In the realm of health and nutrition, there's growing interest in how our diets affect more than just our weight. One area of concern is the impact of certain foods on the levels of testosterone, the hormone responsible for various aspects of our health, from muscle strength to mood regulation. Yes, testosterone is found in both men's and women's bodies, but it's critical for men's reproductive health.
This article delves into the concept of 'testosterone-killing' foods, investigating whether certain dietary choices can indeed lower testosterone levels in light of scientific evidence.
What is testosterone, and is it connected to diet?
Testosterone holds a critical role in male physiology and reproductive health, with low levels associated with increased risks of chronic diseases and overall mortality. Many recent studies have shown a secular decline in men's serum total testosterone, a trend partially attributed to changes in dietary patterns.
Particularly, the significant increase in processed food consumption and decrease in whole food intake, which is also known as the Western diet, may influence testosterone levels. Alterations in macronutrient composition, such as a notable decrease in fat intake since the mid-20th century, have sparked inquiries into potential connections between dietary changes and testosterone levels.
While studies on fat intake's association with testosterone levels have yielded conflicting results, recent meta-analyses have shed light on the impact of high-protein diets on testosterone levels, prompting further exploration into the relationship between diet and testosterone regulation.
From a scientific standpoint, it's not entirely clear whether individual foods can significantly impact hormone levels, as dietary effects result from the combination of all foods consumed in a specific pattern. Therefore, it's more accurate to suggest that the Western diet could potentially lower testosterone levels due to its high consumption of sugar, fat, and processed foods, which can elevate body mass index, increase body fat, and disrupt overall metabolism.
Nevertheless, there is some scientific evidence that warrants consideration regarding the relationship between dietary choices and testosterone levels.
Foods with polyunsaturated fatty acids
Some of us may have heard about the benefits of vegetable oil, as its high level of unsaturated fatty acids is considered beneficial and preventative for many chronic diseases, ranging from cardiovascular diseases to diabetes, when compared to saturated fats from animal sources.
However, a recent study in 2023 revealed that among strength-training men with an average age of 27 years, a higher intake of polyunsaturated fatty acids (PUFAs) was associated with lower testosterone concentrations.
Sunflower, corn, and soybean oils are high in PUFAs, but olive oil might be a better option if you are concerned about PUFA levels in your diet in terms of maintaining testosterone levels. Olive oil is high in monounsaturated fatty acids, containing about 75% of its concentration, and it is also suggested to be beneficial for the prevention of chronic diseases and cancer.
Several grains, such as rice, millet, and wheat, may increase the protein SHBG (sex hormone-binding globulin) in the body. SHBG binds testosterone and plays a crucial role in regulating the bioavailability of testosterone and other sex hormones in the bloodstream. However, this binding reduces free testosterone concentration in the body and makes testosterone less biologically active. Therefore, higher levels of SHBG typically result in lower levels of free testosterone.
It's important to note that while SHBG binds to testosterone, it does not decrease the overall production of testosterone in the body. Instead, it influences the amount of testosterone available for physiological activity. Therefore, a balanced consumption of grains in your dietary pattern wouldn't pose a significant risk, but it may be advisable to avoid excessive consumption.
A study from Taipei Medical University showed that high-frequency consumption of bread, pastries, and desserts is linked with low total testosterone levels. Also, this research showed that the participants who frequently ate baked goods experienced a decrease in muscle mass and an increase in body fat.
However, it is worth noting that the primary relationship might be attributed to the increased body fat resulting from high consumption of baked goods, rather than the direct effects of these foods, as it is known that elevated body fat levels decrease testosterone levels in men.
Due to contradictory research results, soy's effects on lower testosterone levels are still open for debate.
Soy is rich in phytoestrogens, which are plant-derived compounds that may mimic the effects of estrogen, the primary female sex hormone in the body. A study from 2005 involving 35 men found that consuming soy protein for 57 days led to decreased testosterone levels. Similarly, research on rats showed that phytoestrogen consumption reduced testosterone levels.
However, other studies have produced conflicting results. A review of 15 studies found no significant effect of soy consumption on testosterone levels in men.
Despite the mixed findings, it may be beneficial to consume soy in moderation, especially for individuals with clinically low testosterone levels.
Alcohol consumption has been linked to decreased testosterone levels. A study conducted among 314 men from 2022 shows that heavy drinkers are at increased risk of testosterone deficiency.
Further research indicates that even a single day of heavy alcohol intake can lead to significantly reduced testosterone levels, similar to those observed in long-term alcohol dependence.
Beyond diet: supporting healthy testosterone levels
Dietary decisions play a crucial role in maintaining appropriate testosterone levels, but it's also important to consider other factors that can decrease testosterone levels in the body.
- Aging. Testosterone levels naturally decline with age, particularly after the age of 30, leading to a gradual decrease in hormonal production.
- Diabetes. Especially when poorly managed, can contribute to lower testosterone levels, creating a complex interplay between hormonal regulation and metabolic health.
- Lack of physical activity. Sedentary lifestyles and a lack of regular exercise have been linked to lower testosterone levels, emphasizing the importance of maintaining an active and healthy lifestyle.
- Long-term substance abuse. Prolonged substance abuse of drugs, tobacco, and marijuana can negatively impact testosterone production, influencing hormonal balance and overall well-being.
- Excessive body weight. Obesity is associated with lower testosterone levels, as excess body fat can lead to increased estrogen production, further disrupting the hormonal equilibrium in the body.
Overall, regular exercise, particularly strength training and resistance training, ranks among the best methods to increase muscle mass and enhance testosterone levels. Furthermore, consistent exercise aids in managing fat mass and body weight, leading to improved metabolic health. Exercise can also serve as a supportive activity in quitting smoking and curbing alcohol abuse while facilitating the adoption of healthier habits. Thus, while promoting overall well-being, exercise also plays a crucial role in maintaining testosterone levels in men.
Can a poor diet lead to hormonal imbalances?
Yes, a poor diet — like the Western diet with high sugar, fat, and processed food consumption — can contribute to hormonal imbalances including testosterone levels.
Does exercise increase testosterone?
Regular exercise, particularly strength and resistance training, can increase testosterone levels by increasing muscle mass and decreasing body fat.
Do eggs lower testosterone?
No, eggs do not lower testosterone levels. They are a good source of protein and other nutrients, which is even beneficial for your muscle mass.
- The Journal of Steroid Biochemistry and Molecular Biology. Low-fat diets and testosterone in men: systematic review and meta-analysis of intervention studies.
- Nutrition and Health. High-protein diets and testosterone.
- European Journal of Clinical Nutrition. Dietary fat quality and serum androgen concentrations in middle-aged men.
- Korean J Fam Med. Relationship between alcohol consumption and testosterone deficiency according to facial flushes among middle-aged and older Korean men.
- Nutrients. Testosterone-associated dietary pattern predicts low testosterone levels and hypogonadism.
- Fertil Steril. Clinical studies show no effects of soy protein or isoflavones on reproductive hormones in men: results of a meta-analysis.