Knee Pain and Nutrition: Dietary Approaches Recommended by Singaporean Doctors
Obesity is another factor that predisposes one to knee pain. It has been proven that the prevalence of knee pain is higher in obese individuals. This is because the knee joints have to support a higher load in obese individuals. It is 3-4 times of one’s body weight when climbing up and down stairs and doing other basic activities such as walking and standing. Weight loss has been shown to be associated with delayed progression of knee osteoarthritis. So dietary modifications and weight loss are important considerations in the management of knee pain. But what are the specific dietary recommendations that will help patients with knee pain? This paper focuses on this aspect.
Knee pain is a common complaint both in the elderly population as well as in individuals who engage in sports or regular physical activity. There are various causes of knee pain. Acute injuries such as a ruptured ligament or torn cartilage can cause significant pain. Often, chronic injuries over a long period of time such as muscle imbalances or poor posture cause pain. Other conditions associated with knee pain include osteoarthritis, gout, or infection.
Dietary Approaches for Managing Knee Pain
In a US-based study in 2007, it was found that knee osteoarthritis was much less prevalent in Japanese women compared to white women and that when Japanese women moved to the US, their prevalence of knee osteoarthritis increased. This was linked to a change in diet, and it was hypothesized that this was due to the higher intake of soy and green tea in Japan. An increased soy protein intake was tested in a rat model with positive results, and it was found in a 3-year study of 293, 1101, and 1259 participants that a higher flavonoid intake was associated with fewer symptoms and less joint space narrowing in the knees.
It is well-known that many natural plant products such as fruits and vegetables have antioxidative and anti-inflammatory effects. Many of these products act through the same pathways as pharmaceutical anti-inflammatory agents. While fruits and vegetables have a lower concentration, in general, they are a lot safer and can have other beneficial effects, and so it is recommended to have a diet with an increased portion of fruits and vegetables. Some more specifically have anti-inflammatory action such as onions, apples, green tea and, although it is not a fruit or vegetable, soy.
Diet can play a crucial role in health and in combating health conditions. Osteoarthritis is a common joint condition that affects many older individuals, and it can be particularly debilitating for sufferers of knee osteoarthritis. A study published in 2005 found that the odds of developing knee osteoarthritis were 6.3 times greater in people who are obese. This suggests that a significant amount of knee osteoarthritis is preventable if weight management can be achieved. It is thus beneficial to be aware of what types of food and diet regimens are beneficial in combating knee osteoarthritis.
Anti-inflammatory Foods
Overall, the diet should be aimed at reducing excessive levels of omega 6 fatty acids found in abundance in processed foods and increasing omega 3 fatty acids. The balance of these two fats can affect the inflammatory process in the body. Many types of fish are high in omega 3, but omega 3 is also found in good quantities in flaxseed oil and, to a lesser extent, in nuts. Increased omega 3 can benefit rheumatoid arthritis, and the use of fish oils has shown to reduce the use of NSAIDs.
The list is extensive, but well-recognized effects include the spices ginger and turmeric, omega 3 fish oils, and foods high in quercetin (e.g., onions, garlic, and apples).
Anti-inflammatory foods help to control the inflammatory process. Inflammation is the body’s response to injury. In acute conditions, this can help the healing process, but in chronic disease, the inflammatory process does not shut down, increasing the levels of inflammation, which increases pain and leads to further tissue damage. Although it is not always possible to avoid medications, there are certainly powerful anti-inflammatory effects in foods that many patients are not aware of.
Omega-3 Fatty Acids
Marine fish oils are regarded as the best source of Omega-3’s, and it is recommended that at least 2 servings of Omega-3 rich fish are consumed weekly. Examples of this type of fish include mackerel, herring, salmon, sardines, and tuna. An average 100g serving would be equivalent to a small fillet and a drained can. Unfortunately, fish is a very perishable product, and it can be expensive. There are also concerns about the levels of mercury found in fish, and this has led to many people choosing fish oil capsules as an alternative to increase Omega-3 levels in the diet. Fish oils could be seen as an omega-3 supplement, and although they are not enhancing your diet with the food source, it can be a cheap and reliable source, with fewer worries about mercury content and spoilage. Other sources of Omega-3’s include flax and canola oil, and walnuts.
Throughout the years, many studies have shown the benefits Omega-3 fatty acids provide, especially in reducing inflammation in the body. Although there is no damage to the gut, it is thought that Omega-3’s offset the balance of Omega-6’s consumed in the Western diet. Omega-6’s promote the inflammatory pathways in the body, which may explain why there is an inflammatory response to cartilage in the knee joint when the body has to repair damage, because Omega-6’s are involved in the repair process. By decreasing the Omega-6:Omega-3 ratio in the diet, it is thought to decrease inflammation and lessen the severity of the knee pain. This ratio is something that is measured in many clinical studies looking at the effect of diet on disease.
Vitamin D and Calcium
Low vitamin D can result in negative effects on joint health, such as osteoarthritis. Sources of vitamin D include sunlight, fatty fish such as salmon, mackerel, and sardines, and fish liver oils. Since the action of sunlight on the skin is the major source of vitamin D, spending 10-15 minutes in sunlight several times every week is essential. However, it is important to avoid excessive exposure to sunlight due to the risk of skin cancer. Vitamin D can also be consumed as a supplement. An adequate intake of vitamin D will help to bolster joint health, in turn preventing knee pain caused by depletion of cartilage. A study has shown that an intake of approximately 130 IU each day was associated with a decreased risk of osteoarthritis in the knee by 20%. Calcium is the most abundant mineral found in the body, and it plays several key roles. Primarily, 99% of the body’s calcium is stored in the bones and teeth, where it maintains their structure and hardness. Calcium is also required for blood clotting, nerve function, and muscle contraction. If there is an insufficient intake of dietary calcium, these necessary bodily functions will instead draw calcium from the bone; this is a cause of osteoporosis. Calcium is important for optimum bone health, and it can prevent the onset of knee pain resulting from stress fractures or osteoporosis. Sources of calcium include dairy products, tofu, soy milk, almonds, Brazil nuts, leafy green vegetables, and shellfish. Like vitamin D, calcium can also be taken as a supplement.
Weight Management
Excessive weight exacerbates knee joint pain because extra body weight increases stress on these joints. An extensive study of 1756 women showed that over an 11-year period, an increase in weight was associated with an increase in the risk of symptomatic knee osteoarthritis. The knees undergo an impact force of 3-6 times a person’s body weight with each step taken, hence for every pound gained, 3 pounds of added stress is exerted on the knees. This implies that losing a few extra pounds can help reduce pain symptoms. According to experts, every 2.2 pounds of weight loss can translate to a reduction of 9-18 pounds of force exerted on the knee. This can be achieved through dietary modifications, exercise, and behavioral changes. High body mass index is a predisposing factor for knee osteoarthritis, and weight loss can also help prevent its development.
Foods to Avoid for Knee Pain Relief
Trans Fats – Well, everybody knows that trans fats are bad. High levels of processed and fast foods add to trans fat levels in the body, and this increases the inflammatory response in the body, thereby causing more pain in the knees. High trans fat levels are also linked to osteoarthritis. So it would be a good idea to make sure that the diet has less than one percent of its calories from trans fats.
Sugar and sugary drinks – Excessive sugar has been shown to increase the advanced glycation end products (AGEs). Increased AGEs result in inflammation, which is something that knee pain sufferers should avoid.
Processed foods – Processed foods of all kinds, especially those made from white flour, are not good at all for any pain in the body. So many rich foods are made from white flour, and these are also some of the most loved foods worldwide. However, those suffering from any kind of joint pain will do themselves a big favor by avoiding white flour products. This means not only bakery items but also other items such as various kinds of pasta. White rice is another item that would contribute to knee pain by increasing inflammation due to its high glycemic index. So it is better to avoid rice and stick to wheat.
Judging by certain known facts and what is expected from a perfect diet, here is a summary of the types of foods to abstain from for knee pain relief.
Processed Foods
Overeating has an obvious link to knee pain. Weight gain on the body just puts added stress onto the knees. For as little as 10 pounds of extra weight on the body, the force on the knees with each step can increase by 30-60 pounds. This leads to an increased risk of knee osteoarthritis and also increases the severity of the condition. So you can see how devastating sugars and refined carbs can be for knee pain. Try to avoid these foods and stick to whole foods such as fruits, vegetables, lean meats, and whole grains.
Studies have also connected sugars and refined carbs to the production of Advanced Glycation End products. These are proteins or lipids that, when interacting with sugars, can cause an increase in inflammation. Sugars and refined carbs also rob your body of vital minerals and vitamins. These are the essential nutrients your body needs to promote healing and immunity. When foods are stripped of these nutrients and it’s just empty calories, your body will still feel hungry, even after consuming a ton of calories. This can lead to overeating and obesity.
It is difficult to ignore processed foods in the grocery store. Everywhere we turn, there’s something from a box, can, or package. While processed foods are convenient and quick, they can be highly damaging to your overall health and your knees. Many processed foods are high in sugars and simple carbohydrates. These promote inflammation and also cause weight gain. This puts added stress on the knees. Some examples of these foods are cookies, cereals, and also sweetened drinks.
Sugar and Sugary Drinks
Limiting sugar in your diet is a very intelligent idea. Nonetheless, it’s hard to do because sugar has been. One thing to look out for is the products that you would not suspect to have sugar, such as ketchup which is loaded with it. A few pointers on what to avoid are sugary desserts, sugar-sweetened soft drinks, any fruit drinks, and any items containing high fructose corn syrup. An important find to why this is will help you learn exactly what sugar does when it’s consumed. It was found in the Nurses Health Study, over 16 years with 47,000 middle-aged women, those who consumed more sugar had much higher levels of C-reactive protein in their blood. High levels of this protein are markers for possible inflammation in the body. Persistent inflammation has been linked to Knee Osteoarthritis (patients with osteoarthritis who have higher CRP levels tend to experience more pain). Another study has shown that mice who were given high levels of sugar showed higher signs of inflammation in comparison to the mice who were not given the sugar. These studies provide evidence that sugar is a strong pro-inflammatory. There is still much that is unknown on the issue, but the evidence provided shows a strong case to why sugar has an effect on knee pain.
Trans Fats
The bottom line for trans fats is that they are unhealthy for everyone, and it is recommended that they are avoided. This is because they contribute to cardiovascular disease and have harmful effects on blood lipid levels, with a tendency to increase LDL cholesterol (the bad type). But for those with knee pain, they have further detrimental effects and provide yet another good reason to avoid them.
Exposure to trans fats has been shown to increase the levels of Interleukin-6, a protein involved in the regulation of the immune system, and is likely to cause inflammation. This then has a significant impact on knee pain for anyone suffering from osteoarthritis. Increased ingestion of trans fats is likely to lead to a greater prevalence and severity of osteoarthritis down the line. A study showed that there was a greater occurrence of knee osteoarthritis in those who had high trans fat intakes, and a follow-up study from men in the US linked greater severity in osteoarthritis to higher intakes of these trans fats.
Trans fats are oils that have been hydrogenated to make them solid, have a higher melting point, and have a longer shelf-life. This process of hydrogenation results in the formation of trans fatty acids, and they are not found anywhere else in nature. The classic example is margarine, where oils have been hydrogenated to make it spreadable, and it is loaded with trans fats. Cookies, crackers, cakes, and most baked goods will utilize trans fats to give a nicer texture to the product and to make the product last longer. Fried foods and fast foods are also notorious for their use of trans fats. In essence, any cheap food is going to be loaded with trans fats because they are made from cheap oils, and this will be a primary reason for their avoidance.
The practical application and future of a plant-based diet for athletes will depend on evidence indicating favorable outcomes. Although current available literature can provide rationale for individual behaviors, prospective studies are needed with athletic performance and health outcomes as the primary endpoint. Athletes interested in a plant-based diet should align themselves with dieticians and other health professionals in order to make strategic, individually tailored plans. For those who are successful in optimizing a plant-based diet, they could serve as examples of growing environmentally sustainable food systems. With interest from athletes and evidence to drive change, the broader sports community could eventually see major shifts in dietary recommendations and food environments.
This viewpoint presents the theoretical basis for an improved plant-based diet for training and competitive athletes. Although benefits are possible, recommendations will not universally apply. Chronic injuries and other medical problems are sometimes difficult to resolve. In these cases, athletes may have to reduce their training load or stop training altogether as part of the rehabilitation process. Athletes may also have a need for more rapid weight loss or increased satiety that cannot be addressed with the high-carbohydrate density of a plant-based diet. Furthermore, an athlete may already be extremely successful with their current diet, and changing would involve much risk with an uncertain outcome. Because these concerns will be athlete-specific, ultimately a cost-benefit analysis should be made when considering the feasibility of dietary change.
