Dietary tips to prevent senile dementia | Updated: 2023-06-06
Senile dementia is a common neurodegenerative disease in the elderly, with memory impairment as the main clinical symptom. 
"Degenerative disease" means that the risk of the disease will increase with age in elderly individuals. Alzheimer's is its most common type.
According to the 2016 Global Burden of Disease Study, there were more than 43 million dementia patients worldwide, -over two times that of 1990. 
For people over the age of 70, dementia is the second leading cause of death after ischemic heart disease. Due to the huge population base, China has 15.07 million dementia patients aged 60 and above, the largest number in the world.
Since there is no effective treatment for dementia at the current stage, the key is how to prevent it. Diet has proved to be an important modifiable factor in cognitive decline.
Foods that can slow cognitive decline
Fish, especially salmon, hairtail, and tuna, are rich in polyunsaturated fatty acids, among which omega-3 polyunsaturated fatty acids are closely related to cognitive function. 
Studies have shown that eating at least 100 grams of fish per week can help slow cognitive decline among Chinese residents aged 65 and over. In addition, eating fish could delay the decline of comprehensive memory and language memory.
Fruits and vegetables
Fruits and vegetables are sources of antioxidant components, which can delay brain decline. Several studies have shown that a higher intake of fruits and vegetables can prolong the decline of cognitive function. 
Following the World Health Organization's advice, eating five or more servings of vegetables and/or fruits per day (≥400 g/day) can reduce the risk of cognitive impairment by 47 percent.
Notably, green vegetables are associated with better memory function in senior citizens, which can decrease the risk of cognitive impairment by about 20 percent.
Nuts are not only rich in polyunsaturated fatty acids (omega-3 and omega-6) and monounsaturated fatty acids, but also have a large amount of minerals (such as phosphorus, potassium, magnesium, calcium, iron and sulfur) and vitamins (such as vitamin B1, B2, B6 and E). 
A study on elderly women found that a higher nut intake (i.e., ≥5 times/week) was associated with better cognitive performance; those who eat walnuts one to three times per month are more likely to have better cognitive ability than those who eat walnuts less than once a month.
Dietary patterns to prevent senile dementia
At present, there are three dietary patterns that are good for senile dementia prevention, namely Mediterranean diet, DASH diet (Dietary Approaches to Stop Hypertension diet) and MIND diet (Mediterranean-DASH Intervention for Neurodegenerative Delay). 
Chinese residents are not recommended to completely follow the above-mentioned dietary patterns because of different eating habits. However, the patterns provide a reference for our dietary choices.
Of course, there are studies based on the Chinese population. A recent cohort study based on the 1997-2018 survey data of the China Health and Nutrition Survey found that a dietary pattern characterized by a higher intake of soy products, vegetables, fruits, nuts, pork, aquatic products, and vegetable oils may reduce the risk of cognitive impairment in the elderly aged 55 and over in China.