With the rise of fad diets, so-called superfoods, and a growing range of dietary supplements on the market, it's hard to know what to eat to prevent dementia and increase our lifespan. But there is solid science behind the power of certain foods to protect your brain from oxidative damage and improve cognition and memory.

More and more studies are pointing to lifestyle changes to protect our brains from diseases including Alzheimer's. Noted expert Dr. Gary Small, author of "2 Weeks to a Younger Brain" and editor of The Mind-Body Health Report, tells Newsmax that according to researchers at the University of California at San Francisco, up to half the Alzheimer's cases are potentially attributable to "modifiable risk factors."

"In our book we focus on nutrition as well as stress management, physical exercise, and mental stimulation to keep the brain healthy and potentially delay the symptoms of dementia," says Small. In fact, studies have shown that sticking to the MIND diet is associated with 30 to 35 percent lower risk of cognitive impairment in older adults. The MIND diet, which stands for the Mediterranean-DASH Intervention for Neurodegenerative Delay, is a hybrid of both the famous Mediterranean and DASH diets.

As we age, our metabolism becomes less efficient and is less able to get rid of compounds generated from what is termed "oxidative stress." The toxic compounds generated by oxidative stress steadily build up, slowly damaging the brain and eventually leading to symptoms of Alzheimer's disease.

"Antioxidant fruits and vegetables protect the brain from oxidative stress, which causes wear and tear on our neurons as we age," notes Small. "Omega-3 fats from fish fight brain inflammation, helping us reduce the risk for age-related cognitive decline. Minimizing consumption of processed foods and refined sugars reduces the risk for diabetes, which further protects brain health throughout life."

Here are the five top foods to boost brain power:

1. Fish. According to Inverse, eating fish provides your body with a good source of protein. Oily fish in particular are chock full of the omega-3 fats Dr. Small recommends to protect memory, cognitive function, and prevent Alzheimer's disease. There's also a healthy amount of vitamin D in fish. Vitamin D deficiency has been linked to many dreaded diseases, including Parkinson's, vascular dementia, and others.
2. Berries. Colorful berries are excellent antioxidants and it's important to eat a variety of them to reap the full benefits. Blueberries, for example, contain anthocyanins, which have been shown to protect our brains against Alzheimer's disease, while strawberries are high in vitamin C, a vital antioxidant molecule in the brain.
3. Sweet potatoes. Folks in the Blue Zone area of Okinawa, Japan, where people live the longest, eat an abundance of purple sweet potatoes. However, the orange ones are also rich in antioxidants that protect your body and brain from free radical damage, according to Healthline.
4. Green vegetables and herbs. As Dr. Small points out, eating veggies and herbs like those found in the Mediterranean diet reduces your risk of Alzheimer's disease. Green vegetables are rich in vitamins A and C, folate, and polyphenols that protect brain neurons against toxins and help reduce inflammation.
5. Beetroot. This vegetable is an excellent source of folate and polyphenols, as well as copper, manganese, and other nutrients that reduce oxidative stress and inflammation. Beets also contain nitrates, which may help increase blood flow to the brain, improve cognitive function, and reduce the risk of dementia.