Cardiovascular disease prevention by diet modification

• Diet, both in terms of quality of food and drink and amount of calories consumed has the potential to reduce cardiovascular disease (CVD).
• Food supplements are useful for some groups but eating a healthy diet is best.
• Many factors effect food choice and these can be influenced by governmental and educational strategies.
• Healthcare professionals need good nutritional knowledge and the interest and ability to promote healthy eating patterns for all age groups.

This review summarises the current evidence base for food groups and nutrients on CVD prevention and then explores the factors that influence individual food choice and the actions that can be put in place to help promote a healthy eating environment. Barriers to implementing change are also discussed.

Excess caloric intake is an important factor in cardiometabolic health; restricting calories improves insulin sensitivity, blood glucose and inflammation. Unfortunately, many people find significant sustained weight loss difficult to achieve but emerging evidence suggests that the quality of the diet consumed is important for avoiding overeating and that low-carbohydrate and Mediterranean diets are superior to low fat diets for maintaining a healthy weight.

The article outlines the evidence for a healthy diet;

• Food supplementation overall has not shown a significant reduction in CVD therefore dietary recommendations for CVD prevention should focus on whole foods and diet quality.
• Consuming fruit and vegetables reduces CVD risk. This is thought to be due to phytochemicals and micronutrients in fruit and vegetables such as folate, potassium, fibre and flavonoids.
• The consumption of whole grains reduces CVD risk. This is because the bran and germ layers (which are removed from refined grains) are a rich source of fibre, lignans, micronutrients, fatty acids and other phytonutrients. As a result whole grain consumption generally results in a high sense of satiety and a lower glycemic response when compared with refined grains.
• Marine fish are a rich source of omega-3 fatty acids which can reduce arrhythmias, thrombosis, inflammation, blood pressure and improve lipid ratios thereby reducing CVD risk.
• Nuts and legumes are high in unsaturated fat, fibre, micronutrients and phytochemicals which can reduce CVD risk.
• Processed red meats increase the risk of CVD due to bioactive molecules such as haem iron, sodium, nitrates and L-carnitine which can cause increased blood pressure, oxidative stress, lipid peroxidation and unfavourable changes to the gut microbiome.
• Alcohol shows a ‘u-shaped’ relationship with CVD risk where both abstainers and heavy drinkers have an increased risk of CVD when compared with moderate drinkers.
• Sugar sweetened beverages increase the risk of CVD in a dose dependent manner.
• Regular coffee drinking (3-5 cups a day) and regular tea drinking can lower CVD risk.

The article further looks at drivers for a poor-quality diet and actions necessary at all societal levels to achieve a cardio-protective diet. Drivers of poor diet quality include lack of knowledge, lack of availability, the pricing of food, time scarcity, social and cultural norms, marketing and taste.

Examples of actions across society that can be used to improve a population’s diet include:

• Making cardiovascular disease a global priority
• Nutritional and agricultural policies
• Nutritional labelling
• Regulation of marketing
• School and workplace interventions
• Standards of education and care in nutrition for health care professionals
• Individual behavioural change.

One of the strengths of this article is that it explores the biological, physical, social and psychological factors that influence why people make certain dietary choices and recognises that scientific evidence alone is not enough to change the food a population consumes. The authors conclude :

‘A concerted effort from all levels of society will be needed to fundamentally change the current food environment and the global food system.’