Meta-analysis supports carotenoids for cardio-metabolic health benefits

Writing in Nutrition Reviews​,​ scientists from the National Institute on Aging at the National Institutes of Health report that alpha- and beta-carotene, as well as retinyl esters, were inversely associated with MetS. However, no association was found between serum retinol and MetS occurrence.

Metabolic syndrome (MetS) is a condition characterized by central obesity, hypertension, and disturbed glucose and insulin metabolism. The syndrome has been linked to increased risks of both type 2 diabetes and cardiovascular diseases.

“To the authors’ knowledge, this is the first review and meta-analysis to comprehensively assess the relationship of serum retinol (vitamin A), retinyl esters, and carotenoids with the clustering of cardiometabolic risk factors known as the metabolic syndrome (MetS),”​ they wrote.

“Among the key findings of this meta-analysis is the strong inverse associations of serum total carotenoids and b-carotene with MetS occurrence; these associations yield the most convincing evidence that consuming a diet rich in mixed carotenoids may be beneficial to cardio-metabolic health.”​

Welcome​

The meta-analysis’ findings were welcomed by ExcelVite, which offers the EVTene ingredient, a natural mixed-carotenoid extract from sustainably-sourced palm fruits.

Diyanah Roslan, Nutritionist of ExcelVite, commented: “Metabolic syndrome (MetS) is one of the major threats to public health because it increases disability, healthcare cost and mortality rates. The prevalence of MetS has also increased over the past decades. ​

“The putative role of serum carotenoid in regulating the risk for MetS has been evidenced in this meta-analysis that collected and reviewed research from the past 20 years linking serum carotenoids to MetS.”​

“ExcelVite’s EVTene is a natural mixed-carotenoid extract from sustainably-sourced palm fruits containing high level of alpha- and beta- carotene with some amounts of other carotenoid such as gamma-carotene and lycopene,” ​explained Bryan See, Business Development Manager of ExcelVite.

“The carotenoid composition in EVTene is similar to that found in carrots and can be incorporated into various type of food and beverage products as well as dietary supplement, hence providing a convenient way to acquire high level of alpha- and beta-carotene in our daily diet.”​

Meta-analysis details​

The researchers conducted a systematic review and meta-analysis of case–control, cross-sectional, and cohort studies published between 1997 and 2017. Thirty-three studies were included in the systematic review, while 11 were included in the meta-analysis, providing data for 29,673 participants.

The results indicated higher carotenoid intakes were inversely associated with the presence of MetS for all individuals. The strongest associations were observed for beta-carotene, followed by alpha-carotene and beta-cryptoxanthin.

While the data shows correlation and not causation, there is plausible mechanism of action for carotenoids to benefit cardio-metabolic health, linked to oxidative stress

“[T]his meta-analysis confirms a putative beneficial role of higher serum carotenoid in the regulation of the clustering of cardiometabolic risk factors associated with MetS,” ​wrote the researchers. “The role of retinol remains controversial and needs further inquiry.​

“Although there are a host of factors that explain inter-individual variability and carotenoid bioavailability in humans, these data suggest that carotenoids may play an essential role in adipose tissue biology, including the control of adipogenesis, oxidative stress, and the production of adipokines and inflammatory mediators that affect the distribution of central adiposity and the occurrence of insulin resistance. ​

“Because [beta]-carotene intake in a typical Western diet can be as low as 1–5 mg/day from natural dietary sources, these data argue for establishing a recommended daily intake, which may be useful in preventing cardiometabolic disease.” ​

The study authors were affiliated with the ational Institute on Aging at the National Institutes of Health, Massachusetts Department of Public Health, the Nemours Children’s Clinic (Jacksonville, FL), and Johns Hopkins All Children’s Hospital (St. Petersburg, FL). 

Source: Nutrition Reviews​​
Published online ahead of print, doi: 10.1093/nutrit/nuy044​
“Carotenoids, vitamin A, and their association with the metabolic syndrome: a systematic review and meta-analysis”​
Authors: M.A. Beydoun  et al.