Multisport Magazine Issue 22 - Page 43

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, ca մ̰ͽմ)٥х́ı́ݕ)хչͅɅѕ䁅́)ɽѕ̸)=,$ѕȁЁȸ)ݰ$ѡ)Ёɍ͔ɕٕ)$ѼЁѡ)ݑȽɽ镸ձ5剔MЁ$ݽձ)ɽٔͅЁȁ͵ѡ́ɕѱ)ѕȁɅѼ᥵̸͔ )ɕȰѡȁٕх́ɥ)ͼхѥᥑ́٥х́)Ʌ̸ѡ́ɕձ)ɍ͔ݥѠͽ́ѕͥ)ɔѼѥѠMeЁ)ԁɔЁݥѼɬЀ)ݑȸeԁѥѡ)ͽ䁽()$8LP$PTP