Final answer:
Alpha-linolenic acid (ALA) is an omega-3 fatty acid that is essential for human health and must be obtained through diet. It can be found in nuts, seeds, certain oils, whole grains, legumes, and leafy vegetables.
Step-by-step explanation:
Alpha-linolenic acid (ALA) is a type of polyunsaturated fatty acid that is classified as an omega-3 fatty acid. It is essential for human health, but our bodies cannot synthesize it, so it must be obtained through our diet. Rich sources of ALA include nuts like walnuts, flaxseeds, hemp seeds, chia seeds, as well as certain plant oils such as flaxseed oil, canola oil, and soybean oil. Furthermore, whole grains, legumes, and dark green leafy vegetables also provide ALA. Incorporating these foods into your diet can help ensure you're getting enough of this important fatty acid.