Collagen

Beef tendon, used in dishes like pho, is a good source

I've been adding collagen to my diet and a collagen supplement to the array of morning vitamins. Lately there seems to be slightly less pain in the knee and shoulder, the reason I started taking the supplement in the first place.

The current science about collagen is slightly positive:

Some research has suggested there are benefits to supplements. A 2021 meta-analysis, or a review of existing research, on collagen supplements and skin aging published in the International Journal of Dermatology concluded that collagen supplements can improve skin hydration, elasticity and wrinkles. The analysis looked at 19 studies involving 1,125 participants between 20 and 70 years old.

Health publications recommend that seniors eat more protein and fewer carbohydrates, so I've been eating fish, poultry, meat, and eggs, which also have collagen. Like with coffee, modern science seems to say that many of the things I already enjoy consuming have health benefits.

They should stop further research before science changes its mind.