Do sardines provide more bioavailable calcium and collagen than meat or eggs?

Sardines are small fish eaten whole, including the bones and skin, which are rich in calcium and collagen. Unlike muscle meats like beef or chicken, which contain little to no bone, and eggs, which have minimal collagen and almost no calcium in the edible parts, sardines offer these nutrients in forms the body can absorb more easily. The calcium in sardine bones is naturally bound in a way that may improve its uptake, and the collagen comes from the soft, edible skeleton and connective tissues that are typically removed in other animal foods.

What we’ve found so far suggests that if someone is looking to increase their intake of these two nutrients through food, sardines could be a more concentrated source than meat or eggs. However, this is based on a single assertion with no detailed breakdown of the 10.0 supporting points — we don’t know the study designs, sample sizes, or how “bioavailable” was measured.

We don’t yet have comparisons from controlled human trials or direct measurements of absorption rates between sardines and other foods. The evidence we’ve reviewed leans toward sardines being a stronger source, but we can’t say how much stronger or if this applies to everyone.

If you’re trying to get more calcium and collagen from your diet, including whole sardines — bones and all — might be a practical choice, but more research is needed to understand how this compares across different people and diets.