including unhealthy foods in an otherwise healty diet

[corybroo]

This study of 5,000 65+ year old adults between 1993 and 2012 examined the association between Mediterranean diet scores and changes in participants' global cognitive function, episodic memory and perceptual speed.  I interpret the results to mean that there are benefits to making good food choices and more benefits to making more good choices.

Including unhealthy foods may diminish positive effects of an otherwise healthy diet

researchers at Rush University Medical Center have reported diminished benefits of a Mediterranean diet among those with high [emphasis added] frequency of eating unhealthy foods

Eating a diet that emphasizes vegetables, fruit, fish and whole grains may positively affects a person's health

But when it is combined with fried food, sweets, refined grains, red meat and processed meat, we observed that the benefits of eating the Mediterranean part of the diet seems to be diminished.

Every three years, the study participants completed a cognitive assessment questionnaire … and they filled out a questionnaire about the frequency with which they consumed 144 food items.

Participants with slower cognitive decline over the years of follow-up were those who adhered closest to the Mediterranean diet, along with limiting foods that are part of Western diet, whereas participants who ate more of the Western diet had no beneficial effect of healthy food components in slowing cognitive decline.

"Western diets may adversely affect cognitive health," Agarwal said. "Individuals who had a high Mediterranean diet score compared to those who had the lowest score were equivalent to being 5.8 years younger in age cognitively."

Agarwal said. "To benefit from diets such as the Mediterranean diet, or MIND diet, we would have to limit our consumption of processed foods and other unhealthy foods such as fried foods and sweets."