Large-scale randomized clinical trials of bioactives and nutrients in relation to human health and disease prevention - Lessons from the VITAL and COSMOS trials

Long-Term Effect of Randomization to Calcium and Vitamin D Supplementation on Health in Older Women : Postintervention Follow-up of a Randomized Clinical Trial

BACKGROUND

Although calcium and vitamin D (CaD) supplementation may affect chronic disease in older women, evidence of long-term effects on health outcomes is limited.

OBJECTIVE

To evaluate long-term health outcomes among postmenopausal women in the Women's Health Initiative CaD trial.

DESIGN

Post hoc analysis of long-term postintervention follow-up of the 7-year randomized intervention trial of CaD. (ClinicalTrials.gov: NCT00000611).

SETTING

A multicenter (n = 40) trial across the United States.

PARTICIPANTS

36 282 postmenopausal women with no history of breast or colorectal cancer.

INTERVENTION

Random 1:1 assignment to 1000 mg of calcium carbonate (400 mg of elemental calcium) with 400 IU of vitamin D3 daily or placebo.

MEASUREMENTS

Incidence of colorectal, invasive breast, and total cancer; disease-specific and all-cause mortality; total cardiovascular disease (CVD); and hip fracture by randomization assignment (through December 2020). Analyses were stratified on personal supplement use.

RESULTS

For women randomly assigned to CaD versus placebo, a 7% reduction in cancer mortality was observed after a median cumulative follow-up of 22.3 years (1817 vs. 1943 deaths; hazard ratio [HR], 0.93 [95% CI, 0.87 to 0.99]), along with a 6% increase in CVD mortality (2621 vs. 2420 deaths; HR, 1.06 [CI, 1.01 to 1.12]). There was no overall effect on other measures, including all-cause mortality (7834 vs. 7748 deaths; HR, 1.00 [CI, 0.97 to 1.03]). Estimates for cancer incidence varied widely when stratified by whether participants reported supplement use before randomization, whereas estimates on mortality did not vary, except for CVD mortality.

LIMITATION

Hip fracture and CVD outcomes were available on only a subset of participants, and effects of calcium versus vitamin D versus joint supplementation could not be disentangled.

CONCLUSION

Calcium and vitamin D supplements seemed to reduce cancer mortality and increase CVD mortality after more than 20 years of follow-up among postmenopausal women, with no effect on all-cause mortality.

PRIMARY FUNDING SOURCE

National Heart, Lung, and Blood Institute of the National Institutes of Health.

Multivitamin Supplementation Improves Memory in Older Adults: A Randomized Clinical Trial

BACKGROUND

Maintenance of cognitive abilities is of critical importance to older adults, yet few effective strategies to slow cognitive decline currently exist. Multivitamin supplementation is used to promote general health; it is unclear whether it favorably affects cognition in older age.

OBJECTIVES

To examine the effect of daily multivitamin/multimineral supplementation on memory in older adults.

METHODS

The COcoa Supplement and Multivitamin Outcomes Study Web (COSMOS-Web) ancillary study (NCT04582617) included 3562 older adults. Participants were randomly assigned to a daily multivitamin supplement (Centrum Silver) or placebo and evaluated annually with an Internet-based battery of neuropsychological tests for 3 y. The prespecified primary outcome measure was change in episodic memory, operationally defined as immediate recall performance on the ModRey test, after 1 y of intervention. Secondary outcome measures included changes in episodic memory over 3 y of follow-up and changes in performance on neuropsychological tasks of novel object recognition and executive function over 3 y.

RESULTS

Compared with placebo, participants randomly assigned to multivitamin supplementation had significantly better ModRey immediate recall at 1 y, the primary endpoint (t(5889) = 2.25, P = 0.025), as well as across the 3 y of follow-up on average (t(5889) = 2.54, P = 0.011). Multivitamin supplementation had no significant effects on secondary outcomes. Based on cross-sectional analysis of the association between age and performance on the ModRey, we estimated that the effect of the multivitamin intervention improved memory performance above placebo by the equivalent of 3.1 y of age-related memory change.

CONCLUSIONS

Daily multivitamin supplementation, compared with placebo, improves memory in older adults. Multivitamin supplementation holds promise as a safe and accessible approach to maintaining cognitive health in older age. This trial was registered at clinicaltrials.gov as NCT04582617.

Antioxidants and Bioactive Compounds in Food: Critical Review of Issues and Prospects

This review paper gives an insight into the effective delivery mechanisms for health-promoting substances and highlights the challenges of using antioxidants and bioactives in foods. The selection criteria for choosing bioactives and their extraction in bioavailable form with their adequate incorporation techniques and delivery mechanisms are covered. Moreover, an overview of existing methods for determination of bioactivity is given. The importance of scientifically evaluating the effects of foods or food components on consumer health before making claims about the healthiness is aligned. Finally, a scientific perspective on how to respond to the booming demand for health-promoting products is given, and we acknowledge that despite the work done, there are still many challenges that need to be overcome.

OUP accepted manuscript

Background

Objective

Method

Results

Conclusions

Highlights

Impact of Diet on Plasma Lipids in Individuals with Heterozygous Familial Hypercholesterolemia: A Systematic Review of Randomized Controlled Nutritional Studies

BACKGROUND

Conclusive data on the effectiveness of dietary interventions in heterozygous familial hypercholesterolemia (HeFH) management are unavailable. Whether this is due to a true lack of effects or biases in intervention designs remains unsettled. We systematically assessed the impact on LDL-C of published dietary randomized controlled trials (RCTs) conducted among individuals with HeFH in relation to their design and risk of bias.

METHODS

We systematically searched PubMed, Web of Science, and Embase in November 2020 to identify RCTs that assessed the impact of: (1) food-based interventions; (2) dietary counseling interventions; or (3) dietary supplements on LDL-C in individuals with HeFH. We evaluated the risk of bias of each study using the Cochrane Risk of Bias 2 method.

RESULTS

A total of 19 RCTs comprising 837 individuals with HeFH were included. Of those, five were food-based interventions, three were dietary counseling interventions and 12 were dietary supplement-based interventions (omega-3, n = 3; phytosterols, n = 7; guar gum, n = 1; policosanol, n = 1). One study qualified both as a food-based intervention and as a dietary supplement intervention due to its factorial design. A significant reduction in LDL-C levels was reported in 10 RCTs, including eight dietary supplement interventions (phytosterols, n = 6, omega-3, n = 1; guar gum, n = 1), one food-based intervention and one dietary counseling intervention. A total of 13 studies were judged to have some methodological biases in a way that substantially lowers confidence in the results. Studies at low risk of biases were more likely to report significant reductions in LDL-C concentrations, compared with studies at risk of bias (chi-square statistic: 5.49; p = 0.02).

CONCLUSION

This systemic review shows that the apparent lack of effectiveness of diet manipulation in modulating plasma levels of LDL-C among individuals with HeFH is likely due to biases in study designs, rather than a true lack of effects. The likelihood of reporting significant reductions in LDL-C was associated with the concurrent risk of bias.

Biomarker-estimated flavan-3-ol intake is associated with lower blood pressure in cross-sectional analysis in EPIC Norfolk

Flavan-3-ols are a group of bioactive compounds that have been shown to improve vascular function in intervention studies. They are therefore of great interest for the development of dietary recommendation for the prevention of cardio-vascular diseases. However, there are currently no reliable data from observational studies, as the high variability in the flavan-3-ol content of food makes it difficult to estimate actual intake without nutritional biomarkers. In this study, we investigated cross-sectional associations between biomarker-estimated flavan-3-ol intake and blood pressure and other CVD risk markers, as well as longitudinal associations with CVD risk in 25,618 participants of the European Prospective Investigation into Cancer (EPIC) Norfolk cohort. High flavan-3-ol intake, achievable as part of an habitual diet, was associated with a significantly lower systolic blood pressure (- 1.9 (- 2.7; - 1.1) mmHg in men and - 2.5 (- 3.3; - 1.8) mmHg in women; lowest vs highest decile of biomarker), comparable to adherence to a Mediterranean Diet or moderate salt reduction. Subgroup analyses showed that hypertensive participants had stronger inverse association between flavan-3-ol biomarker and systolic blood pressure when compared to normotensive participants. Flavanol intake could therefore have a role in the maintenance of cardiovascular health on a population scale.

Design and baseline characteristics of the cocoa supplement and multivitamin outcomes study for the Mind: COSMOS-Mind

BACKGROUND

Large simple trials are potentially efficient and cost-effective approaches to assess interventions to preserve cognitive function in older adults. High-dose cocoa flavanols supplementation is a promising intervention that warrants additional testing. We describe the design, recruitment success, and baseline characteristics of the Cocoa Supplement and Multivitamin Outcomes Study for the Mind (COSMOS-Mind) trial.

METHODS

COSMOS-Mind is an ancillary study to the large-scale and predominantly mail-based COSMOS randomized controlled clinical trial. COSMOS is assessing whether cocoa extract (including 600 mg/d cocoa flavanols) and a multivitamin reduce risks for major cardiovascular events and total invasive cancer. COSMOS-Mind uses telephone-based interviews to assess cognitive function and impairment to determine whether cocoa flavanols benefit cognitive function in adults aged 65 years or older, targeting the enrollment of 2000 participants to provide >90% statistical power across 3 years of annual follow-up.

RESULTS

Of the 3224 COSMOS screenees who expressed interest in COSMOS-Mind, 2350 (76%) successfully completed baseline cognitive assessments and 2262 (96%) geographically diverse, eligible individuals were ultimately enrolled over one year. At baseline, the primary outcome, a composite of cognitive test scores, was inversely associated with age in a manner consistent with assumptions used in projections of statistical power.

CONCLUSIONS

Older adults are willing to enroll in large simple trials that include telephone-based cognitive assessments. Embedding these trials in large studies of other health outcomes is efficient and expands the scientific knowledge gained from the research. ClinicalTrials.gov Identifiers: NCT03035201 (COSMOS-Mind); NCT102422745 (parent COSMOS).