Case-control studies overall support a significant reduction in the risks of cancers of the esophagus, lung, stomach, and colorectum associated with both fruit and vegetables.
Breast cancer is associated with vegetables but not with fruit.
Bladder cancer is associated with fruit but not with vegetables.
The overall relative risk estimates from cohort studies suggest a protective effect of both fruit and vegetables for most cancer sites considered, but the risk reduction is significant only for cancers of the lung and bladder and only for fruit.
Seed is an embryonic plant enclosed in a protective outer covering. The formation of the seed is part of the process of reproduction in seed plants. Seeds have been an important development in the reproduction and success of gymnosperms and angiosperms plants, that now dominate biological niches on land.
The term "seed" also has a general meaning of anything that can be sown, e.g. "seed" potatoes (tubers), "seeds" of corn or sunflower "seeds".
Many structures commonly referred to as "seeds" are actually dry fruits. Different groups of plants have other modifications, the so-called stone fruits (such as the peach) have a hardened fruit layer (the endocarp) fused to and surrounding the actual seed.
Nuts are the one-seeded, hard-shelled fruit of some plants with an indehiscent seed (acorn, hazelnut).