Recently we’ve been hearing more about cardiometabolic syndrome in the news, particularly around its relationship with COVID-19. As in, patients with metabolic syndrome, especially those with cardiovascular related comorbidities, have worse outcomes. The news has especially honed in on the fact that poor diet may contribute to coronavirus risk.
So I thought it was time to begin to address this for my own educational clarity. This post will focus on cardiometabolic disease, which is usually chronic and encompasses anything to do with the cardiovascular and metabolic systems. In terms of the cardio half of cardiometabolic disease, this includes: hypertension, atherosclerosis, high cholesterol, hyperlipidemia, angina, CHF, etc. The list is expansive and typically goes hand in hand with metabolic syndrome, which is a cluster of conditions that increase the risk of heart disease, stroke, and diabetes.
So let’s start with the basics
Years ago (thought not as prevalent so now), nutrition doctrine was heavily centered around the fact that dietary cholesterol translates to serum cholesterol. Aka eat a lot of cholesterol = get high cholesterol in lab work. But this isn’t the whole story and typically doesn’t happen in such a 1:1 fashion.
Cholesterol is a necessary substance in your body in order to make hormones, vitamin D, and substances to help you digest food.
25% of cholesterol comes from diet and the other 75% is synthesized by the liver. And it’s a tightly regulated system. When cholesterol intake decreases, the body makes more and vice versa. In the large majority of the population (~75%), intake of dietary cholesterol has little impact on blood cholesterol levels, or rather serum cholesterol – the number you get from lab work when you go for your annual physical. However, a quarter of population is a “hyper-responder,” in which dietary cholesterol modestly increases both LDL (the “bad) and HDL (the “good”) cholesterol ( 5 ).
Along these lines is the conversation about saturated fat. In that saturated fat consumption resulted in increased blood cholesterol levels. This hasn’t held up in longer term studies. In fact, a study with over 350,000 participants found no association between saturated fat and heart disease ( 6 ).
These tenets of nutrition have led to the “low fat, high carb” diet, which has played much a role in the current epidemics in obesity, lipid abnormalities, type 2 diabetes, heart disease, and stroke, aka cardiometabolic syndromes.
In addition to the standard American diet, there are many antecedents that precede the diagnoses. These include: chronic stress, chronic inflammation, visceral adiposity, nutrient insufficiencies, high glycemic load / glycemic index diet, lack of aerobic exercise, decreased muscle mass, smoking, genetic predisposition, and gestational diabetes.
And it’s typically not just one isolated incident or behavior that leads to the development of chronic cardiometabolic disease. Hence the word chronic. It’s years and years of decisions and behaviors that end up leading to this diagnosis. Which means it may take more than just one behavior change in order to prevent it from worsening or even work to reverse it.
Nutrition combined with smoking cessation, as well as other changes in lifestyle such as increased movement, better sleep, and stress reduction, must be all incorporated to improve cardiometabolic health ( 4 ).
Let’s start with nutrition.
Let’s start with nutrition.
The general recommendation is a modified Mediterranean approach, which is low in glycemic index and glycemic load foods (the foods that spike blood sugar), and contains lots of phytonutrients, balanced quality fats, and high in fiber with regular eating times and a targeted amount energy consumption ( 1 ). Whole food and phytonutrient concentrates of fruits, vegetables and fiber with natural combinations of balanced phytochemicals, nutrients, antioxidants, vitamins, minerals and appropriate macronutrients and micronutrients are generally superior for the prevention and treatment of hypertension and cardiovascular disease ( 4 ).
While cardiac diseases (hypertension, hypercholesterolemia, hyperlipidemia) and metabolic syndrome (diabetes) diets are largely the same, the general tenets do vary ever so slightly.
The specific nutrients to be mindful of with cardiac disease in particular are: sodium, magnesium, potassium, and calcium. Americans consume 3-4 times the sodium and about one third the magnesium and potassium that is recommended by current guidelines. A high intake of potassium, magnesium, and possibly calcium through increased consumption of fruits and vegetables, the modified Mediterranean or DASH diet (dietary approaches to stop hypertension) supplements, and reduced intake of sodium are important for the prevention hypertension, stroke, and kidney disease ( 2 ).
In the case of insulin/leptin resistance in metabolic syndrome, some suggest the best approach is a low-carb Paleo diet, ie. 10–15 % of total calories per day in the form of fruit and starchy vegetables like sweet potatoes, potatoes, plantain, yuca and taro (with unlimited amounts of non-starchy vegetable). The purpose of this approach is to improve insulin and leptin sensitivity and promote weight loss ( 5 ).
Getting into the specifics, there are certain macro and micronutrients to be keyed into.
The first, and no surprise here, is sodium.
The average sodium intake in the US is 5000 mg per day with some areas of the country consuming 15,000-20,000 mg per day. However, the minimal requirement for sodium is probably about 500 mg per day. So in some cases, we’re getting 40x the amount of sodium than we need on any given day ( 4 ). Some studies have shown a direct relationship between sodium intake and increased platelet reactivity, stroke (independent of BP), left ventricular hypertrophy, MI (heart attack), and sudden death ( 4 ). A balance of sodium with other nutrients is important, not only in reducing and controlling blood pressure, but also in decreasing cardiovascular and cerebrovascular events ( 4 ).
While we all know that sodium = salt, be wary of sneaky sodium sources. Foods like smoked, cured, or canned fats / fish, as well as frozen meals, canned entrees, fast food, salted nuts, and canned beans all may have high amounts of sodium.
In terms of nutrients you want to get MORE of, here are a few:
Numerous epidemiologic, observational and clinical trials have demonstrated a significant reduction in blood pressure with increased dietary potassium intake ( 4 ). A high potassium intake reduces the incidence of cardiovascular and cerebrovascular accidents independent of the blood pressure reduction ( 4 ). Foods that are rich in potassium include: potatoes, leafy greens, lentils, prunes, tomatoes, apricots, beans, as well as full-fat milk and yogurt.
A high dietary intake of magnesium of at least 500-1000mg per day reduces blood pressure in most of the reported epidemiologic, observational and clinical trials, but the results are less consistent than those seen with sodium and potassium ( 4 ). Magnesium supplementation has been shown to be associated with: inverse risk of heart disease in men, inverse risk of metabolic syndrome through improvements in glucose and insulin metabolism, as well as improvements in cardiac arrhythmias ( 1 ).
In most epidemiologic studies, there is an inverse relationship between dietary magnesium intake and blood pressure, meaning that more magnesium results in decreased blood pressure ( 4 ). This is because magnesium competes with sodium for binding sites on vascular smooth muscle and acts similar to a calcium channel blocker, in turn inducing vasodilation and decreasing blood pressure ( 4 ).
One study demonstrated significant decreases in blood pressure in a double‐blind placebo‐controlled trial of 91 middle‐aged to elderly women with mild to moderate hypertension using magnesium asparate‐HCl for 6 months. There was a significant decrease in systolic and diastolic blood pressure ( 2 ). In another study of 48 patients with mild uncomplicated hypertension, those given magnesium 600 mg/d with lifestyle changes vs those with lifestyle changes only had significant reductions in 24‐hour systolic BP and diastolic BP during daytime and nighttime readings ( 2 ).
However, further meta‐analysis of magnesium supplementation has revealed conflicting results. A review of 29 studies of magnesium was inconclusive as a result of flaws in methodology but suggested that a negative association of blood pressure with magnesium was not present. Other studies revealed a dose‐dependent BP reduction with magnesium supplementation, as in the amount of blood pressure reduction depended upon the dose of magnesium taken. A more recent meta‐analysis of 105 trials randomizing 6805 participants with at least 8 weeks of follow‐up found no evidence that magnesium supplements had any important effect on BP ( 2).
Because the supplement studies are overall inconclusive, it is best to reach for food sources of magnesium: green leafy vegetables, fruits (figs, avocado, banana, raspberries), nuts, seeds, legumes, many vegetables, seafood, whole grains, raw cacao, dark chocolate, tofu, baked beans, and chlorella powder.
Population studies show a link between hypertension and calcium, but clinical trials that administer calcium supplements to patients have shown inconsistent effects on BP. Again, because the supplement trials are inconclusive, best to get from food. Food sources of calcium include: full-fat well-sourced dairy, green leafy vegetables, tofu, molasses, sardines, tinned salmon/fish, sesame seeds, and tahini.
In terms of macronutrients that are important to have in a diet, both well sourced proteins and fats are important.
Observational and epidemiologic studies demonstrate a consistent association between a moderate protein intake and a reduction in blood pressure. The protein source is an important factor in the blood pressure effect, animal protein being less effective than nonanimal protein. Aim for well-sourced, wild or pasture-raised animal protein with more essential omega-3 and omega-6 fatty acids, as these may reduce blood pressure, lipids and heart disease risk ( 4 ).
Some studies show low protein intake coupled with low omega-3 fatty acid intake may contribute to hypertension in animal models. The optimal protein intake, depending on level of activity, kidney function, stress and other factors, is about 1.0 to 1.5 g/kg/day ( 4 ).
Omega-3s and polyunsaturated fats
Alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA) comprise the primary members of the omega-3 polyunsaturated fat family, otherwise known as PUFAs. Omega-3 PUFAs significantly lower blood pressure in observational, epidemiologic and in some small prospective clinical trials ( 4 ). The studies on the effects of fish oil on blood pressure have shown a dose-related response in hypertension as well as a relationship to the specific diseases associated with hypertension ( 4 ).
The ideal ratio of omega-3 fatty acid to omega-6 fatty acid is between 1 : 1 to 1 : 2 ( 4 ). This balanced ratio of omega-6 to omega-3 fatty acids helps prevent platelet aggregation and vasoconstriction, both of which can lead to hypertension.
Omega-3 fatty acids are found in coldwater fish (herring, haddock, Atlantic salmon, trout, tuna, cod and mackerel), fish oils, flax, flax seed, flax oil and nuts ( 4 ). Other examples of omega-3 fatty acids: fish, flax seed, walnuts, soybeans, pasture raised eggs and grass fed animals. In fact, eating cold water fish three times per week is as effective as high-dose fish oil in reducing blood pressure in hypertensive patients, and the protein in the fish may also have antihypertensive effects ( 4 ). One study found that regular fish consumption or consumption of fish oil would reduce total mortality or deaths from all cause by 17% ( 5 ).
Olive oil is rich in monounsaturated fats as well as omega-9 fatty acids, which have been associated with BP and lipid reduction in Mediterranean and other diets ( 4 ) Monounsaturated fats have been shown to reduce LDL and triglycerides and increase HDL. They also decrease oxidized LDL, reduce oxidation and inflammation in general, lower blood pressure, decrease thrombosis, and they may reduce the incidence of heart disease. The best sources of monounsaturated fat are olives, olive oil, macadamia nuts, and avocados ( 5 ).
Some studies have shown that nut consumption may reduce the risk of cardiovascular disease, including body mass index, waist circumference, and systolic blood pressure, compared to non-consumers of nuts ( 5 ).
Fiber / whole grains:
Fiber intake is inversely associated with cardiovascular disease. It has been shown to decrease total and LDL cholesterol as well as slow the absorption of sugar, preventing blood sugar spikes and impaired glucose response. Soluble fiber binds bile acids or cholesterol, upregulates LDL receptors in the liver, increases clearance of LDL, inhibits fatty acid synthesis by producing short-chain fatty acids like acetate, butyrate, and propionate, improves insulin sensitivity, and increases satiety with lower overall energy intake. In one study, subjects followed for more than 19 years with the highest quartile of dietary soluble fiber intake had a 15% lower risk of heart disease and had a 10% lower risk of cardiovascular events. Soluble fiber, such as guar gum, guava, psyllium and oat bran reduce blood pressure and reduce the need for antihypertensive medications in hypertensive subjects, diabetic subjects and hypertensive diabetic subjects ( 4 ). Soluble fiber is found in vegetables like brussels sprouts, turnips, carrots, sweet and white potatoes, squash and asparagus, and fruits like apricots, prunes, pears, oranges, grapefruit and mangoes.
Other forms of insoluble fiber and whole grains include: oats, brown rice, quinoa, barley, millet, freekeh, farro, and even popcorn.
If diabetes or prediabetes is present, focus mainly on the soluble forms of fiber with only 10-15% of diet derived from fruits and starches. This helps improve insulin and leptin sensitivity.
OTHER IMPORTANT MICRONUTRIENTS
- Low serum zinc levels in observational studies correlates with hypertension as well as cardiovascular disease, type II DM, hyperlipidemia, elevated lipoprotein a, 2-hour postprandial plasma insulin levels and insulin resistance ( 4 )
- Good sources of zinc include: shellfish, well-sourced red meat (if this is in your diet), legumes, seeds, nuts, well-sourced full fat dairy, pasture raised eggs, whole grains, vegetables, and dark chocoalte
- Mechanism of action of chromium involves increased insulin binding, increased insulin receptor number and increased insulin receptor phosphorylation, so this nutrient is important for those with prediabetes and/or diabetes ( 1 )
- Supplemental chromium improves blood glucose, insulin, cholesterol, and hbA1c in type 2 diabetes in dose-dependent manner ( 1 )
- Food sources of chromium include: broccoli, whole grains, potatoes, garlic, basil, apples, and bananas
- Vitamin D3 affects calcium-phosphate metabolism, renin angiotensin aldosterone system (the system that the body that can lead to hypertension), the immune system, and control of endocrine glands. Its role in electrolytes, volume and blood pressure homeostasis indicates that Vitamin D3 is important in the control of hypertension ( 4 ).
- There is a positive correlation of 25(OH)D (Vitamin D) concentration with insulin sensitivity, and a negative effect of hypovitaminosis D on beta cell function – the cells responsible for pumping out insulin ( 1 ). Therefore, subjects with hypovitaminosis D are at higher risk of insulin resistance and metabolic syndrome ( 1 ). And in fact increasing 25(OH)D from 10 to 30 ng/mL can improve insulin sensitivity by 60% ( 1 )
- Foods that are rich in Vitamin D include: salmon, herring, sardines, cod liver oil, canned tuna, pasture raised egg yolks, and mushrooms.
Antioxidant-rich foods protect against heart disease in a number of important ways. Our antioxidant defense system is what protects us from oxidative damage, which is a major risk factor for heart disease. Strengthening this system has two sides: reducing our exposure to oxidative stress and increasing our intake of antioxidant-rich foods. To increase your antioxidant consumption, a good rule of thumb is to eat the rainbow, choose a variety of colors of fruits and vegetables, as well as organ meats, meats, eggs, and full fat grass-fed dairy.
- Vitamin C: Numerous epidemiologic, observational and clinical studies have demonstrated that the dietary intake of vitamin C or plasma ascorbate concentration in humans is inversely correlated to systolic and diastolic BP and heart rate ( 4 ). Hypertensive subjects were found to have significantly lower plasma ascorbate (vitamin C) levels compared with normotensive subjects ( 4 ).
- Food sources of vitamin C include: chili peppers, bell peppers, guava, citrus, thyme, parsley, spinach, kale, kiwis, broccoli, brussels sprouts, persimmons, papaya, strawberries
- Flavonoids: potent free radical scavengers that inhibit lipid peroxidation, prevent atherosclerosis, promote vascular relaxation and have antihypertensive properties. In addition, they reduce stroke and are cardioprotective ( 4 ).
- Food sources of flavonoids include: fruits, vegetables, red wine, tea, soy, and licorice
- Lycopene: Lycopene has recently been shown to produce a significant reduction in BP, serum lipids and oxidative stress markers ( 4 )
- food sources of lycopene include tomatoes and tomato products, guava, pink grapefruit, watermelon, apricots and papaya.
- CoQ10: a potent lipid phase antioxidant, free radical scavenger, cofactor and coenzyme in mitochondrial energy production and oxidative phosphorylation that lowers systemic vascular resistance (SVR), lowers blood pressure and protects the myocardium from ischemic reperfusion injury ( 4 ).
- While supplementation is most common, food sources of CoQ10 include: organ meats, fatty fish, vegetables, fruits, legumes, nuts, seeds and olive oil
- Polyphenol-rich foods: shown to lower blood pressure and LDL cholesterol and improve insulin sensitivity, prevent the increase in oxidized fats that occur after consuming a meal high in oxidized and potentially oxidizable fats, as well as lower blood pressure in people with hypertension.
- Food sources of polyphenols include: tea (especially green tea and hibiscus tea) blueberries, extra-virgin olive oil, red wine, citrus fruits, dark chocolate, coffee, turmeric, and other herbs and spices
Before moving on from the stratosphere of nutrition, it is important to note the microbiome when discussing heart disease and metabolic syndrome. An altered gut microbiota seems to be correlated with type 2 diabetes. Chronic intake of diets high in unhealthy, inflammatory fats and sugars may alter intestinal environment, including microbial composition and mucosal structure/functions, and result in a vulnerable microbial barrier and increased permeability of the intestines or leaky gut. This may lead to chronic illness within the realm of cardiometabolic disease.
To read more about gut health, check out this post.
Beyond nutrition, getting the right amount of movement in per day is also important. This will vary depending on your baseline and starting point. If you’re new to exercise, try beginning with 15-20 minutes of light walking daily ( 1 ). For those who are seasoned in moving their bodies, aim for 30 minutes 5 days per week of moderate exercise with 2 of those days including weight and resistance training exercise ( 1 ).
In addition to distinct periods of exercise, it’s also important to sit less and stand / walk more, aiming for at least 60 minutes of movement, 6 days per week to reduce overall inflammation. In fact, some research suggests that this “non-exercise” physical activity may have a greater impact on our cardiovascular health than exercise. This could be as easy as a 30 minute yoga class and a 30 minute walk. Or 45 minutes of exercise followed by picking up around the kitchen for 15 minutes. Anything to get you moving!
Exercise has been shown to reduce LDL particle concentration (reminder: the “bad” cholesterol) even independently of diet. Regular exercise prevents the development and progression of atherosclerosis, improves lipids, and reduces vascular symptoms in patients that already have heart disease. The benefits of exercise are related to maintenance of body weight or weight loss, blood pressure control, return of insulin sensitivity, and beneficial changes in lipids, all of which in turn promote endothelial stabilization and vascular health ( 5 ).
Sleep is also important when discussing cardiometabolic health. In fact, disorders of circadian behavior and sleep are associated with increased hunger, decreased glucose and lipid metabolism, and broad changes in the hormonal signals involved in satiety ( 1 ). Sleep deprivation has been associated with weight gain, insulin resistance, increased appetite and caloric intake, overconsumption of highly palatable and rewarding food, decreased energy expenditure and a reduced likelihood of sticking with healthy lifestyle behaviors ( 5 ).
Sleep duration and quality are inversely associated with blood pressure in epidemiological studies, and high blood pressure is one of the strongest independent risk factors for cardiovascular disease. One study found that those who reported fewer than 5 hours of sleep at night had a 38% greater risk of coronary heart disease (CHD) than those reporting 8 hours of sleep ( 5 ).
Aim for 7-9 hours of sleep per night with a 15 minute bedtime relaxation ritual (no screens!).
Finally, an emphasis on stress reduction is also important! Stress increases the risk of cardiovascular disease in numerous ways. It increases intestinal permeability, impairs blood sugar control, depresses immunity (which increases the risk of infection), contributes to fat storage in the liver, and promotes consumption of comfort and junk foods. It also promotes inflammation by increasing circulating inflammatory markers like C-reactive protein (CRP) and interleukin-6 (IL-6), both of which are associated with heart disease ( 5 ).
Stress management can have a profound impact on heart disease risk. One recent randomized trial showed that regular meditation decreased the risk of death from heart attack, stroke and all causes by up to 48% ( 5 ).
Managing stress can take the form of meditation/prayer, deep breathing (check out this post to learn more about diaphragmatic breathing), relaxation, guided imagery, clinical hypnosis, and biofeedback ( 1 ). In terms of movement based meditation, yoga, tai chi / qi gong, exercise, dance, and biofeedback are all helpful ( 1 ).
DOWNLOADABLE PDFS FOR CARDIOMETABOLIC FOOD PLANS
I received these through my Master’s program through University of Western States. I firmly believe we should all have as many resources as possible as we begin to make dietary and lifestyle changes, so I hope you find these helpful!
( 1 ) Saxena, S.P. (2014). Clinical Solutions: Functional Medicine to the Metabolic Disease Rescue. Powerpoint. From M.S. Human Nutrition and Functional Medicine. University of Western States.
( 3 ) Chaney, K. (2015). Gut microbiome and metabolic syndrome clinical pearls. Powerpoint. From M.S. Human Nutrition and Functional Medicine. University of Western States.
( 4 ) Houston, M.C. The role of cellular micronutrient analysis, nutraceuticals, vitamins, antioxidants and minerals in the prevention and treatment of hypertension and cardiovascular disease. Therapeutic Advances in Cardiovascular Disease, 4(3), 165-183. Doi: doi-org.ezproxy.neu.edu/10.1177/1753944710368205
( 5 ) Kresser, C. The Diet-Heart Myth. E-book.