Cerebral Blood Flow Measurements in Adults: A Review on the Effects of Dietary Factors and Exercise

Abstract

Improving cerebrovascular function may be a key mechanism whereby a healthy lifestyle, of which a healthy diet combined with increased physical activity levels is a cornerstone, protects against cognitive impairments. In this respect, effects on cerebral blood flow (CBF)—a sensitive physiological marker of cerebrovascular function—are of major interest. This review summarizes the impact of specific dietary determinants and physical exercise on CBF in adults and discusses the relation between these effects with potential changes in cognitive function. A limited number of randomized controlled trials have already demonstrated the beneficial effects of an acute intake of nitrate and polyphenols on CBF, but evidence for a relationship between these effects as well as improvements in cognitive functioning is limited. Moreover, long-term trans-resveratrol supplementation has been shown to increase CBF in populations at increased risk of accelerated cognitive decline. Long-term supplementation of n-3 long-chain polyunsaturated fatty acids may also increase CBF, but related effects on cognitive performance have not yet been found. Significant decreases in cerebral perfusion were observed by commonly consumed amounts of caffeine, while alcohol intake was shown to increase CBF in a dose-dependent way. However, the long-term effects are not clear. Finally, long-term exercise training may be a promising approach to improve CBF, as increases in perfusion may contribute to the beneficial effects on cognitive functioning observed following increased physical activity levels.

Keywords: arterial spin labeling; brain health; cerebral blood flow; cognitive function; diet; exercise; magnetic resonance imaging; vascular function.

Figure 1

Schematic overview of the relationships described in the present review paper. The impact of both specific dietary factors (i.e., dietary nitrate, polyphenols, dietary fatty acids, caffeine, and alcohol) and physical exercise on cerebral blood flow (CBF)—a sensitive physiological marker of vascular function in the human brain—is summarized, and the relation between these effects in adult subjects with changes in cognitive performance is examined.

Figure 2

Arterial Spin Labeling (ASL) cerebral blood flow map in units of milliliters of blood per 100 grams of brain tissue per minute (mL/100 g tissue/min).

Figure 3

Arterial Compliance (AC) map showing the percentage change in arterial blood volume per millimeter of mercury (%/mmHg); obtained using short inversion time arterial spin labeling.