This blog post was kindly sponsored by California Walnuts. This February (National Heart Month), California Walnuts is working on a campaign titled The Power of 3, which will aim to raise awareness of the heart health benefits of California Walnuts and the fact that they are the only tree nut to contain a significant amount of the plant-based omega-3, alpha-linolenic acid (ALA), as they contain 2.7g per 30g serving (1). Head over to californiawalnuts.co.uk for more information on where to buy, how to store, and also for some creative ways to get more walnuts into your diet.
Cardiovascular disease (CVD) is an umbrella term that describes all diseases of the heart and blood vessels. It includes everything from conditions that are inherited, or those that people are born with, to those that are developed later in life such as coronary heart disease, heart failure, stroke and vascular dementia (2).
There are around 7.4 million people living in the UK with heart and circulatory diseases and more than a quarter (27%) of all deaths that occur in the UK are due to these conditions (2). Coronary heart disease (CHD) is one of the leading causes of death in the UK and the most common cause of premature death – it is also the leading cause of death worldwide (2).
There are a number of factors which increase our risk of CVD – unfortunately some which we can’t change such as our family history, sex, ethnicity, and age, but others that we can, such as; cigarette smoking, low levels of physical activity, high blood pressure, high blood cholesterol levels, and a poor diet (3, 4).
Despite the fact we can change all of these things, It’s not always easy to make that change. Hopefully with this article however, we can point you in the right direction of some dietary changes that can support the health of your heart and blood vessels.
There are three main types of dietary fat; unsaturated fats (monounsaturated and polyunsaturated), saturated fats, and trans fats. The structure of these fats is what makes them behave differently in the body, and ultimately determines how they impact our health.
The amount and type of fat in our diet influences our risk of CVD. The evidence suggests that when we replace foods high in saturated fat and trans fatty acids for foods high in monounsaturated fats and polyunsaturated fats , we can reduce our risk of heart disease and death from these causes (5). Monounsaturated fats can be found in olive oil, nut oils, avocados, nuts and seeds, and polyunsaturated fats, such as omega 3 and omega 6, can be found in oily fish, plant oils, nuts and seeds. Walnuts are particularly unique in that they are the only tree nut to contain significant amounts of the plant based omega-3, alpha-linoleic acid (ALA) (6). Consuming at least 2g of ALA per day has been found to improve cholesterol levels (7). Walnuts appear to reduce the risk of CVD by improving the function of the blood vessels and by contributing to the maintenance of normal blood cholesterol levels (8). It is recommended that in order to achieve these benefits, a handful (30g) of walnuts should be consumed per day (8).
Saturated fat is found in: butter, coconut oil, lard, pastries, the visible fat on meat and fried foods. Trans fat is found in fried foods, and some types of cakes, biscuits and margarine – however trans fat levels in food products have significantly reduced in many countries, including the UK, in recent years (9).
Note: saturated fat is also found in dairy foods but appears to behave differently than other saturated fats due to the food matrix it is in; which means the impact of the chemical structure of food, as well as the interaction between different nutrients within the whole food (10) As such dairy foods appear to have a neutral, and even favourable, effect on reducing the risk of cardiovascular disease (11) – So the type of food also matters, rather than just focusing on the individual nutrients!
- When cooking, swap cooking oils and lards that are high in saturated fat such as butter, ghee, lard and coconut oil for those high in unsaturated fats such as olive oil, rapeseed oil, and nut oils.
- Where possible, try to cut back on consumption of processed meats such as sausages, ham, burgers, which can often be high in saturated fat, as can fried foods, takeaway meals, biscuits, cakes or pastries.
- Baking? Try adding a handful of chopped walnuts to muffins or banana bread or blitz with oats to make a quick crumble to have with warm, stewed fruits.
Whole Grain carbohydrates
Different types of carbohydrates (i.e. refined vs wholegrain) have opposite effects on CVD risk (12,13). Carbohydrates can be largely classified as refined, in which part of the grain is removed during milling and processing, or whole grain, in which contains all of the original constituents of the grain (bran, endosperm, and germ). Wholegrains appear to reduce risk of CVD – with greatest reduction at three or more 30g servings per day (13,14).
Whole grains / whole grain foods include: whole wheat, wholemeal flours, wholemeal bread, whole grain cereals (e.g. wheat biscuits), oats (porridge), whole barley, amaranth, rye, spelt, quinoa, brown, red and wild rice, bulgur wheat, buckwheat, sorghum, teff, triticale, millet and even popcorn.
- Snack on plain popcorn, or oatcakes with peanut butter, or rye crackers and hummus
- Have oats for breakfast as porridge, muesli, or homemade granola
- Opt for wholegrain bread most of the time
- Double up when cooking brown pasta for dinner, and save the leftovers for a cold pasta salad for lunch the next day
- Swap white flour in some of your recipes when baking for whole wheat or spelt flour, or do half and half – trust me, they will still taste just as good!
Also in wholegrains, but in all plant based foods – dietary fibre has the potential to lower LDL (often referred to as “bad”) cholesterol and reduce CVD risk (16). Dietary fibre is the edible parts of plants resistant to digestion and absorption in the small intestine. It is completely or partially broken down by bacteria in the large intestine. Adults should be aiming for around 30g of fibre a day, but for the most of us here in the UK and Ireland massively undershoot that (17).
- Increase the variety of plant-based foods in your diet. Be a rebel this week and add a new fruit, vegetable, grain or nut to your shopping basket that you wouldn’t typically choose.
- Have porridge for breakfast – Beta glucan, a soluble dietary fibre in oats and barley, appears to have a particularly positive effect on total and LDL cholesterol levels (18).
- Sprinkle a tablespoon of flaxseed, mixed seeds or a handful of nuts to your breakfast.
- Swap half of your minced meat based dishes for lentils or even walnuts (after a few pulses in the food processor) – this works particularly well for bolognese!
- Save on time (and fibre!) by keeping the skin on vegetables.
- Feeling peckish by 3pm? Make your own upgraded trail mix with nuts, fresh blueberries, and dark chocolate pieces.
Antioxidants and Polyphenols
Evidence supports high fruit and vegetable intake and the reduced risk of CVD and early death (19,20). This beneficial effect is, in part, due to plant chemicals known as polyphenols which have antioxidant properties (20). You can find them in a variety of plant-based foods including cocoa, tea, colourful fruits and vegetables, nuts, and soybeans.
- Aim to get at least 5-a-day and the more colour the better – think colourful bell peppers, sweet potatoes and butternut squash, rainbow carrot and red cabbage slaw.
- Add a 1-2 handfuls of berries to your breakfast – blackcurrants, blueberries, blackberries, raspberries and strawberries. Of all the fruit and veg, these guys have undoubtedly gained the most attraction in the scientific research due to their rich source of antioxidants.
- Nibble on dark chocolate – the benefits of dark chocolate can be attributed in part to a group of polyphenols known as flavonols – and the darker the chocolate, the higher the amount of these beneficial compounds! Flavanols have attracted a huge amount of interest due to their potential ability to lower blood pressure, a known risk factor for heart disease and stroke (21).
- Go nuts – In addition to their healthy fats and fibre, nuts are very high in antioxidants. One study comparing 9 types of raw and roasted nuts found that walnuts have the highest polyphenols in both raw and roasted samples (22).
To summarise, from the evidence we have, the best diet to support your heart and blood vessels is one which is high in fruit and vegetables, nuts and seeds, legumes and whole grain cereals, olive oil and plant oils, with a moderate consumption of fish and dairy and limited consumption of red or processed meats and processed foods. In addition to diet, there are many other things in our lifestyle which we can address such as stopping smoking, reducing our alcohol consumption, being physically active and getting enough (and good quality) sleep.
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(6) Food Standards Agency. McCance & Widdowson’s The Composition of Foods, Seventh summary edition. Cambridge: Royal Society of Chemistry. 2002.
(7) EFSA panel on Dietetic Products, Nutrition and Allergies (NDA). Opinion on the substantiation of health claims related to alpha linolenic acid and maintenance of normal blood cholesterol concentrations (ID 493) and maintenance of normal blood pressure (ID 625) pursuant to Article 13(1) of Regulation (EC) No 1924/2006.
(8) EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Scientific Opinion on the substantiation of health claims related to walnuts and maintenance of normal blood LDL-cholesterol concentrations (ID 1156, 1158) and improvement of endothelium-dependent vasodilation (ID 1155, 1157) pursuant to Article 13(1) of Regulation (EC) No 1924/2006. EFSA Journal 2011; 9( 4):2074. [19 pp.]
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