Eating fresh strawberries boosts red blood cells
12 July 2011
Eating strawberries for two weeks can improve the antioxidant
capacity of blood and the ability of the body to protect itself from a
range of diseases and physiological stresses.
Scientists have previously tried to confirm the antioxidant
capacity of strawberries using in vitro laboratory
experiments. Now, a team of researchers from the Marche Polytechnic
University (UNIVPM, in Italy) and the University of Granada (UGR, in
Spain) have demonstrated this effect in vivo, in a study on
In the study , a group of volunteers ate half a kilo of
strawberries every day for two weeks. Each day, the scientists fed
12 healthy volunteers 500 grams of strawberries (of the 'Sveva'
variety) over the course of the day. They took blood samples from
them after four, eight, 12 and 16 days, and also a month later. The
results show that regular consumption of strawberries can improve
the antioxidant capacity of blood plasma and also the resistance of
red blood cells to oxidative haemolysis (fragmentation).
"We have shown that some varieties of strawberries make
erythrocytes more resistant to oxidative stress. This could be of
great significance if you take into account that this phenomenon can
lead to serious diseases", said Maurizio Battino, lead author of the
study and a researcher at the UNIVPM.
The team is now analysing the variations caused by eating smaller
quantities of strawberries (average consumption tends to be a 150g
or 200g bowl per day). "The important thing is that strawberries
should form a part of people's healthy and balanced diet, as one of
their five daily portions of fruit and vegetables", Battino points
Professor Battino told MTB Europe that the antioxidative
capacity of strawberries remains higher than other fruit after
processing such as freezing or jam making. In a previous study 
he reviewed the range of bioactive compounds in berries that are
relevant to human health. These include several antioxidants, such
as vitamin C, polyphenols, anthocyanins, which are present in
different amounts in different fruits and vary with environmental
and genetic factors.
The search for the most antioxidant variety
"Various strawberry varieties are also being analysed in the
laboratory, since they each contain antioxidants in differing
amounts and proportions", explains José Luis Quiles, the Spanish
participant in the study and a researcher at the UGR.
The body has an extensive arsenal of very diverse antioxidant
mechanisms, which act at different levels. These can be cellular
tools that repair oxidised genetic material, or molecules that are
either manufactured by the body itself or consumed through the diet,
which neutralise free radicals. Strawberries contain a large amount
of phenolic compounds, such as flavonoids, which have antioxidant
These substances reduce oxidative stress, an imbalance that
occurs in certain pathologies, (such as cardiovascular disease,
cancer and diabetes) and physiological situations (birth, ageing,
physical exercise), as well as in the battles between "reactive
kinds of oxygen" — in particular free radicals — and the body's
When the level of oxidation exceeds these antioxidant defences,
oxidative stress occurs. Aside from causing certain illnesses, this
is also implicated in phenomena such as the speed at which we may
age, for example.
1. Sara Tulipani, José M. Álvarez-Suarez, Franco Busco, Stefano
Bompadre, José L. Quiles, Bruno Mezzetti , Maurizio Battino.
"Strawberry consumption improves plasma antioxidant status and
erythrocyte resistance to oxidative haemolysis in humans". Food
Chemistry 128 (1): 180-186, September 2011 (available on line 9
March 2011). Doi:10.1016/j.foodchem.2011.03.025.
2. Maurizio Battino, Jules Beekwilder, Beatrice Denoyes-Rothan,
Margit Laimer, Gordon J McDougall, and Bruno Mezzetti. Bioactive
compounds in berries relevant to human health. Nutrition Reviews,
Vol. 67(Suppl. 1):S145–S150. doi:10.1111/j.1753-4887.2009.00178.x