Smorgasbord Health Column – UnSeasonal Affective Disorder – Keeping your focus – Tryptophan by Sally Cronin

Normally I would refer to Seasonal Affective Disorder in February as the winter months take their toll on our physical, mental and emotional health. However, reading the various reports in the media on Vitamin D Deficiency being one of the causes for susceptibility to Covid-19 and raised concerns on the levels of mental health issues including depression, the comments from readers who are experiencing lack of energy and focus, I began to see some parallels to SAD, but six months ahead of schedule. You can find more about the Vitamin D connection to SAD and the foods to include on a daily basis to help reduce the likelihood of deficiency in Part Two

In the last two posts I explored the reasons why hundreds of thousands around the world may be experiencing an Unseasonal Affective Disorder in response to reduced sunlight during lockdown and travel restrictions resulting in reduced levels of Vitamin D. A risk factor that has been recognised by scientists in relations to Covid-19 and the immune system. I also shared my thoughts on our evolutionary process which has not moved as quickly as modern technology or lifestyle.

There is another chemical element to our well-being during the winter months and addresses the way we feel mentally. It is reported that depression is understandably already taking hold in the community, especially those who are isolated away from families and friends. The small gestures we take from granted are being denied and we feel the loss of their therapeutic benefits. Such as hugging and kissing a cheek; even talking face to face.

An essential winter additive.

In this post I want to cover other critical factors about our chemical makeup that requires re-tuning for the cold weather. It is similar to what we will do to our car to ensure it starts and keeps running at lower temperatures.

Only the fuel additive we need is L-tryptophan one of the 10 essential amino acids extracted from the food we eat, and used by the body to synthesize the proteins we need.  Its crucial role for those suffering from depression, anxiety, insomnia and other symptoms, particularly when the days become shorter, is in the production of two key brain hormones and Niacin or vitamin B3.

Only a small amount of the tryptophan that we eat is converted to B3 by the liver.  However, B3 has a vital role in the metabolism of carbohydrates, fats and proteins to obtain the fuel we need (ATP) as well as helping regulate cholesterol.  It is necessary for the formation of red blood cells and hormones and when it is formed, it continues to work with the tryptophan and also B6 to stimulate the production of serotonin and melatonin transmitters within the brain.

If you do not have sufficient B vitamins in your diet there is a risk of deficiency disease most commonly skin infections, diarrhea and if prolonged can lead to dementia).

Serotonin and Melatonin are key neurotransmitters are absolutely essential if your body and brain are going to function efficiently throughout the winter months.  Melatonin is a sleep related hormone secreted by the pineal gland and regulates our sleep patterns.  It would normally increase its activity in the dark months when the sunlight is not there to regulate when we sleep and wake, however in people who suffer from SAD it appears that levels rise much later in the night compared to those who do not suffer from it, causing insomnia.

The other neurotransmitter which for me is more key in the management of this winter cycle is Serotonin.  It regulates appetite, sleep patterns and our mood. Low levels are associated with depression, anxiety, inability to concentrate, carbohydrate cravings, overeating and insomnia.  There is some very interesting research into Serotonin and SAD but there is a clear indication that depleted levels of L-tryptophan in the diet, resulting in even lower natural serotonin levels in the winter months, will cause these very common symptoms.

Foods providing Tryptophan

vegetablesSo – back to my basic diet with lots of vegetables, lean proteins, oily fish, olive oil, dairy, nuts, seeds, wholegrains, eggs and natural sugars like honey.  Here are some key foods to include on a daily basis to ensure that you are getting sufficient tryphophan to produce a balanced level of B3, Melatonin and Serotonin.

The highest concentration is found in

  • poultry – chicken and turkey
  • soybeans for vegetarians. 

Great amounts in

  • red meat,
  • tuna,
  • lamb,
  • salmon,
  • sardines,
  • halibut (good for Vitamin D too),
  • cod,
  • shellfish,
  • dairy products such as grass fed milk and butter
  • nuts,
  • seeds,
  • legumes
  • green leafy vegetables such as spinach,
  • asparagus,
  • Brussel sprouts 

There is smaller amounts in the carbohydrates

  • potatoes,
  • brown rice
  • wholegrain pasta
  • wholegrain bread
  • Oats

Although important for carbohydrates to be included as part of a balanced diet, if you are planning on eating a low fat, high carbohydrate based diet through the winter you are far more likely to suffer from SAD.

fruit-and-veg-bannerAnother key point about our diet during the winter months is that today we have access to so much more variety of fruit and vegetables year round.  Although I prefer seasonal vegetables and fruit as I think my body expects them at specific times and processes them more efficiently, I still love the fact that this whole range of nutrients is available whenever I choose.  The added benefit is additional Vitamin C which is so important during the cold and flu season.  More about those in later blogs……..

Next time – Despite restrictions on our movement and less incentive to get out in the winter weather we still need activity and stimulation for body and mind to overcome the blues……

©Sally Cronin – Just Food for Health – 1998 – 2020

I am a qualified nutritional therapist with twenty-two years experience working with clients in Ireland and the UK as well as being a health consultant on radio in Spain. Although I write a lot of fiction, I actually wrote my first two books on health, the first one, Size Matters, a weight loss programme 20 years ago, based on my own weight loss of 154lbs. My first clinic was in Ireland, the Cronin Diet Advisory Centre and my second book, Just Food for Health was written as my client’s workbook. Since then I have written a men’s health manual, and anti-aging programme, articles for magazines and posts here on Smorgasbord.

If you would like to browse my health books and fiction you can find them here: My books and reviews 2020

Your feedback is always welcome and if you do find that following any of the programmes that I have shared are beneficial then it would be great to hear about it.. you can email me on