Sardine is a Green-Green food. Green-Green foods are very safe to eat as a regular part of a diet.
Guideline related quotes related to Finfish and Green-Green throughout Geoff Bond's publications.
For the meat, poultry, eggs, and fish group, Preferably consume two servings a day of “Green-Green” foods. If unavailable, you can consume two servings a day of “Green” foods. ~Paleo in a Nutshell p.102
For the meat, poultry, eggs, and fish group Restrict total food group servings per session to one. ~Paleo in a Nutshell p.102
For the meat, poultry, eggs, and fish group, Restrict total food group servings per day to two. ~Paleo in a Nutshell p.102
Specific references to Sardine throughout Geoff Bond's publications.
All seafood is an acceptable component of the Savanna Model feeding pattern. The "oily fish," rich in omega-3 oils, are best, such as wild salmon, sardines, herring, and mackerel. Other fish and shellfish have an excellent essential fatty acid profile and are also good. ~Paleo in a Nutshell p.70
With regard to animal matter, many methods of conservation are acceptable. Canned oily fish (such as sardines) are, in nutritional terms, just as good as fresh. Just choose the versions that are preserved in olive oil, canola oil, or unsalted water. Smoked salmon or kipper are good, although watch out for high salt content. ~Paleo in a Nutshell p.92
Up until the 1970s, virtually the only fish on our plates were ones caught in the wild. Now, we have seen the huge volume of fish, notably salmon and trout, that are produced by fish farms. Even so, most other species that we find in our supermarkets (fresh, frozen, or canned) are still wild. Cod, halibut, tuna, sardine, plaice, mackerel, pollock, herring, and many others, for the time being at least, are all caught in the wild. We can say that many of them conform to the Savanna Model while the others, if not conforming, are certainly not harmful. ~Deadly Harvest p.63
Omega-3 EFAs are found in plants and animal matter. In plants, the most common form is alpha-linolenic acid (ALA), found particularly in walnuts, flaxseed, hempseed, and rapeseed (canola oil). In animals, omega-3 oils are particularly found in "oily" fish, such as sardines, salmon, trout, and tuna. ~Deadly Harvest p.104