Is TMAO from Fish, Meat and Eggs Harmful?

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In another confusing nutrition story that should be titled “is there anything left for us to eat?” recent research threw a curveball. Fish, a staple of the Mediterranean diet, as well as meat and eggs may be doing more harm than good thanks to a compound called trimethylamine-N-oxide (TMAO). TMAO is found in fish and produced in the body after eating meat and eggs. TMAO is linked to greater risk for heart attack, stroke and death; yet the research isn’t crystal clear. Is it time to give up fish meat and eggs or ignore the recent media headlines?

This post will cover:

  • TMAO: More than a Gut Reaction—What gives us higher TMAO levels?
  • TMAO and health?
  • The bottom line

TMAO: More than a Gut Reaction

Blood levels of TMAO are ~ 50 times higher after eating fish compared to eggs or beef. The human body absorbs intact TMAO like the kind found in fish, easily. However, the human body’s production of TMAO, after eating foods containing the essential nutrient choline (found in eggs and meat) and the compound l-carnitine (found in meat and pork and in much smaller quantities in chicken breast and dairy products), depends on the makeup of bacteria in your gut, kidney functioning and genetics.

In one study, regular meat eaters produced more TMAO than a vegetarian did after eating steak (which contains ~ 180 mg of l-carnitine). After wiping out their gut bacteria with antibiotics, the carnivores didn’t produce any TMAO after consuming 250 mg l-carnitine. The makeup of gut bacteria in the habitual meat eaters was presumably responsible for greater TMAO production compared to the vegetarian, yet this was a small study and we don’t know anything else about the participants’ diet. Was it the meat that altered gut bacteria or something else in their diet? After all, a steady diet of red meat may mean double cheeseburgers on white bread with regular servings of French fries and soda on the side. This isn’t exactly the diet you want for promoting good bacteria in your gut.

Another study found blood levels of TMAO were greater in those with a less diverse makeup of microbes and greater amounts of a less healthy type of bacteria (firmicutes), compared to one that is healthy (bacteroidetes). A diet higher in saturated fat will promote this environment.

While bacteria seem to influence TMAO production from l-carnitine, l-carnitine also influences the makeup of gut bacteria. A study in mice found those with their gut bacteria wiped out thanks to antibiotics produced a different makeup of bacteria in the gut after consuming l-carnitine while also doubling the risk of plaque buildup in their arteries.

Higher TMAO levels come from:

  • Eating fish
  • Less diverse array of gut bacteria and increased levels of bad versus good bacteria
  • Consuming l-carnitine (mouse study)

TMAO and Health

A few human studies found higher blood levels of TMAO were associated with greater risk for heart disease. However, all research isn’t pointing in the same direction. One study in over 300 patients found blood TMAO levels were not associated with heart attack or heart disease over the course of eight years, following the initial test for TMAO. However, TMAO levels were higher in those with diabetes, patients with metabolic syndrome and those with declining kidney functioning. Another study examined over 800 people between the age of 33 and 55 and found blood TMAO levels were not associated with clogged arteries, insulin resistance (this comes before type 2 diabetes) and inflammatory markers or negative changes in blood lipids suggesting TMAO levels might not contribute significantly to the progression of clogged arteries. However, this study shows TMAO levels were significantly lower than in previous research, showing an association between TMAO and heart disease.

TMAO is considered a risk factor for cardiovascular disease. In those with type 2 diabetes, higher TMAO levels are associated with greater risk for death, heart attack, heart failure and unstable angina (chest pain). Also, higher levels of circulating TMAO are associated with higher risk of death in those with chronic kidney disease and greater risk of certain cancers. Yet, there are several confounding factors. Fish is the primary culprit for higher acute circulating TMAO levels, yet fish-based diets are associated with reduced risk for heart disease. Also, levels of TMAO are dependent upon disease state and the makeup of gut bacteria. Therefore, at this time it isn’t entirely clear which came first – does TMAO cause disease or does TMAO increase due to disease?

The Bottom Line

The story on TMAO isn’t crystal clear, so there’s no reason to avoid fish, meat and eggs in an effort to decrease TMAO levels. All three of these foods are good sources of several nutrients important for health. Though processed red meats are linked to higher risk of colorectal and stomach cancers, when cooked appropriately (lower, moist heat for example) red meat can fit into a healthy diet and deliver important nutrients including iron, zinc and vitamin B12. Eggs are an economical source of protein and contain many nutrients and compounds that contribute to health including two antioxidants important for eyesight.

Though there is no reason to completely avoid these foods, you can alter your diet to help diversify gut bacteria and also increase the amount of good versus bad bacteria. Probiotic rich foods such as yogurt and kefir with live and active cultures, miso soup, tempeh and other fermented foods contain good bacteria. Fiber-rich plant foods (fruits, vegetables, legumes) are important food sources for bacteria to thrive in your body.

Disclosure: this post was sponsored by USFRA. All views are my own and backed by research.

References
Koeth RA, Wang Z, Levison BS et al. Intestinal microbiota metabolism of l-carnitine, a nutrient in red meat, promotes atherosclerosis. Nat Med 2013 Apr 7.

Cho CE, Caudill MA. Trimethylamine-N-Oxide: Friend, Foe, or Simply Caught in the Cross-Fire? Trends Endocrinol Metab 2016 Nov 4. [Epub ahead of print]

Cho CE, Taesuwan S, Malsheva OV, Bender E, Tulchinsky NF, Yan J, Sutter JL, Caudill MA. Trimethylamine-N-oxide (TMAO) response to animal source foods varies among healthy young men and is influenced by their gut microbiota composition: A randomized controlled trial. Mol Nutr Food Res 2016 Jul 5.

Carnitine. Health Professional Fact Sheet, NIH. https://ods.od.nih.gov/factsheets/Carnitine-HealthProfessional/

Mueller DM, Allenspach M, Othman A, Saely CH, Muendlein A, Vonbank A, Drexel H, von Eckardstein A. Plasma levels of trimethylamine-N-oxide are confounded by impaired kidney function and poor metabolic control.Atherosclerosis 2015;243(2):638-44.

Meyer KA, Benton TZ, Bennett BJ, Jacobs DR Jr., Lloyd-Jones DM, Gross MD, Carr JJ, Gordon-Larsen P, Zeisel SH. Microbiota-Dependent Metabolite Trimethylamine N-Oxide and Coronary Artery Calcium in the Coronary Artery Risk Development in Young Adults Study (CARDIA). J Am Heart Assoc. 2016 Oct 21;5(10). pii: e003970.

Get Cultured: Probiotics can Help You Lose Weight & Stay Healthy

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From Greek to Icelandic Skyr, yogurt is everywhere. Choose the right kind, one packed with probiotics and protein, and yogurt can help you trim your waistline while supporting overall health at the same time.

In this article, I’m covering:
• How gut bacteria influence your weight and health
• Probiotic-rich foods for health & healthy weight

Your Gut Bacteria Influence Your Weight & Health

There is an entire community of over one trillion microbes (bacteria) taking up valuable real estate in your gut. Some are good, some are bad and the rest are neutral. The good guys are key players for digestive and immune functioning (remember about 70% of your immune system is located in your gut). They have many other functions as well:
bacteria, probiotics and body weight

Research studies show lean and obese people have a different makeup of bacteria in their gut. In addition, lean individuals have a greater diversity of bacteria in their gut. Diversity is important –  think of bacteria like a team of people each one has a different job and they work better together than in isolation.

If an obese person loses weight their overall makeup of bacteria more closely resemble’s a lean person’s gut. Greater weight loss = even greater the changes in gut bacteria. Also, changing bacteria seems to influence weight, though scientists know less about the influence of altering gut bacteria and changing body weight. Lean mice transplanted with bacteria from obese mice experienced a 60% increase in body fat without changing their food intake (calories in) or physical activity (calories out). The authors of this study believe the change in gut bacteria resulted in an increased absorption of some carbohydrates, increase in the production of fat and increase in fat storage. Authors from another study, this one examining human twins, also found a connection between types of bacteria in the gut and body weight, particularly visceral fat – deep layers of fat that coat the organs and are tied to higher risk of certain chronic diseases such as heart disease. The authors of this study believe, like the study in mice, obese individuals may be absorbing more calories from the food they eat.

Probiotic-Rich Foods for Health & Healthy Weight

How did they swap out bacteria in studies? Poop transplants. This isn’t exactly something you should try at home. But there’s another, easier way to keep your gut healthy. Get cultured by picking up foods that contain healthy bacteria including yogurt (with live and active cultures), kefir (drinkable yogurt, it’s so good!), miso soup, homemade sauerkraut, and tempeh (made from soy, this has a nutty taste). There might be something special about yogurt – a meta-analysis (a study that combined the results of other studies) looked at dairy intake and weight changes over time. They found greater yogurt intake was associated with lower body weight. Plus the protein in Greek yogurt seems to help people feel full so they eat less at their next meal. Also, feed the bacteria by eating plenty of fruits, vegetables and whole grains, particularly onions, greens, beans, legumes, berries and bananas, to get enough prebiotics (food) to support their growth.

 

References
Benno Y. Mitsuoka T. Development of intestinal microflora in human and animals. Bifidobacteria Microflora 1986; 5:13-25.

Quigley EMM, Quera R. Small Intestinal Bacterial Overgrowth: Roles of Antibiotics, Prebiotics, and Probiotics. Gastroenterology 2006;130:S78-S90.

O’Hara AM, Shanahan F. The gut flora as a forgotten organ. EMBO Rep 2006;7:688-93.

Ramakrishna B. The normal bacterial flora of the human intestine and its regulation. J Clin Gastroenterology 2007;41:S2-S6.

Douglas LC, Sanders ME. Probiotics and prebiotics in dietetics practice. J Am Diet Assoc 2008;108:510-521.

Million M, Maraninchi M, Henry M et al. Obesity-associated gut microbiota is enriched in Lactobacillus reuteri and depleted in Bifidobacterium animalis and Methanobrevibacter smithii. Int J Obesity 2012;36:817-825.

Hempel S, Newberry SJ, Maher AR, Wang Z et al. Probiotics for the Prevention and Treatment of Antibiotic-Associated Diarrhea. A Systematic Review and Meta-analysis. JAMA 2012;307(18):1959-1969.

An Introduction to Probiotics. National Center for Complementary and Alternative Medicine. National Institutes of Health. http://nccam.nih.gov/health/probiotics/

Marik PE. Colonic flora, probiotics, obesity and diabetes. Front Endocrinol 2012;3:87.

Bäckhed F, Ding H, Wang T, Hooper LV, Koh GY, Nagy A, Semenkovich CF, Gordon JI. The gut microbiota as an environmental factor that regulates fat storage. Proc Natl Acad Sci U S A. 2004;101:15718-23.

Ley RE, Turnbaugh PJ, Klein S, Gordon JI. Microbial ecology: human gut microbes associated with obesity. Nature 2006;444(7122):1022-3.

Kalliomäki M, Collado MC, Salminen S, Isolauri E. Early differences in fecal microbiota composition in children may predict overweight. Am J Clin Nutr 2008;87(3):534-8.

Yang YX, He M, Hu G, Wei J, Pages P, Yang XH, Bourdu-Naturel S. Effect of a fermented milk containing Bifidobacterium lactis DN-173010 on Chinese constipated women. World J Gastroenterol 2008;14(40):6237-43.

Yaeshima T et al. Effect of yogurt containing Bifidobacterium longum BB536 on the intestinal environment, fecal characteristics and defecation frequency: a comparison with standard yogurt. Bioscience Microflora 1997;16:73-77.

Hempel S et al. Probiotics for the Prevention and Treatment of Antibiotic-Associated Diarrhea
A Systematic Review and Meta-analysis. JAMA 2012;307;1959-1969.

Semova I, Carten JD, Stombaugh J et al. Microbiota Regulate Intestinal Absorption and Metabolism of Fatty Acids in the Zebrafish. Cell Host & Microbe 2012;12:277.

Schwingshackl L, Hoffmann G, Schwedhelm C, Kalle-Uhlmann T, Missbach B, Knuppel S, Boeing H. Consumption of Dairy Products in Relation to Changes in Anthropometric Variables in Adult Populations: A Systematic Review and Meta-Analysis of Cohort Studies. PLoS One 2016; 11(6): e0157461.

Top 10 Flat Belly Foods

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Your abs are made in the gym and revealed in the kitchen. A good training program develops the muscles in your midsection and the right diet helps banish bloating so you can see your abs. Here are the 10 flat belly foods you should add to your diet for a better looking (and better feeling) mid-section):Greek yogurt for belly fat

Greek Yogurt with Live and Active Cultures

Look for Greek yogurt with “live cultures (aka good bacteria)” or the “Live & Active Cultures” seal. The cultures are good bacteria that take up valuable real estate in your gut, helping your body digest food and decreasing gas and bloating. The amount of healthy, versus harmful, bacteria influences body weight and how much weight you can lose while following a lower calorie diet. Plus, a study published in the International Journal of Obesity found people who get their calcium from yogurt, as opposed to other foods, may lose more weight in their belly. Even more evidence to support yogurt consumption comes from a study showing dieters who ate five servings of dairy, such as Greek yogurt, daily lost more weight and abdominal fat than those who ate just three servings every day. A more recent review of the research found higher dairy intake was associated with lower risk of obesity in the midsection and yogurt seems to help keep weight in check.

2 Nuts

Though nuts are relatively high in calories for a small amount of food,  people don’t gain weight when they add nuts to their previously nut-free diet. A study in over 13,000 adults revealed nut eaters, those who ate at least ¼ ounce of nuts or peanuts (technically a legume) per day had smaller waists than adults who didn’t eat nuts. Additionally, tree nuts and peanuts contain a considerable amount of monounsaturated fat. Dieters who eat more foods containing monounsaturated fats may lose more belly fat than those who eat the same number of calories per day with less monounsaturated fat.

3 Asparagus

When examining dietary patterns, weight and waist circumference in close to eighty thousand people over a 10-year period, researchers found those who ate more vegetables every day had both a lower BMI and smaller waistline compared to adults who ate few vegetables. Asparagus contains prebiotic fiber, a type of fiber that is food for the good bacteria in your gut. Plus, asparagus is a natural mild diuretic making it the perfect food before hitting the beach or wearing a more formfitting outfit.

4 Avocados

Avocados contain a good amount of monounsaturated fat, not to mention nineteen vitamins and minerals. But, their monounsaturated fat is the ticket to a smaller waistline. In one study scientists gave obese adults with type 2 diabetes diets rich in saturated fat, monounsaturated fat or  carbohydrates. Those on the high carbohydrate diet ended up with fat redistributed to their stomachs while the monounsaturated fat rich diet prevented fat redistribution to the belly area. Plus, a look at dietary intake data from close to 18,000 adults found body weight, BMI and waist size were all significantly lower in avocado consumers versus those who didn’t include avocados in their diet.

5 Popcorn

Popcorn is a whole grain and when you pop it yourself on the stovetop (or in a brown paper bag in the microwave, just add good old fashioned popcorn kernels in a brown paper bag and fold the top) and top it with a little spray butter or spices for flavor, you’ll end up with a snack that takes a long time to eat and fills you up on relatively few calories. In addition, several studies show people who eat about three servings of whole grains per day weight less and have a smaller waistline compared to those who don’t.

6 Cold Pea Salad

Peas are naturally rich in resistant starch, a type of fiber that isn’t completely broken down or absorbed during digestion. Cooking and cooling peas to make a pea salad will significantly increase the amount of resistant starch they content. Rodent studies show resistant starch helps reduce stomach fat and increase hormones that tell the brain it’s time to stop eating.

7 Eggs

Choose eggs over cereal in the morning and you’ll tame hunger pangs for hours after breakfast, decreasing the likelihood of overeating later in the day. Make a meal containing at least 25 – 30 total grams of protein (the protein is in the white of the egg so this equates to 4 – 5 egg whites though you can choose any combination of whole eggs and egg whites as long as you consume at least 4 -5 of the whites) so you can cash in on the satiety-enhancing benefits of eggs. Added bonus: following a high protein diet for a short period of time can lead to significant reductions in belly fat.

8 Green Tea

The combination of caffeine and antioxidants in green tea may lead to small to moderate reductions in body fat and waist size. However, you need to consume quite a bit of it so get creative and cook with green tea by brewing it and using it to cook rice (it’s particularly good with jasmine rice), make stews, soups or stocks. You can also poach fruit green tea or use dried green tea leaves as part of a rub for meats, tofu or fish.

9 Barley

Barley is a cereal grain with a nutty taste and consistency that is a cross between pasta and rice. In a double-blinded trial (both the men and the researchers didn’t know which food they were getting), Japanese men were given rice or a mixture of rice with pearl barley. The group receiving the pearl barley and rice mixture lost a significant amount of visceral fat, the kind that covers your organs like a thick winter blanket and increases risk of heart disease, stroke and type-2 diabetes. Compared to the rice only group, the group who ate pearl barley decreased their waist size.

10 Blueberries

Blueberries are an excellent source of dietary fiber, which will not only help keep you full but also help keep your waistline in check. Plus they are a natural source of prebiotic fiber – the kind that the good bacteria in your gut munch on.

A flat belly is one of the most recognized signs of a fit body. Blast away abdominal fat with high-intensity cardio and build the underlying muscle by regularly switching up your training program. Also, incorporate a 30-minute abs classes to your routine. At least one study found you can spot reduce if you exercise the same muscle group for at least 30 minutes at a time. Keep in mind abs are made in the gym but revealed in the kitchen. Add the top 10 flat belly foods to your diet while cutting down on sugar alcohols (sorbitol, maltitol, and mannitol are the worst for causing gas and bloating), fizzy drinks and chewing gum (all of these can increase bloating at least temporarily) and you may fall in love with skinny jeans.

 

References
Clifton PM, Bastiaans K, Keogh JB. High protein diets decrease total and abdominal fat and improve CVD risk profile in overweight and obese men and women with elevated triacylglycerol. Nutr Metab Cardiovasc Dis 2009;19(8):548-54.

O’Neil CE1, Keast DR, Nicklas TA, Fulgoni VL 3rd. Nut consumption is associated with decreased health risk factors for cardiovascular disease and metabolic syndrome in U.S. adults: NHANES 1999-2004. J Am Coll Nutr 2011;30(6):502-10.

Kahn HS, Tatham LM, Rodriguez C, et al. Stable behaviors associated with adults’ 10-year change in the body mass index and likelihood of gain at waist. Am J Public Health 1997;87:747-54.

Ridaura VK, Faith JJ, Rey FE, Cheng J, Duncan AE et al. Gut microbiota from twins discordant for obesity modulate metabolism in mice. Science 2013;341:6150.

Turnbaugh PJ, Ley RE, Mahowald MA, Magrini V et al. An obesity-associated gut microbiome with increased capacity for energy harvest. Nature 2006;444:1027-1031.

Vidrine K, Ye J, Martin RJ, McCutcheon KL et al. Resistant starch from high amylose maize (HAM-RS2) and dietary butyrate reduce abdominal fat by a different apparent mechanism. Obesity (Silver Spring) 2014;22(2):344-8.

Bisanz JE, Reid G. Unraveling how probiotic yogurt works. Sci Transl Med 2011;3:106.

Dhurandhar NV, Geurts L, Atkinson RL et al. Harnessing the beneficial properties of adipogenic microbes for improving human health. Obesity Reviews 2013;19:721-735.

Delzenne NM, Neyrinck AM, Bäckhed F, Cani PD. Targeting gut microbiota in obesity: effects of prebiotics and probiotics. Nat Rev Endocrinol 2011;7(11):639-46.

Furet JP, Kong LC, Tap J et al. Differential adaptation of human gut microbiota to bariatric surgery-induced weight loss: links with metabolic and low-grade inflammation markers. Diabetes 2010;59:3049-3057.

Ley RE, Turnbaugh PJ, Klein S, Gordon JI. Microbial ecology: human gut microbes associated with obesity. Nature 2006;444: 1022–1023.

Santacruz A, Marcos A, Warnberg J et al. Interplay Between Weight Loss and Gut Microbiota Composition in Overweight Adolescents. Obesity 2009;17:1906–1915.

Harland JI, Garton LE. Whole-grain intake as a marker of healthy body weight and adiposity. Public Health Nutr 2008;11(6):554-63.

Yadav BS, Sharma A, Yadav RB. Studies on effect of multiple heating/cooling cycles on the resistant starch formation in cereals, legumes and tubers. Int J Food Sci Nutr 2009;60 Suppl 4:258-72.

Keenan MJ, Zhou J, McCutcheon KL et al. Effects of resistant starch, a non-digestible fermentable fiber, on reducing body fat. Obesity (Silver Spring) 2006;14(9):1523-34.

Nagao T, Komine Y, Soga S et al. Ingestion of a tea rich in catechins leads to a reduction in body fat and malondialdehyde-modified LDL in men. Am J Clin Nutr 2005;81(1):122-9.

Paniagua JA, Gallego de la Sacristana A, Romero I et al. Monounsaturated fat-rich diet prevents central body fat distribution and decreases postprandial adiponectin expression induced by a carbohydrate-rich diet in insulin-resistant subjects. Diabetes Care 2007;30(7):1717-23.

Fulgoni VL 3rd, Dreher M, Davenport AJ. Avocado consumption is associated with better diet quality and nutrient intake, and lower metabolic syndrome risk in US adults: results from the National Health and Nutrition Examination Survey (NHANES) 2001-2008. Nutr J 2013;12:1.

Shimizu C, Kihara M, Aoe S et al. Effect of high beta-glucan barley on serum cholesterol concentrations and visceral fat area in Japanese men–a randomized, double-blinded, placebo-controlled trial. Plant Foods Hum Nutr 2008;63(1):21-5.

Du H, van der A DL, Boshuizen HC et al. Dietary fiber and subsequent changes in body weight and waist circumference in European men and women. Am J Clin Nutr 2010;91(2):329-36.

Peters EM, Anderson R, Nieman DC, et al. Vitamin C supplementation attenuates the increases in circulating cortisol, adrenaline and anti-inflammatory polypeptides following ultramarathon running. Int J Sports Med 2001;22(7):537-43.

 

The Ketogenic Diet Craze: Fat-Filled Lies, Part 1

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ketogenic diPicture this: a thick, juicy, tender eventeak grilled to perfection with melted butter glazed on top, gently dripping down the sides. Lying next to the steak there’s a side of dark green asparagus sautéed in coconut oil and dusted with a sprinkle of sea salt. Could a diet loaded with fat help you lose diet-resistant body fat that’s been taunting the seams of your dress pants and poking through buttons on your shirt? Will eating fat turn you into an all-star athlete? This is part 1 of a 2 part series on the ketogenic diet.

Here is what I will cover in this blog post:

  • What is the ketogenic diet?
  • Adverse health effects.

Here is what I will cover in tomorrow’s blog on this topic:

  • The issue with ketogenic research studies.
  • Is the ketogenic diet superior for losing fat?
  • How will the ketogenic diet affect muscle?
  • How will the ketogenic diet impact athletic performance?

What is the Ketogenic Diet?

For nearly a century, epileptic patients have used ketogenic diets to control seizures when common medications provide no relief. Scientists aren’t sure why following a ketogenic diet decreases the incidence and severity of seizures but it works.

The ketogenic diet contains – 80-90% of calories from fat, 15% from protein and 5% from carbohydrate (1, 2). Food choices may include heavy cream, bacon, eggs, non-starchy vegetables, mayonnaise and sausage while fruits, starchy vegetables, breads, pasta, cereal and other carbohydrate-rich foods are not allowed.

During the first several days on a ketogenic diet, your body’s limited supply of carbohydrate stored in liver and muscle tissue decreases dramatically. As a result, you will feel like you have mono – exhausted, with headaches and easy exercise will feel like you’re climbing Mount Everest (3). Once your stored carbohydrate has dwindled, ketones, formed from the breakdown of dietary fat, become the primary source of energy for brain and body. Ketogenic means “ketone forming.” It takes at least seven days to reach nutritional ketosis and several weeks to fully adapt to the diet (12). If you aren’t in nutritional ketosis (as measured by blood, urine or breath ketones; ketone levels > 0.5 mmol/L), then you aren’t following a ketogenic diet, you are on a low carbohydrate diet.

Adverse Health Effects from the Ketogenic Diet

Much of the research on adverse effects comes from studies in epileptic children since they have been on the diet for long periods of time. These studies show soon after starting a ketogenic diet, blood cholesterol levels and artery stiffness increase (4, 5). High total and LDL cholesterol are risk factors for cardiovascular disease (diseases of the heart and blood vessels). When arteries are stiff, they cannot expand as well in response to changes in blood pressure. Think of this like a garden hose when you turn up the water pressure, your hose either expands or the water bursts out of the space between the faucet and the hose. When arteries cannot open widely to accommodate increases in blood flow, blood pressure increases leading to microscopic tears on artery walls, development of scar tissue and the perfect surface for plaque buildup (6). Blood cholesterol levels returned to normal in patients who went off the diet and in those who stayed on it, they returned to normal after 6 to 12 months. Artery stiffness returned to normal after 24 months on a ketogenic diet.5 Studies in obese patients suggest ketogenic diets improve blood sugar and blood cholesterol levels over time, either due to the diet, weight loss from the diet, a combination of the two or carbohydrate restriction (7, 8). Lose weight, regardless of what you eat and blood cholesterol, blood pressure, inflammation, blood sugar and many other disease risk factors will improve.

Ketogenic diets are typically low in calcium, vitamin D, potassium, magnesium, folic acid and fiber. There are several potential consequences associated with consistently low intake of each of these micronutrients including softening of the bones, decreased bone density, muscle damage, muscle weakness or spasms, and abnormal heart rhythm. However, with careful planning, a fiber supplement, multivitamin and under the guidance of a physician who may prescribe potassium and sodium supplements (blood sodium could drop to dangerously low levels while on this diet), nutrient needs can be met. Also, to prevent constipation when on a ketogenic diet, a fiber supplement may be necessary along with more water / fluid intake then you are used to.

Here are some other potentially bad side effects from following a high fat diet:

  • Harm to your Brain. Studies in mice show a high fat diet, even when followed for as little as two months leads to chronic inflammation, sedentary immune cells in the brain – these cells typically act like janitors picking up trash and infectious compounds but when they become sedentary they stop doing their job, leading to cognitive impairment (9). Does this happen in humans and resolve over time? We don’t know.
  • Mad Bacteria in Your Gut. A diet with no probiotics (healthy bacteria) and low in prebiotics (certain types of fiber that the healthy bacteria much on for food keeping them happy) will likely change the composition of bacteria in your gut so you have more harmful and less beneficial bacteria.
  • Leaky Gut. High saturated fat meals increase bacterial toxins (endotoxins) in the intestines and intestinal permeability. In other words: leaky gut (10, 11). If you are on this diet, consider opting for foods lower in saturated fat and higher in unsaturated fats (liquid oils, avocado, nuts, seeds, olives).
  • Free radicals in overdrive? If you can’t eat a number of colorful foods including blueberries, beets, corn, oranges, and more, chances are you won’t get a wide array of antioxidant compounds to quench free radicals (compounds that are important for good health but can wreck your body when they aren’t tamed by antioxidants) as well as other plant-based compounds that keep your arteries, muscles and other parts of your body healthy. Will your body adapt? We don’t know at this time.

Are the side effects and potential negative side effects worth it if you can lose weight on this diet? Stay tuned for tomorrow’s post on how the ketogenic diet impacts body fat and athletic performance.

References

1 Freeman JM, Freeman JB, Kelly MT. The ketogenic diet: a treatment for epilepsy. 3rd ed. New York, NY: Demos Health; 2000.

2 Paoli A, Bianco A, Damiani E, Bosco G. Ketogenic Diet in Neuromuscular and Neurodegenerative Diseases. BioMed Research International 2014, Article ID 474296, 10 pages, 2014.

3 White AM, Johnston CS, Swan PD et al. Blood ketones are directly related to fatigue and perceived effort during exercise in overweight adults adhering to low-carbohydrate diets for weight loss: a pilot study. J Am Diet Assoc 2007;107(10):1792-6.

4 Tanakis M, Liuba P, Odermarsky M, Lundgren J, Hallböök T. Effects of ketogenic diet on vascular function. Eur J Paediatr Neurol 2014;18(4):489-94.

5 Coppola G, Natale F, Torino A et al. The impact of the ketogenic diet on arterial morphology and endothelial function in children and young adults with epilepsy: a case-control study. Seizure 2014;23(4):260-5.

6 Cecelja M, Chowienczyk P. Role of arterial stiffness in cardiovascular disease. JRSM Cardiovascular Disease 2012;1(4):1-10.

7 Dashti HM, Mathew TC, Hussein T, Asfar SK, Behbahani A, Khoursheed MA, Al-Sayer HM, Bo-Abbas YY, Al-Zaid NS. Long-term effects of a ketogenic diet in obese patients. Exp Clin Cardiol 2004; 9(3): 200–205.

8 Volek JS, Feinman RD. Carbohydrate restriction improves the features of Metabolic Syndrome. Metabolic Syndrome may be defined by the response to carbohydrate restriction. Nutr Metab (Lond) 2005;2:31.

9 Hao S, Dey A, Yu X, Stranahan AM. Dietary obesity reversibly induces synaptic stripping by microglia and impairs hippocampal plasticity. Brain Behav Immun 2016 Jan;51:230-9.

10 Mani V, Hollis JH, Gabler NK. Dietary oil composition differentially modulates intestinal endotoxin transport and postprandial endotoxemia. Nutr Metab (Lond) 2013; 10: 6.

11 Lam YY, Ha CW, Campbell CR, Mitchell AJ, Dinudom A, Oscarsson J, Cook DI, Hunt NH, Caterson ID, Holmes AJ, Storlien LH. Increased gut permeability and microbiota change associate with mesenteric fat inflammation and metabolic dysfunction in diet-induced obese mice. PLoS One 2012;7(3):e34233.

12 Paoli, A, Grimaldi K, D’Agostino D, Cenci L, Moro T, Bianco A, Palma A. Ketogenic diet does not affect strength performance in elite artistic gymnasts. J Int Soc Sports Nutr 2012;9:34.