Acai is native to the rainforests of South America, and can be more than 40% of the nutritional intake of some tribes. It gained popularity as a superfood due to its high concentration of antioxidants.

Acai's impact on actual disease has not been studied extensively, and has been the subject of legal action for false claims. While high in antioxidants, the health benefits of acai are yet to be fully determined.

Moringa is a fruit tree native to Southern India. Though people eat the fruits, most of the antioxidant value is in the leaves and roots. The plant contains over 90 well-studied  nutrients and phytonutrients.

Moringa can be toxic at high levels. It is not appropriate for pregnant women because it has been shown to induce abortions in various mammals.

Spirulina is a form of cyanobacterium, a kind of photosynthetic bacteria. It can't really be considered a fruit, vegetable or animal, but it is highly sought after as a superfood, rich in iron and protein. 

Spirulina contains microcystins which, when taken over a long period of time, can cause liver toxicity and intestinal upset. The disease-fighting benefits have not been extensively studied.

Goji berries are considered a superfood that is high in antioxidants, and increases energy levels, athletic performance, quality of sleep, mental acuity, calmness, and significantly reduced fatigue and stress.

Goji berries can interact with medications like Warfarin and some diabetes drugs. Also, goji berries have been documented to cause sleep problems.