Back then people could live up to 100 years (according to Huang Di Nei Jing) as they lived harmoniously to nature and cultivated themselves, thus they could prevent disease and lived a long life.
Winter represents the Yin aspect of the four seasons. Yin is quiet, passive, cooling, dark, the energy moves inwards.
In traditional Chinese medicine, winter belongs to water of the five elements and is pertained to Kidney and Bladder, and opens to the ear orifice. The quality and nature of water nourishes all plants for its growth and development; and in human body, it plays a vital role for congenital function, growth, development, maturation and corresponds to human's reproductive system in health. The kidney stores substantial essence "Jing" for reproduction, fertility and is therefore, known as "the root of life".
A person's constitution is determined by the Jing inherited from the parents when conceived. Children who has slow growth and development or maturation (puberty) may have weak kidney essence; couples who faces the challenge of infertility may also indicate a weak kidney qi (function) and jing (essence).
The kidney's function manifests in the hair and bone, as the kidney Jing forms the marrow which will then nourish the bone and the hair. So strong,healthy and coloured hair (eg. the darker the colour the hair the healthier in Asians) strong dense bone, good hearing ability is an indication of strong kidney vitality.
As we age, the kidney essence naturally decreases, unable to nourish the hair and the bone therefore we see more white or grey hair appear with age, our bones "calcify" and becomes weak and fragile; our hearing also becomes poor. Symptom of frequent & chronic lower back pain and weak knees or leg may also appear.
Fear is an emotion manifested and exercised by kidney or water element. An easy metaphor I always use is when a child pee their pants when they are too afraid or in shock.
Determination and willpower on the other hand is also determined by the kidney function. If the kidney Qi is strong then the perseverance will be strong; if the kidney qi is weak then one be more doubtful and fearful of failures. However, like the 'first comes chicken or egg' theory, when one's mentality cannot be reflected upon and be overcome, it can also affect one's health and in turn affect the kidney function over a long time.
For example, if you weren't always a person who is fearful and undetermined, but happens to encounter an event in life which have caused you to become fearful, being like this over a long period of time can in turn affect your health by exhausting your kidney function.
In traditional chinese medicine, the body, mind and spirit are as one and can affect one another.
It is seen in movies when a main character experiences a tragic event in life and over time, their hair turns grey or white just over a short period of time.
Flavour: Saltiness is closely related with kidney; It can be used to nourish the kidney however excessive amount can also impair the kidney function. Anything should only be in moderation.
In winter, it is important to keep warm and avoid from ice, cold food and drinks, so have cooked food and less or little salad; avoid exposure to cold - so dress warm and cover up!
I can't stress enough that this means to wear a scarf while you're out; a hat and also socks to keep your feet warm! The kidney meridian runs from the small toe - middle of the sole - inner ankle and medial side of the lower leg! So it is important to keep your feet warm by putting socks on, or do feet soaks in warm-hot water (simmered ginger water is also good!) for 5-10 min before bedtime!
Use this season to strengthen your kidney, tonify and heal any bone problems. Rest up, rejuvenate to revitalize our kidney (the same as to why animals hibernate during winter too!) and take time to look inwards (reflecting on ourselves); Rest early and sleep later; do slow and quiet activities (such as yoga, taichi or chigong). These practices help us connect to our inner selves and support kidney energy. They are very helpful to relax the mind, calm our emotions and raise the spirit.
Lastly, a quote to share for self-reflection! :)