Despite its many benefits for training outcomes and health, its safety remains controversial
Some articles claim that too much whey protein can damage the kidneys and liver, and even lead to osteoporosis
In empirical medicine, is whey protein really good (efficacy)? Are there any side effects of whey protein? See text analysis for details
What is whey protein?
Milk actually contains two main proteins: casein (80%) and whey protein (20%).
Whey protein is a protein mixture isolated from whey that contains a variety of amino acids, including all essential amino acids, as well as some immunoglobulins and growth factors.
Whey, on the other hand, is the liquid part of the cheese production process that is separated from milk and consists of protein, lactose, minerals, immunoglobulins and trace fats.
After several processing steps, it finally becomes a commercially available whey protein powder, the most common sports supplement.
What are the proven benefits of whey protein?
Whey protein increases muscle mass and strength (with resistance training)
The human body is made up of more than 500 nervous system-controlled skeletal muscles that connect and support the skeletal system, which allows the body to perform many different movements, from fast and powerful movements to tiny and fine movements.
However, with aging, malnutrition, hormonal changes, after the age of 30, the quality of skeletal muscle decreases by about 3% to 8% per decade, a phenomenon known as sarcopenia, which leads to reduced mobility, weakness, cachexia, osteoporosis, metabolic syndrome.
A meta-analysis (48 randomized controlled trials, 1863 participants) showed that protein supplementation significantly improved one-repetition maximum, fat-free mass, and muscle size changes during sustained and regular resistance training, regardless of age. Note 1
For changes in fat-free mass index, protein supplementation was more effective in resistance training individuals, less effective in older people, and not helpful after daily intake above 1.6 g/kg.
*Conclusion: Protein supplementation (less than 1.6 g/kg per day) can further increase changes in muscle mass and strength during resistance training
Whey protein is beneficial to vascular endothelial function
Endothelial cell dysfunction is the basis of atherosclerotic cardiovascular disease.
Flow-mediated dilation (FMD), a marker for assessing vascular endothelial function, is the most widely used non-invasive assay and reflects the influence of multiple mechanisms, including vascular tone regulation, cell proliferation, and inflammatory response.
FMD values predict the risk of cardiovascular events in healthy people and patients with cardiovascular disease, and for every 1% increase in FMD values, the combined relative risk of cardiovascular events is 0.87 (in healthy individuals, the average FMD is typically 8% to 15%). Note 1
A systematic literature review and meta-analysis (including six randomized controlled trials) suggested that whey protein supplementation helped increase flow-mediated dilation, but had no effect on arterial stiffness measurements and circulating biomarkers of vascular function (nitric oxide). Note 2
*Conclusion: Whey protein supplementation may have a positive effect on vascular endothelial function, but limited by the small sample size, more studies are still needed for further verification
Whey protein adjuvant cancer treatment
Malnutrition is a common comorbid condition in cancer patients and increases the risk of infection, delays wound healing, increases treatment toxicity, lengthens hospital stay, and increases health-related costs.
Nutritional impairment was reported in 51.1% of cancer patients and weight loss in 64% 6 months after diagnosis, which is associated with wasting caused by tumor metabolism, muscle wasting, cachexia, treatment-related complications, or both.
A randomized placebo-controlled trial (6 months, 47 colorectal cancer patients) showed that whey protein supplementation during chemotherapy improved nutritional status, improved lean body mass, reduced the incidence of sarcopenia, and reduced severe toxicity associated with chemotherapy. Note 1
*Conclusion: Whey protein supplementation during chemotherapy may be of positive help in improving the nutritional status of patients and reducing chemotherapy toxicity, but limited by the small sample size, more large trials are still needed to support it.
Whey protein promotes recovery of muscle function after exercise
Exercise-induced muscle fatigue is defined as a decrease in the ability to produce appropriate muscle strength or force during sustained contraction activity, either shortly after the onset of exercise (acute muscle fatigue) or after sustained high-intensity exercise for a longer period of time (delayed exercise-induced fatigue).
The degree may vary depending on the cause or underlying mechanism, and the speed of recovery varies and can last minutes, hours, or even days.
A literature review and meta-analysis (13 randomized controlled trials) suggested that whey protein supplementation helped restore muscle contraction after resistance training. Note 2
*Conclusion: Whey protein supplementation before and after resistance training may help promote post-exercise muscle recovery, but more studies are needed to support this due to the heterogeneity of the included studies
Whey protein is good for diabetes blood sugar control
Type 2 diabetes is a chronic, progressive disease that causes high blood sugar due to an imbalance between the body’s need for insulin and its ability to produce insulin.
The first step in worsening glycemic metabolism is the loss of postprandial glycemic control, followed by morning hyperglycemia, and eventually nocturnal hyperglycemia.
Postprandial glycemic control is not only important for regulating blood sugar, but is also an independent risk factor for cardiovascular disease, stroke, retinopathy, renal failure, and neurological complications.
A study on type 2 diabetes showed that whey protein combined with a high-carbohydrate diet stimulated insulin release and reduced the rate of postprandial blood sugar rise. Note 3
Another randomized, open-label crossover trial (in 15 well-controlled patients with type 2 diabetes) showed that whey protein intake before a high glycemic index diet increased insulin secretion and lowered postprandial blood glucose levels. Note 4
*Conclusion: In patients with type 2 diabetes, whey protein intake before or during meals may help regulate blood glucose levels, but limited by small sample sizes, more large, precisely designed trials are needed to support this
Whey protein suppresses appetite
With the increasing prevalence of obesity and metabolic disorders, the fattening and metabolic effects of specific micronutrients have received a lot of attention.
Dietary protein, in particular, has been extensively studied in recent years, and there is growing evidence that protein-rich dietary energy can help with weight loss and prevent weight gain.
The beneficial effects of high protein intake may be related to diet-induced thermogenesis of food and increased satiety and reduced hunger.
A meta-analysis (8 randomized controlled trials) showed that whey protein intake reduced long-term and short-term appetite, but whey protein did not make a significant difference in short-term appetite reduction compared to carbohydrates. Note 5
*Conclusion: Whey protein intake may have an appetite suppressant effect, but limited by the small sample size, more long-term large trials are still needed to support it
Whey protein reduces inflammation indicators (C-reactive protein)
C-reactive protein is the most widely studied biomarker of acute inflammation, mainly synthesized by liver cells, but also by smooth muscle cells, macrophages, endothelial cells, lymphocytes and fat cells.
The average CRP in healthy people is about 0.8 mg/L, and many factors can alter CRP levels, including age, sex, smoking status, obesity, rheumatoid arthritis, cardiovascular disease, and diabetes, especially where infection or inflammation occurs, can increase up to 1000-fold.
A meta-analysis (including 9 randomized controlled trials) showed that ingestion of whey protein and related derivatives had a slight reduction in C-reactive protein, but not statistically significant. Note 6
Subgroup analysis further found that whey had the most significant C-reactive protein reduction effect on whey doses ≥ 20 g per day and baseline CRP≥3 mg/L.
*Conclusion: Overall, oral whey protein has not been significantly helpful in reducing C-reactive protein, except in high-dose populations or with high baseline CRP levels
Whey protein is good for weight loss or weight maintenance
Obesity is mainly defined as abnormal or excessive fat accumulation in adipose tissue (BMI greater than 30 kg/m2) with health effects.
Diseases directly associated with obesity include type 2 diabetes, hypertension, stroke, coronary heart disease, gout, sleep apnea, gastroesophageal reflux disease, osteoarthritis, infertility, gallbladder disease and cancer (endometrial cancer, breast cancer, prostate cancer, colon cancer).
A meta-analysis (14 randomized controlled trials with 626 adult participants) suggests that whey protein intake, whether as a supplement in combination with resistance exercise or as part of a weight loss or weight maintenance diet, helps improve body composition parameters (including body weight, body fat, and lean body mass). Note 7
The mechanism behind it may be related to the regulation of satiety hormones, the change of liver gluconeogenesis, and foodborne thermogenesis.
*Conclusion: Whey protein is helpful in improving body composition parameters, either in combination with resistance training or as part of a weight loss diet, but more studies are needed to support this due to possible publication bias and heterogeneity of the included studies
Whey protein can lower blood fat (triglycerides)
It is estimated that nearly 2030 percent of the U.S. population will have more than one cardiovascular disease by 44.
Hyperlipidemia is currently known as the main cardiovascular pathogen, and in the United States is regarded as the top ten most costly medical events (about hundreds of billions of dollars in medical expenses per year), without proper treatment, it will become a silent killer over time, slowly eroding health
A meta-analysis (13 randomized controlled studies) suggested that whey protein supplementation helped reduce triglyceride levels (up to 0.11 mmol/L), but no significant improvement in total/low-density or HDL cholesterol. Note 13
In addition, subgroup analysis showed that whey protein’s triglycerides were not significantly effective in participants with low body mass index, low whey supplementation, or exercise training/energy restriction
The mechanism behind it may be related to the fact that the components in whey (beta-lactoglobulin, sphingolipids) regulate gene expression and reduce intestinal lipid absorption
*Conclusion: Whey protein may have the effect of regulating some blood lipid indexes, but limited by the small sample size, more studies are still needed to support it
Are there any side effects of whey protein?
Whey protein is safe for most healthy people in appropriate doses, but possible side effects or adverse effects that have been reported include: increased bowel movements, decreased appetite, fatigue, headache, nausea, thirst, bloating, stomach cramps, etc. (especially at high doses)
Safety precautions (12 contraindications for use)
1. Do not use by pregnant and lactating women (due to unknown related safety)
2. Most gastrointestinal-related side effects (bloating, gas, stomach cramps and diarrhea) are mostly related to lactose intolerance, if such symptoms occur, switch to isolated or hydrolyzed whey protein products, or try non-dairy protein powders such as soy, pea, egg, rice or hemp protein.
3. Do not use for those who have been allergic to milk, it may induce allergic reactions, and related symptoms may include red rash, swollen tongue, runny nose, nasal congestion, rash, swelling of the face or throat, anaphylactic shock
4. For healthy people, there is no evidence that too much protein will damage liver and kidney function, but for those with poor liver and kidney function, it is best to confirm with a doctor before use. Notes 10-11
5. It has been reported that too much protein can lead to calcium loss from bones and increase the risk of osteoporosis, but so far, there is no evidence that eating too much protein is harmful to bone health, on the contrary, protein intake has a positive help for bone health. Note 8
6. High-protein diet (daily intake > 2.0 g/kg) will reduce urine pH and increase the risk of uric acid stones, so it is recommended not to exceed the recommended daily intake of protein (0.8 to 1.4 g/kg). Note 9
7. May induce the production of pimples, which is due to the growth factors contained in whey protein: TGF, IGF-I, PDGF, FGF-1 increases the production of sebum and is thought to be related to acne growth. Note 12
8. Do not use with Parkinson’s disease treatment drugs: Levodopa may reduce the effectiveness of the drug
9. Do not use it in combination with osteoporosis drugs: Alendronate may reduce the effectiveness of the drug
10. Do not combine with quinolone antibiotics and tetracycline antibiotics, may reduce drug efficacy, common drug names are: ciprofloxacin, enoxacin, norfloxacin, sparfloxacin, trovafloxacin, grepafloxacin, Demeclocycline, minocycline (dimethylaminetetracycline), tetracycline
11. Do not use it in combination with tetracycline antibiotics, which may reduce the effectiveness of the drug, common drug names are: Demeclocycline, minocycline (dimethylaminetetracycline), tetracycline
12. Do not use in combination with parasite treatment (Albendazole), which may reduce the effectiveness of the drug
How do you drink whey protein? What is the dose?
The usual recommended dosage for whey protein is 1-2 scoops (25-50 grams) per day, but the exact amount depends on an individual’s goals, lifestyle, body composition, and dietary protein content.
The average man’s total protein intake is about 56 to 91 grams per day, while women should consume 46 to 75 grams per day.
If you are an athlete or highly active person and your goal is to lose body fat while maintaining lean muscle mass, the recommended daily intake of protein is about 1.5 to 2.2g/kg.
The best time to use whey protein is in the morning, at breakfast and after exercise, and consuming whey protein 30 minutes after exercise can help with muscle recovery.
When is the best time to consume protein?
The best time to take a protein supplement depends on whether you want to lose weight, build and maintain muscle, improve athletic performance and recovery.
What’s more, taking it at the right time can further help you achieve your goals.
Here are the best times to take protein based on your specific goals.
Weight loss: Protein-rich snacks between meals are ideal for weight loss, and it may help curb hunger so you can eat fewer calories at your next meal.
Build Muscle: Fitness enthusiasts often recommend taking protein supplements 15 to 60 minutes after workout, but protein intake within two hours of a workout is considered ideal
Prevent muscle loss: Studies have shown that muscle mass is reduced by about 30 to 3 percent for every decade after the age of 8, and to prevent muscle loss, 25 to 30 grams of protein should be consumed at each meal.
Main types of whey protein:
Most of the Whey Protein on the market is divided into the following three, but there are also mixed three formulations to facilitate consumers’ choice
１． Whey Protein Concentrate: WPC is the cheapest and most common form and contains small amounts of fat. Lactose and carbohydrates, while protein content generally ranges from 30% to 90% (depending on the degree of concentration).
２． Whey Protein Isolate: WPI, as its name suggests, is further processed to remove fat and lactose, contains at least 90% protein, and is more expensive.
３． Whey Protein Hydrolysate: WPH is a hydrolysis technology that mimics protein digestion in the body, partially hydrolyzing protein to achieve the purpose of pre-digestion, reducing possible protein allergies, so the body does not need to use too much digestive power to break down, often used for medical protein supplementation and added to infant milk powder