Blueberries are loaded with nutrients and fiber, but if you have certain medical conditions, they may cause side effects such as gastrointestinal symptoms.

The convenience of frozen blueberries allows you to enjoy the antioxidant-rich fruit any time of year. Frozen berries are less likely to spoil and are often less expensive than fresh.

Blackberries are small fruits composed of tiny pockets called drupelets, according to the textbook "Biology: Life on Earth with Physiology." Like raspberries, they are not true berries and are called aggregate fruits. They contain large quantities of fiber, vitamin C and other important nutrients.

Ruby-red cranberries often appear on holiday tables, but they are a healthy and flavorful fruit for any time of year. Cranberries supply a good source of vitamin C and the fruits contain antioxidants that help prevent heart diseases, according to the University of Georgia.

Acai berries have been dubbed a "super fruit," with the media touting these berries as the key to the world's weight loss woes and the cure to a host of adverse health conditions. Despite these claims, scientists have not found conclusive evidence of these benefits.

Juniper berries are used in herbal medicine, and also flavor certain foods and gin. Although they are called berries, they are part of the cone and not a true berry. Most people can safely consume juniper berries in the amounts used in food, but some people should avoid consuming juniper in medicinal amounts.

Urine can become discolored due to certain foods, food dyes and supplements you consume. Berries, including cranberries, can stain your urine. Your level of hydration and what else you ate with the cranberries will vary the color of your urine.

Cranberry juice contains a number of nutrients such as vitamins C, E and K that your body needs. Along with being a rich source of antioxidants, cranberry juice contains calcium, phosphorus and potassium, and it is low in cholesterol and saturated fat.

Like most berries, blackberries and blueberries are low in calories and fat. They are good sources of fiber and offer several essential vitamins and minerals. Either berry is a healthy and nutritious addition to your diet, but there are a few specific nutritional differences between blackberries and blueberries.

As strawberries pass their peak to the point of becoming overripe, they begin to lose their vibrant flavor, color and juiciness. You don’t have to toss them just yet, as there are several recipes where overripe strawberries will work just as well as fresh berries.

The benefits of eating blueberries and strawberries may far outweigh any health risks. Dr. Eric Rimm of Harvard Medical School advises people of all ages to eat more berries for heart health. Some people may have allergic reactions to berries or experience digestive problems, however, if they consume too many.

A food allergy occurs when the body's immune system mistakes an ingredient in food as harmful, which triggers antibodies in the immune system to attack the food.