PURE PERFORMANCE | NUTRITION brain cells and has an anti-inflammatory effect on mouse immune cells . However , there have been very few clinical trials involving human subjects consuming açaí .
A study from 2008 found that the levels of serum antioxidants increased in human subjects 1 hour and 2 hours after they drank a juice blend containing mostly açaí when compared to subjects drinking a placebo . A study from the same year showed that anthocyanin concentrations in plasma increased after human subjects consumed açaí pulp or juice ( remember anthocyanins are one of the major antioxidants in açaí ). Anthocyanins levels peaked at two hours and were higher after consuming açaí pulp compared to juice . This tells us that the antioxidants found in açaí enter the human circulation following consumption .
Another study looked at the effects of consuming açaí pulp ( 100 grams ) as a smoothie twice per day for one month in overweight subjects who were at risk for developing metabolic syndrome . Consumption of açaí reduced total cholesterol levels , LDL-cholesterol levels and fasting glucose and insulin levels , however , consumption of açaí had no effect on body weight , blood pressure or levels of C-reactive protein , which is a marker of inflammation .
I came across a study that was of interest to me as an endurance athlete . This study looked at the effects of supplementation with açaí juice on the blood antioxidant defence capacity in junior hurdlers . Why did these sports scientists investigate this ? Well , it is accepted that strenuous exercise is associated with increased production of free radicals and reactive oxygen / nitrogen species ( ROS / RNS ). Antioxidant supplementation in athletes may prevent exercise-induced tissue injury and assist recovery . These ROS / RNS are also important in muscle adaptation to exercise . So too much ROS / RNS can cause damage but at the same time they are required to signal to our muscles resulting in adaptation .
In the study I mentioned above elite junior hurdlers drank 100ml of an açaí juice blend daily for 6 weeks . The açaí juice had no effect on performance as assessed by 300m running times , however it did cause increases in the antioxidant capacity of the plasma of the hurdlers . It also improved the lipid profile by reducing total cholesterol , LDL cholesterol and triglycerides . These young hurdlers were within normal ranges at the start of the study anyway , but these values improved over the 6 weeks .
Supplementation with the açaí juice also lowered the levels of the enzymes creatine kinase and lactatedehydrogenase post-exercise .
These enzymes are markers of muscle damage . This means that supplementation with açaí may help your muscles recover after training .
Traditionally in the Amazon river basin açaí is used for its antidiarrheal activity . This has not been substantiated in any scientific studies .
To summarise , the human studies conducted on açaí consumption show us that the antioxidants from açaí do enter the blood stream and could potentially have a beneficial impact . These studies also show that açaí may have a cholesterol lowering effect but does not seem to impact cardiovascular outcomes , such as blood pressure or heart rate . Also , açaí may be useful for recovery after exercise and training .
Are there any negative effects from consuming açaí ? Açaí pulp is rich in the essential minerals calcium , iron , magnesium and zinc , but the levels of copper and manganese are exceptionally high . In some parts of Brazil , up to 300mls of açaí pulp can be consumed per day . This means that the daily intake of manganese could be six times the recommended amount . This could be a problem , especially for children , vegetarians / vegans and people with anemia , as iron absorption is impaired by manganese .
Conclusions Açaí certainly is abundant in antioxidants and these compounds are bioavailable in humans . There is also evidence that the juice and pulp from this fruit can lower LDL-cholesterol levels . It is also very nutritious being rich in potassium , magnesium , calcium , phosphorus , sodium and vitamins E and B1 , as well as containing unsaturated fatty acids and proteins .
OK , I feel better about spending $ 12.50 on an açaí bowl , and I like the findings about exercise recovery .
Am I going to go out and buy the powder / frozen pulp ? Maybe – but I would probably save it for smoothies directly after training to maximise benefits . But remember , other vegetables and berries also contain antioxidants and vitamins and minerals . And the benefits of regular exercise with some bursts of high-intensity are key to optimal health . So don ’ t feel bad if you are not willing to fork out $ 50 for açaí powder . You can still be a healthy person in my opinion .
INSTITUTE FOR GLYCOMICS GRIFFITH UNIVERSITY GOLD COAST , AUSTRALIA
DR LUCY SHEWELL E : l . shewell @ griffith . edu . au icantbelievethatshealthy . com
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