Various brown seaweed water extracts contain sulphated polysaccharides, such as alginate, fucoidan, and laminaran, that possess antioxidant and free-radical quenching properties, which are related to their sulphates, anion groups, and molecular weights. The atherogenic index of plasma (AIP) were decreased in all experimental diabetic mammals treated with brown seaweed extract. The decrease in AIP values in experimental diabetic mammals by the brown seaweed extract indicated that the brown seaweed extracts were protective against atherosclerosis and Cardiovascular disease risk, which was reportedly better than metformin. The hepato-protective properties of the brown seaweed Sargassum polycystum in non-diabetic conditions were also reported in rats induced with hepatitis, acetaminophen-related lipid peroxidation, or hyper-calorie diet. The brown seaweed extracts help reduce cholesterol and are beneficial for diabetics with high blood cholesterol and an atherosclerosis risk. Low doses of brown seaweed or metformin may reduce the severity of pancreatic injuries in diabetic individuals, and may even help the pancreas to recover towards normal conditions.