Why Low Serotonin Makes You Crave Carbs

Low levels of serotonin are associated with major depression, anxiety, panic disorders and insomnia.

While this is certainly true, there is another, more common symptom that can be caused by even mild serotonin deficiency: carb craving.

I’d like to give you a brief overview of why low serotonin makes you crave carbs and how you can boost your levels naturally without resorting to serotonin re-uptake inhibitors (SSRIs) drugs.

Why low serotonin causes carbohydrate craving

When we eat a carb-rich meal, insulin is released from the pancreas to remove the excess blood glucose for storage into the liver, muscle and fat tissue. Insulin decreases levels of branched-chain amino acids (BCAA) in the blood stream. These amino acids compete with tryptophan, a precursor to serotonin, to enter the brain. When there are equal levels of BCAA and tryptophan in the blood stream, the brain favours the BCAA, leading to a reduction of serotonin.

When we are low in serotonin, our body makes us crave carbohydrate in order to reduce the amount of BCAA and increase the level of available tryptophan. Interestingly, carb craving due to low serotonin occurs mainly in the evenings, when serotonin levels should naturally be higher to induce sleepiness before bedtime. So if you find yourself fighting really intense cravings for bread, cookies or chocolate after your evening meal, this might be the reason why.

How to boost serotonin naturally

  1. Serotonin receptors are boosted by sunlight: make sure you get outdoors daily. Early morning exposure, within an hour of waking, is particularly good for boosting serotonin levels. Walking the dog for 20 minutes before breakfast, walking your kids to school or even just eating your breakfast in the backyard will go a long way to start increasing your serotonin levels. This activity must be done consistently for it to have an effect.
  2. Boost your vitamin B6: This is one of the most common deficiencies we see in clinic. I’d hazard a guess that 80% of the population have a B6 deficiency. If you suffer from PMS, mood swings, anxiety, insomnia, digestive issues, any inflammatory or autoimmune condition or infection you’ll be low in vitamin B6. This vitamin is safe to supplement, even at relatively high doses. In Australia, you can purchase Blackmores B6 240mg tablets in most supermarkets. You can safely take one tablet daily with breakfast.
  3. Boost your zinc: This is another major deficiency we see in virtually all adults and children. Poor immunity, insomnia, mood changes, digestive issues, bloating, white spots on nails, PMS, pregnancies, breastfeeding, stretch marks, pyroluria, anxiety, depression, intolerances, acne are all conditions that either cause or are caused by zinc deficiency. Zinc-rich foods include red meat and seafood. Although to be honest, if you have a frank deficiency of zinc, you really need to supplement as when you’re low in zinc you won’t produce the necessary stomach acid to absorb this mineral from foods. Zinc picolinate or zinc citrate are good forms.
  4. Boost your magnesium: need I say more? We all know how depleted our diets are in magnesium rich foods such as leafy greens. Increase your intake of fruit, veg and nuts. Supplementing may be necessary while you optimise your digestion and clean up your diet. We like magnesium citrate and magnesium glycinate.
  5. Check your vitamin D levels: 1 in every 2 patients we see in clinic has inadequate levels of vitamin D. Ideally, your blood levels of 25-hydroxy vitamin D should be around 100nmol/L. Despite its many great qualities, cod liver oil doesn’t have sufficient vitamin D levels to restore a deficiency. Supplementation with 2000-5000IUs daily is usually necessary.
  6. Ensure you have adequate protein in your diet: small amounts of good quality protein from a variety of sources (animal and vegetarian) is the best way to ensure a wide array of amino acids in your diet. You need good stomach acid to digest protein, so if you suffer from bloating and gas, I’d recommend you address that with a naturopath first.
  7. Eat blueberries: in a recent animal study, blueberries significantly increased serotonin levels while keeping noradrenaline levels in check.
  8. Exercise: regular exercise boosts serotonin levels by reducing circulating BCAA in the bloodstream.
  9. Get hugging: studies have shown that giving and receiving hugs and cuddling increases your levels of serotonin. If you’re not currently in a meaningful relationship and don’t feel like hugging the neighbour getting a pet or receiving a regular massage will have the same effect.
  10. If all else fails…if you’ve committed and tried all the above suggestions consistently for 2 months and still find your symptoms haven’t budged, you may want to consider supplementing with 5-HTP, the direct precursor of serotonin. 5-HTP doesn’t compete with BCAA to enter the brain barrier so, provided you have adequate levels of co-factors B6, zinc, magnesium, it will increase your levels of serotonin. You should not take 5-HTP if you’re currently on a SSRI or SNRI medication without medical supervision.

If you suffer from chronic insomnia and low moods or anxiety, the above suggestions may not be enough as you may have other contributing factors such as inflammation, intolerance and autoimmunity that may be compounding the problem. If that’s the case, book you appointment with either myself or Susan to have a comprehensive medical assessment.