Testosterone is popularly known as the “sex hormone”, with “sex” referring to both its masculinizing effects that gives rise to sex differences between men and women, as well as sex (the activity).
In terms of the latter, testosterone is well known for its libido boosting effect, in both men [1-4] and women [5-9] regardless of age.
Testosterone increases sex drive even in older women, and has thus been designated as the "infallible aphrodisiac" as early as 1940.
But does it work the other way around also… Does sexual activity increase testosterone levels? Let’s see what research shows…
Testosterone, historically believed to be important only for male reproduction and sexuality, has over the past decades transformed from niche hormone to multi-system player. A rapidly accumulating body of research is showing that testosterone is an important metabolic hormone with marked effects on energy metabolism and body composition.
In USA, 36% of the adult population are obese (BMI >30), (affecting a similar proportion of men and women) , and obesity prevalence is escalating worldwide. According to the McKinsey Global Institute (MGI) report “Overcoming obesity: An initial economic analysis”, obesity is “one of the top three preventable social burdens (along with smoking and violence/war/terrorism) generated by human beings” imposing an estimated annual global direct economic burden amounting to 2 trillion USD.
Obesity treatments with comprehensive lifestyle modification and/or drugs are notorious for their poor long-term efficacy and inability to achieve long-term weight loss maintenance.[5-9] Even with continued lifestyle treatment, significant weight regain occurs.[7, 9, 10] And obesity drugs have side effects which limit their long-term and widespread use. [11, 12] Therefore, new interventions are urgently needed to combat this alarming preventable threat to society.
Here I summarize a recent study that investigated the effects of long-term testosterone treatment – up to 8 years - on weight loss and waist size in 411 testosterone deficient men with obesity classes I-III.
Niacin confers tremendous beneficial effects on both lipids, inflammation and endothelial function. For more, see my previous article:
Despite this, two media attention grabbing studies - AIM-HIGH and HPS2-THRIVE - did not find any benefits of niacin supplementation in heart disease patients who were already on intensive statin treatment.
Here I will summarize these studies and expose their multiple flaws, which never made it to the headlines...
In previous articles I have talked about the multiple beneficial effects of niacin supplementation – on both lipids (blood fats and cholesterol) and non-lipid outcomes.
While flushing is often reported to be the main side-effect of niacin supplementation, the flush is a natural reaction to high-dose niacin, and is not dangerous. Thus, while some people may find it uncomfortable, it is not a harmful side-effect. For more on that, see “Niacin - How to Beat the Flush”
Other, potentially harmful side effects, are liver strain/damage, insulin resistance and blood glucose elevations, and uric acid elevations. Here I will summarize what research shows on the severity of these side effects, and whether it is something you should worry about…
In 2010, the Endocrine Society published a Clinical Practice Guideline “Testosterone Therapy in Adult Men With Androgen Deficiency Syndromes”, which addressed important issues regarding the diagnosis and treatment of male hypogonadism.
Since publication of this Guideline, several high-quality trials have been conducted, warranting an update of the 2010 recommendations in several areas, especially that of testosterone therapy in men with the metabolic syndrome, type 2 diabetes, sexual dysfunction, and frailty.
In addition, many of the previously stated contraindications to testosterone therapy – including severe lower urinary tract symptoms (LUTS) and untreated obstructive sleep apnea (OSA) - have been reexamined in recent trials.
Here I summarize the results of a recent systematic analysis of the latest high-quality studies, which call for some important updates of the 2010 Endocrine Society Clinical Practice Guidelines for Male Hypogonadism.
Krill oil is becoming increasingly popular, and many people use it as an alternative to fish oil, since both provide the long-chain “marine” omega-3 fatty acids EPA and DHA.
In addition, krill oil has some unique properties, and marketing claims about krill oil’s purported superiority over fish oil abound, centering on the following:
- Krill oil provides some of the EPA and DHA in phospholipid form, which has been suggested to be absorbed more effectively.
- Krill oil contains astaxanthin, a carotenoid with health promoting effects.
- Krill oil contains the essential nutrient choline.
- There are supposedly fewer contaminants in krill oil than fish oil.
- Krill oil supposedly does not cause any fishy burping or other gastro-intestinal side effects.
In this article I will summarize the research on each of these points, and critically evaluate the related marketing claims...
Both exercise, supplements, medications and drugs may cause blood elevations of enzymes that are commonly included in liver function and/or liver disease testing - alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP).[1-6]
Elevations in these enzymes are one of the most common "problems" encountered in everyday clinical practice.
But how does one distinguish pathological elevations vs. those caused by intense exercise?
In a previous articles I covered the tremendous health benefits of niacin supplementation, mediated via both lipid (cholesterol and blood fat) and non-lipid mechanisms, and what you need to know about niacin products:
Here I will explain what the notorious niacin flush is all about, and give you hands-on practical tips on how to beat it.
In a previous article I presented the wide array of health benefit of niacin – a.k.a vitamin B3 – supplementation, related to both its lipid and non-lipid effects "Niacin – a.k.a vitamin B3 – the Neglected Broad Spectrum Cholesterol Drug! "
In this article you will get critical information about the different niacin products and names, and what to look for when shopping niacin supplements…
Typically, research on aging is done in older people. The problem with studying aging in old people is that most of them already have age-related diseases, which anti-aging interventions aim to prevent.
Age-related changes in the body start to accumulate early in life and affect physiological function years before disease diagnosis; atherosclerosis is a prime example. Thus, intervention to reverse or delay the development of age-related diseases must be done while people are still young , before aging-related diseases become established.
Up to this point, the main obstacle to studying aging before old age and before the onset of age-related diseases has been the absence of methods to quantify the pace of aging (i.e. aging rate) in young people. However, a recent study shows that aging processes can be measured in people still young enough for prevention of age-related disease, and that physical manifestations of aging are already present in young adults.
- Effects of Testosterone Therapy for 3 Years on Subclinical Atherosclerosis Progression in Older Men
- Normalization of testosterone level is associated with reduced risk of heart attack, stroke and mortality in men
- Niacin – a.k.a vitamin B3 – the neglected broad spectrum cholesterol drug!
- Long-term testosterone treatment with different testosterone preparations - provocative results on diagnosis and adherence