Eating Blueberries Every Day Reduces Heart Risk

A new study pub­lished in the American Journal of Clinical Nutrition pro­vided more evi­dence that the rep­u­ta­tion of blue­ber­ries for being a super­food is well deserved. It showed eat­ing one cup of the fruit per day may reduce the risk of car­dio­vas­cu­lar dis­ease by 15 per­cent.

Researchers at the University of East Anglia (UEA) led the inves­ti­ga­tion, and col­leagues from Harvard and other U.K. insti­tu­tions col­lab­o­rated. The team con­cluded that blue­ber­ries and other berries should be included in a dietary approach to lower the like­li­hood of car­dio­vas­cu­lar dis­ease, espe­cially among peo­ple at high risk.

The study’s goal was to deter­mine if blue­ber­ries might have an effect on meta­bolic syn­drome, a dis­or­der affect­ing one-third of adults in Western coun­tries. The syn­drome is defined as hav­ing three of the fol­low­ing risk fac­tors: high blood sugar, high blood pres­sure, high lev­els of triglyc­erides, low lev­els of good cho­les­terol and exces­sive fat in the waist­line.

“Having meta­bolic syn­drome sig­nif­i­cantly increases the risk of heart dis­ease, stroke and dia­betes and often statins and other med­ica­tions are pre­scribed to help con­trol this risk,” lead researcher Professor Aedin Cassidy, of UEA’s Norwich Medical School, said. ​“It’s widely rec­og­nized that lifestyle changes, includ­ing mak­ing sim­ple changes to food choices, can also help.

“Previous stud­ies have indi­cated that peo­ple who reg­u­larly eat blue­ber­ries have a reduced risk of devel­op­ing con­di­tions includ­ing type 2 dia­betes and car­dio­vas­cu­lar dis­ease,” Cassidy added.

The par­tic­i­pants were 138 over­weight and obese indi­vid­u­als between age 50 and 75, all of whom had meta­bolic syn­drome. One group ate one cup of blue­ber­ries per day, another ate a half cup of blue­ber­ries per day, and a third ate a placebo with arti­fi­cial color and fla­vor­ing that was designed to look and taste like blue­ber­ries. The inter­ven­tion period was six months.

According to co-lead author Peter Curtis, the group who ate one cup of blue­ber­ries per day showed sus­tained improve­ments in arte­r­ial stiff­ness and vas­cu­lar func­tion. These ben­e­fits resulted in low­er­ing the risk of car­dio­vas­cu­lar dis­ease by 12 to 15 per­cent. The pos­i­tive effects were not seen in the group who ate a half cup of blue­ber­ries per day.

The find­ings sug­gest that greater con­sump­tion of the fruit is needed to improve heart health in the obese than the con­sump­tion needed in the gen­eral pop­u­la­tion, Curtis explained, and his take­away was clear.

“The sim­ple and attain­able mes­sage is to con­sume one cup of blue­ber­ries daily to improve car­dio­vas­cu­lar health,” he said.

Meanwhile, Cassidy told Olive Oil Times why blue­ber­ries may be of value for the heart.

“Blueberries con­tain pow­er­ful bioac­tive com­pounds called antho­cyanins, which are part of the flavonoid fam­ily,” she said. ​“In lab and ani­mal exper­i­ments we know that antho­cyanins, the ingre­di­ent that imparts the bril­liant red-blue col­ors in fruits and other plant foods, can reduce inflam­ma­tion, keep arter­ies healthy, improve blood flow and reduce cho­les­terol lev­els.”

While eat­ing one cup of blue­ber­ries per day seems like a siz­able amount, Cassidy told Olive Oil Times that peo­ple who are not at risk of heart dis­ease could receive a sim­i­lar ben­e­fit from eat­ing fewer berries each day.

“This is the first long-term trial in at-risk peo­ple to show heart-health ben­e­fits and pro­vide evi­dence of mech­a­nisms to back up the ben­e­fits,” she said. ​“Although in these par­tic­i­pants we didn’t see any pos­i­tive effects with a half cup a day, we think the gen­eral pop­u­la­tion may expe­ri­ence a ben­e­fit from this amount.”

“We have great pop­u­la­tion-based data from large cohorts show­ing that the habit­ual intake of just three serv­ings a week reduces the risk of hav­ing a heart attack,” she added. ​“The next step in research is a clin­i­cal trial in health­ier peo­ple.”

• The American Journal of Clinical Nutrition


• University of East Anglia