There's a miracle berry that can help you live longer and healthier and chances are you've never heard of it.It's called acai and it could help you ward off cancer, protect your heart, even prevent Alzheimer's disease, according to some research.Acai berries contain mind-boosting chemicals that may delay dementia. They can lower cholesterol and a new study even found they kill leukemia cells."Whether they drink it as a juice, or whether they use it in a smoothie or take it as a supplement, it will boost the antioxidants in their diet. It has been recommended by the USDA to increase our antioxidants. High antioxidants in the blood have an inverse reaction to disease," said Lailina Wisoff, a Kaiser Permanente dietician.Local health food stores sell acai berries in natural fruit juices and you can also find acai smoothie mixes in the frozen fruits section.The berries are very tart, so dieticians suggest adding a little apple juice as sweetener.