How to Stop Touching Your Face to Prevent Viruses

Dayna Dye

Touching the face transfers microbes on the hands to the openings of the human face
A handshake, a kiss on the cheek, a hug: gestures of greeting and affection we’ve come to expect
from those we know . . . and even strangers. In the era of the novel coronavirus and other communicable diseases that never went away, are these gestures a good idea? And what about touching your own face?

The Science Behind Human Touch

Touch is a part of human bonding, particularly among infants. “The most effective and critical stimulus in the formation of mammalian pair and maternal-infant bonds is soft tactile stimulation,” wrote Yu Fu and colleagues in the Nature journal Scientific Reports.1

The need for skin to skin contact with a parent after birth has long been recognized as essential to the subsequent physical and emotional health of the newborn. “Nurturing touch is a powerful way to provide human connections that help foster infant attachment behaviors. This type of touch typically involves skin-to-skin (STS) contact between a newborn and a primary caregiver,” writes Lisa Cleveland and colleagues in the Journal of Obstetric, Gynecologic & Neonatal Nursing. “The evidence supports that STS contact in the immediate period after birth for full-term, healthy newborns is not only safe but also effective to improve short- and long-term outcomes for newborns and their families.”2

oxytocin is a hormone believed to be responsible for the bonding of a parent to a child
Human to human touch stimulates the release of oxytocin, a hormone believed to be responsible for the bonding of a parent to a child, a lover to their beloved and even a dog to its guardian.3 This “love hormone,” produced by the brain’s hypothalamus, may benefit those with anxiety, depression and autism.4,5

A mother’s touch also delivers the bacteria that reside on the surface of her skin to the infant, which develops the child’s own microbiome. This protective skin barrier helps ward off infectious agents and can be disrupted by overzealous cleansing.

Why does the CDC advise us not to touch our faces and practice social distancing?

Human proximity and human touch also provide an opportunity for pathogenic bacteria and viruses from one person to invade another host to further propagate their species. Hands—the primary source of human touch— are a source of disease transmission. Touching the face transfers microbes on the hands to the openings of the human face—eyes, nose and mouth, which provide access to mucous membranes and the respiratory tract, where many communicable infections take hold.

Why do people touch their faces?

People touch their faces out of habit. Often it is due to feeling distracted or anxious.6 Nervousness, social anxiety, worry or discomfort might respond favorably to oxytocin released by touching.

How often, on average, do people touch their faces?

According to scientists at the Paul Flechsig Institute of Brain Research at the University of Leipzig in Germany, “Every human being spontaneously touches its eyes, cheeks, chin and mouth manifold every day. These spontaneous facial self-touches are elicited with little or no awareness.”6

In one study, face-touching was observed an average of 23 times per hour among each of 26 medical students who did not know they were being videotaped. Forty-four percent of those touches involved contact with a mucous membrane, including 36% to the mouth, 31% to the nose, 27% to the eyes and 6% to a combination of these areas. The researchers involved in the study urge increased self-awareness of touching one’s face and note that hand hygiene is an essential method to stop the colonization and transmission cycle associated with self-inoculation with microbes that cause respiratory infections.7

In another investigation, clinicians and staff members at seven offices of the Cincinnati Area Research and Improvement Group (CARInG) practice-based research network touched their eyes, nose or mouth an average of 19 times during a two-hour period. Additionally, only 9% of hand washings observed met the US Centers for Disease Control and Prevention criteria for hand washing effectiveness.8

Of course, some hand to face contact is inevitable. This further emphasizes the importance of thoroughly washing one’s hands for 20 seconds or more before a meal and at other times, particularly after encountering others who may be suffering from respiratory or other infections. In this way, when we do touch our faces, there is a lower risk of transmitting infectious microorganisms.

Related Article: Coronavirus Prevention: Hand Washing vs. Hand Sanitizer

How to Stop Touching Your Face

the role that touching the face plays in disease transmissionPeople may have spent a lifetime frequently touching their faces without it ever having been brought to their attention. Awareness is the first step in control. Understanding the role that touching the face plays in disease transmission can motivate people to avoid this often-subconscious habit.

Creating new habits or breaking old ones requires a fair amount of self-discipline. It may take weeks to stop touching/scratching the face, rubbing the eyes, nail-biting, resting the chin on one’s hand or hands, etc. Ignore the urge when it presents itself. Reminder notes in conspicuous places are useful for some individuals. Wearing gloves can also help you kick the habit.

Noli Me Tángere - Touch Me Not

“Social distancing,” a term almost unheard of until recently, can refer to anything from the avoidance of large, crowd-drawing events, to maintaining a distance of at least 6 feet between ourselves and others. Some people even choose to (or are asked to) self-quarantine or stay home except for essential activities.

Social distancing makes sense during cold and flu season. The viruses that cause these illnesses can be transmitted prior to the appearance of symptoms in an infected individual, making it nearly impossible to avoid exposure. Social distancing also protects others from what we, ourselves, may be unknowingly carrying.

What are some other ways to prevent disease transmission?

• Get screened/tested. If testing reveals the presence of illness, treatment can be rapidly initiated.

• Don’t share personal items (towels, eating utensils etc.), particularly with people who are exhibiting symptoms of illness.

• Sanitize high-touch surfaces such as keyboards with a solution of bleach and water or other accepted sanitizing products.

• If you are experiencing symptoms, don’t leave your home unless necessary. When visiting a medical provider, ask in advance whether you need to wear a mask or take other precautionary measures.9

Being able to mount a healthy immune response is key. Michael Smith M.D. explains which nutrients support the immune system:

Touching is an essential and pleasurable part of human existence that no one wants to be without. Just make sure not to be indiscriminate with touching, including touching one’s own face, especially during cold and flu season.

About the author: Dayna Dye has been a member of the staff of Life Extension® since shortly after its inception. She has served as the department head of Life Extension® Wellness Specialists, is the author of thousands of articles published during the past two decades in Life Extension® Update, Life Extension Magazine® and on, and has been interviewed on radio and TV and in newsprint. She is currently a member of Life Extension’s Education Department.

  1. Fu Y et al. Sci Rep. 2018 Jun 13;8(1):9004.
  2. Cleveland L et al. J Obstet Gynecol Neonatal Nurs. 2017 Nov - Dec;46(6):857-869.
  3. Thielke LE et al. Biol Rev Camb Philos Soc. 2017 Feb;92(1):378-388.
  4. Yamasue H et al. Curr Top Behav Neurosci. 2018;35:449-465.
  5. Yoon S et al. Adv Exp Med Biol. 2020;1191:103-120.
  6. Mueller SM et al. PLoS One. 2019 Mar 12;14(3):e0213677.
  7. Kwok YL et al. Am J Infect Control. 2015 Feb;43(2):112-4.
  8. Elder NC et al. J Am Board Fam Med. 2014 May-Jun;27(3):339-46.
  9. Centers for Disease Control and Prevention. Coronavirus Disease 2019 (COVID-19): How to Protect Yourself.

Coronavirus Prevention: Hand Washing vs. Hand Sanitizer

Dayna Dye

Hand Sanitizer vs Soap

Hand washing is the most important preventative measure for the reduction of contagious diseaseWhich one is better to prevent the coronavirus? Hand sanitizer is flying off the shelves in the face of the coronavirus threat, leaving people scrambling to find alternatives. But while the use of hand sanitizer has been shown to lower the risk of transmission of certain bacteria and viruses, plain old soap and water may be better.

Although the value of hand cleansing has been known at least as far back as during the lifetime of disinfection pioneer Ignaz Semmelweis in the 19th century, dismayingly, it still isn’t practiced regularly among many members of the general populace and even by some of those in the healthcare sector.

“Hand washing is the most important preventative measure for the reduction of contagious disease,” Lynn G. Bowman and colleagues from the Kennedy Krieger Institute unequivocally affirm. “Although hand washing is easy to perform, non-adherence is a ubiquitous problem.”1

The ability to wash one’s hands with soap and water is something long taken for granted in wealthier countries that have access to running water in the home, at work and elsewhere. Hand sanitizers are a more recent development. Their portability and ease of use has contributed to an increase in their popularity.

“It is important to keep in mind that alcohol hand sanitizer efficacy is dependent upon which and how much product is used, proper technique, and consistency of use,” cautions Nina A. Gold and Usha Avva in StatPearls. “There are also situations where these products are not ideal, for example, in preventing the spread of certain infections or when the hands are significantly soiled and the bacterial load is too high.”2

Hand Sanitizer Facts and Overuse

Excessive use of alcohol-based sanitizers as well as obsessive hand washing are associated with damage to the epidermal barrierHand sanitizers are alcohol or non-alcohol based. Those that are alcohol-free usually contain
benzalkonium chloride, which is less damaging to the hands than alcohol and has the advantage of continuing to protect against micro-organisms hours after it has dried on the skin. Alcohol-based sanitizers have been around longer and are more commonly used. Their drying effect on the skin is lessened by the addition of humectants, emollients or moisturizers. 2

Portability and, in healthcare settings, easy access to hand sanitizers renders overuse a possibility. While handwashing can also be overdone, the limited locations of running water make this less likely.

Excessive use of alcohol-based sanitizers as well as obsessive hand washing are associated with damage to the epidermal barrier, which could lead to skin irritation and occupational irritant contact dermatitis (ICD) of the hands. The epidermal barrier prevents the loss of moisture and blocks the entry of potentially toxic or infectious agents.3 Disruption of the skin’s microbiome (protective bacteria that exist on the surface of the skin) can result in a greater risk of colonization by staphylococci and other undesirable bacteria.2 “Epidermal barrier damage associated with ICD is not only uncomfortable, it increases the permeability of the skin, thus promoting further uptake of irritants and chemicals, perpetuating epidermal damage and irritation,” writes Erika C. von Grote, PhD, and colleagues in the Journal of Drugs in Dermatology.4

Hand Sanitizer Effectiveness

Washing the hands thoroughly with soap and water (for at least 20 seconds) is more effective than hand sanitizers against specific microorganisms that include bacterial spores, the Cryptosporidium parasite and some nonenveloped viruses, including norovirus, the leading cause of food-borne illnesses in the United States. Hand sanitizer is also less effective than washing with soap at removing microorganisms (including E. coli) that reside under the fingernails.2

Ethyl alcohol (commonly used in alcohol-based sanitizers) at a concentration of 80% or less is not effective against:

  • calicivirus
  • hepatitis A
  • foot and mouth disease
  • polyomavirus
  • poliovirus

However, a concentration of 95% can eliminate most viruses considered to be clinically relevant. And ethanol-based hand sanitizers are more effective than washing with soap for removal of the common cold virus.2

We’ve emphasized the essentiality of washing our hands, but what about drying them? It turns out that how we dry our hands is important, too. One study found that bacteria released from wet hands is ten times more abundant than that released from dry hands.5 A comparison of various methods found that drying the hands in a stationary position under a warm air dryer for 20 seconds removes more bacteria than rubbing the hands under a dryer, as is often directed.6 However, these air dryers increase the aerosolization of bacteria, resulting in dispersion of contaminated droplets within three feet of the surrounding area. Jet dryers have been found to increase nearby bacterial counts to levels of more than four times that of standard warm air dryers.7 Paper towels are less likely to spread infection in a public setting and are preferred by most people due to faster drying time.

What does the CDC say about Hand Sanitizer?

The United States Centers for Disease Control and Prevention has concluded the following: “CDC recommends washing hands with soap and water whenever possible because handwashing reduces the amounts of all types of germs and chemicals on hands. But if soap and water are not available, using a hand sanitizer with at least 60% alcohol can help you avoid getting sick and spreading germs to others. The guidance for effective handwashing and use of hand sanitizer in community settings was developed based on data from a number of studies.”8

They add that hand sanitizers may be less effective when the hands are visibly soiled and that these products may not remove harmful compounds, like metals or pesticides. According to the CDC, the product is to be applied to the palm of one hand using the label-recommended amount and rubbed over the surface of both hands until they are dry.

The Bottom Line

Hand sanitizers are a valuable asset to help lower the risk of transmission of infectious agents as long as they are not overused or depended upon to guarantee elimination of all unwanted microbes. In general, hand washing with plain old soap and water is the best option. (And no, the soap should not be “antibacterial”—regular soap will do!)

Related Blog: Facts about Flu Season

When purchasing a hand sanitizer, benzalkonium chloride, isopropanol, ethanol or n-propanol listed as ingredients are considered to be effective at reducing harmful microorganisms. Hand sanitizers should not contain methanol (methyl alcohol), which can be toxic. Sanitizers with added humectants may be less likely to result in excessive skin drying as are those with a lower alcohol content, but the latter may be less effective than sanitizers that contain a higher percentage of alcohol. Be sure to keep all hand sanitizers out of the reach of young children.

About the author: Dayna Dye has been a member of the staff of Life Extension® since shortly after its inception. She has served as the department head of Life Extension® Wellness Specialists, is the author of thousands of articles published during the past two decades in Life Extension® Update, Life Extension Magazine® and on, and has been interviewed on radio and TV and in newsprint. She is currently a member of Life Extension’s Education Department.

  1. Bowman LG et al. Behav Anal Pract. 2019 Jan 23;12(3):600-611.
  2. Gold NA et al. Alcohol Sanitizer. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Feb 6.
  3. Kemény L et al. Curr Pharm Des. 2016;22(35):5373-5381.
  4. J Drugs Dermatol. 2016 Dec 1;15(12):1504-1510.
  5. Ataee RA et al. Int J Prev Med. 2017 Mar 10;8:16.
  6. Suen LKP et al. Sci Rep. 2019 Sep 24;9(1):13754.
  7. Best EL et al. J Hosp Infect. 2014 Dec;88(4):199-206.
  8. “Show Me the Science – When & How to Use Hand Sanitizer in Community Settings.” Centers for Disease Control and Prevention. 2019.

Japanese Diet Plan and Longevity

Dayna Dye

Diet may be an important contributor to the longevity of the Japanese people.Japan. Land of the rising sun and the cherry blossom. Advanced in technology and rich in tradition.

Of all the countries on the globe, the Japanese have one of the longest life expectancies. As of February 17, 2020, the world’s oldest living person is Kane Tanaka, a woman who is 117 years old and resides in Japan. The oldest living male, Chitetsu Watanabe (aged 112), also lives in Japan. The previous titleholder was Japanese, as well. The Japanese island of Okinawa, a designated Blue Zone (regions of the world where people have above average lifespans), has the greatest percentage of centenarians on the planet.

Japan is not known for a healthy environment or low-stress lifestyles; however, its citizens have modern and accessible health care and a good standard of living and education. Diet may also be an important contributor to the longevity of the Japanese people.

Staples of the Japanese Diet

“The average Japanese lifespan became the longest in the world in 1986,” wrote Yuta Yokoyama and colleagues in an article published last year in Annals of Human Biology. “Washoku, or the traditional Japanese diet, is respected globally for its nutritionally-balanced and healthy eating habits. This uniquely Japanese way of eating may be one factor that helps extend the Japanese lifespan.”1

Although Western eating habits have invaded Japan and other parts of the world over the past several decades, many Japanese people continue to eat a diet similar to that of their ancestors that relies upon fish and soy foods as protein sources. Rice, vegetables (including sea vegetables) and green tea are regularly consumed. The diet is low in saturated fat and added sugar. And unless we’re talking about the diet of sumo wrestlers, food is generally consumed in moderate quantities.

Study: Traditional 1975 Japanese Diet Plan

In a study that utilized National Health and Nutrition Survey data, Tsuyoshi Tsuduki and colleagues reproduced weekly menus from 1960, 1975, 1990 and 2005 and prepared the foods as a freeze-dried, powdered diet.2 Mice bred to experience accelerated aging were divided into groups that received a standard diet supplemented with the powdered diet corresponding to each of the years. A control group of mice received an unsupplemented standard diet.

Animals that consumed the traditional 1975 Japanese diet experienced delayed signs of aging, maintenance of memory and learning abilities, and longer life in comparison with those that received the 2005 diet. “The results of the present study suggested that the traditional Japanese diet is more effective in enhancing life expectancy and delaying senescence than the current Japanese diet,” the authors concluded.

The findings are the basis for the 1975 Japanese diet plan that has been further investigated in animals and humans and discussed in the media.3,4 Analysis of the 1975 diet revealed components contained in fish, fruits, vegetables, seaweed, soy, dashi soup stock and fermented seasonings.3

A study published in 2017 revealed that the traditional 1975 diet was associated with even greater benefits than the popular and healthful Mediterranean diet in mice that received the diets for four weeks—and we know how healthy the Mediterranean diet is!5 Animals that consumed freeze-dried and powdered Japanese diets had lower visceral fat weight, smaller fat cells, lower liver weight and liver triglycerides, and less lipid accumulation in liver cells in comparison with those that received the 2010 Italian diet. In humans, a month of the 1975 Japanese diet’s effects on metabolic factors was investigated in young adults. Participants experienced reductions in body fat percentage, fat mass, serum triglycerides and LDL cholesterol accompanied by a rise in serum HDL cholesterol and magnesium.4 And in a month-long randomized, controlled trial that compared the effects of a modern diet to a 1975-type Japanese diet, participants in the Japanese diet group experienced a decrease in BMI, fat mass, LDL cholesterol, glycated hemoglobin and C-reactive protein (a marker of inflammation) and an increase in HDL cholesterol in comparison with the modern diet group.6

Japanese Diet Secrets: 4 Nutrients to Include in Your Diet

Foods comprising the Japanese diet seem simple enough. Specific components of these foods may be responsible for some of their benefits.

1) Fermented Soy: Nattokinase

Natto (fermented soy) contains nattokinase

Soy foods are popular in Japan and have become more commonly consumed in the U.S. The Japanese frequently consume miso and natto-soy foods fermented with the fungi Aspergillus oryzae and the bacterium Bacillus subtilis, respectively. A study recently evaluated the effects of soy foods among 92,915 participants aged 45 to 74 years upon enrollment in the Japan Public Health Centre-Based Prospective Study.7 Men whose intake of fermented soy products was among the top fifth of participants had a 10% lower risk of dying from any cause during the 14.8 years of follow-up in comparison with those whose intake was among the lowest fifth, while among women, the risk was 11% lower. Fermented soy was also significantly associated with a lower risk of mortality from cardiovascular disease among both sexes. These fermented foods contain bioactive compounds, including polyamine and nattokinase, that may support cardiovascular health.

(This recent study is one of many that have investigated the health effects of miso. For more on miso, refer to past Life Extension blog posts “The Magic of Miso” and “Research Update: Miso Health Benefits.”)

2) Seaweed: Fucoidan

Fucoidan is a compound that occurs in brown seaweeds, which are another common feature of a Japanese diet. Fucoidan continues to reveal new and diverse benefits in scientific studies.

“Fucoidan is a polysaccharide that mainly consists of L-fucose and sulphate groups,” explained Y. Wang and colleagues in a recent article. “Classical activities include antitumor, antioxidant, anticoagulant, antithrombotic, immunoregulatory, antiviral and anti-inflammatory effects. More recently, fucoidan has been shown to alleviate metabolic syndrome, protect the gastrointestinal tract, benefit angiogenesis and bone health.”8

Included in the compound’s known properties is an ability to modulate the microbiome, thereby helping to protect against H. pylori and other undesirable gastrointestinal bacteria, while increasing the abundance of healthful gut bacteria.9 Indeed, it has been observed that the Japanese microbiome is unique in comparison with other populations.10

In a study published this year, fucoidan was shown to have neuroprotective effects in a fruit fly model of Alzheimer’s disease.11 Earlier studies had found that the compound inhibited the effects of amyloid-beta (the protein that forms brain plaques characteristic of Alzheimer’s disease) in roundworms and protected against a decline in the activity of the neurotransmitter acetylcholine in a mouse model of the disease.12,13

Fucoidan’s immune supportive property may contribute to an ability to aid in the inhibition of cancer suggested by cell and other studies. Fucoidan has been shown to activate dendritic cells that communicate information to other immune cells, activate T cells and enhance antiviral and anticancer immune response.14 In a trial involving cancer survivors, supplementation with fucoidan for six months was associated with an increase in white blood cells known as natural killer cells (which can bind to specific tumor cells) among male participants.15

In fruit flies (D. melanogaster) that received fucoidan derived from the seaweed Sargassum fusiforme throughout their lives, antioxidant enzymes were increased, malondialdehyde (a marker of oxidative stress) decreased and lifespan was enhanced.16 Flies treated with fucoidan also exhibited a high survival rate under heat stress. “In this study, we showed that the fucoidan SP2 . . . could markedly prolong the lifespan of D. melanogaster, and to the best of our knowledge, this could be the first direct evidence to support the claim that S. fusiforme is a longevity-promoting vegetable,” the authors announced. “This study has provided direct evidence of a longevity-promoting polysaccharide and revealed the worthiness of further research into SP2 as a health supplement.”

Research published on February 15, 2020 in the International Journal of Biological Macromolecules identified fucoidan derived from one variety of seaweed as having a greater ability to inhibit the starch-digesting enzyme alpha-glucosidase than the commercial antidiabetic treatment acarbose.17 Future research might reveal a similar ability in fucoidan derived from other varieties.

3) Fatty Fish: Omega-3

Fish is a staple of the Japanese diet. The benefits of fish are likely due to the omega-3 fatty acid content, specifically EPA and DHA.

Fish is a staple of the Japanese diet. The benefits conferred by regularly consuming fish are likely due to the food’s omega-3 fatty acid content, specifically EPA and DHA.

Volumes could be written concerning the benefits of omega-3, including associations with longer life. A study that included 520 men and 534 women enrolled in Japan’s National Institute for Longevity Sciences Longitudinal Study of Aging found a 27% lower risk of death from any cause during an 11.7-year follow-up among those whose serum levels of the omega-3 fatty acid DHA were among the top third of subjects. For those whose levels of EPA to arachidonic acid (an essential fatty acid that can be associated with inflammation when imbalanced) was among the highest third, the risk was 29% lower.18

“The Japanese consume about one gram/day of omega-3 polyunsaturated fatty acids (PUFA) as compared to 100-200 milligrams/day in the US,” noted Lewis H. Kuller, MD, DrPH, in the American Heart Association® publication Professional Heart Daily. “Plasma phospholipid measured omega-3 PUFA levels in the blood are much higher in the Japanese than in the US. The key public health question is whether the recommended intake of seafood in the US should be to reach the same levels of omega 3 PUFAs in blood as in Japan, about 9% of total fatty acids in blood versus 4% in the US.”19

4) Green Tea: EGCG

Green tea is part of the traditional Japanese diet, it contains EGCG

Green tea is another component of the traditional Japanese diet. A study that appeared in the Journal of the American Medical Association (JAMA) in 2006 that included 40,530 Japanese adults enrolled in the Ohsaki National Health Insurance Cohort Study found 12% and 23% lower risks of death during a seven year follow-up period among men and women who consumed five or more cups of green tea per day in comparison with those who consumed less than one cup.20 Another study that included 90,914 participants in the Japan Public Health Center-based Prospective Study found 13% and 17% lower risks for men and women who drank more than 5 cups per day.21

A pooled analysis of eight population-based Japanese studies uncovered a 10% lower risk of mortality from all causes among men and an 18% lower risk among women who consumed five or more cups of green tea per day in comparison with those whose intake was less than a cup during a 17.3 year average follow-up.22 For men, the risk of dying from heart disease was 18% lower among those whose intake was highest and for women the risk was 25% lower.

Green tea contains catechins that are believed to be responsible for the numerous health benefits that have been revealed by researchers investigating green tea during the past few decades. The most prominent among these compounds is epigallocatechin gallate (EGCG), which is known as a “geroprotector.” A search that identified ten geroprotective compounds reported in the journal Aging found that EGCG improved senescence-associated properties while having the least side effects of the compounds evaluated.23 EGCG has been shown to increase lifespan in fruit flies and rats.24,25

Japanese Eating Habits

In addition to consuming healthier food, residents of Japan generally consume smaller portions than most Westerners do. While knives, forks and spoons are used, chopsticks are employed by many individuals, which usually makes for smaller bites and slower eating.

With so many benefits associated with the Japanese diet, Westerners would do well to add some of its foods to their daily meals. If eating a lot of fish and seaweed isn’t your cup of (green) tea, the components believed to be responsible for many of these foods’ effects, such as omega-3 fatty acids, fucoidan, and EGCG and other tea flavonoids, are available as supplements.

About the author: Dayna Dye has been a member of the staff of Life Extension® since shortly after its inception. She has served as the department head of Life Extension® Wellness Specialists, is the author of thousands of articles published during the past two decades in Life Extension® Update, Life Extension Magazine® and on, and has been interviewed on radio and TV and in newsprint. She is currently a member of Life Extension’s Education Department.


  1. Yokoyama Y et al. Ann Hum Biol. 2019 Jun;46(4):311-322.
  2. Yamamoto K et al. Nutrition. 2016 Jan;32(1):122-8.
  3. Iwagaki Y et al. Mol Nutr Food Res. 2017 Dec;61(12).
  4. Sugawara S et al. J Oleo Sci. 2018;67(5):599-607.
  5. Mizowaki Y et al. J Oleo Sci. 2017;66(5):507-519.
  6. Asano M et al. Obesity (Silver Spring). 2019 Jun;27(6):899-907.
  7. Katagiri R et al. BMJ. 2020 Jan 29;368:m34.
  8. Wang Y et al. Mar Drugs. 2019 Mar 20;17(3):183.
  9. Shang Q et al. Food Funct. 2016;7(7):3224–3232.
  10. Nishijama S et al. DNA Res. 2016 Apr;23(2):125-33.
  11. Subaraja M et al. Front Biosci (Elite Ed). 2020 Jan 1;12:1-34.
  12. Wang X et al. Food Funct. 2018 Jan 24;9(1):552-560.
  13. Wei H et al. Mar Drugs. 2017 Mar 16;15(3):77.
  14. Zhang W et al. Mar Drugs. 2015 Feb 19;13(3):1084-104.
  15. Nagamine T et al. Mol Clin Oncol. 2020 Jan;12(1):81-88.
  16. Zhang Y et al. Oxid Med Cell Longev. 2019 Aug 14;2019:8918914.
  17. Daub CD et al. Int J Biol Macromol. 2020 Feb 15.
  18. Otsuka R et al. Int J Environ Res Public Health. 2019 May 21;16(10):1806.
  19. Kuller LH. Prof Heart Daily. 2018 May 17.
  20. Kuriyama S et al. JAMA. 2006 Sep 13;296(10):1255-65.
  21. Saito E et al. Ann Epidemiol. 2015 Jul;25(7):512-518.e3.
  22. Abe SK et al. Eur J Epidemiol. 2019 Oct;34(10):917-926.
  23. Aliper A et al. Aging (Albany NY). 2016 Sep 24;8(9):2127-2152.
  24. Wagner AE et al. Oncotarget. 2015 Oct 13;6(31):30568-78.
  25. Niu Y et al. Aging Cell. 2013 Dec;12(6):1041-9.

A ‘Fat Burner’ Combination: CLA and Carnitine

Juanita O. Enogieru MS, RD

One of the top questions I receive from clients is, “What is the best supplement for me to lose
weight?” The problem with this question is there are multiple factors involved in unwanted weight gain and varying degrees of biochemical individuality, so finding one nutrient to support everyone’s needs is impossible. However, creating a regimen of nutrients shown to promote optimal fat metabolism can assist with supporting healthy weight loss. A follow-up question that arises is, “Should I use ‘fat-burning’ supplements?” Conjugated Linoleic Acid (CLA) and L-carnitine are two options that may be considered controversial weight-loss nutrients, but research has shown that these nutrients can play a role in weight management.

What are Fat Burners?

Various supplements claim to be fat burners, but what exactly are fat burners? When I think of the name, I imagine someone taking a match to a huge chunk of fat and setting it on fire, but that’s not exactly how it works! Nutrients are considered fat burners if they increase energy expenditure, enhance fat metabolism, weaken fat absorption, increase weight loss (can include suppressing appetite), prevent weight regain after weight loss, increase fat oxidation during exercise, or promote long-term changes that encourage healthy fat metabolism.1

(Source: PMID 21951331)

Some methods that have been shown to optimize fat metabolism and may help enhance weight loss efforts include:

  • Increasing (or maintaining) lean body mass 2
  • Increasing insulin sensitivity (reducing insulin resistance)3
  • Optimizing fatty acid beta-oxidation by encouraging fatty acid transport into the mitochondria.1

Lean body mass, often referred to as lean tissue mass and muscle mass, includes bones, ligaments, tendons, internal organs, water, and muscles. Lean body mass is associated with your basal metabolic rate (BMR), which is the number of calories burned while resting. A loss of lean body mass has multiple negative health effects, including lowered resting energy expenditure/metabolism, fatigue, a decline in neuromuscular function, and a regain in fat mass.3

Factors Affecting Fat Metabolism

Regardless of total body fat mass, it is important to note that dysfunctional adipose tissue, inflammation, and an imbalance of circulating adipokines (a type of cell-signaling proteins called cytokines that are secreted by adipose tissues) are linked to insulin resistance in obese individuals.4 During insulin resistance, a hormone derived from fat cells called adiponectin (an anti-obesity signaling molecule) can become dysfunctional. Adiponectin decreases the synthesis of fatty acids in the liver and increases β (beta)-oxidation of fatty acids.4 Insulin resistance can lead to uncontrolled glucose levels, which can impair another hormone called leptin from signaling the brain that you are full.4 Without this reminder, when there is a half a plate of food in front of you, overeating, and thus weight gain or weight regain, is inevitable. Inflammation, often measured with increased C-reactive protein (CRP) levels, can also cause leptin insensitivity.5,6 Therefore, lowering inflammation and optimizing fat cell signaling by increasing insulin sensitivity (reducing insulin resistance), is a vital aspect of any comprehensive weight-loss strategy.

Related: Boosting Serotonin for Weight Loss

If a high-calorie or calorie-dense diet is not changed, when fat oxidation decreases, the body can go into a positive energy balance, meaning that you are over the number of calories needed to maintain healthy function. Being in a positive energy balance under conditions of a high-fat diet can lead to weight gain because glycogen stores become depleted, which increases appetite and energy intake.7 Improving fat oxidation pathways can reduce the accumulation of fat. Therefore, you should help reduce fat buildup by providing the body with the tools needed to aid in transporting fatty acids into the mitochondria to be burned for cellular energy. This cellular energy is transferred throughout the body’s organs to boost healthy function.8

glucose and lipid metabolism

(Source: Int. J. Mol. Sci. 2019, 20(5), 1190)

Is Conjugated Linoleic Acid (CLA) Found in Food?

Ruminating animals (cattle, goats, sheep, deer, and bison) produce CLA via bacteria present in the first compartment of the stomach. Also, CLAs can be extracted from plant materials such as safflower and sunflower oil, but are mainly found naturally in dairy and meat products. It is vital to keep in mind that there are various forms of CLA. The c-9, t-11 (cis-9, trans-11) CLA isomer accounts for 90% of CLA in dairy products and 75% of CLA in animal meat. Plant oils have less than 50% of the c-9, t-11 CLA isomer.9 However, this biologically active form may become less active in processed dairy and meat products. The other well studied form of CLA is the t-10, c-12-isomer (trans-10, cis-12 isomer) form, which can also be found in animal products.9 This form is discussed as being the active form that affects energy metabolism and body fat deposition and composition, and may enhance the movement of glucose into muscle cells.10,11 Typically, animal products have a CLA concentration ranging from 0.34 to 1.07 g/100 g fat in milk and 0.12 to 0.68 g/100 g fat in meat, but this CLA concentration is not sufficient to meet the daily requirement (1.5 to 3.5 g/day) for human beings, or meet requirements for promoting lean body mass.9 CLA supplements often contain a mixture of the relevant isomers.

CLA and Weight Management

CLA appears to have a beneficial effect on weight management by increasing insulin sensitivity of fat cells and supporting healthier levels of lean body mass.2,10 With more individuals cutting meat products out of their diet, it certainly leaves one to wonder, what is the best way to supplement with this fatty acid and why should you try it? With all the mixed data on CLA, trying to decide if it is beneficial can be overwhelming. However, here are some of the facts:

  • In a 12-week study of CLA supplementation (3000 mg daily), obese and overweight women saw a decrease in hip circumference.12
  • In a randomized, double-blinded, placebo-controlled clinical trial, obese children were randomly assigned to receive metformin, CLA, or placebo for 16 weeks. After taking 500 mg of CLA six times a day (3000 mg), insulin sensitivity improved.13
  • In a randomized, double-blind clinical trial, 54 adults with class I obesity were given 3000 mg of CLA (in three divided dosages) for 3 months. At the end of the trial, CLA supplementation reduced body fat mass and percentage, as well as serum leptin levels. Fasting glucose and insulin resistance also declined during the 3-month intervention.14
  • 12 weeks of CLA supplementation (3.2 or 6.4 grams/day) reduced body fat mass, body fat percentage, measures of insulin resistance (and fasting blood sugar), as well as serum leptin levels, in 48 obese adults. However, those in the 6.4 g/day group experienced body weight gain, possibly due to increased lean body mass.15
  • Reviews and meta-analyses appear to indicate that CLA can confer modest loss of body fat in people.16
  • From a 2019 review: “The literature to date suggests that CLA, and primarily the 10,12 CLA isomer, consistently confers some degree of body weight and/or adiposity loss in animal models and humans. However, such effects on body energetics may not impart protection against obesity-associated comorbidities, such as type 2 diabetes.”17

Is CLA Supplementation Bad for My Liver?

Adverse effects are very unlikely at suggested dosages with raw materials that contain mixed isomers. Although some data suggests negative liver effects may occur from isolated administration of the t-10, c-12 CLA isomer, these are mostly based on animal studies using extremely high dosages.18 These dosages are exceptionally higher than the typical therapeutic dosage for humans (approximately 3 grams). Clinical studies using ~3 grams/day of the mixed isomers have generally not reported any significant safety issues or adverse effects.19

Nutrient Synergy: Enhancing CLA’s Effects with Sesame

Since CLA is a fatty acid, to fully reap its benefits, find a product that combines it with sesame lignans. Preclinical research suggests that sesame lignans may enhance the body fat-reducing effects of CLA.20 Additionally, sesame lignans may further increase the burning of fat by stimulating fatty acid oxidation in the liver. Sesamin, an abundant lignan in sesame seeds, was shown to stimulate fatty acid beta-oxidation in the liver and reduce serum cholesterol in a preclinical model.20

What is the Recommended Dose of CLA?

To encourage the best possible outcome, select a supplement whose raw material contains both the trans-10, cis-12 isomer, and cis-9, trans-11. The exact amount of each may be variable but look for a raw material where each is typically present at 37.5-42% of the total amount of CLA. As far as dosage is concerned, at least 3-4 g (3000-4000 mg) of CLA should be utilized to promote healthy fat metabolism; however, the latter may support reductions in glucose and improvements in insulin sensitivity.11 Furthermore, one study suggests a daily intake of 5-10 g of CLA for diabetic therapy.21

Synergy is the interaction of nutrients that lead to a combined effect that is better than the effect of the nutrients alone. Some studies suggest that combining CLA with synergistic nutrients can promote healthier outcomes.10 To encourage healthier results, CLA should be paired with nutrients that promote healthy carbohydrate metabolism, specifically insulin metabolism, such as L-carnitine.

What is L-Carnitine?

L-carnitine is an amino acid that is involved in long-chain fatty acid and carbohydrate metabolism—it is required to transport the fatty acid into the cell where it is used to make ATP (adenosine triphosphate), or cellular energy.22 L-carnitine is made inside the body from lysine and methionine and can also be obtained mainly from animal sources. Dietary lipids require carnitine in order to be used as a source of energy. However, there is a theory that with high enough dosages of carnitine, levels build up in muscle cells to increase energy production and build muscle. This may be the wrong way to understand the value of L-carnitine. Instead, it may be best to use carnitine to boost mitochondrial function by fostering the transportation of long-chain fatty acids into the mitochondria.

While some resources imply that carnitine has no benefits for weight loss, at appropriate dosages, L-carnitine consistently confers weight loss benefits for overweight/obese adults.23 The effects would be enhanced with a balanced plant-based diet. A 2020 review and dose-response meta-analysis of 43 clinical studies concluded that L-carnitine decreased body weight, BMI, and fat mass.24 L-carnitine can also be helpful for managing insulin resistance.25 This, amongst other metabolic actions, makes L-carnitine an ideal companion for CLA!

What is the Recommended Dose of L-Carnitine?

Although a meta-analysis of carnitine supplementation concluded that L-carnitine might be effective for weight loss in adults, the dosage that best supports this varies. Dosages analyzed in this study ranged from 2-4 g (2000-4000 mg) daily.

How to Supplement with CLA and L-Carnitine

CLA may be helpful to aid in improving body composition. Its impact on insulin resistance is still unclear, so combining it with L-carnitine is likely beneficial to help weight loss and improve insulin sensitivity.

Start with the lower dosages for one week, or 1000 mg of CLA and 1000 mg of L-carnitine, and note your tolerance and sensitivity. If well tolerated, increase the dosage after week one to 2000 mg of CLA and 2000 mg of L-carnitine. In the third week, you can increase your dosage to 3000 mg of CLA and maintain the 2000 mg of L-carnitine dosage. Over the next few weeks, monitor your responses, and if you feel it is valuable, you can try increasing the dosage of CLA to 4000 mg, and experiment with boosting L-carnitine to 3000-4000 mg. Most importantly, keep in mind that any weight loss supplement regimen should be discussed with a doctor and combined with a healthy lifestyle, which includes monitoring blood work annually.

The Bottom Line

We continuously see that the body thrives on a variety of nutrients to achieve and maintain optimal health. Although most people are looking for one supplement to meet all their health goal needs, it is more likely that more than one nutrient or supplement with comprehensive nutrient profiles are required to achieve weight loss and promote weight loss management. Using multiple quality supplements formulated based on science is safe and provides the body with the tools needed to support healthy function while also promoting weight loss.

A combination of nutrients is more likely to offer the best outcome than one alone. So, combining CLA and L-carnitine, as well as other supportive nutrients like Gynostemma pentaphyllum and green tea extracts, may be ideal for addressing the underlying pathways needed to enhance weight loss and maintain lean body mass.1

About the author: Juanita Enogieru is a Registered Dietitian and Life Extension Wellness Specialist working with the community to build healthy and balanced nutritional habits. While pursuing an education in medicine and attempting to help her body heal, it became apparent that there was a gap in medical practices with regard to nutrition and an abundance of misinformation about balanced nutritional practices. After obtaining a bachelor’s degree in Health Education from the University of Florida, she worked with non-profit organizations to deliver nutrition education to community members. Wanting to learn more about nutrition and how herbs could be used to help the body heal, she pursued a master’s degree in Dietetics and Nutrition and shortly after began working with Life Extension. With the understanding that everyone has a unique biochemical individuality, it is vital to address each individual based on their specific needs and biochemical make-up. Her mission now is to offer guidance, support and education to individuals based on balanced nutritional insights that address the mind, body and spirit.


  1. Obes Rev. 2011 Oct;12(10):841-51.
  2. Adv Clin Exp Med. 2017;26(2):333-338.
  3. Nutrients. 2018 Dec; 10(12): 1876.
  4. Cell Metabolism. 2016 May 16; 23(5): 770-784.
  5. Nat Med. 2006 Apr;12(4):425-32.
  6. Curr Pharm Des. 2014;20(4):609–615.
  7. Obes Rev. 2011 Oct;12(10):859-65.
  8. Food Chem Toxicol. 2019 Jan;123:205-224.
  10. Med Hypotheses. 2000 Mar;54(3):483-7.
  11. Med Sci Sports Exerc. 2004 May;36(5):814-20.
  12. Acta Sci Pol Technol Aliment. 2016 Jan-Mar;15(1):107-113.
  13. J Clin Endocrinol Metab. 2017 Jan 1;102(1):132-140.
  14. Arch Iran Med. 2019;22(5): 255-261.
  15. J Nut. 2007 May;137(5);1188–1193.
  16. Am J Clin Nutr. 2007 May;85(5):1203-11.
  17. Nutrients. 2019 Feb 11;11(2). pii: E370.
  18. Am J Clin Nutr. 2004 Jun;79(6):1153S-1158S.
  20. Biosci Biotechnol Biochem. 2001 Nov;65(11):2535-41.
  21. Med Hypotheses. 2000 Mar;54(3):483-7.
  22. Nutr Metab (Lond). 2010 Apr 16;7:30.
  23. Obes Rev. 2016 Oct;17(10):970-6.
  24. Pharmacol Res. 2020 Jan;151:104554.
  25. Adv Clin Exp Med. 2017;26(2):333-338.

Are Blue Corn Tortilla Chips Healthier?

Holli Ryan RD, LD/N

There’s a wide selection of tortilla chips to choose from at the grocery store. Are those blue corn tortilla chips healthier than the yellow or white corn alternative? If you look at the nutrition facts on the label, you’ll notice they are pretty similar. Both tend to have 2 g of protein and 1-2 g of fiber per 1 oz serving. This same serving size has 15–20 g of carbohydrates, and 6–9 g of fat, mostly from the oil used to fry them (baked chips will have less fat). Corn tortilla chips won’t offer many vitamins, but will provide a small of amount of minerals, including iron. Let’s talk about that blue color, though. Yes, it’s a naturally occurring color.

Are blue corn tortilla chips healthy

Benefits of Blue Corn: Anthocyanins

Blue corn contains anthocyanins, naturally occurring pigments found in plants that give food its blue, red, and purple hues. Anthocyanins are polyphenol flavonoids that act as antioxidants, along with other potential health benefits. Blue corn has a higher protein content and lower glycemic index compared to yellow corn.

Blue corn anthocyanin health benefits

  • Anticancer effects:
    • Blue corn and tortilla extracts exerted antiproliferative effects (inhibited tumor growth) on several cancer cell lines in vitro.1
    • Anthocyanins from blue corn tortillas decreased cell viability and arrested the cell cycle to cause apoptosis (cell death) in prostate and breast cancer cells.2 Notably, this included triple negative cancer cells.
  • Cognitive effects:
    • A preclinical study showed that rats fed blue corn tortillas experienced improved long- and short-term memory (compared to white corn and control food groups).3
  • Antiparasitic effects:
    •  A preclinical study showed that extracts of blue corn had antiparasitic effects (against the parasite Toxoplasma gondii that can cause toxoplasmosis) in infected macrophages. Infected mice treated with blue corn extract also had improved survival rates compared to untreated controls.4
  • Antioxidant effects:
    •  Blue corn displays antioxidant and antimutagenic effects in in vitro studies.5,6
  • Metabolic effects:
    • Extracts from several species of corn, including purple corn, showed inhibition of α-glucosidase and α-amylase (potential benefit for hyperglycemia). Only purple corn samples also showed inhibition of lipase (potential benefit for obesity).7

Blue Corn vs Yellow Corn

  • There are a few varieties of yellow and white corn, or bicolor corn, including sweet corn and dent corn.
    • Sweet corn is the type you buy on the cob for dinner at the grocery store. As the name indicates, it has a higher sugar content.
    • Dent corn is a type of field corn that is commonly used in food manufacturing for products like tortilla chips (but not popcorn – that is a separate variety).
    • Yellow corn contains a different pigment called carotenoids, which provide lutein and zeaxanthin antioxidants.8
Yellow corn contains a pigment called carotenoids
  • Blue corn is a type of flint corn; one of the six major types of corn (maize), and it is grown primarily in Mexico and the United States.
    • Blue corn approximately 30% more protein than yellow corn.
    • Flint corn can also have many colors on the same ear of corn. You may recognize this variety as the ornamental corn used for display on Thanksgiving, but it is also used to make a variety of food products.
    • Some varieties of flint corn are actually distinctly more purple than blue, which is common in Peru.
Blue corn is a type of flint corn

Some varieties of flint corn are purple than blue, common in Peru

The Bottom Line

Are anthocyanins healthful? Research says yes. Are chips healthful? Not particularly. Chips made with stone ground corn are slightly less processed and may offer a slight edge by providing more fiber. How much anthocyanins make it into the final product is unclear. That being said, if you eat tortilla chips often, it could add up. As a general rule of thumb, the more processed something is, the less healthy it is than the whole-food alternative. Even choosing the tortilla over the chip may be a better option.

Making tortillas at home is simple and call for minimal ingredients that include corn flour and water. If you are making blue corn tortillas, you can purchase blue corn flour online or at specialty or ethnic grocery stores. The verdict: to ensure you get the most anthocyanin content, whole blue, red, and purple foods are a better source, not chips.

Holli Ryan is a Registered and Licensed Dietitian/Nutritionist.
About the Author: Holli Ryan is a Registered and Licensed Dietitian/Nutritionist, health and wellness advocate, and blogger/writer based in South Florida. She is a Florida International University graduate and member of the Academy of Nutrition and Dietetics. Her focus as a dietitian is disease prevention and management of health through nutrition education and customized suggestions. Holli believes that quality dietary supplements are an essential tool that have a variety of applications, from maintaining good health to managing chronic disease.


  1. Herrera-Sotero MY, Cruz-Hernandez CD, Trujillo-Carretero C, et al. Antioxidant and antiproliferative activity of blue corn and tortilla from native maize. Chem Cent J. 2017;11(1):110.
  2. Herrera-Sotero MY, Cruz-Hernandez CD, Oliart-Ros RM, et al. Anthocyanins of Blue Corn and Tortilla Arrest Cell Cycle and Induce Apoptosis on Breast and Prostate Cancer Cells. Nutrition and cancer. 2019:1-10.
  3. Aguirre Lopez LO, Chavez Servia JL, Gomez Rodiles CC, Beltran Ramirez JR, Banuelos Pineda J. Blue Corn Tortillas: Effects on Learning and Spatial Memory in Rats. Plant foods for human nutrition (Dordrecht, Netherlands). 2017;72(4):448-450.
  4. Ahmadpour E, Ebrahimzadeh MA, Sharif M, et al. Anti-Toxoplasma Activities of Zea Mays and Eryngium Caucasicum Extracts, In Vitro and In Vivo. J Pharmacopuncture. 2019;22(3):154-159.
  5. Loarca-Pina G, Neri M, Figueroa JD, et al. Chemical characterization, antioxidant and antimutagenic evaluations of pigmented corn. J Food Sci Technol. 2019;56(7):3177-3184.
  6. Mutlu C, Arslan-Tontul S, Candal C, Kilic O, Erbas M. Physicochemical, Thermal, and Sensory Properties of Blue Corn (Zea Mays L.). J Food Sci. 2018;83(1):53-59.
  7. Ranilla LG, Huaman-Alvino C, Flores-Baez O, et al. Evaluation of phenolic antioxidant-linked in vitro bioactivity of Peruvian corn (Zea mays L.) diversity targeting for potential management of hyperglycemia and obesity. J Food Sci Technol. 2019;56(6):2909-2924.
  8. Abdel-Aal el SM, Akhtar H, Zaheer K, Ali R. Dietary sources of lutein and zeaxanthin carotenoids and their role in eye health. Nutrients. 2013;5(4):1169-1185.

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