Author: Chen Xingzuo, Deputy Chief Physician, Department of Orthopedics, China-Japan Friendship Hospital
Joint pain, swelling, affected daily activities, and even a "clicking" sound is a warning from the knee that you may have osteoarthritis of the knee. One of the most important causes of osteoarthritis of the knee is joint cartilage injury.
The so-called articular cartilage refers to a very smooth layer of cartilage on the surface of the joint. When the knee joint is active, it plays a role in bearing load, reducing the impact and concussion of the joint, and reducing friction, and the integrity of the joint cartilage is an important factor in maintaining the normal function of the knee joint.
Due to the lack of blood supply and nutrients of nerve tissue, cartilage itself has weak repair ability, and it is difficult to heal after injury, so in daily life, scientific maintenance of joint cartilage can effectively prevent the occurrence of knee arthritis or delay its development.
It is said that "the people take food as the day", what to eat is also very important for the protection of joint cartilage, let's take a look at which foods are beneficial to knee joint maintenance.
Image source: Stand Cool Helo
1. Water
The cartilage of the joint is mainly composed of extracellular matrix (ECM), and the main component of ECM is water (70%-80%)[1], so maintaining adequate water in the human body is an important way to protect joint cartilage, especially after exercise to replenish water, is necessary. The Dietary Guidelines for Chinese Residents (2016) point out that healthy adults without contraindications such as kidney disease and heart failure should maintain a daily water intake of 1500-1700 ml.
It is recommended to replenish 400-700 ml of water 15 to 20 minutes before exercise, which can be drunk in divided doses;
Supplement 100-300 ml of sports drinks or water every 15 to 30 minutes during exercise, preferably with sports drinks containing sugar and inorganic salts to replenish water;
After exercise, hydration should be made in time to maintain the water balance in the body, and the amount of water replenishment should be roughly the same as the amount of sweat lost. [2]
2. Calcium
Whether a person's bones are strong enough is directly related to the content of calcium, and calcium supplementation is necessary to prevent joint disease caused by osteoporosis. The Chinese Nutrition Society recommends in the "Reference Intake of Dietary Nutrients for Chinese Residents (2013 Edition)" that young and middle-aged people aged 18-49 should consume 800 mg of calcium per day, and the middle-aged and elderly people over 50 years old should consume 1000 mg of calcium per day.
If osteoporosis is identified, 1000-1500 mg of calcium per day is required, along with 800-1200 units of vitamin D3. [3]
Foods with high calcium content: dairy products (milk, yogurt, cheese, etc.), green leafy vegetables (such as cabbage, small rapeseed, kale, hollow cabbage, cabbage, spinach), soy products, sesame paste, shrimp skin, kelp, etc.
The Dietary Guidelines for Chinese Residents (2016) recommend that adults consume 300 grams of milk and dairy products per day and can consume about 300 mg of calcium. A daily intake of 500 grams of green leafy vegetables can contribute more than 500 mg of calcium. Well, with milk and vegetables, we can easily reach the recommended daily intake of 800 mg of calcium.
3. Chondroitin
Chondroitin can promote the production of cartilage, increase the secretion of joint lubrication fluid, so that the cartilage layer thickens, elasticity, slows down the wear and tear of joint cartilage, it is present in the body's connective tissue, can provide nutrition for cartilage, known as "cartilage nutritionist".
For some patients with arthritis, the synovial fluid in the joint cavity can provide a cushioning effect to alleviate the impact and friction during movement, while chondroitin can suck water into the proteoglycan molecule, thicken the cartilage, and increase the amount of synovial fluid in the joint.
The joints of the human body are like the bearings of the car, not that there is a problem that needs to be repaired, but the daily maintenance is more important than the repair, and the daily can be appropriately supplemented with some chondroitin-rich foods to maintain the joints.
Foods rich in chondroitin: beef bone broth, chicken skin, chicken bones, pork cartilage, hoof tendons, etc.
4. Collagen
Osteocollogen is a protein that makes up the human body, which is distributed in the tendons where the muscles of the human body are connected, in the cartilage tissue where the joints are connected, and in the dermis layer of the skin. It can delay osteoporosis, reduce joint pain, improve osteoarthritis symptoms, accelerate bone healing, maintain bone toughness, prevent calcium loss, and improve calcium absorption rate.
In fact, more than 70% of our bone organic matter is bone collagen, which is an important component of bone and joint cartilage, which has a certain effect on maintaining bone toughness and eliminating joint pain.
Bone collagen is metabolized every day, when young, the ability to synthesize bone collagen is still very strong, but with age, the ability to synthesize greatly declines, after the age of 40 years old, the bone collagen content in the human body will drop sharply, resulting in joint problems. Therefore, timely replenishment of collagen, especially for middle-aged and elderly people, is crucial. [4]
Collagen-rich foods: white fungus, chicken feet, pig trotters, pig skin, etc.
5. Glucosamine
As an important component of articular cartilage, glucosamine has the effect of stimulating chondrocytes to synthesize polyglucose, regulating bone metabolism, and anti-inflammatory [5]. In addition, glucosamine can protect joint cartilage from damage from superoxide free radicals, enhance cartilage resistance, improve joint mobility, relieve joint pain, and delay the progression of osteoarticular diseases.
However, the ammonia sugar in the human body will decrease year by year from the age of 30, and the content of ammonia sugar in the body after the age of 45 is only 18% of the age of 18. Therefore, when the morphology of articular cartilage is complete, scientific supplementation of amino sugar is very necessary.
Glucosamine-rich foods: shellfish foods such as oysters, scallops, oysters, clams, gardenia, etc
6. Broccoli
A new study from the University of East Anglia in the United Kingdom found that sulforaphane has a good preventive and alleviation effect on joint cartilage injury, and regular consumption of foods rich in this compound, such as broccoli, may be effective in preventing osteoarthritis [6]. Whether it's for arthritis sufferers or healthy people, regular consumption of sulforaphane-rich foods like broccoli will be a great option.
Warm tips: daily attention to reasonable arrangement of meals, eat more of these foods is conducive to protecting the knee joint, can alleviate the degeneration of joint cartilage, it is recommended that you according to your own physical condition, appropriate supplementation, if you suffer from high blood pressure, high blood lipids and other chronic diseases, you also need to consult a doctor whether the above food is suitable for you.
It should be emphasized that the food recommended in this article is only suitable for daily health care, if you already have joint disease, you should still treat it under the guidance of a doctor. Food supplements can not replace professional treatment, need to be used according to their own condition, together.
bibliography:
[1] Feng Hua and Jiang Chunyan, eds., Modern Orthopaedic Sports Medicine, October 2020, First Edition: 49-50
[2] Lin Wenqiang and Yang Ling, "Hydration and Athletic Ability During Training and Competition", Chinese Sports Coach, Vol. 28, No. 2, 2020
[3] Ma Yuanzheng, Wang Yipeng, Liu Qiang, Li Chunlin, Ma Xun, Wang Yongjun, Deng Lianfu, He Liang, Yang Nailong, Chen Bohua, Qiu Guixing, Zhu Hanmin, Tao Tianzun, Qin Ling, Wang Liang, Cheng Xiaoguang, Chinese Journal of Gerontology. 2019,39(11)
[4] Yujia Tian, Yanfeng Han, Yingshi Song, Jingbo Xu, Wei Liu, "Effects of collagen peptides on bone density and bone metabolism in elderly patients with osteoporosis", Chinese Journal of Osteoporosis. 2019,25(10)
[5] James CB, Uhl TL. A review of articular cartilage pathology and the use of glucosamine sulfate[J]. J Ath1 Train, 2001, 36(4): 413-419
[6] Arthritis&Rheumatism 2013, 65(12): 3130-3140. DOI: 10.1002/art38133