Alterations in the accumulation of phytochemicals in fruits and vegetables may have adverse effects on the health benefits emanating from their consumption. Plants parts possess secondary metabolites in addition to their primary metabolites. Plants secondary metabolites possess many inherent biological activities that include antimicrobial, antiinflammatory, and enzyme inhibitory properties, which are health benefits to humans. Accumulation of phytochemicals in plants is reportedly influenced by environmental factors or growth conditions such as lack of nutrients, pathogens attack, competitive cohabitation plant species, insect predation, and herbivorous attack. Human interventions such as agricultural practices may affect biochemical processes in plants or crops in a manner that may limitations or alterations in the accumulation of phytochemicals. The limitation of phytochemicals accumulation in fruits and vegetables may have the adverse effect on their health benefits in humans that may explain the high prevalence of life style diseases such as diabetes and cancer experienced in today's world. The proper assessment of the influence on phytochemical responses in crops, fruits, and vegetables by modern agricultural practices such as weeding methods, herbicides, insecticides, fertilizer application, crop rotation, and co-habitation needs to be carried out. Such assessment is important since while crop production may be improved, caution should be exercised not to erode, or negatively alter phytochemical biosynthesis in crops.