Could wild blueberries help burn fat during exercise?

Consuming a cup of wild blueberries daily for two weeks can help the body burn more fat during exercise, according to a new study.

The research, published recently in the journal Nutrients, is the first to examine the fat-burning effects of wild blueberries during exercise in non-elite athletes.

The blueberries can help accelerate fat oxidation in the body, the process by which fatty acid molecules are broken down for energy, found scientists, including those from the California Polytechnic State University in the US.

However, citing some of the limitations of the study, researchers said it included only 11 males and no women.

They said further research and including more participants can help verify the results and shed more light on the fat-burning effects of the berries.

The 11 healthy, aerobically trained males were instructed to follow a diet that included consuming 25 grams of freeze-dried wild blueberries each day for two weeks.

Each participant exercised on a bike for 40 minutes at Cal Poly Humboldt’s Human Performance Lab, and their urine and blood samples were collected before and after cycling. Their blood samples were collected every 10 minutes during the workout as well.

The findings suggest the participants notably burned more fat after consuming the blueberries.

The fat oxidation rate rose by about 20 per cent, 43 per cent and 31 per cent at 20, 30 and 40 minutes after cycling, according to the study.

The berries, known previously as a superfood, accelerate fat burning and also decrease the use of carbohydrates by the body – a metabolic change which scientists said could be significant for athletes.

“Increasing the use of fat can help performance, particularly in endurance activities as we have more fat stores to keep us going longer than we do carb stores,” study co-author Taylor Bloedon explained.

Researchers said saving stored carbs also helps when exercise intensity needs to be increased, particularly towards the end of a race or training session.

“At these higher intensities we cannot rely on fat to fuel us as fat cannot be used as a fuel source for high-intensity activities,” Dr Bloedon said.

The scientists also found that drastically cutting carbs when people want to burn more fat “may lead to negative health and performance outcomes”.

They say anthocyanins – the compounds which give fruits and vegetables their blue, red and purple colors – may be responsible for the increased fat oxidation.

“Women tend to have a greater ability to oxidize fat naturally so it will be interesting to see the results,” Dr Bloedon said.

“Results indicate that wild blueberries may increase the rate of fat oxidation during moderate-intensity activity in healthy, active males,” said the study.