powersam said:
misterE said:
powersam said:
1. Decrease testosterone production (low fat/high fiber diet, beta sitosterol, reducing cholesterol levels).
There is little evidence to suggest that this will help male pattern baldness in any way.
You lower testosterone, while increase S.H.B.G. (Sex Hormone Binding Globulin), which regulates the activity of sex hormones.
A high, animal-protein diet decreases S.H.B.G. and promotes "free" testosterone.
A low-fat/high-fiber diet is known to increase S.H.B.G.
Show me a study.
http://jcem.endojournals.org/cgi/conten ... t/85/1/293
Diet and Sex Hormone-Binding Globulin
C. Longcope, H. A. Feldman, J. B. McKinlay and A. B. Araujo
University of Massachusetts Medical School (C.L.), Worcester, Massachusetts 01655; and New England Research Institutes (H.A.F., J.B.M., A.B.A.), Watertown, Massachusetts 02172
Address all correspondence and requests for reprints to: Dr. C. Longcope, University of Massachusetts Medical School, Worcester, Massachusetts 01655.
The serum concentration of sex hormone-binding globulin (SHBG) is inversely related to weight and in animal studies is inversely related to protein intake. As SHBG can affect the biological activity of testosterone and estradiol, we wished to determine the role of protein intake on SHBG levels in men. Using data from the Massachusetts Male Aging Study we examined cross-sectional relationships between dietary components and SHBG levels in 1552 men (aged 40–70 yr) for whom these factors were known.
Analyzed by multiple regression, controlling for testosterone and estradiol levels, age (P < 0.001) and fiber intake (P = 0.02) were positively correlated to SHBG concentration, whereas body mass index (P < 0.001) and protein intake (P < 0.03) were negatively correlated to SHBG concentration. The intakes of calories, fat (animal or vegetable), and carbohydrate were not related to SHBG concentration. We conclude that age and body mass index are major determinants of SHBG concentrations in older men, and fiber and protein intake are also significant contributors to SHBG levels, but total caloric intake and the intake of carbohydrate or fat are not significant. Thus, diets low in protein in elderly men may lead to elevated SHBG levels and decreased testosterone bioactivity.
http://www.ajcn.org/cgi/content/full/84/6/1456
Long-term low-protein, low-calorie diet and endurance exercise modulate metabolic factors associated with cancer risk1,2,3
Luigi Fontana, Samuel Klein and John O Holloszy
1 From the Division of Geriatrics and Nutritional Science and the Center for Human Nutrition, Washington University School of Medicine, St Louis, MO (LF, SK, and JOH), and the Division of Food Science, Human Nutrition and Health, Istituto Superiore di Sanitá, Rome, Italy (LF)
2 Supported by Clinical Nutrition Research Unit grant DK56351, General Clinical Research Center grant RR00036, and Diabetes Research and Training Center grant DK20579.
3 Reprints not available. Address correspondence to L Fontana, Washington University School of Medicine, 4566 Scott Avenue, Campus Box 8113, St Louis, MO 63110. E-mail:
lfontana@im.wustl.edu.
The data from the present study show that consuming a low-protein, low-calorie diet or participating in regular endurance exercise training is associated with a decrease in plasma factors that are linked with some types of cancer. Plasma concentrations of insulin, free sex hormones, and inflammatory markers were lower in subjects consuming a low-protein, low-calorie diet and in subjects who were endurance runners than in nonobese, sedentary subjects who were consuming typical Western diets. Moreover, subjects eating a low-protein, low-calorie diet had much lower plasma IGF-I concentrations and IGF-I:IGFBP-3 than did BMI-matched endurance runners, which suggests that dietary factors may provide additional protective effects, independent of body fat mass. These results help to identify potential mechanisms by which long-term lifestyle modifications in diet or physical activity can selectively reduce circulating factors that are associated with increased cancer risk.
Nutrient intake is a major regulator of circulating IGF-I, which promotes tumor development by stimulating cell proliferation and inhibiting cell death (10–12). Data from epidemiologic studies have shown an association between higher plasma IGF-I concentrations and a greater risk of breast (premenopausal), prostate, and colon cancers (13–16). In rodents, calorie restriction lowers plasma IGF-I concentrations and protects against carcinogenesis, which is reversed by infusing IGF-I (17). Data from several short-term studies conducted in healthy human subjects showed that short-term protein and energy restriction reduces plasma IGF-I concentrations (18, 19).
The results from our study suggest that the effect of protein and energy intakes on IGF-I is not transient and that long-term protein and calorie restriction can cause a chronic decrease in plasma IGF-I concentrations, independent of body fat mass. We found that protein and energy intake were both directly correlated with plasma IGF-I concentrations in sedentary volunteers eating Western diets. Moreover, plasma IGF-I concentrations were lower in our low-protein, low-calorie diet group (9% of calories from protein) than in our lean distance runners and our sedentary control group (16% of calories from protein). The mechanism or mechanisms responsible for the relation between the intake of protein rich in essential amino acids, the intake of calories, and IGF-I that has been shown in other cross-sectional studies (20, 21) is not known, but both decreased IGF-I production and increased clearance may be involved. Decreased dietary protein intake correlates with reduced steady-state concentrations of hepatic IGF-I mRNA (22) and increased clearance of serum IGF-I (23).
Data from epidemiologic studies indicate that obesity is a risk factor for several types of cancer, including colon, breast, endometrial, kidney, and pancreas cancer (1). Increased adipose tissue may be involved in the pathogenesis of specific cancers, because of adipokine production, insulin resistance, hyperinsulinemia, and chronic inflammation (1, 3, 4, 24–27). In addition, higher circulating concentrations of endogenous sex hormones (including estradiol, testosterone, and DHEA) and low plasma SHBG concentrations are associated with an increased risk of breast and endometrial cancers (28–30), possibly because free estrogens and androgens are strong mitogens for mammary cells and stimulate the development and growth of breast tumors (31). We found that our subjects consuming a low-protein, low-calorie diet or performing regular endurance exercise had lower body fat mass and alterations in metabolic factors associated with decreased body fat, including lower plasma concentrations of insulin, leptin, and CRP and greater insulin sensitivity than did nonobese sedentary men and women consuming a Western diet. In addition, our lean subjects had higher plasma SHBG concentrations, which decrease the proportion of free sex hormones (32), than did the sedentary men and women consuming a Western diet. Therefore, the mechanism responsible for the beneficial relation between a low-protein, low-calorie diet or exercise training and these metabolic factors associated with cancer may be related to the effect of reduced calorie intake or increases in energy expenditure on body fat mass.