Final answer:
Trans fatty acid consumption leads to increased LDL levels and decreased HDL levels in the blood, negatively impacting heart health and contributing to heart disease.
Step-by-step explanation:
The consumption of trans fatty acids affects blood cholesterol levels by increasing low-density lipoproteins (LDL) or 'bad' cholesterol and decreasing high-density lipoproteins (HDL), known as 'good' cholesterol. These changes can lead to plaque buildup in the arteries, contributing to heart disease. Health organizations require trans fat content to be listed on food labels to educate consumers about the risks associated with these fats.