Mother's Fears Are Passed to Children Through Smell, Study Suggests

Hereditary Trauma

Story at-a-glance

  • Hereditary trauma can be passed down from generation to generation, such that children may suffer from the same behavioral issues, fears, and phobias as their parents
  • In an animal study, newborn pups learned to fear the smell of peppermint their mothers had been conditioned to fear prior to pregnancy
  • Traumatic stress alters “microRNAs” in mice blood, brains, and sperm, leading to significant alterations in offspring that impact behavior
  • An imbalance in microRNAs in sperm, brought on by trauma, is one way in which emotional trauma is passed down through generations, a factor that is likely triggered when the body produces too much stress hormone

WARNING!

This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.

By Dr. Mercola

Emotional trauma would seem, at face value, to be a highly individual experience, impacting primarily the person going through the ordeal. However, emotional trauma, fears, and phobias also impact people with close ties to the victim, including their children… even if the trauma happened years before they are born.

So-called hereditary trauma can be passed down from generation to generation, such that children may suffer from the same behavioral issues, fears, and phobias as their parents. A new study in rats took this knowledge a step further, shedding light on one way that a mother’s fears or past traumas may impact her children.

Mother’s Fears Passed to Children Via Scent

During the study, female rats were conditioned to fear the smell of peppermint before they were pregnant. Later, the rats’ pups were exposed to the peppermint scent along with a scent of their mother’s reacting to the peppermint odor.

The newborn pups learned to fear the smell even when their mothers weren’t there, after just a single exposure.1 However, when activity was blocked in the pups’ amygdala, a region of the brain that processes emotions, including fear responses, the pups did not learn to fear the peppermint scent.

So it seems that, via scent, “infants can learn from their mothers about potential environmental threats before their sensory and motor development allows them a comprehensive exploration of the surrounding environment.”2 The impact of scent on fear was so strong that some of the rats tried to plug the tubing to stop the scent from coming in, a habit that the researchers plan to study further.

The Power of Scents

The fact that a mother’s fears can be passed on to her offspring via a scent like peppermint adds further support for the use of aromatherapy, as it’s clear that scents trigger real physical and emotional responses. Just as certain scents can evoke fear, others may trigger calm or even help relieve anxiety. For instance, research shows:

  • A systematic review of 16 randomized controlled trials examining the anxiolytic (anxiety-inhibiting) effects of aromatherapy among people with anxiety symptoms showed that most of the studies indicated positive effects to quell anxiety (and no adverse events were reported).3
  • People exposed to bergamot essential oil aromatherapy prior to surgery had a greater reduction in pre-operative anxiety than those in control groups.4
  • Sweet orange oil has been found to have anxiety-inhibiting effects in humans, supporting its common use as a tranquilizer by aromatherapists.5
  • Ambient odors of orange and lavender reduced anxiety and improved mood in patients waiting for dental treatment.6
  • Compared to the controls, women who were exposed to orange odor in a dental office had a lower level of anxiety, a more positive mood, and a higher level of calmness. Researchers concluded, “exposure to ambient odor of orange has a relaxant effect.”7

Anxiety, of course, is only one use for aromatherapy. Other potential uses include:

  • Green apple scent for migraines: One study found that the scent significantly relieved migraine pain. This may also work with other scents that you enjoy, so consulting with an aromatherapist might be beneficial.
  • Peppermint for memory: The aroma of peppermint has been shown to enhance memory and increase alertness.
  • Nausea and vomiting: A blend of peppermint, ginger, spearmint, and lavender essential oils has been found to help relieve post-operative nausea.8
  • Lavender for pain relief: Lavender aromatherapy has been shown to lessen pain following needle insertion.9

How Hereditary Trauma Occurs

University of Zurich researchers unraveled a piece of the puzzle to show just how hereditary trauma may occur, even in the absence of a conditioned scent trigger. They found that traumatic stress altered “microRNAs” in mice blood, brains, and sperm.10

While some of the microRNAs were produced in excess, others were produced in lower amounts than in control animals. The end result was significant alterations in the cellular processes controlled by the microRNAs. Science Daily reported:11

“After traumatic experiences, the mice behaved markedly differently: they partly lost their natural aversion to open spaces and bright light and had depressive-like behaviours. These behavioural symptoms were also transferred to the next generation via sperm, even though the offspring were not exposed to any traumatic stress themselves.”

It wasn’t only their behavior that was altered, either. The traumatized mice had offspring with altered metabolisms, including lower insulin and blood sugar levels. The study shows that an imbalance in microRNAs in sperm, brought on by trauma, is one way in which emotional trauma is passed down through generations, a factor the researchers said is likely “part of a chain of events that begins with the body producing too much stress hormones.”12

Children of Traumatized Parents May Develop Better Coping Mechanisms

The implications of hereditary trauma are significant. It’s estimated, for instance, that 30 percent of children with a parent that served in Iraq or Afghanistan, and developed post-traumatic stress disorder (PTSD), are also struggling with “secondary PTSD.”13

Aside from war, emotional trauma may arise from countless scenarios, from acts of terrorism, a loss in the family, crime, and much more. Along with traveling through generations, such traumas are also known to impact people on a societal level.

One aspect that offers promise, however, is a 2013 study that showed children of Holocaust survivors were less likely to suffer from PTSD after experiencing a traumatic event. This the researchers attributed to “post-traumatic growth,” which they described as a “workable coping mechanism” that helped the children develop more positive self-image and greater personal strength as adults.14, 15

What Else Is Passed Through Generations?

Emotional trauma is only one example of how a mother can impact her children even before they are born. Poor dietary choices can also become encoded into the gene expression patterns (epigenome) of your DNA and your gut microbiome, leading to permanent changes in the balance of bacteria in your body – changes that may be passed onto your children.16

As noted in the Nutrition Journal,17 a mother’s diet may shape her child’s taste preferences in utero, skewing them toward vegetables or sweets, for instance. There’s also evidence that children inherit their microbiome from their mother, and part of this may be “seeded into the unborn fetus while still in the womb.”

If a mother has an imbalance of bacteria, she will pass this imbalance onto her child and “thus fails to present the ideal gut flora for a proper immune education during her child’s most critical developmental window… This developmental dysbiosis leaves the offspring’s immune system poorly trained to fight off infections and encourages autoimmune and allergic diseases,” the study’s author, Dr. Myles, noted.

Even a father’s diet plays a role in his child’s future health, as “paternal epigenetics related to methylation of DNA and histones can also be inherited by the offspring and could alter early development of the immune system.” As Dr. Myles explained:18 “Since the information encoded upon DNA is passed from parent-to-child and even potentially from parent-to-grandchild, cells that learn bad habits like ignoring signs of infection or over-reacting to antigens could combine with microbiome shifts to further worsen a child’s immunologic development.” To give children the best start, then, requires not only attention to emotional health but also physical health via your diet, sound sleep, exercise, and more.

Are You a Trauma Survivor?

It’s essential that you help to heal your emotional scars. Guy Winch, author of Emotional First Aid: Practical Strategies for Treating Failure, Rejection, Guilt and Other Everyday Psychological Injuries, shared five tips for healing your emotional pain that may help:19

1. Let Go of Rejection

Rejection actually activates the same pathways in your brain as physical pain, which is one reason why it hurts so much. The sooner you let go of painful rejections, the better off your mental health will be.

2. Avoid Ruminating

When you ruminate, or brood, over a past hurt, the memories you replay in your mind only become increasingly distressing and cause more anger – without providing any new insights. Ruminating on a stressful incident can also increase your levels of C-reactive protein, a marker of inflammation in your body.20

3. Turn Failure Into Something Positive

If you allow yourself to feel helpless after a failure, or blame it on your lack of ability or bad luck, it’s likely to lower your self-esteem. Blaming a failure on specific factors within your control, such as planning and execution, is likely to be less damaging, but even better is focusing on ways you can improve and be better informed or prepared so you can succeed next time (and try again, so there is a next time).

4. Make Sure Guilt Remains a Useful Emotion

Guilt can be beneficial in that it can stop you from doing something that may harm another person (making it a strong relationship protector). But guilt that lingers or is excessive can impair your ability to focus and enjoy life. If you still feel guilty after apologizing for a wrongdoing, be sure you have expressed empathy toward them and conveyed that you understand how your actions impacted them. This will likely lead to authentic forgiveness and relief of your guilty feelings.

5. Use Self-Affirmations if You Have Low Self-Esteem

While positive affirmations are excellent tools for emotional health, if they fall outside the boundaries of your beliefs they may be ineffective. This may be the case for people with low self-esteem, for whom self-affirmations may be more useful. Self-affirmations, such as “I have a great work ethic” can help to reinforce positive qualities you believe you have, as can making a list of your best qualities.

My Most Highly Recommended Tool for Emotional Healing

Many, if not most, people carry emotional scars -- traumas that can adversely affect your health and quality of life. Using techniques like energy psychology, you can correct the emotional short-circuiting that contributes to your chronic emotional pain. My favorite technique for this is the Emotional Freedom Technique (EFT), which is the largest and most popular version of energy psychology.

EFT is a form of psychological acupressure based on the same energy meridians used in traditional acupuncture to treat physical and emotional ailments for over 5,000 years, but without the invasiveness of needles. Instead, simple tapping with the fingertips is used to transfer kinetic energy onto specific meridians on your head and chest while you think about your specific problem -- whether it is a traumatic event, an addiction, pain, anxiety, etc. -- and voice positive affirmations.

This combination of tapping the energy meridians and voicing positive affirmation works to clear the "short-circuit"—the emotional block—from your body's bioenergy system, thus restoring your mind and body's balance, which is essential for optimal health and the healing of physical disease. The beauty about EFT is that it can reprogram your body’s reactions to the unavoidable stressors of everyday life, thereby providing a more lasting effect. More than any traditional or alternative method I have used or researched, EFT has the most potential to literally work magic.

Clinical trials have shown that EFT is able to rapidly reduce the emotional impact of memories and incidents that trigger emotional distress. Once the distress is reduced or removed, your body can often rebalance itself, and accelerate healing. For a demonstration of how to perform EFT, please see the video below featuring EFT practitioner Julie Schiffman. The first video is a general demonstration, which can be tailored to just about any problem, and the second demonstrates how to tap for depression. While this technique is particularly effective for relieving emotional or mental stress and anxiety, it can be used for all manner of physical pain relief as well.


Total video length: 25:12

While the video above will easily teach you how to do EFT, it is VERY important to realize that self-treatment for serious issues is NOT recommended. For serious or complex issues, you need someone to guide you through the process, as it typically takes many years of training to develop the skill to tap on deep-seated, significant issues. So if you have a serious emotional challenge, please seek a highly qualified and skilled therapist. Just as you wouldn’t do an appendectomy on yourself if you were a surgeon, self-treatment in this area could be highly counterproductive.

Physical Support for Emotional Pain

Your emotional and physical health are intricately connected. You’ll have an easier time bouncing back from emotional setbacks when you’re physically well, and healthy habits will also help keep your mood elevated naturally in the midst of stress. The following lifestyle strategies can significantly help to support emotional wellness and healing:

  • Eat well: What you eat directly impacts your mood and energy levels in both the short and long term. Whereas eating right can prime your body and brain to be in a focused, happy state, eating processed junk foods will leave you sluggish and prone to chronic disease. My free nutrition plan is an excellent tool to help you choose the best foods for both physical and emotional wellness.
  • Proper sleep: Sleep deprivation is linked to psychiatric disorders such as anxiety and bipolar depression, while getting the right amount of sleep has been linked to positive personality characteristics such as optimism and greater self-esteem, as well as a greater ability to solve difficult problems.21
  • Animal-based omega-3 fats: Low concentrations of the omega-3 fats EPA and DHA are known to increase your risk for mood swings and mood disorders. Those suffering from depression have been found to have lower levels of omega-3 in their blood, compared to non-depressed individuals. Krill oil is my preferred source of omega-3 fats.
  • Regular sun exposure: This is essential for vitamin D production, low levels of which are linked to depression. But even beyond vitamin D, regular safe sun exposure is known to enhance mood and energy through the release of endorphins.

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