Introduction

Hyperlipidemia is the medical term used to describe having high levels of lipids (fats) in the blood. Various types of lipids are present in the human body, including cholesterol, triglycerides and phospholipids. Low-density lipoproteins (LDL) and high-density lipoproteins (HDL) carry cholesterol in the blood throughout the body.¹  Based on the underlying cause, hyperlipidemia can be divided into two subgroups as primary and secondary. Primary hyperlipidemia arises from genetic conditions, inherited through birth. Secondary hyperlipidemia originates from alternative root causes such as unhealthy diet, medication use, hypothyroidism and lack of exercise.² Smoking, alcohol consumption,  diet rich in saturated fats, stress, and liver diseases can increase the risk of developing hyperlipidemia.³

Well known to the general public, low-density lipoproteins (LDL) are the bad guys in this story. Hyperlipidemia, in particular hypercholesterolemia, is a common condition  associated with increased cardiovascular risks. High levels of LDL indicate hypercholesterolemia and it increases the risk of atherosclerotic plague and cardiovascular diseases.² High-density lipoproteins (HDL), the good guys, assist in balancing the cholesterol levels in the blood by carrying LDL away from arteries back to the liver. LDL is known as the “bad cholesterol” for a reason; it carries cholesterol and accumulates it around the arteries.⁴ This builds up cholesterol, a condition known as atherosclerosis, which narrows and hardens the arteries, resulting in an increased risk of high blood pressure, stroke and heart conditions.¹  

Adults are recommended to keep their total cholesterol levels below 200 milligrams per deciliter (mg/dL) and LDL levels below 100 mg/dL.⁵ If you have high LDL levels, by paying attention to what you are eating you can reduce your cholesterol levels.

Hyperlipidemia is a chronic progressive condition that requires lifetime management strategies. The initial management strategy of hyperlipidemia centres around diet and lifestyle modifications. If required, adding lipid-lowering medications can be advised by your doctor. Increasing activity levels improves lipid profile and helps in the maintenance of healthy blood lipid levels.² However, given that patients who adopt these lifestyle modifications with a healthier diet often struggle to maintain them long-term, they showed a small impact on improving cholesterol levels over the years. This sparked the interest among researchers in developing natural compounds to improve lipid profiles safely.⁶

Nutraceuticals in hyperlipidaemia management

Nutraceuticals, also referred to as medical foods or nutritional supplements, are food-based substances, often in pill form, that offer not only nutritional value but also medicinal benefits. Through various mechanisms, dietary and lifestyle interventions and the use of nutraceuticals can help to reduce blood cholesterol levels. Dietary fibre, prebiotics, probiotics, antioxidants, and polyunsaturated fatty acids naturally found in our foods can be processed and formulated into tablets, syrups, and oral powders, or further added to foods such as soups and yoghurts at high concentrations for later use as complementary support to medication. Nutraceuticals are used in the management of several chronic conditions, including hyperlipidaemia and due to their natural origin, they can be considered safe; however should be taken with guidance from a health professional.⁷

Nutraceuticals can reduce blood cholesterol levels through blocking the synthesis of cholesterol in the body, reducing the absorption of cholesterol from the diet and increasing the excretion of cholesterol from the body.⁷

Key nutraceuticals with evidence-based Benefits

Plant sterols and stanols

Plant sterols and stanols can reduce blood LDL cholesterol levels by up to 12% through inhibiting the absorption of cholesterol in the intestines from the diet. They are naturally present in almost all vegetables, legumes and nuts.⁶ They are structurally very similar to cholesterol, leading to competition for absorption in the intestines. They mimic cholesterol behaviour and reduce the amount of cholesterol absorbed into the body. Additionally, they stimulate transintestinal cholesterol excretion (TICE), directly increasing the removal of cholesterol from the body via the intestines. Both reduced cholesterol absorption and TICE stimulation result in reduced LDL cholesterol levels within the blood.⁸ Plant sterols and stanols are present naturally in vegetable oils, nuts, seeds and legumes and can be added to yoghurt, fat spreads and milk for consumption.⁹

Omega-3 fatty acids

Omega-3 fatty acids are polyunsaturated fats, and certain types of fish, walnuts, and flaxseed are rich in omega-3 fatty acids. There are 3 different types of omega-3 fatty acids: DHA, EPA and ALA.¹⁰ Research suggests that omega-3 fatty acids reduce very-low-density lipoprotein (VLDL) cholesterol synthesis and secretion by the liver. Additionally, they reduce triglyceride levels by increasing their removal through increased activity of a lipoprotein enzyme, an enzyme that plays a role in breaking triglycerides down.¹¹

Soluble fibre

Soluble fibres are vegetable-based substances that are resistant to digestion in the gastrointestinal tract. β-glucan, psyllium, pectin and guar gum are examples of soluble fibres. They reduce LDL levels by slowing down gastric emptying, inhibiting cholesterol synthesis and increasing faecal excretion of cholesterol.⁶ Oats, barley, legumes and bananas are rich in soluble fibres.¹⁰

Red yeast rice

Red yeast rice contains monacolin K, which is structurally very similar to lovastatin, a medication used to lower cholesterol levels. Monacolin K decreases the level of cholesterol production by inhibiting the enzyme called HMG-CoA reductase, which is used during cholesterol production. Red yeast rice can reduce LDL cholesterol levels in the blood by 20%.⁶

Garlic

Allium sativum, commonly known as garlic, contains an active compound called allicin, which is responsible for the LDL-lowering effect of garlic. Similar to red yeast rice, it inhibits HMG-CoA reductase enzyme and prevents cholesterol synthesis within the body; however, the effect is milder, by only 5% decrease in cholesterol levels.⁶

Berberine

Recent studies have shown that berberine reduces absorption of cholesterol from the intestines, increases faecal excretion and stimulates breakdown of cholesterol in the liver. Overall, berberine use can reduce LDL cholesterol levels up to 15%.⁶

Green tea catechins

Catechins interfere with the absorption of cholesterol, inhibit HMG-CoA reductase enzyme, reducing cholesterol synthesis and stimulate the elimination of cholesterol through bile. Although catechins act on multiple mechanisms, research suggests that the LDL cholesterol reducing effect is only by 5%.⁶

Dietary Approaches

Established Dietary Patterns

Mediterranean diet

The Mediterranean diet is rich in vegetables, olive oil, fruits and whole grains. Fat consumption is moderate, polyunsaturated and monounsaturated fats are preferred, and fibre consumption through vegetables and legumes is high. Low saturated fat consumption and high vegetable and fibre intake help to maintain healthy cholesterol levels.¹²

Dietary approaches to stop hypertension (DASH) 

Although this diet approach is initially planned for individuals with high blood pressure, it also seems to improve cholesterol levels. Reduced consumption of sodium, saturated fats and dairy foods with high vegetables and fruits consumption improves overall health and lower triglyceride and LDL cholesterol levels.¹³

Portfolio diet

Portfolio diet is a plant-based diet and suggests reduced animal product consumption. This diet is low in saturated fat and dietary cholesterol. Through reduced consumption of direct contributors of cholesterol and high fibre intake, the portfolio diet improves the cholesterol profiles of individuals and can reduce cholesterol levels by 17%.¹⁴

Macronutrient modifications

Red meat, butter, French fries, ice cream, and chocolate all sound delicious but may come with a hefty price. They are all high in saturated fats, which increases LDL cholesterol. Health professionals suggest reducing saturated fat consumption and replacing it with polyunsaturated and monounsaturated fats such as avocado, salmon, olive oil and nuts. Trans fats also contribute to LDL cholesterol increase thus consumption should be restricted. Don't fall into the trap of companies; always check the labels and look for hidden saturated and trans fats in the products. 

Intake of fibre is a key component of a healthy diet. Research shows that for each 1g of increase in soluble fibre intake, 1.1mg/dL LDL cholesterol decreases. Vegetables, legumes, and wheat are rich in soluble fibre. Consumption of egg yolks, processed meats and organ meats such as liver should be limited due to their high cholesterol content. In your diet, try to include plenty of fruits, vegetables and whole grains and limit consumption of red meat, beverages, salt and saturated fats. Even minor healthy replacements in your diet can result in significant benefits.¹²

Safety, limitations, and considerations

Unlike medicines, Nutraceuticals and dietary supplements are not strictly regulated by the FDA, and the quality of the supplements produced can vary; thus, the use must be monitored by a health professional. If not taken correctly, side effects like nausea, vomiting, stomach cramps and liver damage can be observed. Before taking any, please seek advice from a health care provider regarding the dosage, indications, side effects and possible drug interactions. For example, the metabolite of catechol found in green tea extract has been associated with liver toxicity in high concentrations.¹⁵ Besides cholesterol-lowering activities, garlic is also known to have blood-thinning properties. If used in combination with an anticoagulant such as aspirin and warfarin, garlic can enhance the blood-thinning activity and may cause serious health risks.¹⁶ It is important to note that each individual is different and individualised dietary and supplementation planning should be done in collaboration with health professionals.

Summary

Hyperlipidemia significantly increases the risk of cardiovascular diseases.¹⁰ Nutraceuticals and dietary alterations can improve an individual's lipid profiles and reduce the risk of cardiovascular diseases and mortality significantly. Evidence supports that adequate use of plant sterols, omega-3 fatty acids, soluble fibre, red yeast rice, berberine, and garlic, combined with individualised health dietary patterns, can reduce blood LDL cholesterol levels and contribute to overall health.⁶ Safe and effective use crucial quality; dosing, interactions and personal health factors should be considered for the best possible outcome. Following diet plans such as the Mediterranean diet, increasing physical activity and weight loss can help to maintain healthy blood cholesterol levels.¹⁰ These approaches are to complement and not replace the actual pharmacological treatment. They should be considered as adjuncts to overall lifestyle modifications for the treatment and should be consumed under the supervision of health professionals.