Dietary Nitrate Prevents Fatty Liver Disease

 

New Research on Dietary Nitrate for Fatty Liver Treatment

 

New research that features in the journal Proceedings of the National Academy of Sciences (PNAS) has discovered that a compound present in green leafy vegetables helps prevent nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD), or liver steatosis, is a condition in which fat builds up in the liver.

 

Between 30 and 40 percent of adults in the United States are living with NAFLD.

 

NAFLD is one of the most common causes of chronic liver disease in Western countries, and experts associate it with obesity, being overweight, and metabolic risk factors.

Currently, there are no approved treatments for NAFLD (non-alcoholic fatty liver disease), which can progress into more serious conditions, such as steatohepatitis, fibrosis, and cirrhosis.

Healthcare professionals recommend losing weight, making healthful food choices, and doing more physical activity to reduce fat in the liver.

 

New research, however, may pave the way for a new treatment.

Scientists at the Karolinska Institutet in Sweden have just published a study in which they show that inorganic nitrate — a compound that occurs naturally in green leafy vegetables — can reduce the buildup of fat in the liver.

 

For more information on NAFLD, read:

 

Dietary Nitrates Benefits

 

 

 

A review published in the American Journal of Clinical Nutrition concluded that:

 

“Data from observational epidemiologic and human clinical studies support the hypothesis that nitrates … of plant origin plays an essential physiologic role in supporting cardiovascular health and gastrointestinal immune function.”

 

Nitric Oxide (NO)

To understand the biological benefits of dietary nitrate, we first have to understand a little about nitric oxide.

Nitric oxide (NO) is one of the most important molecules in the body, involved in virtually every organ system.

Perhaps its most important role is as a potent vasodilator (i.e. it makes blood vessels bigger), which is improves blood flow around the body without the pump (heart) working harder.

The discovery of NO, a structurally simple, colorless and odorless gas, was viewed as so fundamentally important for human health and disease prevention that Science magazine named it as molecule of the year in 1992, and the Nobel Prize in Physiology or Medicine was awarded for its discovery in 1998.

Beets are high in nitric oxide.

NO is produced by an enzyme for an amino acid called L-Arginine. L-Arginine is found in many protein containing foods (e.g. legumes and nuts).

But one problem is that the enzyme doesn’t always work well and can be affected by factors such as smoking and age.

In addition, simply supplying more L-Arginine, either in diet or supplements, does not always increase NO production, and has been demonstrated to be ineffective after long-term use.

When humans ingest dietary nitrate, it is recirculated into the saliva where bacteria in the mouth convert it to nitrite. This nitrite is swallowed and can be further converted into NO either in the stomach, blood vessels, or within tissues (e.g. heart).

 

Dietary nitrate is now recognized as a very significant precursor to nitric oxide in a dose-dependent manner in humans.

 

In other words, more nitrate equals more NO—though there is a plateau at very high doses. So, ingestion of dietary nitrate increases NO and provide benefit in a number of diseases characterized by insufficient NO.

 

Dietary Nitrate Benefits Many Body Systems

Dietary nitrate increases NO production, and because NO is so important throughout the body, this means that nitrate can have wide ranging effects.

Research has shown that dietary nitrate works by making blood vessels bigger, increasing the amount of blood with each heartbeat, increasing the amount of oxygen in muscles, and thus increasing muscle strength.

 

Nitrate Vs Nitrite

 

Note that dietary nitrate is not the same as nitrite, which is often used as a preservative and added to processed meats like bacon and salami to prevent spoilage (e.g. botulism) and to contribute to a pinky color.

Plant foods are the primary sources of nitrate, while processed and cured meats are the primary sources of nitrites for humans.

 

When humans ingest food we metabolize it in the presence of oxygen to produce a molecule called ATP (adenosine triphosphate). ATP produces energy at the cellular level. It has been thought that a certain and constant amount of oxygen was required to produce a molecule of ATP.

Athletes, for example, can produce more ATP than non-athletes, but athletes have bigger, stronger lungs than non-athletes. They also have more oxygen carrying red blood cells and can take in more oxygen for ATP production.

 

Cardiovascular Benefits

 

The effect of dietary nitrate on those with lower fitness levels and/or muscular/heart/lung impairments is convincing.

In fact the effect of dietary nitrate on physical performance seems more pronounced in those with less fitness and with muscular/lung impairments.

Research groups around the world have also reported benefit in COPD, heart failure and peripheral artery disease (also called intermittent claudication).

 

Dietary Nitrate Lowers High Blood Pressure

 

Early studies showed that dietary nitrate decreases blood pressure in young, healthy volunteers.

More recent data show that dietary nitrate can also decrease blood pressure in more at-risk populations—those with high blood pressure, and demonstrated that any blood pressure lowering effect was more pronounced in those with higher blood pressure.

One group of researchers wrote, “an additional strategy, based on intake of nitrate-rich vegetables, may prove to be both cost-effective, affordable and favorable for a public health approach to hypertension.”

 

Benefits to Hypertension Caused by Sleep Apnea

 

Obstructive sleep apnea (OSA) is a serious sleep disorder where a person stops breathing regularly during sleep. Each time the person stops breathing, oxygen levels fall and the person will wake up, usually briefly. 

OSA is associated with high blood pressure which is very difficult to treat, and dietary nitrate has been shown to decrease blood pressure in OSA.

 

Dietary Nitrate Benefits the Brain

 

Research has shown that dietary nitrate can increase blood flow to the brain.  This brings the intriguing question: can increasing dietary nitrate help improve brain disorders such as dementia?

 

Nitrate Heals Fatty Liver

 

 

Mattias Carlström, an associate professor in the Department of Physiology and Pharmacology at the Karolinska Institute is one of the senior researchers and corresponding authors of a new study of the effects of supplementing a high-fat, high-sugar Western diet with dietary nitrate in mice.

They divided the mice into three groups and fed each of them a different diet. The control group received a normal diet, while the high-fat diet group ate the equivalent of a Western diet, and the third group received a high-fat diet with nitrate supplementation.

As expected, the mice in the high-fat diet group gained weight and fat mass, and they had raised blood sugar levels. However, all of these markers were significantly lower in the group that also received nitrate.

Carlström reports on the findings, saying,

 

“When we supplemented with dietary nitrate to mice fed with a high-fat and sugar Western diet, we noticed a significantly lower proportion of fat in the liver.”

 

The researchers also found that the rodents that received the nitrate had lower blood pressure and better insulin sensitivity than those on a high-fat diet without nitrate.

Previous research, the investigators explain, has already shown that dietary nitrate boosts cell metabolism. It has also suggested that green leafy vegetables may protect against metabolic conditions, such as type 2 diabetes.

“We think that these diseases are connected by similar mechanisms,” Carlström hypothesizes, “where oxidative stress causes compromised nitric oxide signaling, which has a detrimental impact on cardiometabolic functions.”

The researchers explain that the medical community still does not know exactly which compounds make leafy greens so healthful. “No one has yet focused on nitrate, which we think is the key,” continues Carlström.

 

We now want to conduct clinical studies to investigate the therapeutic value of nitrate supplementation to reduce the risk of liver steatosis. The results could lead to the development of new pharmacological and nutritional approaches.”

-Mattias Carlström

 

More studies are necessary to clarify which compounds are responsible for these healthful properties and to confirm that nitrate is key for liver and metabolic health. In the meantime, the team advises people to consume more green leafy vegetables.

Those with the highest concentration of inorganic nitrate include “celery, spinach, lettuce, and rocket.”

“[I]t doesn’t take huge amounts to obtain the protective effects we have observed — only about 200 grams per day,” says Carlström. “Unfortunately, however, many people choose not to eat enough vegetables these days,” he adds.

 

Best Food Sources of Dietary Nitrates

 

Arugula

Arugula is the greatest whole-food source of nitrates, packing about 480mg per 100g, according to research published in the American Journal of Clinical Nutrition.

 

Celery

Not only an amazing health food for weight loss, celery is also loaded with nitrates: It’s among a very high class of veggies that have more than 250mg per 100g, according to research published in the American Journal of Clinical Nutrition.

 

Cress

Cress, like other leafy greens, contains a very high level of dietary nitrate (over 250mg/100g), per American Journal of Clinical Nutrition research. Toss it in salad; cress has a peppery flavor.

 

Lettuce

Different varieties of lettuce boast different levels of nitrates. Oak leaf lettuce has 155mg/100g and butter leaf yields 200mg/100g, per research published in the European Food Safety Authority Journal.

 

Red Beetroot and Beet Juice

 

Beets have anywhere from 110 to 177 mg nitrates/100g (per European Food Safety Authority Journal).  

And beet juice has over 250mg/100g, according to data published in Sport Medicine; science backs up the potent potential of beets and their juice.

Beetroot juice powder and other supplements are also an option.  For example, Beet VO2 Max is popular, and has over 700 reviews.

 

Spinach

Spinach will pretty much always be a health food staple because of its nutrient profile and ability to bolster your diet and workouts; it contains well over 250mg of nitrates per 100g according to data published in Sport Medicine. On the high end, it can boast 380mg/100g.

 

Carrots

On the high end, carrots can range from 90 to 195mg of nitrates per 100g, according to research published in the American Journal of Clinical Nutrition.

 

Beet Greens

Beet greens are the leafy bits atop beets. Like their red counterparts, the greens also contain a good amount of nitrates, per research published in the American Journal of Clinical Nutrition.

 

Chinese Cabbage

You might not be familiar with Chinese cabbage, but you can use the leaves to make lettuce wraps. The hearty leaves contain 161mg nitrates per 100g serving, per research published in the American Journal of Clinical Nutrition.

 

Bok Choy

Bok choy can yield anywhere from 102–309mg nitrates per 100g serving, per research published in the American Journal of Clinical Nutrition. The texture is in between cabbage and lettuce, and is best steamed or cooked to remove its bitterness.

 

Rhubarb

Rhubarb is another standout at 281mg nitrate per 100g serving, the European Food Safety Authority Journal shows. Never had rhubarb before? Make sure to remove all the leaves (they can make you seriously sick) before trying.

If you eat it raw, note that it’s tart (like cranberries), so it’s often sweetened. You can also toss it in smoothies, add it to salads, roast it, or make your own sauce and salsa.

 

Swiss Chard

Swiss chard has about 147-270mg nitrates per 100g serving, according to research published in Food Additives & Contaminants. The leaves are tender and similar in taste to spinach—but with a slightly bitter aftertaste.

 

Mustard Greens

Mustard Greens can have up to 116 mg of nitrates per 100g, according to research published in the American Journal of Clinical Nutrition. Eat them raw or cooked—steamed, sautéed, or simmered.

 

Parsley

This vegetable is often used as an herb to flavor dishes; it has 100 mg to 250 mg of nitrates, per research published in the American Journal of Clinical Nutrition.

 

Turnips

Lower on our list, but still noteable, turnips have 100mg of nitrates per 100g, per research published in the American Journal of Clinical Nutrition.

 

 

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