How the speaker casts doubt on the author's claims

The speaker states that the idea of super power food is exaggerated, yet the evidence has not been approved by scientists. However the author's claim super powerful food can bring so many benefits, such as preventing Alzheimer, cancer, and cholesterol related diseases.

First, the orator casts doubt on the idea that blueberries have had positive effects in human, so it does not help to prevent Alzheimer. He mentions that the studies were done in animals, but human. Thus, the information provides by the author cannot be truth, since the evidence is not reliable.

Second, the speaker opposes against the idea that tomatoes and based tomato products could prevent cancer. Thus, it is just speculation rather than direct evidence. According to the speaker, they cannot guarantee that a person who eats tomatoes and vegetables are not going to have cancer later in the future.

Finally, the lecturer challenges the author's claim about garlic benefits. The speaker points out that recent studies made in human show that after 6 months the effects of garlic in human's body disappears. Moreover, the studies that show positive garlic's effect to prevent cancer were conducted on mice and not in people. Therefore, the speaker says that there are not real proves to show garlic's positive effects on human's body.

Through the lecture the speaker opposes against the information provided by the writer regarding the benefits of super power food.