one of two groups. The first group was an exercise group which participated in a 16-week aerobic and resistance exercise intervention and the second group was a usual care group or control group. The women in the study were checked at three different intervals for physical fitness, bone mineral density, serum concentrations of bone biomarkers, and quality of life. The first assessment was at baseline, the second was after the physical activity intervention, and the last assessment was after three months following the physical activity intervention. 

One key finding in this study is that there was a significant difference in patient reported outcomes between the exercise intervention group and the usual care group. The patients in the exercise group reported improved quality of life and physical fitness compared to the usual care group. The exercise group also had superior muscle strength and bone health. 

This study is important clinically because it shows that exercise can potentially improve quality of life for cancer patients. I did not know that exercise could improve quality of life for cancer survivors so I thought that this was an interesting study. I think this study could be beneficial when providing nutritional recommendations to cancer patients. 

 

1.     Significance

This article was important because neurodegeneration is a component of aging. Neuronal death, chronic inflammation, protein aggregation are all common features of an aging brain due to cells becoming senescent. Looking at the issue on a broader level, the financial burden of aging is rapidly rising and costs will continue to rise as a greater proportion of the population become elderly.

2.     Key Finding

The incorporation of foods with anti-inflammatory properties (such as berry juices and curcumin) and those with healthy fat profiles, generally polyunsaturated fatty acids from plant based origins or fish oils, played different roles that worked together to protect the brain. A mixed diet was shown to help promote better cognition and memory performance and a decrease in inflammatory responses that damaged aged neurons

3.     Application

Clinically, emphasizing nutritional modifications over extended periods of time has been correlated with better neuronal aging in individuals. Utilizing these methods before neuronal damage may be a way to see better results in terms of cognition and memory. 

One of the critical findings is L-leucine and medium-chain triglycerides supplement the effect of muscle strength and function. Sixty-four participants took the supplements divided into three groups: L-leucine and medium-chain triglycerides supplement (LD+MCT), medium-chain triglycerides supplement (MCT), and long-chain triglycerides supplement (LCT) for three months. The participants take the LD+MCT or MCT supplements significantly change in right-hand grip strength, right knee extension time, and ten-second leg open and close test performance.

The study provides older adults fatty acid sources in their diet. Moreover, the clinicians could give efficient treatment for the patients with sarcopenia.

 

Citation: Eleni A, Panagiotis P. Romero-Gómez M, Zelber-Sagi S, Trenell M. Treatment of NAFLD with diet, physical activity and exercise. J Hepatol. 2017;67(4):829-846. doi:10.1016/j.jhep.2017.05.016

 

Question 1:   Why is this study important?

Non-Alcoholic Fatty Liver Disease (NAFLD) has increased associated risk of progression to liver cirrhosis, liver cancer and cardiovascular effects. Prevalence of NAFLD varies largely from 20% to 30% and increases with age, with an annual incidence of around two new cases/100 patients/year. Patients with NAFLD are frequently obese and/or have diabetes, and insulin resistance is a key pathogenic trigger. Nutritional interventions are focused on weight loss in NAFLD due to associated obesity and DM. This study reviews role of total calories and type of weight loss diet, micro- and macronutrients, evidence-based benefits of physical activity and exercise and finally support these modifications through established behavioral change models and techniques for long-term maintenance of lifestyle modifications.

Identify one key finding of this study and describe how it relates to nutritional sciences

Primary take home points are from nutritional aspect:

1)     Mediterranean diet can reduce liver fat even without weight loss and is most recommended diet in NAFLD

2)     The traditional Mediterranean diet is characterized by a high intake of olive oil, which is rich in monounsaturated-fat [MUFA], nuts, fruits and legumes, vegetables, and fish and a low intake of red meat, processed meats, and sweets (wine in moderation). In contrast to the low-fat diet, which contains up-to 30% fat, 40% of the calories in the Mediterranean diet are derived from fats, mostly MUFA and omega-3 PUFA. MUFA has a favorable effect on lipid profile. Moreover, the Mediterranean diet plays a beneficial role in metabolic profile and has been shown to reduce the risk of cardiovascular disease and diabetes, two outcomes highly relevant in NAFLD patients.

3)     Gradual weight reduction achieved by caloric restriction, with or without increased physical activity, leads to an improvement in serum liver enzymes, liver fat, degree of hepatic inflammation and fibrosis.

4)      Role of micro nutrients is unclear, may be Vitamin D is beneficial.

 

 

What are the clinical implications of this study? 

NAFLD is growing into a significant health burden with strong associations with risk of other metabolic conditions. dietary habits and physical activity, are and should be the first line of treatment in NAFLD and NASH. Weight reduction is the most established treatment for both NAFLD and NASH, with a clear dose-response association. Mediterranean diet with its effect on weight loss along with other system advantages is the recommended diet.