Perhaps a nutrient deficit is associated with depression? This study found that eating a Mediterranean diet or a similar diet in which fruits, vegetables, legumes (beans), nuts, and low in processed meats is associated with lower rates of depression. From Medical Xpress:
Fruit and vegetables aren't only good for a healthy body—they protect your mind too
Eating a Mediterranean diet or other healthy dietary pattern, comprising of fruit, vegetables, legumes, and nuts and low in processed meats, is associated with preventing the onset of depression, according to research published in the open access journal BMC Medicine. A large study of 15,093 people suggests depression could be linked with nutrient deficits..
The researchers compared three diets; the Mediterranean diet, the Pro-vegetarian Dietary Pattern and Alternative Healthy Eating Index-2010. Participants used a scoring system to measure their adherence to the selected diet, i.e. the higher the dietary score indicated that the participant was eating a healthier diet. Food items such as meat and sweets (sources of animal fats: saturated and trans fatty acids) were negatively scored, while nuts, fruits and vegetables (sources of omega-3 fatty acids, vitamins and minerals respectively) were positively scored.
The study included 15,093 participants free of depression at the beginning of the study. They are former students of the University of Navarra, Spain, registered professionals from some Spanish provinces and other university graduates....Questionnaires to assess dietary intake were completed at the start of the project and again after 10 years. A total of 1,550 participants reported a clinical diagnosis of depression or had used antidepressant drugs after a median follow-up of 8.5 years.
The Alternative Healthy Eating Index-2010 was associated with the greatest reduction of risk of depression but most of the effect could be explained by its similarity with the Mediterranean Diet. Thus, common nutrients and food items such as omega-3 fatty acids, vegetables, fruits, legumes, nuts and moderate alcohol intake present in both patterns (Alternative Healthy Eating Index-2010 and Mediterranean diet) could be responsible for the observed reduced risk in depression associated with a good adherence to the Alternative Healthy Eating Index-2010.
Almudena Sanchez-Villegas says, "A threshold effect may exist. The noticeable difference occurs when participants start to follow a healthier diet. Even a moderate adherence to these healthy dietary patterns was associated with an important reduction in the risk of developing depression. However, we saw no extra benefit when participants showed high or very high adherence to the diets....This dose-response pattern is compatible with the hypothesis that suboptimal intake of some nutrients (mainly located in low adherence levels) may represent a risk factor for future depression."
Two recent meta-analyses of studies looked at depression. The first found that in 12 out of 26 studies eating fish (but NOT fish-oil supplements) was linked to lower rates of depression. The researchers hypothesize that "Fish is rich in multiple beneficial nutrients, including n-3 polyunsaturated fatty acids, high-quality protein, vitamins, and minerals." Another meta-analysis looked at dietary patterns and depression and found that a high intake of fruit, vegetables, fish, and whole grains may be associated with a reduced depression risk. From Medscape: Fish-Rich Diet May Significantly Reduce Depression Risk
More research support for extra virgin olive oil and the Mediterranean diet being associated with anti-cancer effects, In a study conducted in Spain, women supplementing their diet with extra EVOO (extra virgin olive oil) had a lower incidence of breast cancer after about 5 years.
New research has found that low vitamin D levels among older adults is associated with accelerated cognitive decline and impaired performance (particularly in areas of memory and executive function). The next research in this area will have to look at whether vitamin D supplementation will change (slow down) the decline. Please note that it is widely accepted that an average daily intake of 1000 IU of D3 daily is safe. The best source of vitamin D is sunlight. From Science Daily:
Artificial trans fats in foods are bad for health in so many ways: linked to increased risk of coronary heart disease, atherosclerosis, inflammation, and risk of early death. And even though the FDA is finally phasing out partially hydrogenated oils (because they have high levels of
Trans fats are commonly used in processed foods to improve taste, texture, and shelf life. Artificial trans fats are found in partially hydrogenated oils and in other ingredients, such as refined oils, emulsifiers, flavors and colors. Even those processed foods that say zero trans fats may contain trans fats - due to a loophole in labeling laws (if it has less than .5 grams per serving, then it can be rounded down to zero - thus allowing the incorrect claim of zero trans fats). Eating a variety of processed foods, each containing a little trans fats, easily adds up to eating a significant amount daily.Trans fats in the diet have long been linked to cardiovascular disease, artherosclerosis, obesity, oxidative stress, and inflammation, but now research finds that it is linked to a poorer memory in middle-aged men under the age of 45. From Science Daily: