Menopausal women searching for safe and effective alternatives to hormone replacement therapy (HRT) will inevitably come across “phytoestrogens”, either in their whole food form or as a concentrated extract in a supplement. But what exactly are phytoestrogens and how do they work in the human body? Are they even safe? Many answers remain unknown to the general public and the literature can offer mixed results as well. Let’s clear up some of the confusion. The term “phytoestrogen” can literally be translated into “plant estrogen”. In the 1950’s, this estrogenic activity was discovered in plants when researchers investigated the cause of
There is a special feeling associated with conquering a challenging workout. As part of an active daily lifestyle, it is healthy to safely test our body’s boundaries of strength and endurance. This challenge is different for everyone; attempting more weight or repetitions at the gym, extending your long run by a few extra kilometres, or holding onto those new yoga poses as long as possible. Overcoming these new obstacles not only leaves us with a great sense of accomplishment but also feeling very sore the next day! To reduce muscle soreness and improve muscle function for further training, a proper recovery plan that includes optimized protein and antioxidant intake should be adopted. Further, close attention should be paid to nutrient timing during the post-exercise period (1).
How Much Protein Should I Have?
Protein is an essential part of our diet and provides the building blocks required for all tissues of the body, including muscle. That said, depending on the type of exercise you enjoy, the amount of protein needed to support your muscles may vary. Both endurance and strength-based exercises increase the body’s demand for protein, specifically branch-chain amino acids including leucine, to help boost repair. These branched chain amino acids are structurally important for stimulating growth and repair in our muscles. Higher protein diets containing more than 1 g of protein per kilogram of body weight are shown to promote healthy ageing, improve appetite regulation, and weight management (2). Higher protein intake can also help with improving fat loss, reduction in body weight, and improved immune function, when combined with exercise and caloric control.
Are There Dangers of Consuming Too Much Protein?
There have been recent studies that have looked at huge protein intakes, equivalent to eating your body weight in protein per day, to determine whether or not there is any health risk associated with increased protein consumption. These studies have shown no adverse health effects, specifically no damage to liver or kidneys and no change in bone health (2, 3). While those with certain medical conditions must adhere to low protein diets, those who are healthy and active will benefit from increased protein consumption; consumption of 1-1.6 g/kg of body weight is a realistic goal.
Should Protein Intake Change with Age?
There is new evidence that supports the idea that as we age our muscles do not respond as quickly to protein and that more leucine, a branch chain amino acid, is needed to stimulate adequate recovery (4). Many mistake leucine as just another protein building-block for muscle, but leucine is responsible for signalling muscle growth and maintaining the integrity of the muscle cellular membrane. As children, our muscles respond quickly to leucine, reflecting our young body’s rapid state of growth. As we age, the need for growth becomes less critical, but our need for recovery is still needed. It has been demonstrated that those 66 years and older have a reduced muscle protein manufacturing response and that to boost recovery more leucine is required – a requirement that may be filled through diet as well as healthy supplementation with a clean protein supplement.
What is the Best Source of Protein?
Discussing sources of protein can often lead to heated conversations over the merits of animal versus vegetarian sources. For this reason, it is important to look at the leucine content in these sources to ensure that you reach the amount needed to stimulate recovery, post-workout. A serving of protein, regardless of source, should look to deliver 2-3 g of leucine per serving to maximize muscle repair; which equates to a 3-4 oz chicken breast or 2-2.5 cups of lentils.
Animal protein sources such as chicken, fish and whey contain higher leucine content per serving compared to vegetarian sources such as hemp, pea and soy. Your muscles will be just as happy eating animal or vegetarian sources provided you are getting 2-3 grams of leucine per serving. The moral of the story; the source is not as important provided you are getting enough high-quality protein through your day (5).
The timing of protein containing meals is important for recovery from all types of exercise. For 24 hours after exercise, your muscle is very accepting of protein. Repair of skeletal muscle appears to be optimized when 20-30 grams of protein is consumed right after exercise and again every 3-4 hours (6).
Exercise is a crucial component of a happy, healthy life. Ensuring that we recover properly helps ensure that we can continue to do the activities we love more often. While arguments over what is the best protein source exist, the research is unequivocal, as long as you are consuming protein every 3-4 hours after exercise, and it contains enough leucine, then you are optimizing your recovery.
1. Ives, S J, et al. Effects of a combined protein and antioxidant supplement on recovery of muscle function and soreness following eccentric exercise. Journal of the International Society of Sports nutrition. 2017;14(21).
2. Phillips, SM, et al. Protein “requirements’ beyond the RDA: implications for optimizing health. Applied Physiology, Nutrition and Metabolism, 2016;41(5):565-572.
3. Antonio, J, et al. A high protein diet (3.4 g/kg/d) combined with a heavy resistance training program improves body composition in healthy trained men and women – a follow up investigation. Journal of the International Society of Sports medicine. 2015;12:1-9.
4. Katsanos, C, et al. A high proportion of leucine is required for optimal stimulation of the rate of muscle protein synthesis by essential amino acids in the elderly. American journal of physiology. Endocrinology and metabolism. 2016;291(2):381-387.
5. Joy, JM, et al. Effects of 8 weeks of whey or rice protein supplementation on body composition and exercise performance. Nutrition Journal. 2013;12(1):86-92.
6. Jager, R, et al. International Society of Sport Nutrition Position Stand: Protein and Exercise. Journal of the International Society of Sports Nutrition. 2017;14(20).