As you walk down the supplement aisle, it's not always easy to decide which ones are best suited to your needs. It's true that seniors have different supplement needs from athletes, who have different needs from growing teens. But there is one supplement that can benefit people of all ages: collagen. Here are four reasons to add a collagen supplement to your diet.

1. Collagen keeps your joints healthy.

Each of your joints contains collagen as a component of the connective tissue that attaches your tendons to your bones. A lack of collagen can perpetuate arthritis, making activity painful. Taking collagen throughout your lifetime can help keep your joints healthy, which will reduce the risk of injuries due to physical activity -- and also reduce the risk of arthritis as you age.

2. Collagen keeps your skin supple.

Who does not like strong, supple skin? Your skin contains collagen, but as you age, that collagen starts to become depleted, leading to the formation of wrinkles and fine lines. If you take collagen supplements, you may be able to slow this aging process, which could mean you don't require such expensive skin care products or dermatology treatments when you're older.

3. Collagen is a good source of protein.

Collagen is a protein. It's actually a complete protein, which means it contains all of the essential amino acids your body needs. If you don't eat a lot of meat, you may not get enough of certain amino acids in your diet, and collagen supplements can help. You can get a gluten-free bone broth collagen protein, although collagen is generally not a vegetarian product — since most of the good collagen supplements are derived from a bone broth.

4. Collagen may help reduce cellulite.

Are your upper legs or arms covered in cellulite? There is no miracle cure for cellulite, but if you combine collagen supplements with healthy exercise, you're likely to see cellulite decrease. The collagen will help firm up your skin, and the exercise will help build the muscles underneath to stretch the skin. If you are younger, taking collagen may help keep you from developing cellulite as you get older.

If you want to improve your diet, collagen supplements are a smart choice. Make sure you buy supplements from a reputable brand and look for ones that are gluten-free for best results. Keep in mind that collagen supplements are basically like concentrated bone broth. If you've benefited from bone broth in the past, you'll get similar effects from collagen supplements.