Yes, heavy pantry items should be stored on bottom shelves to improve stability and prevent potential injuries from falling objects. This also makes them easier to access.
Storing heavy items like canned goods, large jars, bags of flour, and bulk spices on the bottom shelves of your pantry offers several advantages. First and foremost, it significantly lowers the center of gravity of your pantry setup. This increased stability reduces the risk of the entire shelving unit tipping over, especially if it's not securely anchored to the wall. Secondly, placing heavy items lower down minimizes the potential for injury. If a heavy can were to fall from a high shelf, it could cause a serious injury. Keeping it low reduces the distance it can fall and therefore the impact. Finally, it's simply easier to lift and move heavy items from a lower position. Bending down is generally safer than reaching up and struggling to maintain balance with a heavy load.
Before stocking your pantry, reinforce your shelves, especially if they are adjustable. Over time, the weight of heavy items can cause shelves to sag or even collapse. Consider adding extra supports or using thicker shelving material for the bottom shelves.