We received an interesting question about whether or not infants (under age one year) should be given flaxseeds on a regular basis as a source of alpha-linolenic acid (ALA). Based on our research, we don’t recommend using flaxseeds as the only source of ALA for infants.
Although flaxseeds contain only a relatively small amount of cyanide (1, 2), the amount of flaxseeds needed to supply an adequate amount of ALA for an infant (3, 4) would come with more cyanide than is considered safe for an infant (5).
Exclusively breastfed infants of well-nourished mothers will get the ALA they need from breast milk. ALA is added to infant formulas.
As infants begin eating solid foods, small amounts of flaxseed—about 1/4 tsp of ground seeds per day—can supply additional ALA while not exceeding the safe level of cyanide. Infants can also get ALA from small amounts of canola oil, flaxseed oil, walnut oil, and chia seeds.
Update August 2020:
Hemp seed oil is no longer on our list of ALA sources for infants because of reports that some, but not all, samples of hemp seed oil had concentrations of total cannabinoids or of Δ-9-tetrahydrocannabinol (THC) that are considered excessive (6, 7) and that could potentially lead to neurological symptoms. This is of concern for infants and young children who could more easily exceed the upper safe limit for THC on a body weight basis (8).
References
3. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: National Academies Press, 2002.