Hard-core carb addicts may feel powerless when confronted with cookies, candy, bread and pasta. But constant caving in to carb cravings could hurt your mental functioning in the long run. That’s the jarring implication of a new study recently published in the Journal of Alzheimer’s Research.

Mayo Clinic researchers followed 937 seniors of both genders (average age 80) with assessed neurological exams and periodic food intake assessments. After four years, 21% showed signs of mild cognitive impairment. While previous research found that, in general, too much food may lead to forgetfulness — and excess weight increases your risk of dementia — this study broke it down to actual food components. The upshot: Risk of mental decline was 89% higher among those who ate the most carbs (e.g., accounting for at least two-thirds of calories). While those with relatively normal carb intake (50% of calories) showed no increased risk, those with high protein intake enjoyed a 34% risk reduction.

Retain wisdom longer by choosing protein sources wisely: Seniors who eat  fish regularly slowed age-related mental decline by the equivalent of three to four years. Choose carbs carefully too: Fruits and vegetables contain a bevy of phytochemicals under study for their potential benefits. Some specific examples: Beets may help increase blood flow to the brain. Leafy and/or cruciferous veggies might also help you maintain mental acuity in later years. Lab research has also linked luteolin — found in green bell peppers, celery and carrots — to reduced inflammation of the brain.

Published January 1, 2013