My family takes garlic supplements to prevent colds and flu. Is there a way to give garlic to my 1 year old?

Garlic as seasoning. Gradually add garlic to foods as seasoning so that everyone in the family becomes used to the flavor. Garlic powder, chopped fresh garlic or dried garlic sautéed and added to dishes adds tons of flavor and replace most of salt used in recipes - a lower salt diet as a benefit. At a year of age children can eat all the "adult" foods just in smaller bites - no need for stage 3 or "toddler" foods.
Not for a baby. Garlic oil has hypolipidemic effects, reducing plasma cholesterol, triglyceride levels, and elevating HDL levels. Garlic oil also inhibits platelet aggregation, thus reducing the risk of thrombosis. Taken together, garlic oil may reduce the risks of cardiovascular disease. However, protection against catching cold or flu is not well supported by modern day science.