Triglycerides

A change to a plant-based diet affects not only food choices but also body biochemistry. Often this switch is made to gain healthier blood lipid levels and we can rejoice when our cholesterol levels diminish, knowing that this result means that our potential of suffering a cardiovascular event such as atherosclerosis will decrease. But sometimes other aspects of our blood lipids will change in ways that we didn’t anticipate. Two such lipid levels, those of HDL-cholesterol and triglycerides, can raise questions in people’s minds and leave them wondering if this diet makeover is really the right way to go. In this article we’ll focus on the type of fats known as triglycerides.

Triglycerides are fats in the form used by the body for storage. Processes in the liver create complexes of lipid and protein called VLDL (very low density lipoproteins) which are then distributed to body tissues as a source of immediate energy or stored as fat for later use as fuel for body functions. VLDL is about 85% triglyceride and carries almost all the triglycerides in the bloodstream from the liver to storage sites in fat tissue (5).

The diagnosis of hypertriglyceridemia (high blood triglyceride level) is based on fasting blood levels. (This means that no food has been consumed in the 10 to 12 hours before the test is performed). Blood levels of triglyceride are considered elevated if a test indicates that they are equal to or greater than 1.7 mmol/L. Elevated triglycerides are associated with increased risk of cardiovascular disease but this does not necessarily mean that the high triglyceride level is the cause of the elevated risk. There is certainly conflicting literature on this topic however high triglycerides may simply be a signal to look into other factors that may be the actual promotors of the increase in risk, factors such as insulin resistance, obesity, hypertension, high blood sugar and consuming too much fat, refined carbohydrates or alcohol (1,18).

Clinical practice guidelines in the US recommend that initial treatment for high triglyceride levels should be lifestyle therapy including diet modification and weight loss (10,3). Medications such as niacin or fibrate drugs are used only when lifestyle changes, often because of lack of compliance, fail to lower the triglyceride level. In rare cases the triglyceride level can rise higher than 11 mmol/L (severe hypertriglyceridemia) introducing an increased risk of pancreatitis (inflammation of the pancreas). Pancreatitis is a serious condition marked by abdominal pain, nausea, and vomiting. Severe cases may lead to organ damage. Immediate treatment is required which may involve fasting and medication (10).

Triglyceride levels are influenced by both lifestyle and non-lifestyle factors. Non-lifestyle factors include inherited genetic problems, thyroid disease, diabetes and serious kidney disease (13). For example, familial hypertriglyceridemia is a genetic condition that occurs in about 1 in 500 people in North America and can cause chronically high blood triglyceride levels. Many medications can also raise triglycerides. Some of these include birth control pills and estrogens, testosterone, blood pressure lowering medications such as thiazide diuretics and beta-blockers, steroids such as prednisone, acne medications such as isotretinoin and medications that affect the immune system such as tacrolimus and cyclosporine (2).

Fortunately lifestyle factors are the more common cause of high triglyceride levels and the power is in our hands to fight these triglyceride boosters.

 

The following are aspects of lifestyle that can increase triglyceride blood level.

Eating fatty food, especially food high in saturated fat, will increase triglyceride level. If foods high in
cholesterol (such as eggs, dairy products and meats) are part of the excess fatty food ingestion, the subsequent
triglyceride spike will be even more pronounced (6,19).

Eating simple carbohydrates such as white bread, white rice, white pasta or sugary desserts and beverages
will cause blood sugar spikes and a corresponding sudden rise in insulin to deal with the excess sugar (glucose).
This is known as post-prandial dysmetabolism and results in immediate oxidative stress and inflammation (9).
Once the body’s cells have all the glucose they need immediately for energy and the glycogen storage in the
liver is full, the extra glucose is converted into triglycerides which can then be stored as fat (11). Note that
consumption of plant-based carbohydrates in their whole state do not cause any increase in triglycerides (6,9).

Stress can increase triglyceride level by increasing the blood level of cortisol, the “stress hormone”. Cortisol
increases triglyceride production by the liver. Interestingly, eating animal-based foods can also elevate cortisol
level (6).

Smoking introduces nicotine to the body which increases the release of stored triglycerides from fat tissues
thereby increasing blood triglyceride levels (26). Studies show that non-smokers have a 32% lower fasting
triglyceride level than do smokers (25).

Excessive alcohol consumption causes an immediate rise in triglyceride level (7,8). This effect is attributed to the inhibition by alcohol of the enzymes that promote lipid breakdown resulting in an increase in VLDL level (20,21). One standard alcoholic drink is considered to be 14 gm of alcohol which is found in 341 ml of regular beer (5% alcohol), 142 ml of wine (12% alcohol) or 43 ml of distilled spirits (40% alcohol). Consuming about 30 gm of alcohol from wine with a healthy dinner can result in a triglyceride increase of 15% that returns to normal after overnight fasting. If a meal contains saturated fat but no alcohol, the increase in triglycerides can be as much as 70%; the same saturated fat-containing meal with the addition of 40 gm of alcohol can increase triglycerides by 180%. Excessive alcohol consumption will raise triglycerides after a meal that remain high even after fasting overnight (20).

A sedentary lifestyle is associated with higher triglyceride levels but fortunately exercise is very efficient at
reducing this effect (3).

 

Ways to lower blood triglyceride level.

Eat lots of fiber. North Americans generally eat about 15 to 20 gm of fiber a day; recommendations for
health are to consume more than 40 gm daily. High-fiber complex carbohydrates from whole grains, fruit and
vegetables do not increase triglyceride levels. Their content of protective fiber slows down the release of
sugars from these complex carbohydrates. Studies have shown that diets high in plants and therefore high in
fiber actually protect against the production of triglycerides from excess glucose in the blood so that high-
carbohydrate high-fiber diets result in lower fasting blood triglyceride levels than low-carbohydrate high-
fat diets (12). Results from interventional studies show that substituting more complex carbohydrates for
refined carbohydrates in a low-fat high-carbohydrate diet can lower blood triglycerides by 15% to 25% (14). A
three week intensive dietary and exercise program was found to reduce triglycerides along with insulin levels,
high blood pressure, and obesity. The diet used was predominantly plant-based and low-fat (15). All plant
foods contain fiber but especially rich sources are beans, leafy greens, flaxseeds, and whole grains.
Beans and other legumes are particularly effective at lowering triglyceride levels. This may be simply
due to their high fiber content but it could also stem from the specific phytonutrients that they contain (6).

Consume less saturated fat, cholesterol and processed sugars. These measures can significantly lower
triglyceride levels (6,19). Cut down total fat as much as possible. Use monounsaturated or polyunsaturated fats
such as canola oil or olive oil if a circumstance arises where you feel you must use fat (18). Avoid sugary foods.

Include a good source of omega-3 fatty acids in your diet. A 2016 review of 61 randomized clinical trials and
37 observational studies concluded that there is good evidence that omega-3 fatty acids will reduce the
triglyceride level by up to 0.6 mmol/L even though omega-3s have not been found to decrease the risk of major
cardiovascular events or early death from all causes (16). Suggested doses of omega-3s for lowering
triglycerides are 3 to 4 grams daily of EPA and/or DHA. This is a high amount that is difficult to obtain from
food. Adding supplements can ensure your diet contains enough omega-3. Plant-based sources of omega-3
include flaxseeds, walnuts, black beans, kidney beans, winter squash and soy foods such as tofu or tempeh.
Since omega-6 fatty acids compete for the same enzymes that omega-3 fatty acids need for their
conversion to the longer-chain fatty acids EPA and DHA, limiting intake of omega-6 fatty acids will allow your
body to convert much higher amounts of these plant-sourced omega-3s into DHA and EPA (28). Omega-6 fats
are found in most vegetable oils, in animal-based foods such as chicken and eggs and in oily foods such as salad
dressings, mayonnaise and processed foods.

Spice up your food. A placebo-controlled study showed that adding two tablespoons of antioxidant spices (in
this case a combination of rosemary, oregano, cinnamon, turmeric, black pepper, cloves, garlic powder and
paprika) to a high-fat meal resulted in a 30% reduction in triglyceride response (23). Another study illustrated
that eating food containing Indian spices (namely garlic, black pepper, coriander, ginger, turmeric and
cinnamon) results in a significantly lower rise in triglycerides after the meal (24).

Avoid or limit alcohol to two drinks or less per week to reduce triglycerides.

Lose some weight. Even a small loss in weight can reduce triglyceride levels. A 2016 study showed that a
5 to 10% weight loss results in up to a 20% decrease in triglycerides and also that the more weight lost, the
greater the decrease in triglycerides (19).

Ramp up your exercise level. Studies show that aerobic exercise can reduce triglyceride levels by up to 20%
(3). Resistance training is less effective than endurance training (27). Aim for at least 30 minutes of moderate-
intensity physical activity on five or more days each week for a total of at least 150 minutes per week (18).

Get plenty of sleep. Poor sleep has been linked with higher triglyceride levels as well as metabolic syndrome,
obesity and lower HDL levels (17). Add strategies to improve sleep to your lifestyle. These might include
exercise, meditation and yoga. Be sure to dedicate enough time for sufficient sleep.

Manage stress. From PCRM, the Physicians’ Committee for Responsible Medicine, come the following ideas for
reducing stress. Learn time management skills and how to say no to activities or situations with the potential
to add stress to your daily routine. Spend time with family and friends, your support network. Practice meditation, yoga or tai chai either as part of a group or at home through on-line classes. Eat healthfully of antioxidant and fiber-rich foods. Exercise daily. Get lots of sleep. Set aside time for hobbies and other interests. Avoid alcohol and drugs that provide only short-term stress relief and can harm your health (29).

 

What happens to triglyceride levels after switching to a plant-based diet?

People eating long-term plant-based diets show consistently lower levels of triglycerides (4). However, the process of switching to a plant-based diet can cause either increases or decreases in triglycerides, usually by less than 0.7 mmol/L (4). Paradoxically, a person starting out with normal triglycerides (less than 1.7 mmol/L) might see a small rise in triglyceride level while a person with borderline high levels (1.7 to 2.2 mmol/L) or high levels (2.3 mmol/L or more) is more likely to experience a reduction in triglyceride level. A triglyceride rise may occur simply because eating plant-based involves a much higher volume of food. After all, one of the tenets of a plant-based diet is to eat until satisfied. The triglyceride level will fall again as the appetite becomes satisfied and food quantities decrease, especially as some weight loss occurs.

There is another reason for a rise in triglycerides during a change to a plant-based diet. The function of the liver changes depending upon the level of insulin in the body and the sensitivity of the liver to that insulin. After eating, blood glucose levels and insulin levels increase. In a normal insulin-sensitive liver these changes trigger absorption of that glucose into the liver. These processes occur at a normal physiological rate and result in normal fasting blood glucose and normal fasting blood lipid levels. Once in the liver the glucose is packaged in glycogen bundles and stored, filling up liver cells. When glucose levels drop, as happens regularly between meals and overnight, the corresponding drop in insulin signals the liver to release some of that stored glucose back into the blood to provide energy to the brain and other tissues. In severe food shortage the liver even has the ability to produce glucose from amino acids (gluconeogenesis). When the liver glycogen stores become full, the liver will convert any excess glucose it absorbs into fatty acids which are released into the blood as triglycerides and sent to fat tissues in the body for storage (30,31).

An insulin-resistant liver reacts in a different way. It is unresponsive to the message of insulin to absorb and store glucose. Instead, any food consumed, including both whole carbohydrates from a whole-food plant-based diet and refined carbohydrates from a standard Western diet, is converted into fatty acids and immediately dumped back into the bloodstream along with any extra glucose that the liver cannot handle. This results in higher fasting triglycerides and higher fasting blood glucose. This situation occurs in chronic conditions such as metabolic syndrome, obesity, type-2 diabetes and liver disease. In NAFLD (non-alcoholic fatty liver disease), an increasingly common chronic disease, dealing with extra glucose can actually accelerate the further development of fat in the liver (30,31).

The good news is that the rise in triglycerides during the transition to a plant-based diet is usually temporary. Continuing with a diet of low-fat whole plant-based foods along with regular exercise of 30 to 45 minutes daily will quickly work towards reversal of insulin resistance although, depending on the fat level in the liver, complete reversal of insulin resistance may take between 3 and 12 months. The end result will be normal levels of fatty acids and glucose being released into the blood, thus lowering blood triglyceride level.

What to do if triglycerides do not decrease as expected

If you switch to a low-fat plant-based diet and your triglycerides remain high, make sure that you are eating mostly whole complex carbohydrates. Eating refined carbohydrates are a sure way to keep triglycerides high. Also, look closely at the type of grains you are eating. Many foods labeled as “whole grain” actually consist of grain ground into such a fine flour that it is treated in the body almost the same way that refined white flours are treated. When buying grains, examine their nutrition label for the content of total carbohydrates in the product and compare that to the fiber content. This ratio should be at least 5:1. In other words, for every 5 gm of total carbohydrate in the product there should be 1 gm or more of fiber content. This ensures that the grain used is really more whole than refined. See my blog article entitled “The 5 to 1 Rule and the Hierarchy of Whole Grains” for further information. Another tactic can be to swap your usual whole grains for more intact grains such as wheat berries; steel-cut oats; barley; brown, black or red rice; millet and quinoa.

In 2002 a statement was released by the National Heart, Lung and Blood Institute panel on “Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (ATP III)”. It was suggesting that very high intakes of carbohydrates (greater than 60% of total calories) can cause a rise in triglycerides in some people. It also stated that fiber consumption can negate this effect (22). In the ensuing fifteen years, thousands of studies have corroborated this last statement. There is no need for an upper limit on carbohydrate intake if the carbohydrates eaten are whole foods. When it comes to eating carbohydrates, the type of carbohydrates eaten is of utmost performance.

Your mission is simple really. Eat plant-sourced food with as little processing as possible. Include all kinds of vegetables but especially legumes (beans, peas and lentil), leafy greens, brightly coloured vegetables of all kinds and cruciferous vegetables (broccoli, cauliflower and cabbage for example). Eat a range of fruits daily, especially berries. Eat grains in as whole a state as you can manage every day. Add in daily moderate amounts of ground flaxseed, nuts and seeds and generous shakes of herbs and spices. Stay away from refined or sugary foods. Do not eat animal sourced foods. Your triglycerides will reflect the results.

 

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