More dietary diversity means longevity
The more varied people over the age of 60 eat, the less likely they are to die. In particular, the risk of death from cancer decreases through a varied diet. This is evident from an epidemiological study by the Japanese National Center for Geriatrics and Gerontology.Study
The researchers used data collected in the Japanese National Institute for Longevity Sciences-Longitudinal Study of Aging. Thanks to these data, they were able to study a group of 386 Japanese men and 413 Japanese women, who were 60-79 years old when the study began.

Because the study participants completed questionnaires, the researchers knew the study participants' diet. The researchers followed the participants for almost 16 years. During that period, a third of the participants died.
The researchers determined the dietary diversity of the study participants by looking at the amount of energy supplied by separate food groups such as breakfast foods, whole grains, potatoes, beans, nuts and seeds, red, yellow and pink vegetables, green vegetables, fruits, mushrooms, seaweeds, fish and shellfish, meat, eggs and dairy.Results
The more varied the diet of the study participants, the older they could get. A varied diet resulted in a statistically significant decrease in mortality in general [All-cause mortality] and the risk of death from cancer.

A varied diet had no effect on the risk of death from cardiovascular disease.
Nutrients. 2020 Apr 10;12(4):E1052.