User:Sherry72/sandboxannotatedbib

Impacts of Western Diet on Immunity
This review article discusses the mechanisms that excessive amounts of sugar, salt and fat impose various negative effects on human immune system. It provides both in vitro and in vevo evidences that clearly demonstrate the immunologic impacts of each macronutrient, for example simple sugars reduce leukocyte phagocytosis, salt exacerbates symptoms of autoimmune diseases, omega-6 fatty acids activate TLR4 to increase inflammation. Western pattern diet is characterized by foods high in saturated fat, refined sugar and sodium. This article has provided strong evidence to support the presence of Western diet's negative effects on normal immune functions; however, one major weakness of this article is that by examining each nutrient separately, it fails to show the health impacts of Western diet as a whole. Different nutrients affect different parts of human immune system, but the question is how these separate modifications are connected and contribute to the overall human health.

Association between Western Diet and Adult Asthma
This article reviews a total of ten studies conducted from 1980-2014 on potential effects of Western pattern diets on adult asthma. The findings suggest a positive association between Western diet consumption and adult asthma morbidity. With high fast food or other processed food intake, the frequencies of wheeze and asthma attacks increased. One major strength of this article is that it is representative of general populations by examining studies conducted in different countries, including the USA, Japan and several European countries. Also, most of the studies have relatively large sample sizes, up to 70,000 participants. However, one weakness is that two out of the ten studies showed conflicting results. One study was conducted across three European countries, and increased asthma symptoms were observed in participants with western pattern diets from the UK and Norway but not in participants from Germany, indicating a potential regional variation. Another study in the UK failed to show any significant association between Western pattern diet and asthma quality-of-life scores.

Western Diet and Cognitive Impairment
This article reviews evidence supporting that intake of two primary components of Western pattern diet, saturated fats and simple carbohydrates, leads to cognitive impairment. Hippocampus plays an important role in normal functions of learning and memory. Several studies with rodents show that high levels of sucrose and saturated fatty acids intake interfered with hippocampus functions and disrupted performance in spatial learning and memory tasks. Other studies also show that a short period of Western diet, for example nine days of a high-fat diet, could impair working memory. A "vicious cycle" model was constructed proposing that memory inhibition due to impaired hippocampal function resulted from Western diet would lead to increased appetite reinforcing excessive intake of Western diet. This article argues that neurological dysfunction contributes to obesity following a Western pattern diet, but it lacks further evidence to support this "vicious cycle". The onset of this cycle is unclear, and no data has shown that stopping consumption of a Western diet would restore hippocampal functions.

Impacts of Western diet on Hippocampal Volume
The article discusses the results of meta-analyses confirming an association between dietary pattern and human hippocampal volume. A longitudinal study has collected data from Personality and Total Health Through Life Study and established a linear regression between dietary factors and hippocampal volumes over time. Data suggested that participants with high intake of unhealthy foods from Western diets had smaller left hippocampal volume. This is the first human study that successfully establishes a relationship between diet and human hippocampal volume, but one major weakness is that all subjects were aged 60-64 years old, so the sample could not represent general populations. The observed association between diet and hippocampus size may be mediated by aging effect.