Arterial Stiffness, Cognition and Equol
Arterial Stiffness, Cognition and Equol
The ACE Trial, funded by the National Institute on Ageing/National Institutes of Health (NIH), is a multicenter clinical trial. The ACE Trial will determine if taking the dietary supplement Equol could slow the progression of stiffening of the arteries, small blood vessel disease in the brain and memory decline. Equol is a soy-based supplement that has plant estrogen-like compounds in it.
Equol is a metabolite of soy isoflavone. Our studies in Japan and other studies suggest that Equol may slow mechanisms related to memory decline. No previous studies in the United States have tested the effect of Equol on these mechanisms or memory decline. Supplementation of Equol in the ACE Trial is approved by the Food and Drug Administration (FDA).
Researchers at the University of Pittsburgh, Pittsburgh, Pennsylvania, Wake Forest University, Winston-Salem, North Carolina, and Emory University, Atlanta, Georgia, are recruiting participants.
The ACE Trial will ask participants to complete 7 clinic visits over a two-year period. The participants are asked to take Equol tablets daily for 24 months. Clinic procedures include Pulse Wave Velocity (to measure arterial stiffness), Magnetic Resonance Imaging (MRI) of the brain and tests of awareness and thinking.
The ACE trial is an early-stage multi-center randomized controlled trial (RCT) designed to test the effect of a 24-month intervention of 10 mg/day equol supplementation on arterial stiffness, white matter lesions (WMLs) in the brain and cognitive decline among 400 individuals aged 65 and 85 without dementia. Recent studies in Japan reported that a diet high in soy and soy isoflavones is inversely associated with incident cognitive impairment and dementia. The Women's Isoflavone Soy Health (WISH) in the US, an RCT of soy isoflavones, however, showed no significant effect on cognition. We posit that the discrepant result is due to the difference in equol-producing capability. Equol, a metabolite of soy isoflavone daidzein transformed by the gut microbiome, is the most bioactive among all soy isoflavones and their metabolites. 50-70% of Japanese convert daidzein to equol in contrast to 20-30% of Americans. Arterial stiffness, a significant predictor of cognitive decline, is significantly improved in a short-duration RCT of 10 mg/day equol supplementation in middle-aged subjects. WMLs are a risk factor for age-related cognitive decline and dementia. We reported a longitudinal association of equol-producing status with WML% (WML volume normalized to total brain volume) in cognitively normal elderly in Japan. The subgroup analysis of WISH showed that equol producers had better cognition than the control group, suggesting that equol may slow cognitive decline. No previous study has tested the effect of equol supplementation on arterial stiffness, WMLs or cognitive decline in older adults.
Inclusion Criteria:
Men and women age between 65 and 85 at entry of European Americans or African Americans
Inclusion criteria via screening visit:
Exclusion Criteria:
Exclusion criteria via initial screening by phone
Exclusion criteria via screening visit
In addition, individuals with the following condition will be excluded because these conditions do not allow subjects to undergo examinations the investigators proposed in the project:
Exclusion criteria at structural brain MRI Any other conditions which, in the opinion of the investigator, might pose a risk to the participant or make participation in the study not in the participant's best interest
*1 Few studies have investigated the association of equol, a metabolite of soy isoflavone daidzein, with breast cancer. These studies reported no significant association of serum or urine equol with the risk of breast cancer. Dietary intake of soy and soy isoflavones is generally considered to have benefits for menopausal symptoms, cardiovascular health, bone health, and cancers of the breast and prostate. Observational studies show that soy consumption is associated with a reduced risk of many cancers including breast cancer. Moreover, a prospective cohort study of 6,000+ North American women with breast cancer showed that dietary intake of soy and isoflavones was associated with reduced all-cause mortality. However, there is little evidence to support that the use of supplements containing soy isoflavones or soy protein powder to reduce cancer risk. A recent large prospective cohort study in France reported that supplementation of soy isoflavones increased the risk of estrogen receptor-negative breast cancer, especially among women who had a history of breast cancer in first-degree relatives.
Exclusion criteria at the baseline visit
The investigators recruit subjects without dementia. Thus, at the initial screening by phone, the investigators exclude individuals whose score for the Telephone Interview for Cognitive Status is 22 and below. Then, at the screening visit, investigators will exclude individuals with a Quick Dementia Rating System score ≥ 6.0.